Tags: Acyclovir

Rubella

General Considerations A. Epidemiology. The epidemiology of rubella, commonly referred to as German measles or 3-day measles, has changed dramatically in the past 30 years, owing exclusively to the widespread use of the rubella live attenuated virus vaccine. Before the use of this vaccination (1969), the virus had an epidemic cycle of 6-9 years. It is primarily a winter and early spring infection. The incidence of rubella infection in developed countries has declined by 99%, compared with pre-vaccine era data. In the vaccine era, current data suggest that 10% of young adults are still susceptible. The majority of these young adults lack vaccination. A major concern of rubella is infection of …

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Mumps

Essentials of Diagnosis • Epidemic parotitis, usually seen in childhood. • Most common heralding symptom is painful parotid swelling. • Headache and meningismus common. • Orchitis is uncommon late complication seen in post-pubertal males; rarely leads to sterility. • Other glandular tissue may be inflamed. General Considerations A. Epidemiology. Mumps, historically known as epidemic parotitis, was one of the most common early childhood infections before the routine use of mumps vaccination starting in 1968. Reported cases of mumps have dropped 98% when compared with the prevaccine era. It is spread primarily during the late winter and early spring. Before the vaccination era, mumps epidemics occurred in 3- to 4-year cycles. B. …

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Measles

Essentials of Diagnosis • Epidemic systemic viral illness, primarily of children and young adults. • Exanthematous disease with fever, cough, coryza, and conjunctivitis. • Exanthem is a maculopapular, confluent rash that is centrifugally spread from the head to the extremities. • Koplik’s spots are a pathognomonic enanthem that occurs on the buccal mucosa. • Incidence has drastically dropped in the postvaccination era. General Considerations A. Epidemiology. Rubeola, commonly known as measles, is a virus spread primarily in the winter and early spring. Like mumps and rubella, vaccination has drastically changed the epidemiology of measles. In the prevaccination era, rubeola followed a biannual epidemic cycle. It is prevalent throughout the world. Measles …

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Herpesviruses

The herpesvirus group of the family Herpesviridae comprises large, enveloped, double-stranded DNA viruses found in both animals and humans. They are ubiquitous and produce infections ranging from painful skin ulcers to chickenpox to encephalitis. The major members of the group to infect humans are the two herpes simplex viruses (HSV-1 and -2), cytomegalovirus (CMV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), herpesvirus 6, and the recently discovered human herpesvirus types 7 and 8. Occasionally, the simian herpesvirus, herpes B virus, has caused human disease. All herpesviruses are morphologically similar with an overall diameter of 180-200 nm. The nucleic acid core is ~ 30-45 nm in diameter, surrounded by an icosahedral capsid. The …

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Human Herpesvirus Type 6

Essentials of Diagnosis • Infant with high fever for several days; maculopapular rash after defervescence • Can be isolated in cultures of monocytes but takes 10-30 days and may be false negative • Detection of specific IgG and IgM by indirect immunofluorescence are diagnostic tests of choice • Blood or saliva PCR for HHV-6 DNA may be positive, but diagnostic significance uncertain due to intermittent excretion in asymptomatic patients • PCR positively in CSF diagnostic of encephalitis General Considerations In 1986 a human herpesvirus, now called human herpesvirus type 6 (HHV-6), was identified in cultures of peripheral blood lymphocytes from patients with lymphoproliferative diseases (Box 2). The virus, which is genetically …

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Epstein-Barr Virus

Essentials of Diagnosis • Atypical lymphocytes in peripheral blood smear • Heterophile antibody present in high titer in serum • Immunoglobulin G (IgG) seroconversion or development of antibody to EB nuclear antigen • Adolescent, young adult with fever, lymphadenopathy, splenomegaly, pharyngitis, and prolonged fatigue • Infectious mononucleosis may be complicated by laryngeal obstruction, CNS disease, splenic rupture General Considerations EBV is the etiologic agent of infectious mononucleosis and certain lymphoproliferative syndromes (Box 10). A. Epidemiology. EBV can be cultured from the saliva of 10-20% of healthy adults. Excretion may persist weeks to months. Infection with EBV is by contact with infected secretions such as saliva. It is of low contagiousness, and …

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Cytomegalovirus

Essentials of Diagnosis • “Owl eye” cells in tissue biopsy, cytology • Cultured in diploid fibroblast cells • Antibody detection of those patients seroconverting or at risk for reactivation • CMV detection in blood or bodily fluids by antigenemia, PCR, or other DNA-based assays, eg hybrid capture, or by culture General Considerations A. Epidemiology. CMV is ubiquitous, and in developed countries ~50% of adults have developed antibody (Box 7). Age-specific prevalence rates show that ~ 10-15% of children are infected by CMV during the first 5 years of life, after which the rate of new infections levels off. The rate subsequently increases during young adulthood, probably through close personal contact or …

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Varicella-Zoster Virus

Essentials of Diagnosis • Vesiculopustular, generalized rash in a febrile child (varicella or chicken pox) • Dermatomal pustular eruption in elderly or immunocompromised patient (herpes zoster or shingles) • Multinucleated, giant epithelial cells with intranuclear inclusions in skin scrapings, tissue biopsy Slow growth of virus (5-7 days) in diploid fibroblast cells if fresh vesicles are cultured • Detection of VZV antigen by immunofluorescence of skin vesicles (best diagnostic test) General Considerations A. Epidemiology. VZV infection, the cause of both varicella (chickenpox) and herpes zoster, is ubiquitous (Box 4). Nearly all persons contract chickenpox before adulthood, and 90% of cases occur before the age of 10. The virus is highly contagious, with …

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Herpes Simplex Virus

Essentials of Diagnosis • Intranuclear inclusions and multinucleated giant cells in tissue cytology. • Grows rapidly in many types of tissue culture. • HSV antigen can be detected in tissue by immunofluorescence. • Polymerase Chain Reaction (PCR) analysis of cerebrospinal fluid (CSF) now considered best assay for HSV encephalitis. General Considerations A. Epidemiology. The term herpes (from the Greek herpein, to creep) and the clinical description of cold sores date back to Hippocrates. Two distinct epidemiologic and antigenic types of HSVs exist (HSV-1 and HSV-2). HSVs have worldwide distribution. There are no known animal vectors, and humans appear to be the only natural reservoir (Box 33-1 shows the syndromes caused by …

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Adenoviruses: Clinical Syndromes

Adenoviruses cause primary infection in children and, less commonly, adults. Reactivation of virus occurs in immunocompromised children and adults. Several distinct clinical syndromes are associated with adenovirus infection (Box 1). ACUTE RESPIRATORY DISEASE A. Signs and Symptoms. Acute pharyngitis is usually nonexudative but is associated with fever. Acute respiratory disease is a syndrome of fever, cough, pharyngitis, and cervical adenitis seen primarily in outbreaks among military recruits usually with serotypes 4 and 7. Adenoviruses are definite but infrequent causes of true viral pneumonia in both children and adults including military recruits. Laryngitis, croup, and bronchiolitis may also occur. Pertussis-like illness with a prolonged clinical course has been associated with adenoviruses. Adenovirus …

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