tailieunhanh - Ebook Clinical virology manual (4/E): Part 2

(BQ) Part 2 book “Clinical virology manual” has contents: Human papillomaviruses, human polyomaviruses, human herpesviruses, rodent borne viruses, poxviruses, the human retroviruses human immunodefi ciency virus and human T-lymphotropic retrovirus, and other contents. | Arboviruses JOHN T. ROEHRIG AND ROBERT S. LANCIOTTI 23 LABORATORY PROCEDURES FOR DETECTING VIRUSES Introduction The term arbovirus is a contraction of “arthropod-borne virus” and has no phylogenetic or classification significance. This term describes the mechanism by which these viruses are transmitted and maintained in nature: through the bite of a hematophagous arthropod. Most medically important arboviruses are transmitted by either mosquitoes or ticks. In the United States alone, representatives from at least five virus families can be transmitted by biting arthropods (Table 1). This review will focus on the medically important arboviruses. Because these viruses are transmitted by arthropods, arboviral disease usually manifests itself during the warmer months in the temperate climates of the world. Arboviral disease can, however, be contracted in the winter months in milder climates, and disease transmission can occur year round in the tropics. During the milder times of the year, or depending on the patient’s travel history, testing for arboviruses should be included in the laboratory diagnosis of cases compatible with arboviral infections. There are 535 arboviruses listed in the International Catalogue of Arboviruses (Karabatsos, 1985), but most have not been associated with human disease. Continued encroachment on the world’s tropical rainforests, however, coupled with rapid transport of humans and animals, makes arboviruses emerging and reemerging pathogens. This observation means that new arboviruses may be associated with human diseases or known arboviruses may cause outbreaks in previous or new locales. The discovery of West Nile (WN) virus (WNV) in the United States in 1999 is a recent example of arbovirus movement. Identification of emerging agents will, by definition, be difficult, with the medical and veterinary community depending on specialty reference laboratories capable of working with and identifying these biosafety level 3 and 4 pathogens (Centers