INFECTIOUS DISEASES - PART 4 ppt

Control Measures: People should avoid swimming in warm, stagnant, polluted fresh water. Acanthamoeba organisms are resistant to freezing, drying, and the usual concentrations of chlorine found in drinking water and swimming pools. Only sterile saline solutions should be used to clean contact lenses. Anthrax Clinical Manifestations: Depending on the route of infection, anthrax disease can occur in 3 forms: cutaneous, inhalational, and gastrointestinal. Cutaneous anthrax begins as a pruritic papule or vesicle that enlarges and ulcerates in 1 to 2 days, with subsequent formation of a central black eschar. The lesion characteristically is painless, with surrounding edema, hyperemia, and regional lymphadenopathy. Patients may have associated fever, malaise, and headache. Inhalational anthrax is the most lethal form of disease. A prodrome of fever, sweats, nonproductive cough, chest pain, headache, myalgias, malaise, and nausea and vomiting may occur initially, but more distinctive clinical symptoms occur 2 to 5 days later, in some cases following a period of improvement. These manifestations include dyspnea, hypoxia, and fulminant shock occurring as a result of hemorrhagic mediastinal lymphadenitis, hemorrhagic pleural effusions, bacteremia, and toxemia. A widened mediastinum is the classic finding on imaging of the chest; pleural effusions and hemorrhagic infiltrates can be present, but initially changes on chest radiography may be subtle. Gastrointestinal tract disease can present as 2 clinical syndromes, intestinal and oropharyngeal. Patients with the intestinal form have symptoms of nausea, anorexia, vomiting, and fever progressing to severe abdominal pain, massive ascites, hematemesis, and bloody diarrhea. Oropharyngeal anthrax may include posterior oropharyngeal ulcers that typically are unilateral and associated with marked neck swelling, regional adenopathy, and sepsis. Hemorrhagic meningitis can result from hematogenous spread of the organism after acquiring any form of disease. The case-fatality rate for patients with appropriately treated cutaneous anthrax usually is 1%, but for inhalational or gastrointestinal tract disease, mortality often exceeds 50% and approaches 100% for meningitis. Etiology: Bacillus anthracis is an aerobic, gram-positive, encapsulated, spore-forming, nonmotile rod. Spore size is approximately 1  2 um. Bacillus anthracis has 3 major virulence factors: an antiphagocytic capsule and 2 exotoxins, called lethal and edema toxins. The toxins are responsible for the primary clinical manifestations of hemorrhage, edema, and necrosis. Epidemiology: Anthrax is a zoonotic disease that occurs in many rural regions of the world. Bacillus anthracis spores remain viable in the soil for decades, representing a potential source of infection for livestock through ingestion. Natural infection of humans occurs through contact with infected animals or contaminated animal products, including carcasses, hides, hair, wool, meat, and bone meal. Internationally, outbreaks of gastrointestinal tract anthrax have occurred after ingestion of undercooked or raw meat. In the United States, the incidence of naturally occurring human anthrax decreased from an estimated 130 cases annually in the early 1900s to no cases in 2004. The vast majority (95%) of these cases were cutaneous infections among animal handlers or mill workers. The last case of naturally acquired inhalational anthrax in the United States occurred in 1976 in a person who worked with imported yarn. Bacillus anthracis is one of the most likely biological agents to be used as a weapon, because (1) its spores are highly stabile; (2) spores can infect via the respiratory route; and (3) the resulting inhalational disease has a high mortality rate. In addition to aerosolization, there is a theoretic health risk associated with B anthracis spores being introduced into food products or water supplies. In 1979, an accidental release of B anthracis spores from a military microbiology facility in the former Soviet Union resulted in 69 deaths. In 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified in the United States after intentional contamination of the mail; 5 (45%) of the inhalational cases were fatal. Use of B anthracis in a biological attack would require immediate response and mobilization of public health resources. Because naturally occurring anthrax is rare in the United States, every suspected case should be reported immediately to the local or state health department (see Biological Terrorism, p 105). The incubation period for all forms of anthrax generally is less than 2 weeks. However, because of spore dormancy and slow clearance from the lungs, the incubation period for inhalational anthrax may be prolonged to as long as several months. Discharge from cutaneous lesions potentially is infectious, but person-to-person transmission rarely has been reported. Both inhalational and cutaneous disease have occurred in laboratory workers. Diagnostic Tests: Depending on the clinical presentation, Gram stain and culture should be performed on specimens of blood, pleural fluid, cerebrospinal fluid, and tissue biopsy or discharge from cutaneous lesions. However, previous treatment with antimicrobial agents significantly decreases the yield of these studies. Gram-positive bacilli seen on peripheral blood smears or in cerebrospinal fluid can be an important initial finding. Definitive identification of suspect B anthracis isolates can be performed through the Laboratory Response Network (LRN) in each state. Additional diagnostic tests for anthrax, including tissue immunohistochemistry, real-time polymerase chain reaction, time-resolved fluorescent assay, and an enzyme immunoassay that measures immunoglobulin G antibodies against B anthracis protective antigen in paired sera, also can be accessed through state health departments. The commercially available QuickELISA Anthrax- PA Kit (Immunetics Inc) can be used as a screening test. Clinical evaluation of patients with suspected inhalational anthrax should include a chest radiograph and/or computed tomography scan to evaluate for widened mediastinum and pleural effusion. Treatment: A high index of clinical suspicion and rapid administration of effective antimicrobial therapy to people suspected of being infected are essential for effective treatment of anthrax. No controlled trials in humans have been performed to validate current treatment recommendations for anthrax, and there is limited clinical experience. Case reports suggest that naturally occurring cutaneous disease can be treated effectively with a variety of antimicrobial agents, including penicillins and tetracyclines, for 7 to 10 days. For bioterrorism-associated cutaneous disease in adults or children, ciprofloxacin (500 mg, orally, 2 times/day or 20-30 mg/kg per day, orally, divided 2 times/day for children) or doxycycline (100 mg, orally, 2 times/day or 5 mg/kg per day, orally, divided 2 times/day for children younger than 8 years of age) are recommended for initial treatment until antimicrobial susceptibility data are available. Because of the risk of concomitant inhalational exposure, consideration should be given to continuing an appropriate antimicrobial regimen for postexposure prophylaxis as well as administration of vaccine (see Control Measures). On the basis of in vitro data and animal studies, ciprofloxacin (400 mg, intravenously, every 8-12 hours) or doxycycline (200 mg, intravenously, every 8-12 hours) is recommended as part of an initial multidrug regimen for treating inhalational anthrax, anthrax meningitis, cutaneous anthrax with systemic signs, and gastrointestinal anthrax until results of antimicrobial susceptibility testing are known.* Other agents with in vitro activity suggested for use in conjunction with ciprofloxacin or doxycycline include rifampin, penicillin, ampicillin, vancomycin, imipenem, chloramphenicol, clindamycin, and clarithromycin. Other fluoroquinolones, including levofloxacin, gatifloxacin, and ofloxacin, have excellent in vitro activity against B anthracis, as do newer agents, such as quinupristin/dalfopristin and the ketolide, telithromycin. Because of intrinsic resistance, cephalosporins and trimethoprim- sulfamethoxazole should not be used for therapy. Treatment should continue for at least 60 days. Neither ciprofloxacin nor tetracyclines are used routinely in children or pregnant women because of safety concerns. However, ciprofloxacin or tetracycline should be used for treatment of anthrax in children for life-threatening infections until antimicrobial susceptibility patterns are known. * Centers for Disease Control and Prevention. Update: investigation of bioterrorism-related anthrax and interim guidelines for exposure management and antimicrobial therapy, October 2001. MMWR Morb Mortal Wkly Rep. 2001;50:909-919; and Centers for Disease Control and Prevention. Notice to readers: update: interim recommendations for antimicrobial prophylaxis for children and breastfeeding mothers and treatment of children with anthrax. MMWR Morb Mortal Wkly Rep. 2001;50:1014-1016 Isolation of the Hospitalized Patient: Standard precautions are recommended. In addition, contact precautions should be implemented when draining cutaneous lesions are present. Contaminated dressings and bedclothes should be incinerated or steam sterilized to destroy spores. Autopsies performed on patients with systemic anthrax require special precautions. Control Measures: BioThrax (formerly known as Anthrax Vaccine Adsorbed [manufactured by BioPort Corp, Lansing, MI]) is the only human vaccine for prevention of anthrax currently licensed in the United States. This vaccine is prepared from a cell-free culture filtrate. Immunization consists of 6 subcutaneous injections at 0, 2, and 4 weeks and 6, 12, and 18 months followed by annual boosters. The vaccine currently is recommended for people at risk of repeated exposures to B anthracis spores, including selected laboratory workers and military personnel. a The vaccine is effective for preventing the occurrence of cutaneous anthrax in adults. Although protection against inhalational disease has not been evaluated fully in humans, studies in nonhuman primates have shown the vaccine to be effective. Adverse events usually are local injection site reactions with rare systemic symptoms, including fever, chills, muscle aches, and hypersensitivity. No data on vaccine effectiveness or safety in children are available, and the vaccine is not licensed for use in children or pregnant women. The currently available anthrax vaccine is not licensed for postexposure in preventing anthrax. New anthrax vaccines are in development. a Centers for Disease Control and Prevention. Notice to readers: use of anthrax vaccine in response to terrorism: supplemental recommendations of the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 2002;51:1024-1026 On the basis of limited available data, the best means for prevention of inhalation anthrax after exposure to B anthracis spores is prolonged antimicrobial therapy in conjunction with a 3-dose regimen (at 0, 2, and 4 weeks) of anthrax immunization. Because BioThrax vaccine is not licensed for postexposure prophylaxis, for use as a 3-dose regimen, or for use in children, this program can be administered only under an investigational new drug (IND) application as part of an emergency public health intervention. When no information is available about antimicrobial susceptibility of the implicated strain of B anthracis, initial postexposure prophylaxis for adults or children with ciprofloxacin or doxycycline is recommended. Although fluoroquinolones and tetracyclines are not recommended as first-choice drugs in children because of adverse effects, these concerns may be outweighed by the need for early treatment of pregnant women and children exposed to B anthracis after a terrorist attack. As soon as susceptibility of the organism to penicillin has been confirmed, prophylactic therapy for children should be changed to oral amoxicillin, 80 mg/kg per day, divided every 8 hours (not to exceed 500 mg, 3 times/day). Bacillus anthracis is not susceptible to cephalosporins and trimethoprim-sulfamethoxazole; therefore, these agents should not be used for prophylaxis. Ascaris lumbricoides Infections Clinical Manifestations: Most infections are asymptomatic. Moderate to heavy infections may lead to malnutrition, and nonspecific gastrointestinal tract symptoms may occur in some patients. During the larval migratory phase, an acute transient pneumonitis (Loffler syndrome) associated with fever and marked eosinophilia may occur. Acute intestinal obstruction may develop in patients with heavy infections. Children are prone to this complication because of the small diameter of the intestinal lumen and heavy worm burden. Worm migration can cause peritonitis, secondary to intestinal wall penetration, and common bile duct obstruction resulting in biliary colic, cholangitis, or pancreatitis. Adult worms can be stimulated to migrate by stressful conditions (eg, fever, illness, or anesthesia) and by some anthelmintic drugs. Ascaris lumbricoides has been found in the appendiceal lumen in patients with acute appendicitis, but a causal relationship is uncertain. Etiology: Ascaris lumbricoides is the most widespread of all human intestinal roundworms. Epidemiology: Adult worms live in the lumen of the small intestine. Females produce 200,000 eggs per day, which are excreted in stool and must incubate in soil for 2 to 3 weeks for the embryo to form and to become infectious. Ingestion of infective eggs from contaminated soil results in infection. Larvae hatch in the small intestine, penetrate the mucosa, and are transported passively by portal blood to the liver and subsequently to the lungs. Larvae then ascend through the tracheobronchial tree to the pharynx, are swallowed, and mature into adults in the small intestine. Infection with A lumbricoides is widespread but is most common in the tropics, in areas of poor sanitation, and where human feces are used as fertilizer. If infection is untreated, adult worms can live for 12 to 18 months, resulting in daily excretion of large numbers of ova. The incubation period (interval between ingestion of the egg and development of egg-laying adults) is approximately 8 weeks. Diagnostic Tests: Ova can be detected by microscopic examination of stool. Occasionally, patients pass adult worms from the rectum, from the nose after migration through the nares, and from the mouth in vomitus. Treatment: Albendazole in a single dose, mebendazole for 3 days, or ivermectin in a single dose is recommended for treatment of asymptomatic and symptomatic infections (see Drugs for Parasitic Infections, p 790). Although limited data suggest that these drugs are safe in children younger than 2 years of age, the risks and benefits of therapy should be considered before administration. Reexamination of stool specimens 3 weeks after therapy to determine whether the worms have been eliminated is helpful for assessing therapy but is not essential. In cases of partial or complete intestinal obstruction attributable to a heavy worm load, piperazine solution (75 mg/kg per day, not to exceed 3.5 g) may be given through a gastrointestinal tube but is not available in many countries, including the United States. If piperazine is not available, conservative management (nasogastric suction, intravenous fluids) may result in resolution of obstruction, at which point albendazole, mebendazole, or ivermectin may be given. Surgical intervention occasionally is necessary to relieve intestinal or biliary tract obstruction or for volvulus or peritonitis secondary to perforation. If surgery is performed for intestinal obstruction, massaging the bowel to eliminate the obstruction is preferable to incision into the intestine. Endoscopic retrograde cholangiopancreatography has been used successfully for extraction of worms from the biliary tree. Isolation of the Hospitalized Patient: Only standard precautions are recommended, because there is no direct person-to-person transmission. Control Measures: Sanitary disposal of human feces stops transmission. Children's play areas should be given special attention. Vegetables cultivated in areas where uncomposted human feces are used as fertilizer must be thoroughly cooked or soaked in a diluted iodine solution before eating. Household bleach is ineffective in killing A lumbricoides. Despite relatively rapid reinfection, periodic deworming targeted at school-aged children has been used to prevent morbidity (nutritional and cognitive deficits) associated with intestinal helminth infections. Arboviruses (also see West Nile Virus, p 729) (Including California Serogroup [Primarily La Crosse] Encephalitis, Eastern and Western Equine Encephalitis, Powassan Encephalitis, St Louis Encephalitis, Venezuelan Equine Encephalitis, Colorado Tick Fever, Dengue Fever, Japanese Encephalitis, and Yellow Fever) Clinical Manifestations: Arboviruses (arthropodborne viruses) (Table 3.1) are spread by mosquitoes, ticks, sandflies, or other biting arthropods (eg, midges) and produce 4 principal clinical syndromes: (1) central nervous system (CNS) disease (including encephalitis, aseptic meningitis, and flaccid paralysis); (2) an undifferentiated febrile illness, often with rash and headache; (3) acute polyarthropathy; and (4) acute hemorrhagic fever, sometimes accompanied by hepatitis. Some arboviruses can cause congenital infection. Selected arboviruses that cause encephalitis in the Western hemisphere are shown in Table 3.2 (p 213). When present, clinical illness ranges in severity from a self-limited febrile illness with headache to a syndrome of aseptic meningitis or acute encephalitis. La Crosse virus produces aseptic meningitis or encephalitis with acute seizures and focal neurologic findings in more than 25% of cases, stupor or coma in 50%, and death in less than 1%. Eastern equine encephalitis (EEE) typically is a fulminant illness leading to coma and death in 40% to 70% of cases and serious neurologic sequelae in one third; the highest mortality rates are in infants and children. Western equine encephalitis (WEE) is associated with a case-fatality rate of 5%; neurologic impairment is common in infants, and congenital infection resulting in mental retardation has been described. Powassan encephalitis is associated with long-term morbidity and has a case-fatality rate of 10% to 15%. Characteristics of symptomatic infection caused by St Louis encephalitis (SLE) include confusion, fever, headache, slow disease progression, lack of focal findings, generalized weakness, and tremor; 7% of cases are fatal. Japanese encephalitis (JE) virus occurs in Asia and can produce a severe encephalitis characterized by coma, seizures, paralysis, abnormal movements, and death in one third of cases. Serious sequelae occur in 40% of survivors. Most infections are asymptomatic. Several arboviruses in the Western hemisphere are associated with acute, febrile diseases and hemorrhagic fevers. These arboviruses are not characterized by encephalitis (Table 3.3). Colorado tick fever (CTF) generally is an acute, self-limited illness consisting of fever, chills, myalgia, arthralgia, severe headache, and ocular pain. Illness is biphasic in 50% of cases and rarely may be complicated by encephalitis, pericarditis, and rarely, fatal systemic illness with hemorrhage. Transient but significant leukopenia and thrombocytopenia in the absence of anemia are hallmarks of disease. Infection with any of the 4 serotypes of dengue virus produces dengue fever, an acute febrile illness with headache, retro-orbital pain, myalgia, arthralgia, rash, nausea, and vomiting. Criteria for dengue hemorrhagic fever (DHF), which is seen most commonly in children younger than 15 years of age, include fever, any hemorrhage including epistaxis and gum bleeding, thrombocytopenia (platelet count 100  10 3 /uL [100  10 9 /L]), and increased capillary fragility and permeability. Fluid leakage into the interstitial, pleural, and peritoneal spaces leads to hemoconcentration, pleural effusion, and acute shock. Mortality from DHF can be reduced from 30% to less than 3% with appropriate fluid resuscitation and management of electrolyte abnormalities. Encephalopathy, hepatitis, myocardiopathy, upper intestinal tract bleeding, and pneumonia are complications. Maternal infection during the third trimester can result in congenital hemorrhagic dengue. Severe yellow fever (YF) typically evolves through 3 stages from a nonspecific febrile illness with headache, malaise, weakness, nausea, and vomiting; through a brief period of remission; to a hemorrhagic fever with jaundice, albuminuria, oliguria, and multiple organ dysfunction (liver, kidneys, cardiovascular system); 50% of cases are fatal. Mayaro fever and Oropouche virus fever occur in Central and South America. Both cause a febrile, influenza-like syndrome. Etiology: More than 550 arboviruses are classified in a variety of taxonomic groups, principally in the families Bunyaviridae, Togaviridae, and Flaviviridae (Table 3.1, p 212), with more than 150 arboviruses known to cause human disease. Viruses in these families principally are arthropodborne or spread as zoonoses. Epidemiology: Most arboviruses are maintained in nature through cycles of transmission among birds or small mammals by arthropod vectors. Humans and domestic animals are infected incidentally as "dead-end" hosts. Important exceptions are dengue, YF, Oropouche, and chikungunya viruses, because infected vectors spread disease from person to person (anthroponotic transmission). For the other arboviruses, person-to-person spread does not occur except through blood transfusion, through intrauterine transmission, and possibly through human milk (see Blood Safety, p 106). There also is evidence that Venezuelan encephalitis virus may be spread via respiratory tract secretions. In the United States, mosquitoborne arboviral infections usually occur during summer and autumn, but in the South, cases occur throughout the year. Fewer than 20 WEE and 10 EEE human cases are reported nationally each year. During epidemics of SLE, people of all ages can be infected, but cases of severe clinical illness occur more often at the extremes of age, especially in elderly people. Urban SLE outbreaks have led to hundreds of cases, disproportionately affecting people in lower socioeconomic-status neighborhoods and homeless people. La Crosse virus encephalitis occurs in an endemic pattern in wooded environments in the eastern and midwestern United States. Most of the approximately 100 cases that are reported each year are in children younger than 15 years of age. The incubation periods and geographic distributions of selected medically important arboviral infections are outlined in Tables 3.2 (p 213) and 3.3 (p 214). Diagnostic Tests: A definitive diagnosis is made by viral isolation. Detection of virus-specific immunoglobulin M antibody in cerebrospinal fluid (CSF) is confirmatory, and presence of antibody in a serum specimen is presumptive evidence of recent infection in a patient with acute CNS infection. A greater than fourfold change in serum immunoglobulin (Ig) M or IgG antibody titer in paired serum specimens obtained 2 to 4 weeks apart confirms a case. Polymerase chain reaction assays to detect several arboviruses are available in reference laboratories. Serologic testing for dengue virus and arboviruses transmitted in the United States is available through several commercial, state, research, and reference laboratories. During the acute phase of dengue fever, YF, CTF, Venezuelan equine encephalitis (VEE), and certain other arboviral infections, virus can be isolated from blood and, in VEE infection, from the throat. In patients with encephalitis, viral isolation should be attempted from a CSF specimen or from biopsy or postmortem brain tissue specimens. Serologic results should be interpreted in the context of any previous immunizations with YF and JE vaccines and locations of previous residence and travel. Immunohistochemical staining for specific arboviruses can be performed at reference laboratories on fresh and formalin-fixed tissue specimens. Treatment: Active clinical monitoring and supportive interventions may be life saving in patients with DHF, YF, and acute encephalitis. Isolation of the Hospitalized Patient: Patients with acute dengue fever and acute YF may be viremic, so they should be protected from vector mosquitoes that could feed on them and subsequently transmit infection to others. Control Measures: Protection Against Vectors. Mosquito-control programs are important for controlling vectors. Personal precautions to avoid arthropod bites include repellents and protective clothing and staying in screened or air-conditioned locations. Although many mosquito vectors of arboviruses are most active during twilight hours, certain vectors of EEE and La Crosse encephalitis are daytime feeders. Aedes aegypti, the vector of dengue and urban YF, is found around houses and indoors, even in well-constructed hotels. Travelers to tropical countries should consider bringing mosquito bed nets and aerosol insecticide sprays. Active Immunization. Yellow Fever Vaccine.* * Centers for Disease Control and Prevention. Yellow fever vaccine recommendations of the Advisory Committee on Immunization Practices (ACIP), 2002. MMWR Recomm Rep. 2002;51(RR-17):1-10 Live-attenuated (17D strain) vaccine is available at state-approved immunization centers. A single dose is accepted by international authorities as providing protection for 10 years and may well confer lifelong immunity. Immunization is recommended for all people 9 months of age or older living in or traveling to areas with endemic infection and is required every 10 years by international regulations for travel to and from certain countries. Infants younger than 4 months of age should not be immunized, because they have increased susceptibility to vaccine-associated encephalitis. The decision to immunize infants between 4 and 9 months of age must balance the infant's risk of exposure with the theoretic risks of vaccine-associated encephalitis. Yellow fever vaccine-associated viscerotropic disease and YF vaccine- associated neurotropic disease are rare, well-recognized serious vaccine- associated adverse events. People younger than 50 years of age are at higher risk; however, cases occurring at younger ages have been reported. The YF vaccine can be given concurrently with either typhoid vaccine licensed by the US Food and Drug Administration, hepatitis A and hepatitis B virus vaccines, measles vaccine, poliovirus vaccine, and meningococcal vaccine; chloroquine; and Immune Globulin. Yellow fever vaccine is prepared in embryonated hen eggs and contains egg protein, which may cause allergic reactions. People who have experienced signs or symptoms of allergic reaction after eating eggs should be excused from immunization and issued a medical waiver letter to fulfill health regulations or should undergo skin testing according to the package insert before immunization (also see Hypersensitivity Reactions to Vaccine Constituents, p 46). The vaccine should be administered to pregnant women only if travel to an area with endemic infection is unavoidable and if an increased risk of exposure exists. Administration of YF vaccine to immunocompromised people poses a theoretic risk. The decision to immunize patients who have immunocompromising conditions must balance the traveler's risk of exposure with his or her clinical status. Family members of immunosuppressed people who themselves have no contraindications can receive YF vaccine. Immunization of breastfeeding mothers should be avoided unless the risk of maternal exposure is high. Advice regarding immunization of 4- to 9-month-old children, pregnant women, or immunocompromised people can be obtained from the Division of Vector- Borne Infectious Diseases of the Centers for Disease Control and Prevention (CDC; telephone 970-221-6400). Japanese Encephalitis Vaccine.* * Centers for Disease Control and Prevention. Inactivated Japanese encephalitis virus vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1993;42(RR-01):1-15 The inactivated JE vaccine, derived from infected mouse brain, should be offered to people who travel for extended periods (more than 30 days) to areas of Asia with endemic infection during the JE transmission season. Vaccine-associated hypersensitivity reactions (angioedema, generalized urticaria) occur in 0.3% of vaccine recipients. Therefore, immunization is not recommended for travelers who will be staying for short periods in areas without ongoing JE transmission. Immunization should be considered for short-term travelers if travel includes rural areas experiencing epidemic transmission (eg, travel into an area with epidemic infection or bicycling, camping, or other unprotected outdoor activity in a rural area during transmission season). Current information on locations of JE virus transmission and detailed information on vaccine recommendations can be obtained from the CDC (www.cdc.gov/travel). The recommended primary immunization series for people older than 3 years of age is 3 doses of 1.0 mL each, administered subcutaneously on days 0, 7, and 30. An abbreviated schedule of 0, 7, and 14 days can be used when the longer schedule is precluded by time constraints. The regimen for children 1 to 3 years of age is identical, except that each dose is 0.5 mL. No data are available on vaccine safety and efficacy in infants. Other Arboviral Vaccines. An inactivated vaccine for tickborne encephalitis is licensed in Canada and some countries in Europe where the disease is endemic, but this vaccine is not available in the United States. Arcanobacterium haemolyticum Infections Clinical Manifestations: Acute pharyngitis attributable to Arcanobacterium haemolyticum often is indistinguishable from that caused by group A streptococci. Fever, pharyngeal exudate, lymphadenopathy, rash, and pruritus are common, but palatal petechiae and strawberry tongue are absent. In almost half of all reported cases, a maculopapular or scarlatiniform exanthem is present, beginning on the extensor surfaces of the distal extremities, spreading centripetally to the chest and back and sparing the face, palms, and soles. Respiratory tract infections that mimic diphtheria, including membranous pharyngitis, sinusitis, and pneumonia; and skin and soft tissue infections, including chronic ulceration, cellulitis, paronychia, and wound [...]... Tests: Spirochetes can be observed by dark-field microscopy and in Wright-, Giemsa-, or acridine orange-stained preparations of thin or dehemoglobinized thick smears of peripheral blood or in stained buffy-coat preparations Organisms often can be detected in blood obtained while the person is febrile Spirochetes can be cultured from blood in BarbourStoenner-Kelly medium or by intraperitoneal inoculation... strains Serologic cross-reactions occur with other spirochetes, including Borrelia burgdorferi, Treponema pallidum, and Leptospira species Biologic specimens for laboratory testing can be sent to the Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80522 Treatment: Treatment of tickborne relapsing fever with a 5- to 10-day course of one of the... doxycycline ( 2 -4 mg/kg per day, maximum 200 mg/day, in 2 divided doses) or oral tetracycline (3 0 -4 0 mg/kg per day, maximum 2 g/day, in 4 divided doses) is the drug of choice and should be administered for at least 6 weeks However, tetracyclines should be avoided, if possible, in children younger than 8 years of age (see Antimicrobial Agents and Related Therapy, p 735) Oral trimethoprim-sulfamethoxazole... (trimethoprim, 10 mg/kg per day, maximum 48 0 mg/day; and sulfamethoxazole, 50 mg/kg per day, maximum 2 .4 g/day) divided in 2 doses for 4 to 8 weeks is appropriate therapy for younger children To decrease the incidence of relapse, combination therapy with a tetracycline (or trimethoprim-sulfamethoxazole if tetracyclines are contraindicated) and rifampin (1 5-2 0 mg/kg per day, maximum 60 0-9 00 mg/day, in 1 or 2 divided... milk, including children who have participated in field trips to dairy farms, have occurred Person-to-person spread occurs occasionally, particularly among very young children, and outbreaks of diarrhea in child care centers have been reported but are uncommon Personto-person transmission also has occurred in neonates of infected mothers and has resulted in health care-related outbreaks in nurseries... However, lipid-associated preparations should not be used as first-line drugs Published reports in adults and anecdotal reports in preterm infants indicate that at least one lipid-associated amphotericin B preparation has failed to eradicate renal candidiasis, because this large-molecule drug does not penetrate kidneys Liver toxicity has been reported with lipid formulations Flucytosine (10 0-1 50 mg/kg... neutropenia or, more often, during treatment for graft-versus-host disease Nosocomial outbreaks of invasive pulmonary aspergillosis in susceptible hosts have occurred in which the probable source of the fungus was a nearby construction site or faulty ventilation system Transmission by direct inoculation of skin abrasions or wounds is less likely Person-to-person spread does not occur The incubation period... orally, in 2 divided doses for 7 days Because treatment of BV in high-risk pregnant women who are asymptomatic might prevent adverse pregnancy outcomes, a follow-up evaluation 1 month after completion of treatment should be considered to evaluate whether therapy was successful For nonpregnant and low-risk pregnant women, routine follow-up visits on completion of therapy for BV are unnecessary if symptoms... usually can be managed with antipyretic agents alone Single-dose treatment using a tetracycline, penicillin, or erythromycin is effective for curing louseborne relapsing fever Isolation of the Hospitalized Patient: Standard precautions are recommended If louse infestation is present, contact precautions also are indicated (see Pediculosis, pp 48 8 -4 92) Control Measures: Contact with ticks can be limited... are at increased risk Patients undergoing intravenous alimentation or receiving broad-spectrum antimicrobial agents, especially extended-spectrum cephalosporins, carbapenems, and vancomycin, or requiring long-term indwelling central venous catheters, have increased susceptibility Postsurgical patients can be at risk, particularly after cardiothoracic or abdominal procedures The incubation period is unknown . Advice regarding immunization of 4- to 9-month-old children, pregnant women, or immunocompromised people can be obtained from the Division of Vector- Borne Infectious Diseases of the Centers for. risks of vaccine-associated encephalitis. Yellow fever vaccine-associated viscerotropic disease and YF vaccine- associated neurotropic disease are rare, well-recognized serious vaccine- associated. data and animal studies, ciprofloxacin (40 0 mg, intravenously, every 8-1 2 hours) or doxycycline (200 mg, intravenously, every 8-1 2 hours) is recommended as part of an initial multidrug regimen