Etiology The polioviruses are nonenveloped, positive-stranded RNA viruses belonging to the Picornaviridae family, in the genus Enterovirus, species Enterovirus C and consist of 3 antigenically distinct serotypes (types 1, 2, and 3). Polioviruses spread from the intestinal tract to the…
Mumps is an acute self-limited infection that was once commonplace but is now uncommon in developed countries because of widespread use of vaccination. It is characterized by fever, bilateral or unilateral parotid swelling and tenderness, and the frequent occurrence of…
Rubella ( German measles or 3-day measles ) is a mild, often exanthematous disease of infants and children that is typically more severe and associated with more complications in adults. Its major clinical significance is transplacental infection and fetal damage…
Measles is highly contagious, but endemic transmission has been interrupted in the United States as a result of widespread vaccination; indigenous or imported cases have occasionally resulted in epidemics in the United States in unimmunized or partially immunized American or…
Antiviral chemotherapy typically requires a delicate balance between targeting critical steps in viral replication without interfering with host cellular function. Because viruses require cellular functions to complete replication, many antiviral agents exert significant host cellular toxicity, a limitation that has…
Pneumocystis jirovecii pneumonia (interstitial plasma cell pneumonitis) in an immunocompromised person is a life-threatening infection. Primary infection in the immunocompetent person is usually subclinical and goes unrecognized. The disease most likely results from new or repeat acquisition of the organism…
Etiology Mucormycosis refers to a group of opportunistic fungal infections caused by fungi of the order Mucorales, which are primitive, fast-growing fungi that are largely saprophytic and ubiquitous. These organisms are found commonly in soil, in decaying plant and animal…
Etiology Sporotrichosis is a rare fungal infection that occurs worldwide both sporadically and in outbreaks. The etiologic agent, Sporothrix schenckii, exhibits temperature dimorphism, existing as a mold at environmental temperatures (25-30°C [77-86°F]) and as a yeast in vivo (37°C [98.6°F]).…
Etiology Paracoccidioidomycosis (South American or Brazilian blastomycosis, Lutz-Splendore-Almeida disease) is the most common systemic mycosis in Latin America. It is a fungal infection that is endemic in South America, with cases reported in Central America and Mexico. Brazil accounts for…
Etiology Coccidioidomycosis (valley fever, San Joaquin fever, desert rheumatism, coccidioidal granuloma) is caused by Coccidioides spp., a soil-dwelling dimorphic fungus. Coccidioides spp. grow in the environment as spore-bearing (arthroconidia-bearing) mycelial forms. In their parasitic form, they appear as unique, endosporulating…