By R. Tarok. Boston University. 2019.
The strategy has been to give a standard dose of the antibiotic and then begin the infusion of the drug at an hourly rate that approximates the ordinary total 24-hour administration under conventional delivery methods (Fig buy generic dulcolax online. Some trials have indicated that distributing the infusion rate over 24 hours permits maintenance of antibiotic concentrations at target levels purchase dulcolax 5 mg line, but with a reduction in overall total drug that is given order dulcolax 5 mg visa. Clinical trials that have compared continuous infusion to conventional drug adminis- tration are summarized in Table 3 buy dulcolax 5mg fast delivery. These are time-dependent agents without an appreciable post-antibiotic effect, which makes a sustained antibiotic concentration that is above the target threshold a treatment goal (60). Reviews and meta-analysis of continuous infusion have extolled the 532 Fry Table 3 Selection of Studies where Continuous Infusion of Antibiotics Was Compared with Intermittent Infusion Patients continuous/ Authors Antibiotic(s) Type of infection intermittent Adembri et al. A prospective, randomized trial with a large population of well-stratified patients is needed to answer the question of continuous infusion of antibiotics as a superior treatment strategy. Studies have suffered from small number of patients and an absence of consistent severity in the study populations. Because the continuous infusion technique adds an additional therapeutic imposition at the bedside in the intensive care unit, additional evidence is necessary to validate the utility of this method. Prolonged Antibiotic Infusion A compromise position between conventional intermittent and continuous infusion is the concept of prolonged or extended infusion of antibiotics. As was noted in Figure 1, intermittent infusion results in a peak concentration and the peak is in part dictated by the rapidity with which the drug is infused. If the infusion is extended over three hours instead of 30 minutes, then the peak concentration will be somewhat diminished, but the rate of total drug elimination will also be delayed. Prolonged administration affords an extended period of time for the drug to have therapeutic concentrations (Fig. This extension of therapeutic concentrations has the potential for use under circumstances of adverse Vd changes in febrile, multiple-trauma patients. Studies with carbapenems (63,64) and piperacillin-tazobactam (65,66) have shown favorable pharmacokinetic profiles with prolonged infusion, but clinical evidence that compares this method with conventional antibiotic administration strategies are needed. It is clear that more clinical studies are needed and that alternative administration strategies should be explored to improve clinical outcomes. However, it is clear that antibiotic concentrations are adversely affected for most drugs as the injured and septic patient progressively accumulates “third space” volume. Clearance of antibiotics appear to be highly variable and clearly are influenced by drug concentration changes, cardiac output changes and their influence upon Antibiotic Kinetics in the Multiple-System Trauma Patient 533 kidney and liver perfusion and the intrinsic coexistent dysfunction of the kidney or liver. For most antibiotics used in the multiple-trauma patient, it is likely that they are underdosed and that inadequate antibiotic administration contributes to both treatment failures and to emerging patterns of antimicrobial resistance. More studies of antibiotic pharmacokinetics in the multiple-system injured patient are necessary. Inadequate antimicrobial prophylaxis during surgery: a study of b-lactam levels during burn debridement. Gentamicin pharmacokinetics in 1,640 patients: method for control of serum concentrations. Effect of altered volume of distribution on aminoglycoside levels in patients in surgical intensive care. Pharmacokinetic monitoring of nephrotoxic antibiotics in surgical intensive care patients. Variability in aminoglycoside pharmacokinetics in critically ill surgical patients. Aminoglycoside pharmacokinetics: dosage requirements and nephrotoxicity in trauma patients. Pharmacokinetics of vancomycin: observations in 28 patients and dosage recommendations. The pharmacokinetics of once-daily dosing of ceftriaxone in critically ill patients. Intermittent and continuous ceftazidime infusion for critically ill trauma patients. Pharmacokinetic-pharmacodynamic evaluation of ceftazidime continuous infusion vs intermittent bolus injection in septicemic melioidosis. Low plasma cefepime levels in critically ill septic patients: pharmacokinetic modeling indicates improved troughs with revised dosing. Pharmacokinetics of aztreonam and imipenem in critically ill patients with pneumonia. Pharmacokinetics and pharmacodynamics of imipenem during continuous renal replacement therapy in critically ill patients. Pharmacokinetic evaluation of meropenem and imipenem in critically ill patients with sepsis. Ertapenem in critically ill patients with early-onset ventilator-associated pneumonia: pharmacokinetics with special consideration of free-drug concen- tration. Fluid shifts have no influence on ciprofloxacin pharmacokinetics in intensive care patients with intra-abdominal sepsis. Ciprofloxacin pharmacokinetics in critically ill patients: a prospective cohort study. Pharmacokinetics of intravenous and oral levofloxacin in critically ill adults in a medical intensive care unit. Pharmacokinetics and pharmacodynamics of intravenous levofloxacin in patients with early-onset ventilator-associated pneumonia. Pharmacokinetics and pharmacodynamics of levofloxacin in critically ill patients with ventilator-associated pneumonia. Bacteremic pneumonia due to Staphylococcus aureus:a comparison of disease caused by methicillin-resistant and methicillin-susceptible organisms. Staphylococcus aureus bacteremia: recurrence and the impact of antibiotic treatment in a prospective multicenter study. Linezolid vs vancomycin: analysis of two double-blind studies of patients with methicillin-resistant Staphylococcus aureus nosocomial pneumonia. Linezolid versus vancomycin in treatment of complicated skin and soft tissue infections. Antibacterial dosing in intensive care: pharmacokinetics, degree of disease and pharmacodynamics of sepsis. Linezolid pharmacokinetic/pharmacodynamic profile in critically ill septic patients: intermittent versus continuous infusion. A randomized study of carbenicillin plus cefamandole or tobramycin in the treatment of febrile episodes in cancer patients. Pharmacokinetics of ceftazidime in serum and peritoneal exudate during continuous versus intermittent administration to patients with severe intra- abdominal infections. A comparative trial of sisomicin therapy by intermittent versus continuous infusions. Cefepime in critically ill patients: continuous infusion vs an intermittent dosing regimen. Randomized, open-label, comparative study of piperacillin- tazobactam administered by continuous infusion versus intermittent infusion for treatment of hospitalized patients with complicated intra-abdominal infection. Cost-effectiveness of ceftazidime by continuous infusion versus intermittent infusion for nosocomial pneumonia. Is continuous infusion ceftriaxone better than once-a-day dosing in intensive care? Population pharmacokinetics and pharmacodynamics of continuous versus short-term infusion of imipenem-cilastatin in critically ill patients in a randomized, controlled trial. Continuous versus intermittent infusion of vancomycin in severe staphylococcal infections: prospective multicenter randomized study. Better outcomes through continuous infusion of time-dependent antibiotics to critically ill patients? Continuous versus intermittent intravenous administration of antibiotics: a meta-analysis of randomized controlled trials. Piperacillin-tazobactam for Pseudomonas aeruginosa infection: clinical implications of an extended-infusion dosing strategy. Optimal dosing of piperacillin-tazobactam for the treatment of Pseudomonas aeruginosa infections: prolonged or continuous infusion? Antibiotic Therapy in the Penicillin Allergic 30 Patient in Critical Care Burke A. Cunha Infectious Disease Division, Winthrop-University Hospital, Mineola, New York, and State University of New York School of Medicine, Stony Brook, New York, U. Several factors go into antibiotic selection including (i) spectrum of activity against the presumed pathogens, which is related to the source of infection or organ system involved; (ii) pharmacokinetic and pharmacodynamic considerations which affect dosing and concentration in the source organ for the sepsis; and (iii) the resistance potential of the antibiotic needs to be considered. The fourth consideration is the safety profile of the drug, which has to do with adverse side effects and interactions, as well as the patient’s allergic drug history.
Do not partially cook meat and poultry one day and reheat the next purchase dulcolax american express, unless it can be stored at a safe temperature discount dulcolax 5mg mastercard. Large cuts of meat must be thoroughly cooked; for more rapid cooling of cooked foods order discount dulcolax line, divide stews and similar dishes prepared in bulk into many shallow containers and place in a rapid chiller discount 5 mg dulcolax visa. Control of patient, contacts and the immediate environment, Epidemic measures and Disaster implica- tions: See Staphylococcal food intoxication (I, 9B, 9C and 9D). Identiﬁcation—An intoxication characterized in some cases by sudden onset of nausea and vomiting, and in others by colic and diarrhea. In outbreak settings, diagnosis is conﬁrmed through quantitative cul- tures on selective media to estimate the number of organisms present in the suspected food (generally more than 105to 106organisms per gram of the incriminated food are required). Isolation of organisms from the stool of 2 or more ill persons and not from stools of controls also conﬁrms the diagnosis. Two enterotoxins have been identiﬁed: one (heat stable) causing vomiting, is produced in food when B. Reservoir—A ubiquitous organism in soil and environment, com- monly found at low levels in raw, dried and processed foods. Mode of transmission—Ingestion of food kept at ambient tem- peratures after cooking, with multiplication of the organisms. Outbreaks associated with vomiting have been most commonly associated with cooked rice held at ambient room temperatures before reheating. Various mishandled foods have been implicated in outbreaks associated with diarrhea. Preventive measures: Foods should not remain at ambient temperature after cooking, since the ubiquitous B. Refrigerate leftover food promptly (toxin formation is unlikely at temperatures below 10°C/50°F); reheat thoroughly and rap- idly to avoid multiplication of microorganisms. Control of patient, contacts and the immediate environment, Epidemic measures and Disaster implica- tions: See Staphylococcal food intoxication (I, 9B, 9C and 9D). Symptoms resolve spontaneously within 12 hours and there are no long-term sequelae. Occurrence is worldwide; the syndrome was initially associated with ﬁsh in the families Scombroidea and Scomberesocidae (tuna, mackerel, skipjack and bonito) containing high levels of histidine that can be decarboxylated to form histamine by histidine-decarboxylase-producing bacteria in the ﬁsh. Nonscombroid ﬁsh, such as mahi-mahi (Coryphaena hippurus), and blueﬁsh (Pomatomus saltatrix), are also associated with illness. Risks appear to be greatest for ﬁsh imported from tropical or semitropical areas and ﬁsh caught by recreational or artisanal ﬁshermen, who may lack appropriate storage facilities for large ﬁsh. Adequate and rapid refrigeration, with evisceration and removal of the gills in a sanitary manner prevents this spoilage. In severe cases, patients may also become hypotensive, with a paradoxical bradycardia. Neurological symptoms, including pain and weakness in the lower extremities and circumoral and peripheral paresthaesias, may occur at the same time as the acute symptoms or follow 1–2 days later; they may persist for weeks or months. Symptoms such as temperature reversal (ice cream tastes hot, hot coffee seems cold) and “aching teeth” are frequently reported. In very severe cases neurological symptoms may progress to coma and respiratory arrest within the ﬁrst 24 hours of illness. Most patients recover completely within a few weeks; intermittent recrudescence of symptoms can occur over a period of months to years. This syndrome is caused by the presence in the ﬁsh of toxins elaborated by the dinoﬂagellate Gambierdiscus toxicus and algae growing on under- water reefs. Fish eating the algae become toxic, and the effect is magniﬁed through the food chain so that large predatory ﬁsh become the most toxic; this occurs worldwide in tropical areas. Ciguatera is a signiﬁcant cause of morbidity where consumption of reef ﬁsh is common—Australia, the Caribbean, southern Florida, Hawaii and the South Paciﬁc. Incidence has been estimated at 500-odd cases/100 000 population/year in the South Paciﬁc, with rates 50 times higher reported for some island groups. The consumption of large predatory ﬁsh should be avoided, especially in the reef area, particularly the barracuda. Where assays for toxic ﬁsh are available, screening all large “high-risk” ﬁsh before consumption can reduce risk. The occurrence of toxic ﬁsh is sporadic and not all ﬁsh of a given species or from a given locale will be toxic. Intravenous infusion of mannitol (1 gram/kg of a 20% solution over 45 minutes) may have a dramatic effect on acute symptoms of ciguatera ﬁsh poisoning, particularly in severe cases, and may be lifesaving in severe cases that have progressed to coma. In severe cases, ataxia, dysphonia, dysphagia and muscle paralysis with respiratory arrest and death may occur within 12 hours. Symptoms usually resolve completely within hours to days after shellﬁsh ingestion. This syndrome is caused by the presence in shellﬁsh of saxitoxins and gonyautoxins produced by Alexandrium species and other dinoﬂagel- lates. Concentration of these toxins occurs during massive algal blooms known as “red tides” but also in the absence of recognizable algal bloom. Blooms of the causative Alexandrium species occur several times each year, primarily from April through October. Shellﬁsh remain toxic for several weeks after the bloom subsides; some shellﬁsh species remain toxic constantly. Most cases occur in individuals or small groups who gather shellﬁsh for personal consumption. On an experi- mental basis, saxitoxins have been demonstrated in serum during acute illness and in urine after acute symptoms resolve. Illness results from eating mussels, scallops, or clams that have fed on Dinophysis fortii or Dinophy- sis acuminata. In scallops, the distribution of toxins was localized in the hepatopan- creas (midgut gland), the elimination of which renders scallops safe to eat. Cases were reported in the Atlantic provinces of Canada in 1987, with vomiting, abdominal cramps, diarrhea, headache and loss of short term memory. When tested several months after acute intoxication, patients show antegrade memory deﬁcits with relative preservation of other cognitive functions, together with clinical and electromyographical evidence of pure motor or sensorimotor neuropathy and axonopathy. Canadian au- thorities now analyse mussels and clams for domoic acid, and close shellﬁsh beds to harvesting when levels exceed 20 ppm domoic acid. The clinical signiﬁcance of ingestion of low levels of domoic acid (in persons eating shellﬁsh and anchovies harvested from areas where Pseudonitzschia species are present) is unknown. The causative toxin is tetrodotoxin, a heat-stable, nonprotein neurotoxin concentrated in the skin and viscera of puffer ﬁsh, porcupine ﬁsh, ocean sunﬁsh, and species of newts and salamanders. Toxicity can be avoided by not consuming any of the tetrodotoxin-producing species of ﬁsh or amphibi- ans. Japan implements control measures such as species identiﬁcation and adequate removal of toxic parts (e. Symptoms occur 12 to 24 hours after consumption and persist for up to 5 days: they include severe diarrhea and vomiting with abdominal pain and occasional nausea, chills, headaches, vomiting, stom- ach cramps. Identiﬁcation—A bacterial infection causing chronic gastritis, pri- marily in the antrum of the stomach, and duodenal ulcer disease. Infection with Helicobacter pylori is epidemiologically associated with gastric adenocarcinoma. Development of atrophy and metaplasia of the gastric mucosa are strongly associated with H. Oxidative and nitrosative stress in combination with inﬂamation plays an important role in gastric carcinogenesis. Diagnosis may be made from a gastric biopsy specimen through the use of culture, histology or the detection of H. The organism requires nutrient media for growth, such as Brain-Heart Infusion Agar with added horse blood. Selective media have been developed to prevent contaminating growth when culturing gastric biopsy material. Speciﬁc urea-based breath tests may also be used and are based on the organism’s extremely high urease activity. Infectious agent—Helicobacter pylori is a Gram-negative, “S” and “U” spirally shaped bacillus, catalase-, oxidase- and urease-positive. It could reach up to 70% in developing countries and up to 20%–30% in industrialized countries. Although individuals infected with the organism often have histological evidence of gastritis, the vast majority are asymptomatic.
Exchange transfusion as an adjunct therapy in severe Plasmodium falciparum malaria: a meta-analysis buy discount dulcolax 5mg on-line. Hemofiltration and peritoneal dialysis in infection-associated acute renal failure in Vietnam buy dulcolax 5mg free shipping. The clinical spectrum of severe imported falciparum malaria in the intensive care unit: report of 188 cases in adults cheap dulcolax 5 mg otc. Respiratory tract infections in travelers: a review of the GeoSentinel Surveillance Network order dulcolax mastercard. Risk of infection with Mycobacterium tuberculosis in travelers to areas of high tuberculosis endemicity. Miliary tuberculosis: epidemiology, clinical manifestations, diagnosis, and outcome. Miliary tuberculosis: rapid diagnosis, hematologic abnormalities, and outcome in 109 treated adults. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care facilities. Retreatment tuberculosis cases* factors associated with drug resistance and adverse outcomes. Outbreak of Legionnaires’ disease among cruise ship passengers exposed to a contaminated whirlpool spa. Prevalence and diagnosis of Legionella pneumonia: a 3-year prospective study with emphasis on application of urinary antigen detection. Clinical features that differentiate hantavirus pulmonary syndrome from three other acute respiratory illnesses. Discriminators between hantavirus-infected and -uninfected persons enrolled in a trial of intravenous ribavirin for presumptive hantavirus pulmonary syndrome. Prospective, double-blind, concurrent, placebo- controlled clinical trial of intravenous ribavirin therapy of hemorrhagic fever with renal syndrome. Placebo-controlled, double-blind trial of intravenous ribavirin for the treatment of hantavirus cardiopulmonary syndrome in North America. Multicenter prospective randomized trial comparing ceftazidime plus co-trimoxazole with chloramphenicol plus doxycycline and cotrimoxazole for treatment of severe melioidosis. A large outbreak of histoplasmosis among American travelers associated with a hotel in Acapulco, Mexico, spring 2001. A clinical prediction rule for diagnosing severe acute respiratory syndrome in the emergency department. Who rapid advice guidelines for pharmacological management of sporadic human infection with avian influenza A (H5N1) virus. Eosinophilic meningitis caused by Angiostrongylus cantonensis: a case report and literature review. Salmonella typhi infections in the United States, 1975–1984: increasing role of foreign travel. Relative efficacy of blood, urine, rectal swab, bone- marrow, and rose-spot cultures for recovery of Salmonella typhi in typhoid fever. Multidrug-resistant typhoid fever in children: epidemiology and therapeutic approach. Reduction of mortality in chloramphenicol-treated severe typhoid fever by high-dose dexamethasone. Global burden of Shigella infections: implications for vaccine development and implementation of control strategies. Acute liver failure: established and putative hepatitis viruses and therapeutic implications. Lamivudine therapy for severe acute hepatitis B virus infection after renal transplantation: case report and literature review. Leptospirosis—an emerging pathogen in travel medicine: a review of its clinical manifestations and management. Acute lung injury in leptospirosis: clinical and laboratory features, outcome, and factors associated with mortality. Leptospirosis as a cause of acute respiratory failure: clinical features and outcome in 35 critical care patients. Ceftriaxone compared with sodium penicillin g for treatment of severe leptospirosis. Acute pulmonary schistosomiasis in travelers returning from Lake Malawi, sub-Saharan Africa. African tick-bite fever: four cases among Swiss travelers returning from South Africa. Update: management of patients with suspected viral hemorrhagic fever—United States. Preheim Departments of Medicine, Medical Microbiology and Immunology, Creighton University School of Medicine, University of Nebraska College of Medicine, and V. The clinical manifestations vary widely from asymptomatic disease (up to 40% of patients) to fulminant liver failure. In the United States cirrhosis has an estimated prevalence of 360 per 100,000 population and accounts for approximately 30,000 deaths annually. The majority of cases in the United States are a result of alcoholic liver disease or chronic infection with hepatitis B or C viruses. A Danish death registry study (5) examined long-term survival and cause-specific mortality in 10,154 patients with cirrhosis between 1982 and 1993. The results revealed an increased risk of dying from respiratory infection (fivefold), from tuberculosis (15-fold) and other infectious diseases (22-fold) when compared to the general population. In a prospective study (6) 20% of cirrhotic patients admitted to the hospital developed an infection while hospitalized. The mortality among patients with infection was 20% compared with 4% mortality in those who remained uninfected. The most common bacterial infections seen in cirrhotic patients are urinary tract infections (12% to 29%), spontaneous bacterial peritonitis (7% to 23%), respiratory tract infections (6% to 10%), and primary bacteremia (4% to 11%) (7). The increased susceptibility to bacterial infections among cirrhotic patients is related to impaired hepatocyte and phagocytic cell function as well as the consequences of parenchymal destruction (portal hypertension, ascites, and gastroesophageal varices). It should be noted that the usual signs and symptoms of infection may be subtle or absent in individuals who have advanced liver disease. Thus a high index of suspicion is required to ensure that infections are not overlooked in this patient population, especially in those who are hospitalized. Occasionally fever may be due to cirrhosis itself (8), but this must be a diagnosis of exclusion made only when appropriate diagnostic tests, including cultures, have been unrevealing. The incidence of infection is highest for patients with the most severe liver disease (6,21–23). Accurate assessment for risk of infection is dependent upon proper classification of the extent of liver disease. The Child–Pugh scoring system of liver disease severity (24) is based upon five parameters: (i) serum bilirubin, (ii) serum albumin, (iii) prothrombin time, (iv) ascites, and (v) encephalopathy. A total score is 342 Preheim Table 1 Modified Child–Pugh Classification of Liver Disease Severity Points Assigned Parameter 1 2 3 Ascites None Slight Moderate/severe Encephalopathy None Grade 1–2 Grade 3–4 Bilirubin (mg/dL) <2. Patients with chronic liver disease are placed in one of three classes (A, B, or C). Despite having some limitations the modified Child–Pugh scoring system continues to be used by many clinicians to assess the risk of mortality in patients with cirrhosis (Table 1). Several mechanisms have been proposed to explain the movement of organisms from the intestinal lumen to the systemic circulation (reviewed in Ref. Cirrhosis-induced depression of the hepatic reticuloendothelial system impairs the liver’s filtering function, allowing bacteria to pass from the bowel lumen to the bloodstream via the portal vein. Cirrhosis also is associated with a relative increase in aerobic gram-negative bacilli in the jejunum. A decrease in mucosal blood flow due to acute hypovolemia or drug-induced splanchnic vasoconstriction may compromise the intestinal barrier to enteric flora, thereby increasing the risk of bacteremia. Finally, bacterial translocation may occur with movement of enteric organisms from the gut lumen through the mucosa to the intestinal lymphatics. From there bacteria can travel through the lymphatic system and enter the bloodstream via the thoracic duct.
Usage subject to terms and conditions of license 70 Red Lesions Hereditary Hemorrhagic Telangiectasia Definition Hereditary hemorrhagic telangiectasia purchase online dulcolax, or Osler–Rendu– Weber disease buy dulcolax, is a rare mucocutaneous disorder characterized by dys- plasia of the capillaries and small vessels discount dulcolax 5 mg free shipping. Clinical features The oral mucosa is frequently involved and the le- sions present as multiple bright red papules discount 5 mg dulcolax, 1–2 mm in size, which disappear on pressure froma glass slide (Fig. Usage subject to terms and conditions of license 72 Red Lesions Anemia Pernicious anemia, iron deficiency anemia, and Plummer–Vinson syn- drome usually affect the oral mucosa. The oral manifestations are early and common, and are characterized by an atrophic, smooth and red tongue (Figs. A burning sensation, taste loss, angular cheilitis, and rarely erosions may be present. The differential diagnosis includes atrophic lichen planus and malnutrition disorders. Usage subject to terms and conditions of license 74 Red Lesions Thrombocytopenic Purpura Definition Thrombocytopenic purpura is a hematological disorder characterized by a decrease in platelets in the peripheral blood. Clinical features The oral manifestations consist of red lesions in the form of petechiae, ecchymoses, or even hematomas, usually located on the palate and buccal mucosa (Fig. Purpuric skin rash, epistaxis, and bleeding from the gastrointestinal and urinary tract are common. Laboratory tests Peripheral platelet count, bone-marrow aspiration, bleeding and clotting times. Differential diagnosis Aplastic anemia, leukemias, polycythemia vera, agranulocytosis, macroglobulinemia, drug reactions. Treatment Steroids, platelet transfusions, cessation of drug treatment if it is drug-related. Infectious Mononucleosis Definition Infectious mononucleosis is an acute, self-limited infectious disease that primarily affects children. Clinical features The oral manifestations are early and common, and consist of palatal petechiae, uvular edema, tonsillar exudate, gingivitis, and rarely ulcers (Fig. Generalized lymphadenopathy, hepato- splenomegaly, maculopapular skin rash, and sore throat are common. Prodromal symptoms such as anorexia, malaise, headache, fatigue, and later fever occur before the clinical manifestations. Laboratory tests Heterophile antibody tests, and other specific anti- body tests (Paul–Bunnell test, monospot test). Usage subject to terms and conditions of license 76 Red Lesions Differential diagnosis Leukemias, secondary syphilis, diphtheria, fel- latio, thrombocytopenic purpura, traumatic hematoma. Reiter Disease Definition Reiter disease is an uncommon multisystemic disorder that predominantly affects young men aged 20–30 years. Etiology The exact etiology remains unknown, although the patho- genesis is mediated by an immunological mechanism. The disease may be triggered by an infectious agent in a genetically susceptible individ- ual. Clinical features The main clinical manifestations are nongonococcal urethritis, cyclic balanitis, symmetrical arthritis of six to seven joints, conjunctivitis, prostatitis, cervicitis, and mucocutaneous lesions. The cutaneous manifestations appear as macular, vesicular, or pustular le- sions involving mainly the palms and soles. Oral lesions occur in 20–40% of the cases and are characterized by diffuse erythematous areas inter- mixed with thin whitish dots or lines and painful superficial erosions (Figs. The buccal mucosa, gingiva, palate, lips, and tongue are more frequently affected. The clinical diagnosis should be confirmed by biopsy and histo- pathological examination. Differential diagnosis The differential diagnosis of oral lesions in- cludes Behçet disease, erythema multiforme, geographic tongue, and drug reactions. Treatment Systemic corticosteroids and nonsteroidal anti-inflamma- tory agents are the drugs of choice. Usage subject to terms and conditions of license 78 Red Lesions Peripheral Ameloblastoma Definition Ameloblastoma is the most common tumor of odontogenic epithelial origin that primarily affects the jaws. The peripheral ameloblastoma probably arises fromdental lamina rests or frombasal epithelial cells. Clinical features Peripheral ameloblastoma is rare and accounts for about 1–2% of all ameloblastomas. It usually presents as a painless, slow- growing, nonulcerated, sessile red mass (Fig. The posterior alveolar mucosa and the gingiva of the mandible are more frequently affected. The clinical diagnosis should be confirmed by a biopsy and histopathological examination. Differential diagnosis Pyogenic granuloma, peripheral giant cell gran- uloma, fibroma, squamous-cell carcinoma, extraosseous calcifying epi- thelial odontogenic tumor, extraosseous calcifying epithelial odontogen- ic cyst, odontogenic myxoma. Sturge–Weber Angiomatosis Definition Sturge–Weber angiomatosis, or encephalotrigeminal an- giomatosis, is a relatively rare, sporadic congenital capillary vascular malformation typically involving areas innervated by the trigeminal nerve. Clinical features The main clinical features are characterized by uni- lateral hemangiomas of the facial skin, oral mucosa, and leptomeninges, brain calcification, ocular disorders, epilepsy, and occasionally mild mental handicap. Oral hemangiomas have a bright red or purple color and are usually flat but may also be raised, causing tissue enlargement (Fig. Dentists and oral surgeons must be careful during tooth ex- traction and periodontal surgery so as to avoid bleeding complications. Facial hemangiomas have a bright red color and are asymptomatic Laskaris, Pocket Atlas of Oral Diseases © 2006 Thieme All rights reserved. Usage subject to terms and conditions of license 81 3 Black and Brown Lesions Pigmented oral lesions are a large group of disorders in which the dark or brown color is the essential clinical characteristic. Usually, the dark color of the lesions is due to melanin production by either melanocytes or nevus cells. In addition, exogenous deposits and pigment-producing bacteria can also produce pigmented lesions. Benign disorders, deposits, benign and malignant neoplasms, and systemic diseases are included in the group of pigmented lesions. O Normal pigmentation O Lentigo O Amalgam tattoo O Lentigo maligna O Heavy-metal deposition O Pigmented nevi O Drug-induced pigmentation O Nevus of Ota O Smoker’s melanosis O Melanoma O Black hairy tongue O Addison disease O Ephelis O Peutz–Jeghers syndrome Laskaris, Pocket Atlas of Oral Diseases © 2006 Thieme All rights reserved. Usage subject to terms and conditions of license 82 Black and Brown Lesions Normal Pigmentation Definition and etiology Increased melanin production and deposition in the oral mucosa may often be a physiological finding, particularly in dark-skinned individuals. Clinical features This type of pigmentation is persistent and symmet- rical, and clinically presents as asymptomatic black or brown areas of varying size. The gingiva are most commonly affected, followed by the buccal mucosa, palate, and lips (Fig. The pigmentation is more prominent in areas of pressure or friction, and usually becomes more intense with increasing age. Differential diagnosis Addison disease, smoker’s melanosis, drug-in- duced pigmentation, pigmented nevi, melanoma, amalgam tattoo. Clinical features The condition presents as a well-defined irregular or diffuse flat area, with a bluish-black discoloration of varying size (Fig. The most common sites of involvement are the gingiva, alveolar mucosa, and buccal mucosa. Differential diagnosis Pigmented nevi, lentigo, freckles, melanoma, normal pigmentation, other metal tattoo. Usage subject to terms and conditions of license 84 Black and Brown Lesions Heavy-Metal Deposition Definition and etiology Heavy-metal deposition is a rare oral condi- tion caused by ingestion or exposure to bismuth, lead, silver, mercury, and other heavy metals. Clinical features Clinically, the most common pattern (bismuth, lead) is a bluish line along the marginal gingiva, or similar spots within the gingival papillae (Fig. Drug-Induced Pigmentation Definition Drug-induced oral pigmentation is a relatively common condition, caused by increased melanin production or drug metabolite deposition. Etiology Antimalarials, tranquilizers, minocycline, azidothymidine, ke- toconazole, phenolphthalein, and others are the most common drugs that induce pigmentation. Clinical features The clinical picture varies, and the condition may appear as irregular brown or black macules or plaques, or diffuse mela- nosis (Fig.
In a manufacturing plant generic 5mg dulcolax, inspect for adequacy of preventive measures as outlined in 9A discount dulcolax 5mg amex. As mentioned in 9B1 order dulcolax 5 mg without prescription, it may be necessary to rule out a case of deliberate use for all human cases of anthrax 5 mg dulcolax, especially for those with no obvious occupational source of infection. Outbreaks related to handling and consuming meat from infected cattle have occurred in Africa, Asia, and the former Soviet Union. Disaster implications: None, except in case of ﬂoods in previously infected areas. The general procedures for dealing with such civilian occurrences include the following: 1) Anyone who receives a threat about dissemination of an- thrax organisms should notify the relevant local criminal investigative authority immediately. Postexposure immunization consists of 3 injections, starting as soon as possible after exposure and at 2 and 4 weeks after exposure. The vaccine has not been evaluated for safety and efﬁcacy in children under 18 or in adults 60 or older. Bleach solutions are usually not required; a 1:10 dilution of household bleach (ﬁnal hypochlorite concentration 0. The bleach solution, to be used only after soap and water decontamination, must be rinsed off after 10 to 15 minutes. Per- sonal items may be kept as evidence in a criminal trial or returned to the owner if the threat is unsubstantiated. Quarantine, evacuation, decontamination and che- moprophylaxis efforts are not indicated if the envelope or package remains sealed. For incidents involving possibly con- taminated letters, the environment in direct contact with the letter or its contents should be decontaminated with a 0. Onset is gradual with malaise, headache, retroorbital pain, conjunctival injection, sustained fever and sweats, followed by prostration. There may be petechiae and ecchymoses, accompanied by erythema of the face, neck and upper thorax. Severe infections result in epistaxis, hematemesis, melaena, hematuria and gingival hemorrhage. Encephalopathies, intention tremors and depressed deep tendon reﬂexes are frequent. Bradycardia and hypo- tension with clinical shock are common ﬁndings, and leukopenia and thrombocytopenia are characteristic. Moderate albuminuria is present, with cellular and granular casts and vacuolated epithelial cells in the urine. Infectious agents—Among the 18 known New World arenaviruses belonging to the Tacaribe complex, 4 have been associated with hemor- rhagic fever in humans: Jun´ın for the Argentine disease; the closely related Machupo virus for the Bolivian; Guanarito virus for the Venezuelan; and the Sabia´ virus for the Brazilian. These viruses are related to the Old World arenaviruses that include the agents of Lassa fever and lymphocytic choriomeningitis. A further virus, Whitewater Arroyo Virus, has been found in rodents in North America. Occurrence—Argentine hemorrhagic fever was ﬁrst described among corn harvesters in Argentina in 1955. The region at risk has been expanding northwards and now potentially affects a population of 5 million. Disease occurs seasonally from late February to October, predominantly in males, 63% in the age group 20–49. A similar disease, Bolivian hemorrhagic fever, caused by the related virus, occurs sporadically or in epidemics in small villages of rural northeastern Bolivia. In 1989, an outbreak of severe hemorrhagic illness occurred in the municipality of Guanarito, Venezuela; 104 cases with 26 deaths occurred between May 1990 and March 1991 among rural residents in Guanarito and neighboring areas. Although the virus continued circulating in the rodent popula- tion, there was an unexplained drop in human cases between 1992 and 2002 (one outbreak with 18 cases). Reservoir—In Argentina, wild rodents of the pampas (Calomys musculinus and Calomys laucha) are the hosts for Jun´ın virus. Cane rats (Zygodontomys brevicauda) were shown to be the main reservoir of Guanarito virus. Mode of transmission—Transmission to humans occurs primarily by inhalation of small particle aerosols from rodent excreta containing virus, from saliva or from rodents disrupted by mechanical harvesters. Viruses deposited in the environment may also be infective when second- ary aerosols are generated by farming and grain processing, when in- gested, or by contact with cuts or abrasions. While uncommon, person- to-person transmission of Machupo virus has been documented in health care and family settings. Fatal scalpel accidents during necropsy as well as laboratory infections without further person-to-person transmission have been described. Period of communicability—Rarely transmitted directly from person to person, although this has occurred in both Argentine and Bolivian diseases. Susceptibility—All ages appear to be susceptible, but protective immunity of unknown duration follows infection. Preventive measures: Speciﬁc rodent control in houses has been successful in Bolivia. In Argentina, human contact most commonly occurs in the ﬁelds, and rodent dispersion makes control more difﬁcult. An effective live attenuated Jun´ın vaccine has been administered to more than 150 000 persons in Argen- tina. In experimental animals, this vaccine is effective against Machupo but not Guanarito virus; it is still not known whether it provides effective cross-protection in humans. Other compounds (inosine-5 monophos- phate dehydrogenate inhibitors, phenothiazines and myr- istic acid analogs) were recently shown to inhibit arena- virus replication in cell culture and animals. Hemorrhagic fevers, including acute febrile diseases with extensive hemorrhagic involvement, frequently serious, associated with capillary leakage, shock and high case-fatality rates (all may cause liver damage, most severe in yellow fever and accompanied by frank jaundice). Polyarthritis and rash, with or without fever and of variable duration, benign or with arthralgic sequelae lasting several weeks to months. Humans are usually an unimportant host in maintaining the cycle; infections in humans are incidental and are usually acquired during blood feeding by an infected arthropod vector. In rare cases such as dengue and yellow fever, humans can serve as the principal source of virus ampliﬁcation and vector infection. Most viruses are transmitted by mosquitoes, the rest by ticks, sandﬂies or biting midges. Agents differ, but in their transmission cycles these diseases share common epidemiological features (related primarily to their vectors) that are important in control. The diseases selected under each clinical syndrome are arranged in 4 groups: mosquito- and midge-borne; tick- borne; sandﬂy-borne; unknown. Diseases of major importance are de- scribed individually or in groups with similar clinical and epidemiological features. The main viruses thought to be associated with human disease are listed in the accompanying table with type of vector, predominant character of recognized disease and geographical distribution. In some instances, observed cases of disease due to particular viruses are too few to be certain of the usual clinical course. Some viruses capable of causing disease have only been recognized through laboratory exposure. Viruses in which evidence of human infection is based solely on serological surveys are not included. Those that cause diseases covered in subsequent chapters are marked on the table by an asterisk; some of the less important or less well studied are not discussed or mentioned. These genera contain some agents that predominantly cause encephalitis; others predominantly cause febrile illnesses. Alphaviruses and bunyaviruses are usually mosquito-borne; ﬂaviviruses are either mosquito- or tick-borne, some ﬂaviviruses having no recognized vectors; phleboviruses are gener- ally transmitted by sandﬂies, apart from Rift Valley fever, transmitted by mosquitoes. Other viruses of the family Bunyaviridae and of several other groups mainly produce febrile diseases or hemorrhagic fevers and may be transmitted by mosquitoes, ticks, sandﬂies or midges. Identiﬁcation—A self-limiting febrile viral disease characterized by arthralgia or arthritis, primarily in the wrist, knee, ankle and small joints of the extremities, lasting days to months. In many patients, onset of arthritis is followed after 1–10 days by a maculopapular rash, usually nonpruritic, affecting mainly the trunk and limbs.
Manifestations • Thirst dulcolax 5 mg with visa, followed by: • decreased skin turgor generic 5mg dulcolax free shipping, tachycardia order dulcolax 5 mg on line, dry mucous membranes order 5mg dulcolax amex, sunken eyes, lack of tears, a sunken anterior fontanelle in infants, and oliguria. Page 70 Module 3 • As the fluid deficit approaches 10% of body Hypotomic dehydration weight, dehydration becomes severe and anuria, Children with diarrhoea who drink large amounts hypotension, a feeble and very rapid pulse, cool of water or other hypotonic fluids containing very and moist extremities, diminished consciousness, low concentrations of salt and other solutes, or who and signs of shock appear. Some children with diarrhoea, especially young infants, develop hypernatraemic dehydration. It usually results from: • serum sodium concentration is low (<130 • the ingestion and inefficient absorption, during mmol/l); and diarrhoea, of fluids that are hypertonic (owing to their • serum osmolality is low (<275 mOsmol/l). Base-deficit acidosis (metabolic acidosis) The hypertonic fluids create an osmotic gradient During diarrhoea, a large amount of bicarbonate that causes a flow of water from extracellular fluid may be lost in the stool. However, this compensating mechanism fails when the renal function deteriorates, as Principal features include: happens when there is poor renal blood flow due • a deficit of water and sodium, but the deficit of to hypovolaemia. Acidosis can also result • serum sodium concentration is elevated (>150 from excessive production of lactic acid when mmol/l); and patients have hypovolaemic shock. These losses are greatest in infants and can be Fluid losses can be replaced either orally or especially dangerous in malnourished children, who intravenously; the latter route is usually needed are frequently potassium-deficient before diarrhoea only for initial rehydration of patients with severe starts. However, when metabolic acidosis is derived from the breakdown of sucrose or cooked corrected by giving bicarbonate, this shift is rapidly starches) or l-amino acids (which are derived from reversed, and serious hypokalaemia can develop. This can be prevented by replacing potassium Fortunately, this process continues to function whilst simultaneously correcting the base deficit. Manifestations • General muscular weakness Thus, if patients with secretory diarrhoea drink an • Cardiac arrhythmias isotonic salt solution that contains no source of • Paralytic ileus, especially when drugs are taken glucose or amino acids, sodium is not absorbed that also affect peristalsis (such as opiates) and the fluid remains in the gut, adding to the volume of stool passed by the patient. However, when an isotonic solution of glucose and salt is given, glucose-linked sodium absorption occurs and this is accompanied by the absorption of water and other electrolytes. To attain the latter cooled before mixing if there is any doubt); two objectives, salts of potassium and citrate (or • 3. Page 73 Oral rehydration therapy solutions are designed to approximate the composition of gut fluid losses Module 3 Page 73 Use of antimicrobials Antimicrobials should not be used routinely. This antibiotics (furazolidone, co-trimoxazole, is because, except as noted below, it is not possible erythromycin, or chloramphenicol) are usually to clinically distinguish episodes that might effective. Selecting an effective but may also cause delayed clearance of Salmonellae antimicrobial requires knowledge of the causative from the intestinal tract. Prognosis The prognosis of infective diarrhoea depends upon Antimicrobial agents are helpful for the treatment the infecting organism, the development of of dysenteric shigellosis and amoebiasis. Antibiotic usage for selected infections Shigella: Antibiotics to which Shigellae are sensitive provide effective treatment, but antibiotic resistance is a common problem. The most useful antibiotics are co-trimoxazole and nalidixic acid; ampicillin is effective in some areas. Campylobacter jejuni: Erythromycin or clarythromycin shortens the illness if given soon after the symptoms start. However, erythromycin is often ineffective if therapy is delayed until the diagnosis is confirmed by a laboratory. Vibrio cholerae 01: Antibiotics can shorten the duration of the illness and thus simplify case management. Tetracycline (or doxycycline) is most widely used, but resistance has been observed in some areas. When resistance occurs, other Page 74 Module 3 Prevention of spread of diarrhoea This is dependent upon: • improving nutritional status by improving the • prevention of diarrhoea; and nutritional value of weaning foods and giving • interruption of transmission of pathogens. Although a wide variety of infectious agents cause Nursing care diarrhoea, they are all transmitted through common Nursing care of the patient with infective diarrhoea pathways such as contaminated water, food, and requires: hands. Measures to interrupt the transmission • assessment and continuous observation of the should focus on the following pathways: clinical state; • supervision and administration of appropriate • giving only breast milk for the first 6 months of fluid and food; life; • maintenance of a fluid input and output chart; • avoiding the use of infant feeding bottles; • maintenance of a stool chart; • improving practices related to the preparation and • monitoring of temperature, pulse and blood storage of weaning fluids and feeds; pressure; • washing hands after defecation or handling faeces, • monitoring of weight, daily if the patient is a and before preparing food or eating; child; • minimizing microbial contamination and growth • encouraging a scrupulous personal hygiene of foods by preventing breaks in the food hygiene regime; and chain including: use of human excrement as • skin care to prevent excoriation. Rehabilitation may be more protracted • the importance of hand washing, safe disposal in individuals with serious underlying disorders. Giving a nutritious diet, appropriate for the child’s age, when the child is well is important. In addition, the hospital must determine the infecting organism and report it to the relevant public health authority; this is of primary importance in epidemic situations. Role of the community The community is responsible for ensuring the maintenance of good standards of food and water hygiene, educating about careful hand washing and other aspects of personal hygiene, and home Page 76 Module 3 Typhoid Definition approximately 600 000 deaths. Typhoid is Typhoid fever (also known as enteric fever) is a predominantly a disease of countries with poor severe systemic infection caused by the Gram sanitation and poor standards of personal and food negative bacterium Salmonella typhi. Multi-drug resistant strains have been a large number of organisms is usually necessary reported in Asia, the Middle East, and Latin America. The organisms are absorbed from the gut and Manifestations transported via the blood stream to the liver and • In the early stages fever, severe headache, spleen. They are released into the blood after 10 to constipation and a dry cough may be present. The • The fever rises in a “step ladder” pattern for 4 or 5 organisms localise in the lymphoid tissue of the days. This • Abdominal tenderness and an enlarged liver or is the main cause of death from typhoid fever. The • If untreated, complications can occur during the incubation period is from 10 to 21 days. Most patients who have typhoid will excrete • Other complications may affect any patient organisms at some stage of their illness. About because of the occurrence of septicaemia during 10% who have typhoid fever excrete the organisms the first week. These may include cholecystitis, for approximately three months after the acute stage pneumonia, myocarditis, arthritis, osteomyelitis of the illness and 2 to 5% of untreated patients and meningitis. Incidence of becoming • Bone and joint infection is seen, especially in a carrier increases with age, especially in females. Epidemiological summary Age groups affected The organism responsible for typhoid fever was Typhoid can affect any age. Typhoid fever affects Case-fatality rates of 10% can be reduced to less 17 million people in the world annually, with than 1% with appropriate antibiotic therapy. Module 3 Page 77 Diagnosis Treatment of carriers: this can often be very Blood culture is the most important method for difficult to implement, but spread through carriers diagnosis. Isolation of the organism from the stool is unusual if good personal hygiene is practised and is more common in the second and third weeks of stools are disposed of hygienically. In some cases, isolation of the bacteria in the urine can be used as a diagnostic method. Selective immunization of groups: during an epidemic in an endemic country, selective Methods of treatment immunization of groups such as school children, Four different antibiotics are often used for institutionalized people and healthcare workers is treatment: Ciprofloxacin, Co-trimoxazole, of great benefit. Effective treatment does not always prevent complications, Immunization against typhoid the disease recurring or the patient becoming a There are three types of typhoid vaccine: carrier. A chronic carrier may be treated for four weeks with aminoquinalones and in some cases it • Monovalent whole cell typhoid vaccine contains may be necessary to perform a cholecystectomy, in excess of 1000 million S. Two doses, given four to Prevention of spread is dependent upon: six weeks apart, give protection for three years, but • Clean water supply: protection and chlorination side effects include a painful reaction at the of public water supplies is necessary. It provides equally effective protection as the whole cell vaccine but with fewer Page 78 Module 3 febrile side effects, although it can cause irritation general examination for complications; at the vaccine site. Length Rehabilitation of protection may be less and vaccination may need Recovery may be complete after treatment, but may repeating after one year. The vaccine is unstable at also be delayed with recurrence of the symptoms room temperature and must be kept refrigerated. Recurrence is more It should be emphasized that whilst these vaccines likely to occur after inadequate treatment. Consequently strict food, water and personal Role of primary health care team hygiene protection continue to be of great • Education regarding food, water and personal importance. Blood • Awareness of the risks and management of patient cultures can provide early confirmation; the with carrier status organism can then be tested for antibiotic sensitivity. Stool and urine culture may also be Role of health education and health promotion performed from one week following confirmation • Heighten public awareness of the disease and of the disease. Water and food samples from its prevention suspected sources also need to be tested.
Oral doxycycline (200 mg daily for four weeks) is recommended and used as an alternative in penicillin-allergic patients dulcolax 5 mg low cost, despite a paucity of supportive studies purchase dulcolax 5mg without prescription. Listeria Listeria is a widely prevalent organism that only rarely causes human disease order dulcolax 5mg free shipping. Infection most often occurs by exposure to contaminated food order dulcolax visa, most often dairy products. Infections are particularly problematic in pregnant women (causing miscarriages) and newborns (causing disseminated infection). Neurologic involvement takes several forms, most typically meningitis, being the commonest cause of bacterial meningitis in the immunocompromised and the second most common in healthy adults over age 50. The clinical picture of this meningitis is often more indolent than in other meningitides; patients appear less ill and the time course is more protracted. The organism is very sensitive to ampicillin and penicillin, but perhaps because of its intracellular location, slow to respond. Consequently, gentamicin is often added for synergy and treatment is typically prolonged. Diagnosis is generally by measuring either cold agglutinins or specific antibody titers. Viral Brain Infections Herpes Simplex Encephalitis Human herpes viruses, similar to polioviruses, differ from many other encephalitis-causing viruses in that they have just one host—humans. Because of this it is at least theoretically possible to eliminate these pathogens entirely—primarily through effective vaccines. While sufficiently potent vaccines are not yet available for herpes simplex, this strategy has eliminated smallpox and hopefully will eliminate polio in the not too distant future. Unfortunately, this approach cannot eliminate the innumerable other viruses, such as West Nile and rabies, which are zoonoses, existing in multiple species. Even with successful vaccination, the best that can be hoped for with zoonotic infections is temporary protection of the immunized individuals, not permanent elimination of the virus and therefore the disease. Periodically the virus will migrate back down the axon, causing a recurrent cutaneous eruption. The sensory neurons of the trigeminal nerve, which innervate the lips, also innervate the meninges of the middle and anterior cranial fossa. Experimentally, reactivating virus can be shown to migrate centrally, affecting the medial temporal and frontal lobes, the primary site of involvement in herpes simplex encephalitis. Two important (and probably interrelated) functions of the medial temporal lobes are olfaction and memory. Early manifestations of this necrotizing, localized infection often consist of focal seizures manifest as olfactory hallucinations and perceptions of deja vu or jamais vu. Often a diagnosis is not made´ ` until the patient has a generalized or at least focal motor seizure. The diagnosis should be considered in a previously healthy individual with abrupt onset of altered mental status and fever; headache is present in most. Since other brain infections can be clinically similar, confirmatory testing is necessary. Its major complication is renal toxicity; this risk can be decreased with aggressive hydration. The role of steroids is unclear, without substantial evidence supporting their use. Other Herpes Viruses Neurologic complications used to accompany about 1 of every 10,000 cases of chickenpox (19). Cytomegalovirus can cause 160 Halperin ventriculoencephalitis and dementia in the immunocompromised. Ebstein–Barr virus has been associated with a similar clinical picture, but has not been shown to respond to acyclovir or other antivirals. Unlike herpes, West Nile is one of the large group of diseases referred to as arthropod borne, or arboviruses. West Nile appears to have been brought to the United States by infected birds and was originally recognized for being highly lethal in some but not all bird species. Key to the transmissibility of any of these infections is its production of prolonged viremia in some host species, and the presence of mosquitoes or other vectors that feed on both the infected reservoir species and on humans (22). This interspecies promiscuity is essential to the transmission of this large group of pathogens, which can persist in the environment in reservoir hosts, and periodically infect humans when a large group of nonimmune individuals is exposed. Since there are hundreds of asymptomatic or minimally symptomatic infections for every neuroinvasive case, “herd immunity” normally takes over after the infection is present in the environment for a period of time—presumably the reason the incidence of cases has moved like a wave across the United States from east to west since its initial introduction. West Nile is a flavivirus (the family that includes and is named for Yellow Fever virus), a broad group that includes dengue, tick borne encephalitis, Japanese encephalitis, and St. In the Middle East, serologic studies indicate up to 40% of the population has had asymptomatic infection. Disease severity increases with age, with most mortality occurring in individuals over 50. Neuroinvasive disease causes meningitis; a polio-like syndrome of flaccid lower motor neuron–type weakness occurs in about half. Involvement of the brainstem and basal ganglia appears to be common with extrapyramidal syndromes, tremors and ataxia occurring with some frequency. Rabies Fortunately human rabies is extremely rare in the United States, with typically 1 case per year nationwide. However there is a significant incidence among animals, and when human cases occur, there often is some delay in diagnosis, resulting in additional individuals being exposed, and then requiring prophylaxis. Transmission requires transfer of virus-containing secretions or tissue through mucosa or broken skin. Since the virus has an affinity for the muscle endplates, infection is particularly efficient when a bite introduces the virus directly into muscle. Once introduced, virions are transported within axons to the dorsal root ganglion neurons and multiply, then on to the spinal cord and brainstem. Once the virus is in the nervous system, patients develop fever, anxiety, muscle aches, and nonspecific symptoms. Neuropathic symptoms ranging from itching to pain may develop at the inoculation site. In the former, patients develop a Guillain Barre–like picture, with fever, sensory and motor symptoms, facial involvement, and sphincter dysfunction. More common is the encephalitic form in which patients develop inspiratory spasms, precipitated by any Encephalitis and Its Mimics in Critical Care 161 contact with the face, including trying to drink (hydrophobia). Hallucinations and fluctuating consciousness proceed to coma, paralysis, and death within a week. Immunofluorescence can often detect virus in nerve twigs surrounding hair follicles in skin biopsied from the nape of the neck. Despite numerous attempts at treatment, only one or two individuals have survived (24). Confusional states in septic patients—even with sources as localized as urinary tract infections or pneumonia—are so commonplace that clinicians rarely question the underlying pathophysiology. In both, the disorder caused by these intracellular organisms probably is less an encephalitis than an infectious vasculitis. Whether ehrlichia infections have significant neurologic involvement remains unclear—although headaches and alterations of consciousness are described frequently, only a few case reports have described focal brain abnormalities. Organisms can sometimes be identified in buffy coat isolates, using special stains. Legionnaire’s disease similarly does not infect the brain but causes altered cognitive function with remarkable frequency—out of proportion to any associated hypoxia or other metabolic abnormalities. This infection can often be suspected clinically by its multisystem involvement—often with prominent early gastrointestinal symptoms (diarrhea and abdominal pain), bradycardia, and hepatic and renal involvement. Diagnosis typically rests on the combination of rapidly worsening changes on chest radiograms, and either serologic or urinary antigen testing. Signs and symptoms are typically nonspecific—except when a septic embolism causes either a stroke or a mycotic aneurysm that ruptures. Again, findings are typically nonfocal; either on exam or imaging, but cerebral edema can be prominent.