Cotton Rats and House Sparrows as Hosts for North and South American Strains of Eastern Equine Encephalitis Virus

Abstract

TOC summary: Wild rodents and wild birds can serve as amplification hosts.

Competency of Reptiles and Amphibians for Eastern Equine Encephalitis Virus

“…This finding, together with the discovery of early season EEEV infections in pools of mosquitoes that feed primarily upon ectothermic hosts provides support to the hypothesis that EEEV may overwinter in seasonal foci in ectothermic vertebrates. These data also reinforce recent studies 7 that suggest other animals in addition to birds may play an important role in the dynamics of the EEEV enzootic transmission cycle.…”

“…25 Recent studies have demonstrated that cotton rats may serve as reservoirs for both North American and South American strains of EEEV. 7 Interestingly, the South American strains of the virus seemed to replicate to higher titers in cotton rats than did the North American strain and the South American strains were less pathogenic to cotton rats than the North American strain. 7 These data suggested that while both North American and South American strains of the virus were capable of using cotton rats as a reservoir, the South American strain might be better adapted to a small mammal reservoir than North American strain.…”

“…7 Interestingly, the South American strains of the virus seemed to replicate to higher titers in cotton rats than did the North American strain and the South American strains were less pathogenic to cotton rats than the North American strain. 7 These data suggested that while both North American and South American strains of the virus were capable of using cotton rats as a reservoir, the South American strain might be better adapted to a small mammal reservoir than North American strain. In this regard, we noted no significant pathology in the reptiles infected with the North American subtype I strain of the virus, suggesting that this strain of the virus may be fairly well adapted to reptile hosts.…”

“…6 Mammals are generally considered dead-end hosts for the virus, though small mammals have recently been implicated as potential amplification hosts for North and South American strains of EEEV. 7 The EEEV circulates year round in Florida, but its transmission is seasonal outside of this state. In the Northeastern United States, recent studies have suggested that the virus is periodically introduced from Florida, where it establishes itself in defined foci.…”

Serological Evidence of Flaviviruses and Alphaviruses in Livestock and Wildlife in Trinidad

“…With regard to EEEV, some avian species that were previously recorded to be EEEV-seropositive in Trinidad (Tikasingh, 1968(Tikasingh, , 1973(Tikasingh, , 2004 were negative in the current study. Considering reports that both birds and rodents become viremic after EEEV infection (Arrigo et al 2010), a larger sample of avian and rodent sera, as well as a more focused survey in EEEV-and VEEV-positive locations, may prove useful to gain further insight into the local circulation and maintenance of these viruses.…”