Tick abundance in Rhode Island is slightly ahead of last year's record numbers, according to early results from the University of Rhode Island's statewide tick survey, and the weather seems to be to blame.
URI tick researcher Thomas Mather said that the warm winter allowed ticks to get an early start on the season, and the moist conditions through the spring and early summer are keeping tick activity high.
"If current weather trends continue, we can expect high numbers of ticks later into the summer than usual, which translates into higher incidence of Lyme disease transmission," Mather said. "Mid-June is usually the peak of the season, but the question now is whether or not the weather will extend that peak, or will it start to dry out and we begin to see a downturn in tick numbers and some relief from disease risk."
Last year, tick numbers in Rhode Island were 109 percent higher than the average of the previous 13 years. This year Mather and his colleagues have already collected 140 more ticks than last year in samples from the first 30 of 61 statewide sampling sites. Sites in northern Rhode Island and Bristol County, which traditionally have had low tick numbers, appear to be increasing at the greatest rate, though numbers in those locations are still low compared to those in South County.
To view a map depicting the distribution of deer tick abundance in Rhode Island, visit www.tickencounter.org and click on Lyme disease maps.
Mather and his team are launching a new research project that he believes will find a direct link between tick activity and relative humidity. If the results prove true, he expects it to be possible to provide accurate weekly tick activity forecasts through the summer months thereby providing people with an index of their risk of being bitten by ticks.
Mather recommends that all Rhode Islanders take precautions to prevent contracting Lyme disease by routinely practicing personal protective measures and implementing tick control strategies around the yard.
Adult deer ticks must be attached for 48 hours to transmit the Lyme disease pathogen, while nymphs, which are tiny and difficult to see, need only be attached for 24 hours to transmit a Lyme infection. It is the tiny nymphal stage that is most active now.