New England News
12:30 pm
Mon June 3, 2013

Officials Warn Against Increased Mosquito Activity, Disease

Officials are warning that the recent wet weather in the Northeast could have an effect on the amount of mosquitoes, and precautions are being taken to control the risk of disease that could be passed on to people and animals. 

Chris Horton, superintendent of the Berkshire County Mosquito Control Project, one of the nine mosquito control districts in Massachusetts, said that in early June, species of native mosquito are currently in their larval stage, which thrive in standing water. Horton predicts that the recent heavy rains and wet weather could have a large effect on the number mosquitoes that will emerge in the coming weeks.

"This year is a wet year. The soil is saturated, water is not sinking into the ground anymore, so the larval habitat has expanded several times as big as it was last year, so this is going to be a more active mosquito year," said Horton.

Last year, the deadly Eastern Equine Encephalitis was first detected in Massachusetts, including in mosquito samples taken from the Pittsfield area.

Horton said that currently the Berkshire County Mosquito Control Project is attempting to eliminate mosquito larvae populations across the region through the use of a bacterial spore treatment that targets the larvae directly. However, Horton added, because of regional flooding that occurred this year and not during last year’s dry spring, eliminating the populations will be a greater challenge as more eggs are hatching.

Dr. Alfred DeMaria, Massachusetts State Epidemiologist, said that the state will begin monitoring for pathogens  carried by the insect this month, even though he expects human cases of diseases to not peak until July.

"But we need to have information ahead of time to see what direction the levels of virus of mosquitoes is going," said DeMaria.

In the meantime, DeMaria said that people should take precautions and begin protecting themselves against the insects and vector-borne diseases like EEE early. DeMaria said that standing water should be eliminated from property, insect screens should be installed in windows, protective clothing and insect repellent should be worn outside, and he encouraged families to educate their children on how to protect themselves, including staying inside during peak hours at dawn and dusk.

"If people do that as a matter of routine then it becomes much easier to deal with it in the face of a threat of infection," said DeMaria.

An invasive species of mosquito also could pose a threat to upstate New York and New England.

Currently, monitoring efforts are being undertaken by researchers at Cornell University for the Asian Tiger Mosquito, a species that was first introduced to Texas, and has now spread northward and is currently found in the New York metro area, New Jersey, and Northeast Pennsylvania.

Dr. Laura Harrington, a professor of entomology at Cornell, said that the Asian Tiger Mosquito has a competitive advantage over native species, and also is prone to carrying more diseases than native species.

Most of the time you have maybe one mosquito that's really important in transmitting one type of virus or one type of parasite. For this mosquito it's permissive to become infected with a lot of different things," said Harrington.

Harrington said the species can be a vector for triple E, West Nile virus, and other pathogens including heartworms that affect dogs.

Harrington said that she thinks the reason the insect is not spreading northward is due to colder temperatures, but she said that climate change could allow the insect to further its range.

"We know with predictions for climate change that we will have increases in temperature, especially warmer winters which will help it survive longer, and possibly increased precipitation. So increased snow cover can also act as an insulator protecting the eggs," said Harrington.

For more information:

http://news.cornell.edu/stories/2012/12/chikungunya-outbreaks-us-are-increasingly-likely

http://www.mass.gov/eohhs/gov/departments/dph/programs/id/epidemiology/providers/public-health-cdc-arbovirus-info.html

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