Bunyaviridae : Bunyaviruses, Phleboviruses, Nairoviruses, and Hantaviruses

Abstract

The family Bunyaviridae is the largest family of animal viruses and includes many viruses that are known human pathogens. The clinical diseases produced in humans range from acute febrile illnesses, such as sandfly fever, to more distinct clinical syndromes such as California encephalitis (CE), Rift Valley fever (RVF), Crimean-Congo hemorrhagic fever (CCHF), hemorrhagic fever with renal syndrome (HFRS), and the recently recognized hantavirus cardiopulmonary syndrome (HCPS), which is also referred to as hantavirus pulmonary syndrome. Representative groups and complexes for the bunyaviruses, phleboviruses, and nairoviruses, including major human pathogens, are discussed. The limited host range and similar phylogenetic relationships among hantaviruses and among the rodent hosts have led to the suggestion that hantaviruses may have coevolved with their rodent hosts. Although infection with the hantaviruses causing HFRS occurs in all age groups, infection and disease peak in adults 15 to 40 years of age; like HCPS, HFRS is uncommon in children. The role of viremia in the pathogenesis of HFRS and HCPS is not known, but there is emerging evidence that viremia with ANDV routinely precedes the onset of symptoms and development of antihantavirus antibodies in HCPS by periods of up to 15 days. In eastern Asia, infection with Hantaan and Seoul hantaviruses is usually diagnosed serologically with immunofluorescence assay (IFA), enzyme-linked immunosorbent assay (ELISA), or bead agglutination formats, and IgM antibody is determined by IgM capture ELISA. Investigational strategies include DNA vaccination for pathogenic hantaviruses, including Hantaan virus and ADNV.