Hepatitis C virus (HCV) was first identified in 1989. Although substantially more prevalent among adults, HCV infection does occur in children and should be considered when relevant clinical or epidemiologic factors are present. , In recent years, new HCV infections…
Description of Pathogen The family Bunyaviridae was recently reclassified, with Bunyavirales becoming an order and several new family names being designated. , However, the genera that have important human pathogens have remained relatively unchanged and include Orthohantavirus, Orthonairovirus, Bandavirus, Phlebovirus…
The flaviviruses are single-stranded, enveloped RNA viruses that are transmitted to humans primarily through the bites of arthropods. Although >40 arthropod-borne flaviviruses have been described, this chapter discusses those that are most important in causing human illness: yellow fever virus…
Alphaviruses are arthropod-borne members of the family Togaviridae. They are small, enveloped, positive-sense RNA viruses. , Members of the western equine encephalitis, eastern equine encephalitis, and Venezuelan equine encephalitis serocomplexes cause encephalitis in equines and humans. Members of the Semliki…
Before the availability of rotavirus vaccines, rotaviruses were the most common cause of severe infant and childhood gastroenteritis worldwide, responsible for 40% of all diarrheal hospitalizations and more than half a million deaths among children aged <5 years annually. To…
Colorado tick fever (CTF) is an acute febrile illness caused by CTF virus, a double-stranded RNA virus in the Coltivirus genus of the family Reoviridae ( Box 215.1 ). , The virus is transmitted to humans through the bite of…
Parvoviruses—small (20–25 nm), nonenveloped, icosahedral, single-stranded DNA viruses with a linear genome of between 4500 and 5600 nucleotides—are common infectious agents of animals, including birds and insects, as well as humans. At least five different genera of parvovirus have been…
Hepatitis B Virus Description of the Pathogen Hepatitis B virus (HBV), a member of the Hepadnaviridae family, is an enveloped virus that contains a circular partially double-stranded DNA genome that is 3.2 kb in length. The small genome consists of…
Polyomaviruses are a subgroup of small, ubiquitous DNA viruses that belong to the family Papovaviridae. The two most commonly known human polyomaviruses are the BK virus and JC virus, which were first described in 1971. , Subsequently, 12 other human…
Papillomaviruses are species specific and widely distributed among mammals and nonmammalian animal species. Human papillomaviruses (HPVs) are strictly epitheliotropic and cause infections and cancer of the skin and mucous membranes. Clinical conditions include anogenital and oral infections and cancers, as…