Vaccines and animal models for arboviral encephalitides

Bats as Potential Reservoir Hosts for Vector-Borne Diseases

“…Regarding the latter species, they conclude with Kelser (1933) that it could not be the transmitting species at it did not occur sufficiently far northwards. Generally, epizootics of EEE occur every 5-10 years and are associated with increased mosquito populations resulting from heavy rainfall and warm weather (Grady et al 1978;Letson et al 1993;Mahmood and Crans 1998;Nalca et al 2003). Although birds seem to be the main reservoir hosts of EEEV, the virus has also been detected in bats.…”

“…EEEV was first recognized as a horse disease in the northeastern USA in 1831 (Hanson 1957;Nalca et al 2003;Scott and Weaver 1989). The most severe outbreak of EEEV was recorded from Texas and Louisiana in 1947, causing 14,344 cases with 11,722 horse deaths (Chang and Trent 1987;Nalca et al 2003). However, suspected EEEV could not be linked to humans till an outbreak in 1938 (Fothergill et al 1938;Getting 1941).…”

“…Following further antigenic studies four different subtypes have been distinguished, which correspond to four genetic lineages (I-IV) (Arrigo et al 2010;Brault et al 1999). EEEV was first recognized as a horse disease in the northeastern USA in 1831 (Hanson 1957;Nalca et al 2003;Scott and Weaver 1989). The most severe outbreak of EEEV was recorded from Texas and Louisiana in 1947, causing 14,344 cases with 11,722 horse deaths (Chang and Trent 1987;Nalca et al 2003).…”

“…Nevertheless in North America, WEEV is a rare cause of encephalitis and only seven cases were reported from 1987 to 2002 (CDC 2002;Romero and Newland 2003). The virus has caused encephalitis epidemics in emus, humans and horses with fatality rates of 10 % for emus and humans and 20-40 % for horses (Ayers et al 1994;Nalca et al 2003). The patients suffer a 2-or 3-day period with fever, headache, vomiting, nausea, somnolence and irritability before manifestations in the CNS begin (Nalca et al 2003).…”

“…The virus has caused encephalitis epidemics in emus, humans and horses with fatality rates of 10 % for emus and humans and 20-40 % for horses (Ayers et al 1994;Nalca et al 2003). The patients suffer a 2-or 3-day period with fever, headache, vomiting, nausea, somnolence and irritability before manifestations in the CNS begin (Nalca et al 2003). Constantine (1970) mentions that WEEV has been isolated from bats and Western equine encephalitis N antibodies were detected in Artibeus jamaicensis from Haiti (McLean et al 1979) and Artibeus lituratus from Tikal, Guatemala (Ubico and McLean 1995).…”