CORTLANDT, N.Y. – An increase in Lyme disease cases is possible in Westchester County this year, and scientists and clinicians say high temperatures, an increased window for infection and a boom in the mouse populations in 2011 could be to blame.
Emergency room staff are always vigilant for this disease, said Barbara Savatteri, director of infection control at Hudson Valley Hospital Center. But a simple series of circumstances has her antennas up.
“We’ll have a heightened awareness of Lyme disease because of the mild winter months, [and[ also because there’s a greater window of transmission because spring is earlier. So there’s more months for these ticks to bite,” Savatteri said.
The spirochete bacterium that causes Lyme disease, Borrelia burgdorferi, is brought about through a bite by an infected black-legged tick, also known as a deer tick. As many as one in four ticks in the Northeast carry the vector, the American Lyme Disease Foundation estimates.
Transmission of most Lyme disease occurs when ticks are in the second of three life cycle phases: the nymph stage. Ticks can be as small as a poppy seed in this stage, thereby avoiding detection. Nymph ticks are most active from May through the summer months, although they can remain active into late fall, according to the foundation.
The infection commonly makes its presence known by presenting a bull’s eye rash forming around the bite, although this may not appear in as much as 40 percent of cases, according to the New York State Department of Health. Early signs of infection include chills, fever, headache, fatigue, stiff neck, muscle or joint pain and swollen glands. If Lyme disease is left untreated, more severe symptoms can occur such as facial paralysis, numbness in the arms or legs, and severe fatigue.
The disease is most successfully treated in the early stages. And even after treatment, people can become reinfected if bitten by a tick again. The increased window of tick exposure is a concern to clinicians, but scientists say that’s not the only reason Lyme disease cases could surge this year.
The record-breaking abundance of acorns produced in 2010 boosted tick populations, not the mild winter, says disease ecologist Richard Ostfeld of the Cary Institute of Ecosystem Studies in Millwood, N.Y.
Deer tick is a misnomer for the black-legged tick, whose preferred host is the white-footed mouse, says Ostfeld. Boom and bust cycles of acorn production created a surge in white-footed mice, thereby allowing more larval staged ticks to survive in 2011 and which are now in the dangerous nymph stage in 2012.
The acorn bust came in 2011, when record low numbers of acorns were produced, which decimated the white-footed mouse population. The parasitic arachnids that grew up with the mice are looking for new hosts — humans or our pets. Not only are white-footed mice the preferred host for larval ticks because they do not groom, but as much as 90 percent of Lyme disease infections in ticks also originates in the white-footed mice.
The surge in Lyme disease hasn’t taken place yet and to pre-empt this phenomenon, checking yourself for ticks is essential.
“Just because you don’t go hiking around, you may be outside watching your kid’s softball game in the park. And the deer ticks are there as well, so you should probably check yourself when you come in from outdoors, no matter what the activities are,” said Savatteri.
Ostfeld said repellents work well for pets, and people should diligently check themselves when coming inside to avoid bites.
Charlie Roberto, an avid bird watcher who often hikes through scrubby hillsides around Croton and Ossining, said people should always be suspicious of a severe summer cold, especially one that persists. Roberto offers several prevention tips, even if “you’re not an outdoorsy person.”
Tuck your pants into your socks and wear light-colored pants, he said. When coming inside from outdoors, check hairlines and moist areas of the body, such as behind knees or armpits. Lastly, he recommends having a pair of tick tweezers, so people don’t squeeze a tick and introduce fluids from the tick into the bloodstream. Lastly, see your doctor if you suspect you have been bitten.