Scientists Plan To Validate Tick Infection Stats

By John Voket

Hot on the heels of a regional report showing that more than 90 percent of ticks captured in Newtown were infected with Lyme disease, the Newtown Health District announced some experts from the scientific community have volunteered to run additional tests that could further validate the level of infection inherent in the tiny insects.

Health District Director Donna Culbert told The Bee this week that Kirby Stafford, vice director, chief scientist and state entomologist at the Connecticut Agricultural Experiment Station in New Haven, and Sam R. Telford III, associate professor at the Cummings School Of Veterinary Medicine at Tufts University’s Department of Biomedical Sciences Infectious Diseases, have offered to test a new round of ticks that will be collected this week at several locations in town where previous collections were performed.

In an email sent to Ms Culbert, Dr Georgina Scholl of the Fairfield County Municipal Deer Alliance said the two noted scientists were motivated to test a new sampling of ticks following the publication of results from a second phase of a study being coordinated by the Alliance, examining deer tick populations in Fairfield County towns.

In that study, Dr Eva Sapi, associate professor and research scholar coordinator, Cellular and Molecular Biology Graduate Program, University of New Haven, analyzed both the number of ticks found in each of the participating towns and the proportion of those ticks that carry the bacteria that cause Lyme disease and the parasite of babesiosis, a malarialike illness.

Dr Sapi is also an expert in the collection and analysis of deer ticks.

Previous studies have reported a rise over the last ten or more years in the percentage of ticks found in Connecticut that carry not only the infectious agents that cause Lyme, but also ehrlichiosis and babesiosis. In 2007 and 2008, adult ticks were collected in the fall and analyzed to determine their rate of infection.

The rate of tick infection is again above previously reported levels, according to Dr Scholl. The Lyme bacteria was present in an average of 60 percent of ticks overall in 2007 and in an average of 90 percent of ticks in 2008.

Newtown, Bethel, Ridgefield, and Redding had ticks analyzed for the Babesia microti parasite in 2008 and with an infection rate of 30 percent, were found to be well above previously reported levels of five to eight percent.

This is the first systematic study of ticks from specific locations across Fairfield County, which for many years has had the highest number of cases of Lyme in Connecticut. The information is expected to help towns understand better how to protect their residents from these infections, and will reinforce the need for vigilance in controlling ticks.

The Alliance study will also serve as a baseline for future studies of changes in tick populations that may result from various intervention programs such as deer population reduction programs.

Another important aspect of this study that sets it apart from previous studies is that these ticks were all collected from parts of town that are in proximity to school play areas, ball fields, parks, and trails. Ongoing studies by others have used ticks submitted by individuals with unknown places of origin.

In Phase Three of the study which began this week, ticks will be collected, counted, and analyzed for the presence of co-infections Borrelia, Babesia and ehrlichiosis in the same tick. Rates will be compared with the first two years to see if the high rates of infection previously found are an indication of an overall trend or are indicative of local conditions.

In Newtown a committee is discussing how best to reduce tick infection risk (see story). Dr Robert Grossman, who chairs the Newtown committee, said there is no downside to having Drs Stafford and Telford independently study the local tick samples.

“Whether they find the numbers are consistent, or even if they are not, the information will be extremely helpful to our committee in completing our charge,” Dr Grossman said.

If Dr Sapi’s results are consistent with the independent study of a new crop of tick samples being collected this week in three towns including Newtown, Dr Scholl said “it would be a very significant finding.”

The current plan is to try and gather 100 or more tick samples from around some or all of the same sites used by Dr Sapi. Once those ticks are collected and processed, Dr Scholl confirmed that Dr Telford will test for Babesia and ehrlichiosis.

In related news, a recent study conducted at the Columbia University Center for Infection and Immunity found as many as 70 percent of deer ticks are capable of passing on conditions like Lyme disease and recurring fevers to the humans they bite.

Symptoms of Lyme disease can range from fever, chills, and body aches to joint swelling, weakness, severe fatigue, trouble concentrating, and temporary paralysis. Many — though not all — people infected will see a bull’s-eye rash between three and 30 days after infection.

According to the Centers for Disease Control and Prevention (CDC), more than 20,000 cases of Lyme disease are reported each year. Yet because most doctors do not report new cases of Lyme disease to the CDC, the actual number of new Lyme disease cases each year has been estimated to be as high as 200,000, says Connecticut-based neurologist Harriet Kotsoris, MD, medical director of Time For Lyme, a nonprofit organization working to eliminate tick-borne diseases through research, education, and both state and national legislation.

“Couple the study results with these statistics, and it’s no wonder the CDC has classified Lyme disease as a health epidemic,” Dr Kotsoris continues, adding that since 1991 the number of those infected with Lyme disease has doubled.

Because deer ticks can carry multiple disease-producing bacteria and microorganisms, it is also possible for a human to develop two or more infections from one bite, researchers say. The Columbia study found that in addition to the bacteria that leads to Lyme disease, it is common for deer ticks (scientifically known as Ixodes scapularis ticks) also to carry:

*Babesia microti, a parasite that can infect red blood cells. Some people with the infection never experience any symptoms. In others, the flulike symptoms can be life-threatening.

*Anaplasma phagocytophilum, bacteria that can lead to an infectious disease called anaplasmosis. Treated with antibiotics, symptoms are flulike and generally range from mild to moderate.

*Also found in a small percentage of ticks (two percent) was Borrelia miyamotoi, a bacterium that is similar to the Borrelia lonestari, but has not yet been proven to cause disease in humans.