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 

Rodent Nest Blamed for Small Fire at University Campus

Rodents are blamed for spreading disease and stealing food and now for causing a small fire on the Dalhousie University campus Wednesday morning.

Firefighters were called to the Macdonald building on Alumni Crescent after flames broke out while workers were using heat guns to remove paint from the outside of the building along the roof line.

The guns don’t use open flame, but the heat was enough to ignite straw and grass used in a small rodent nest in the crevices of the woodwork.

The workers used a garden hose to quell the flames, fire department spokesman Dave Meldrum said. Firefighters checked for any extension of the flames and found some charred wood.

Officials at Dal checked the building for other nests, but didn’t find any, and aren’t sure what type of animal built the nest.

Source = Associated Press

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

More Rodents Carrying Hantavirus Found

Six more rodents trapped by County Vector Control technicians last week have tested positive for the sometimes-deadly hantavirus, County officials said this week.

The rodents, four Harvest mice and two California Meadow Voles, were trapped in Fairbanks Ranch and northern Escondido near the San Luis Rey River bringing this year’s total to 16 rodents testing positive for hantavirus, a news release stated. In 2010, a total of 21 rodents tested positive for hantavirus.

“Recent rains have created an abundance of food for rodents, which can increase the rodent population,” said County Environmental Health Director Jack Miller. “More rodents can lead to more hantavirus.” People should never sweep up or vacuum rodent droppings and nesting materials. Instead, ventilate closed areas and use wet cleaning methods with a 10 percent bleach solution or other full strength disinfectant. The best way to prevent the disease is to keep mice out of houses, garages and sheds by sealing all holes larger than the size of a dime, the news release stated.

Wild rodents, primarily deer mice, carry hantavirus. People can contract it by inhaling dust particles from rodent droppings and nesting materials that contain the virus. The virus can cause hantavirus pulmonary syndrome (HPS), which begins with flu-like symptoms, but can graduate to severe breathing difficulties and even death, according to the news release. There is no vaccine or specific treatment for hantavirus and the national Centers for Disease Control and Prevention report that HPS has killed 36 percent of all the people known to have contracted the disease.

How to Avoid Exposure:

• Eliminate rodent infestations immediately.
• Avoid rodent infested areas. Do not stir up dust or materials that may be contaminated with feces and urine.
• Clean up rodent droppings and urine using the wet cleaning method described below.

Use “wet-cleaning” methods to prevent inhaling the virus:

• DO NOT SWEEP OR VACUUM INFESTED AREAS.
• Ventilate affected area by opening doors and windows for at least 30 minutes.
• Use rubber gloves. Spray a 10 percent bleach solution (2 tablespoons bleach to 1 cup of water), or other full strength disinfectant onto dead rodents, rodent droppings, nests, contaminated traps, and surrounding areas and let the disinfectant stand for at least 15 minutes before cleaning. Clean with a sponge or a mop.
• Place disinfected rodents and debris into two plastic bags, seal them and discard in the trash.
• Wash gloves in a bleach solution, then soap and water, and dispose of them using the same double-bag method. Thoroughly wash your bare hands with soap and water.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA