CDF Bulletin - Rabies

WHAT IS RABIES?

Rabies is a viral infection of mammals, usually transmitted by a bite or scratch of an infected animal. Rabies is most commonly found in raccoons, skunks, foxes and bats.

WHERE DO THE MOST COMMON BATS ROOST?

The big brown bat and the little brown bat are common house bats that roost during spring and summer in attics, behind shutters and in other sheltered areas of human dwellings and outbuildings. It is important to bat-proof your home by blocking any small openings that will allow a bat entrance into your home.

IS RABIES ALWAYS FATAL?

Once symptoms occur, rabies is almost always fatal. The incubation period (the period of time between exposure and onset of disease) ranges from two weeks to many months. Once rabies has progressed from the incubation period, treatment is ineffective. Periodic vaccinations in dogs, cats and livestock can protect these animals against the disease.

WHAT IF A PERSON IS BITTEN BY A BAT?

A bat bite might be difficult or impossible to recognize. Rabies treatment should be considered for any physical contact with a bat, when a bite, scratch or contamination of any open wound or mucous membrane (eye, nose, mouth) cannot be ruled out. Sleeping in a room where bats were found, or may have gained entry, should also be considered an exposure that warrants reporting and, possibly, treatment. Wash any bite, scratch or other exposure site very carefully. then call your doctor or the Westchester County Health Department immediately if you suspect that you have been exposed to rabies (914) 593-5100. If possible, capture the bat and arrange for the Health Department to test the bat for rabies. Be extremely cautious when attempting to capture the bat, to minimize risk of further exposure.

ARE RABID BATS A THREAT TO HUMAN HEALTH?

Since 1980 more people in the United States have been infected with a bat rabies strain than any other strain. Bats infected with rabies may have the virus in their saliva and may transmit the disease to humans and other animals.

ARE ALL BATS RABID?

Most bats are healthy and contribute to our environment in many ways. However, rabies has been confirmed in all nine indigenous species of New York bats. The vast majority of confirmed rabies cases occur in the big brown bats.

HOW CAN SOMEONE TELL IF A BAT HAS RABIES?

Rabid bats may show abnormal behavior, such as outdoor activity during daylight; rabid bats may be grounded or paralyzed, or they may bite a person or animal. Not all rabid bats act abnormally, but bats that do act abnormally are more likely to have rabies.

WHAT IF A PET IS BITTEN BY A BAT?

Whenever a dog, cat or other domestic animal with up-to-date rabies vaccination is bitten or comes into contact with a bat, capture the bat if possible. Immediately arrange with the local health department for the bat to be tested for rabies. If the bat is unavailable for testing, or tests positive for rabies, the pet must be given a rabies booster vaccination within five days. If an unvaccinated pet has contact with a rabid or suspect rabid bat, the animal must be euthanized or strictly confined for six months.

Westchester County Department of Health, Infectious Disease Update - Bat Rabies - Andrew P. O'Rourke, County Executive / Mark S. Rapoport, M.D., M.P.H. Commissioner, Department of Health

Bat variant strains of rabies virus have caused 14 of the last 27 human deaths from rabies in the United States including two in our area, one in 1993 and one in 1995. In most cases unreported bat encounters were postulated. The silver-haired bat variant strain accounts for the majority of bat-related cases.

Human rabies is a rare event in the United States, usually occurring once or twice a year. However, there have been six cases in 1994 and three cases through October 1995.

The physician's role has two elements - early assessment and identification of exposures with Department of health consultation, and early diagnosis of symptomatic cases, although these are rare.

Although only 1% of bats are rabid, most recent human rabies cases were caused by bat rabies virus variants.
MINIMAL CONTACT WITH BATS MAY RESULT
IN RABIES TRANSMISSION.

Since the only survival from rabies has occurred in vaccinated person's, pre- or post-exposure treatment is key.

Early diagnosis is important to limit contacts with the patient's saliva, which would require immunization. Diagnosis of rabies should be suspected if an individual shows signs of encephalitis (fever, headache, confusion) along with hyperesthesia or numbness of the face or extremity. Neck stiffness is also a common initial feature.

Hydrophobia, an aversion to water or other liquid, occurs when spasm of pharyngeal muscles develops; it has been reported in 50% of cases.

Maintain vigilance for bats that might be present during sleep.

FINDING A BAT IN THE ROOM UPON AWAKENING IS AN INDICATION FOR POST-EXPOSURE TREATMENT SINCE CONTACT WHILE ASLEEP CANNOT BE RULED OUT.

Post exposure treatment (with rabies immune globulin and human diploid cell vaccine) is effective in preventing disease if applied soon after exposure. (Exact maximal interval unknown; incubation is usually three weeks to three months, but can be over one year.)

ALL ANIMAL BITES MUST, BY LAW,
BE REPORTED
TO THE WESTCHESTER COUNTRY
DEPARTMENT OF HEALTH:
Days: (914)593-5100
Nights & Weekends: (914)593-5100

Immunization of dogs and cats can eliminate spill over of rabies from raccoons. Cats with strong "mousing" instincts can be infected in the course of catching bats, otherwise known as "mice with wings" (fledermaus.)

For Information about bats in your house, call:
(914)593-5100 or your local wildlife trapper.

For information about rabies vaccine, call: (914)593-5100 or

Dr. Germaine Jacquette, M.D. Deputy Commissioner,
Disease Control, at:
(914)593-5062

In New York State, from January 1 through September 30, 1995, rabies was laboratory-confirmed in 888 animals:

687 raccoons       91 skunks            35 bats

       24 foxes          19 cats               7 woodchucks

  4 cows            2 dogs               2 deer

This bulletin is sponsored by The Children's Dream Foundation. The contents have been adapted from Bat Rabies in New York State, State of New York Department of Health. This public service message is offered to the friends of The Children's Dream Foundation in association with the Westchester County Department of Health. A special thanks to Dr. Mark S. Rapoport, Commissioner.