Massachusetts Department of Public Health
Bureau of Communicable Disease Control

September 26, 2000

Public Health Advisory
Tularemia on Martha’s Vineyard

Since June 1, 2000, the Massachusetts Department of Public Health (MDPH) has received reports of eleven confirmed cases of tularemia among permanent or part-time residents of Martha’s Vineyard. All eleven cases have been treated with antibiotics and have recovered. MDPH is conducting an ongoing investigation of these cases in cooperation with the federal Centers for Disease Control and Prevention (CDC).

Tularemia is a rare bacterial disease that is usually transmitted to people by a tick bite or by touching or eating an infected animal. Animals most likely to be infected include rabbits and rodents such as voles, squirrels, muskrats, and beaver. The ticks that are most likely to transmit tularemia are dog ticks. The deer tick, which is responsible for transmitting Lyme disease, does not transmit tularemia. The bacteria can also be spread by contact with water or soil that has been contaminated by an infected animal, by a bite from an infected animal, or by inhalation of contaminated particles. Tularemia is not directly spread from person to person.

No common source exposure among cases has been uncovered. However, the investigation has found that persons recently involved in outdoor occupations, such as landscapers or construction workers, as well as people who mow their own lawns, may be at an increased risk of being exposed to the bacteria. This may be due to exposure to aerosols of contaminated dust, soil, or grasses during outdoor activity, or due to unrecognized tick exposures.

Martha’s Vineyard residents and visitors should seek medical attention if they develop fever and/or respiratory symptoms within seven days of potential exposure to aerosols of dust, soil, or grasses. Tularemia can be treated and cured with antibiotics.

There are a variety of protective measures people can take to prevent tularemia. Individuals may consider wearing protective dust masks, available in most hardware stores and pharmacies, while engaging in intensive outdoor activities that produce aerosols of dust, soil, or grasses.

In areas where contact with ticks cannot be avoided, individuals should take the following precautions:

Wear long, light-colored pants tucked into socks or boots and long-sleeved shirts.

Stay on trails when walking or hiking and try to avoid areas with high grass.

Use insect repellants appropriately. Repellants that contain DEET (N-N-diethyl-meta-toluamide) should be used in concentrations no higher than 10-15% for children and 30-35% for adults. Repellants should never be used on infants. Repellents that contain permethrin can only be applied to clothing, not exposed skin.

After spending time in tick-infested areas, individuals should check themselves, their children, and their pets for ticks. Parts of the body ticks prefer include the back of the knees, armpits, scalp, groin, and back of the neck.

Promptly remove any attached tick using fine-point tweezers. The tick should not be squeezed or twisted, but grasped close to the skin and pulled straight out with steady pressure. Once removed, the tick should be drowned in rubbing alcohol or in the toilet.

In situations where contact with wild animals cannot be avoided, individuals should take the following precautions:

Use gloves, masks, and protective eye covers when skinning or dressing wild animals.

Use gloves and properly dispose of any dead animals brought home by household pets.

Thoroughly cook any wild game before eating it.

To prevent potential soil and water contamination, individuals should take the following steps to minimize rodent and rabbit populations near their home:

Keep woodpiles off the ground and in sunny areas.

Fence off any garden areas.

Do not feed household pets outside and never feed wild animals.

Secure all garbage in rodent-proof containers.