RI, MA EHS Pest Control Blog

New Tick-Borne Disease Is Discovered

A new tick-borne disease that may be stealthily infecting some Americans has been discovered by Yale researchers working with Russian scientists.

The disease is caused by a spirochete bacterium called Borrelia miyamotoi, which is distantly related to Borrelia burgdorferi, the spirochete that causes Lyme disease.

B. miyamotoi has been found — albeit relatively rarely — in the same deer tick species that transmit Lyme, and the Yale researchers estimate that perhaps 3,000 Americans a year pick it up from tick bites, compared with about 25,000 who get Lyme disease.

But there is no diagnostic test for it in this country, so it is not yet known whether it has actually made any Americans sick.

The same short course of antibiotics that normally cures Lyme also seems to cure it.

In Russia, where a team in the Siberian city of Yekaterinburg developed a test that can distinguish miyamotoi from other tick-borne spirochetes, it caused higher fevers than Lyme disease typically does. In about 10 percent of cases, the fevers repeatedly disappear and return after a week or two.

The study by the two teams is to be published soon in the journal Emerging Infectious Diseases. Since the disease was only recently discovered, it is unknown whether it does serious long-term damage, as untreated Lyme disease can.

The Yale medical school researchers — Durland Fish, an entomologist, and Dr. Peter J. Krause, an epidemiologist — have recently won a grant from the National Institutes of Health to study the symptoms and develop a rapid diagnostic kit.

Dr. Fish found B. miyamotoi in American ticks 10 years ago, but was repeatedly refused a study grant until the Russians proved it caused illness. “It’s been like pulling teeth,” he said. “Go ask the N.I.H. why.”

The discovery will no doubt add to the controversy surrounding Lyme disease. While most Lyme victims are cured by a two-week course of antibiotics, some have symptoms that go on for years and believe they have persistent infections that the antibiotics did not reach.

Most medical authorities, including the Centers for Disease Control and Prevention and the Infectious Disease Society of America, take the position that “chronic Lyme disease” does not exist and that those victims either have other illnesses or are hypochondriacs. They oppose the solution demanded by some self-proclaimed victims: long-term intravenous antibiotics.

Dr. Krause said it was unlikely that the new spirochete could be responsible for chronic Lyme, because the symptoms do not match: Most of those who think they have chronic Lyme complain of fatigue and joint pain, not repeated fevers.

But he said doctors might consider the new infection, especially in patients who think they have been bitten by ticks, come up negative on Lyme tests and have recurrent episodes of fever.

B. miyamotoi does not appear to cause the “bull’s-eye rash” that helps doctors diagnose Lyme disease, the Russian team found.

“People shouldn’t panic,” Dr. Krause said. “And they also should not jump to the conclusion that we’ve found the cause of chronic Lyme disease. It’s not highly likely, but it’s possible. We just don’t know.”

The miyamotoi spirochete was discovered in Japan in 1995. It was at first believed to be limited to those islands.

In 2001, Dr. Fish found it in about 2 percent of the deer ticks in the Northeast and Upper Midwest and proved that mice could pick it up from tick bites.

Source = NY Times

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 

2012 is Slated to Be the Worst Tick Year in History

In Central Park, more than 1,000 trees in the red oak family were spangling the scenery with the colors of autumn.

But this year, they were failing to do something else they generally do in the harvest season: produce acorns.

“I remember going into areas and you’d get the crunch of acorns under your feet,” said Neil Calvanese, vice president for operations at the Central Park Conservancy. “And this year, you kind of have to search around for them.”

It is a phenomenon happening not only in New York but also throughout the Northeast. While last fall set a recorded high for acorn production, at roughly 250 pounds per tree, this year is seeing a recorded low, with a typical tree shedding less than half a pound of its seeds, said Mark Ashton, a forest ecologist at Yale University. On average, oaks produce about 25 to 30 pounds of acorns a year.

“Scarlet oak, black oak, true red oak,” Dr. Ashton said. “These are the ones that dominate our forest, and these are the ones that aren’t producing acorns this year.”

Coming on the heels of an acorn glut, the dearth this year will probably have a cascade of effects on the forest ecosystem, culling the populations of squirrels, field mice and ground-nesting birds. And because the now-overgrown field mouse population will crash, legions of ticks — some infected with Lyme disease — will be aggressively pursuing new hosts, like humans.

“We expect 2012 to be the worst year for Lyme disease risk ever,” said Richard S. Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y. “We are already planning educational materials.”

It will probably turn into a big year for animals’ being killed on highways as well. Deer, in search of alternative sources of food, will leave the cover of the oak trees and wander out closer to roads.

“I would expect that traffic collisions are going to be higher in a year like this year,” Dr. Ostfeld said.

While scientists do not fully understand why this year has produced the lowest acorn crop in 20 years of monitoring, there is nothing unusual about large fluctuations in the annual number of acorns. Fingers are not being pointed at global warming.

Oak trees “produce huge, abundant amounts one year and not in other years,” Dr. Ashton said. “I don’t think it’s bad — the whole system fluctuates like this.”

One theory for why oak trees vary their acorn yield is the so-called predator satiation hypothesis. Under this theory, during bumper years, the trees litter the forest floor with seeds so completely that squirrels, jays, deer and bears cannot possibly eat them all. Then, in off years, the trees ramp down production to keep the predator populations from growing too large to be satiated.

But the variability of weather in New York and New England could also be playing a role in the shortage this year.

“A lot of it has to do with the initial spring,” Dr. Ashton said. Acorn production is high when “everything converges on a perfect spring.”

It takes a red oak 18 months to grow an acorn. The tree is pollinated in the spring of one year, and its acorns drop in the fall of the next year. The rainy spring of 2010 could have dampened the wind-driven transfer of pollen from one tree to another, resulting in the acorn dearth this year.

While acorn fluctuation is normal, what is unusual this year is the abundance followed by the steep drop. “In a sense, it’s just another trough,” Dr. Ostfeld said. “But this is the most extreme pair of years that we’ve seen.”

Dr. Ostfeld describes acorns as an engine that drives the forest ecosystem. “When that engine is cooking along,” he said, “you get these heavy knock-on effects.”

The population of field mice, for instance, exploded this summer. While that was good for the mice, it was bad news for low-nesting birds like the wood thrush, whose nests are susceptible to rodent predation. In addition, the large numbers of mice caused an increase in the tick population.

On the other hand, Dr. Ostfeld said, “when you get a failure of the engine, things just change radically.”

Now the field mouse population is expected to crash — about 90 percent have died off in similar glut-dearth acorn sequences in the past. And the outlook is not good for the low-nesting birds, which face an increased threat from hawks and owls.

“The adult wood thrush will take it on the beak by the one-two punch,” Dr. Ostfeld said.

But in the middle of New York City, Central Park will be buffered from the ecosystem effects of the acorn engine.

“It’s a very managed environment,” said Arthur Elmes, the tree data coordinator for the Central Park Conservancy. “It’s nothing that won’t be corrected in years to come.”

Source = nytimes.com

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

Rodent-Borne Virus Blamed in Death

A rare rodent-borne illness killed a 35-year-old chiropractor last week in Montauk, N.Y., state officials said Thursday.

David Hartstein started feeling ill nearly two weeks ago, according to Juline Godin, a close friend of his widow, Heather. At first, he and his wife thought it was the flu or Lyme disease. But before dawn on June 17, Hartstein had trouble breathing and started shaking and sweating, Godin said.

His wife called an ambulance that took him to Southampton Hospital, where his condition continued to deteriorate quickly as doctors scrambled to figure out what was wrong, Godin said. Hartstein died that evening.

Hartstein’s death is just the second confirmed case of hantavirus pulmonary syndrome in the state since 1995, according to the New York Department of Health. The other case was also fatal. There were 20 confirmed hantavirus cases nationwide in 2010 — mostly in the West, according to the department.

The lung infection is caused by a microbe sometimes found in the rodent droppings, saliva or urine. Health officials said Hartstein’s death appears to be an isolated case.

Family and friends suspect that Hartstein inhaled microscopic particles containing the virus while vacuuming out his family’s basement after a small flood nearly a month ago, Godin said.

Godin described Hartstein as a popular figure among East End surfers who was known for walking around town with his dog, a Rhodesian ridgeback named Naya. He and his wife had three young children, all under the age of six.

“He was a very cared-for member of the community,” Godin said. “Everybody knew him as Dr. Dave with the Rhodesian ridgeback.”

The family is staying with friends in the area while their house is cleaned and tested for more hantavirus particles, Godin said.

Source: Metropolis.com

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA