Toward the incrimination of epidemic vectors of eastern equine encephalomyelitis virus in Massachusetts: abundance of mosquito populations at epidemic foci.

The research investigates the mosquito populations carrying the Eastern equine encephalomyelitis virus (EEE) in Massachusetts, indicating that Coquillettidia perturbans, Aedes canadensis, and Culex salinarius mosquito species are more likely to spread EEE compared to Aedes vexans, Anopheles punctipennis, and Anopheles quadrimaculatus.

Objective and Methodology

• The research’s primary aim was to identify the key vectors, or transmitters, of the Eastern equine encephalomyelitis virus in southeastern Massachusetts, specifically in Bristol and Plymouth counties.
• 15 sites, where recent cases of EEE had been reported between 1982 and 1990 among horses and humans, were analyzed.
• Adult mosquitoes were trapped using light traps baited with carbon dioxide, a method used to estimate the biting risk in these areas known for transmission. This method imitates the presence of a potential host to attract mosquitoes.

Findings and Conclusion

• The research data indicated a high abundance of three specific mosquito species: Coquillettidia perturbans, Aedes canadensis, and Culex salinarius.
• This suggests that these species are more likely vectors or carriers of the EEE virus in Massachusetts.
• By contrast, other species such as Aedes vexans, Anopheles punctipennis, and Anopheles quadrimaculatus were found to be less likely responsible for the virus’s spread.
• This study is significant for public health as it helps pinpoint the mosquito species that should be the primary targets of eradication and control efforts in Massachusetts to curtail the spread of the EEE virus.

Without an understanding of the actual vectors of the disease, efforts to control the spread of this virus could be misdirected, potentially leading to wasted resources and ineffective disease control measures. Therefore, the researchers’ findings can help guide targeted interventions and disease control measures toward specific mosquito populations most likely causing EEE virus outbreaks.