RI, MA EHS Pest Control Blog

Can a tick bite turn you off red meat for good?

It can if it is the bite of a Lone Star tick, a type that's endemic in the southeastern United States. This phenomenon has been known for a while, but now new research published online July 20 in the Journal of General Internal Medicine reports on three case studies to illustrate exactly how it may occur.

The Lone Star tick injects spit into a person's body when it bites. The body then develops antibodies in response to a carbohydrate called alpha-gal that is present in the spit. This carbohydrate substance is also present in red meat. When the bitten person eats meat again, their immune system goes on the warpath, causing an allergic reaction. This reaction is typically delayed, occurring about three to six hours after eating meat.

The reaction can range in severity from mild hives and itching to full-blown anaphylactic shock, according to Dr. Susan Wolver and Dr. Diane Sun at the Virginia Commonwealth University, in Richmond.

This connection was first discovered somewhat serendipitously by researchers who were trying to determine why a cancer drug called cetuximab (Erbitux) was causing severe allergic reactions in people in the southern states. The sugars in Erbitux are also present in beef, pork and cows' milk.

Calling the phenomenon "the cow's revenge," Dr. Bruce Hirsch, an infectious diseases specialist at North Shore University Hospital in Manhasset, N.Y., said, "Lone Star tick bites may well be turning a portion of people in the southeast into involuntary vegetarians."

Tick bites cause a host of other diseases and infections including Lyme disease and Rocky Mountain spotted fever. The best thing to do is to avoid ticks altogether, Hirsch said. For starters, avoid wooded and bushy areas with high grass and use insect repellents that contain 20 percent or more DEET (N, N-diethyl-m-toluamide) on all exposed skin.

Dr. Bernard Feigenbaum, an allergist at the NYU Langone Medical Center in New York City, said that most people think about Lyme disease when they think about ticks and tick bites . "This study shows that there can be other allergic consequences," he said. "If a person discovers having reactions or unusual symptoms after eating meat, follow up with a primary care doctor or an allergist to see what is going on."

If you are allergic to red meat, you will need to avoid beef, pork, lamb, venison and other meat from mammals, said Despina Hyde, a nutritionist at the NYU Langone School of Medicine. "Poultry, fish and chicken are OK."

(SOURCES: Bernard A. Feigenbaum, M.D., allergist, NYU Langone Medical Center, and clinical assistant professor of medicine and otolaryngology, NYU Langone School of Medicine, New York City; Despina Hyde, M.S., nutritionist, NYU Langone Weight Management Program, New York City; Bruce Hirsch, M.D., infectious diseases specialist, North Shore University Hospital, Manhasset, N.Y.; July 20, 2012, Journal of General Internal Medicine, online)

5 TIPS TO REDUCE TICK PRESSURE AROUND YOUR HOME

1. Mow the lawn to keep grasses and weeds short. Current guidelines recommend mowing every 1 to 2 weeks, depending on the season and how fast the grass is growing.

2. Ticks enjoy damp, dark places, and a cozy nest is a great place for them to hide. Remove bird nests and bird feeders from the lawn. Remove wood piles, as these not only serve as nests for tick-carrying rodents, they also can attract termites.

3. Fence your backyard to contain deer and other wildlife.

4. Mulch around swing sets, play areas and sand boxes.

5. Avoid including tick-harboring plants, like pachysandra and other low lying vegetation that provide shading close to the ground.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

Mild Weather Keeps Pest Numbers High

Last year’s unusual weather produced a banner crop of deer ticks in New England, and Sam Telford could not be happier. Well into last month, the researcher was still able to collect ticks - lots of them - for his studies.

“It’s not just me. I have a colleague in Rhode Island. He claims he’s been able to collect more than 15,000 ticks this fall. I am so envious. It’s like one-upmanship among us tick biologists,” Telford said from his office at Tufts University’s Cummings School of Veterinary Medicine in Grafton, where he is a professor of infectious diseases.

Based on collections at sites in Medfield, Dover, Yarmouth, Nantucket, and Martha’s Vineyard, Telford estimates that the tick population was three to five times larger than usual for early winter. He attributed the increase to last summer’s dearth of truly hot and dry weather, which usually kills a lot of ticks.

Telford’s counts involve dragging a light-colored, 1-square-meter cloth behind him as he walks through likely areas. At intervals, he stops and collects any ticks clinging to the cloth, compiling a tick-per-minute count.

“We were getting three ticks per minute at most sites, and as many as five ticks per minute,’’ he said, whereas the year before “we were lucky to get just one per minute.”

Mild temperatures well into last month also kept the ticks active later in the year than usual - a boon for scientists like Telford, but potential trouble for the unwary who do not take the same precautions in cooler months as in summer.

The population spike took place even as authorities continued efforts to curb the spread of tick-borne Lyme disease through expanded hunting of deer in towns like Dover and Medfield. A single deer can feed up to 100 adult ticks a week, with the ticks dropping off after four days of feeding and moving on to their next stage of life: laying eggs.

“Every tick that feeds can lay 2,000 eggs, so you look at places like Dover and Medfield, where they are actively trying to curb their deer populations through hunting, with all these ticks out there, the removal of one deer can prevent an awful lot of reproduction,” said Telford, who had 80 engorged adult female ticks, recently plucked off a single Nantucket deer, living in an incubator in his office.

It is too early to say whether the boom in deer ticks has been accompanied by an increase in Lyme disease cases. The state will not release its tally for last year until spring.

Reports of Lyme disease have risen for most of the past decade across Massachusetts, most dramatically in communities west of Boston. Statewide, there were 4,116 confirmed cases in 2008 and 4,061 in 2009, according to the state Department of Public Health.

But the number dropped off sharply in 2010, with 2,627 confirmed cases. Dr. Catherine Brown, state public health veterinarian, said the decline was directly related to the hot and dry summer of 2010 taking a toll on the tick population.

While Brown expects the number of Lyme cases to rise along with the tick population, Telford is not so certain.

Historically, 95 percent of new cases of Lyme disease are reported in May and June, when ticks are much smaller and harder to spot, Telford said. Just 5 percent of cases get reported in fall, when the ticks have become larger adults.

“That does not mean people should not be aware and remove the ticks, or prevent them coming on to them by using repellents, taking showers after being in the woods, and doing a tick check,’’ Telford said. “You don’t want to kick a dead skunk.”

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA