Rift Valley fever outbreaks in Madagascar and potential risks to neighbouring countries
Rift Valley fever (RVF) is an arthropod-borne viral disease of ruminants, camels and humans. It is a significant zoonosis which may present itself from an uncomplicated influenza-like illness to a haemorrhagic disease with severe liver involvement and ocular or neurological lesions. In animals, RVF may be unapparent in non-pregnant adults, but outbreaks are characterised by the onset of a large number of abortions and high neonatal mortality. The virus (Phlebovirus) is usually transmitted by var ious arthropods. Human infections have also resulted from the bites of infected mosquitoes, most commonly the Aedes mosquito. Mosquitoes from six genera (Aedes, Culex, Mansonia, Anopheles, Coquillettidia and Eretmapodites), including more than 30 species, have been recorded as infected, and some of them are proven to have a role as vectors. Most of these species acquire the infection by biting infected vertebrate animals, but some (specifically Aedes spp.) pass the virus transovarially (vertical transmission). These infected pools of eggs can survive through desiccation for months or years and restart transmission after flooding; then other species (Culex spp.) may be involved as secondary vectors. Vertical transmission (from an infected female mosquito to eggs) explains how the virus can persist for many years or decades between outbreaks.
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| Format: | Book (series) biblioteca |
| Language: | English |
| Published: |
2008
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| Online Access: | https://openknowledge.fao.org/handle/20.500.14283/AJ213E http://www.fao.org/3/a-aj213e.pdf |
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