IN THE SUMMER vacation house my brother and I rented on Long Island Sound, one of his sleeping houseguests felt something wet on the back of her neck and “then woke to the dive bombing bat!” (Turned out there was a space between the roof and outside wall that no one had noticed.)
Although the incident sounds like a terrible nightmare for both host and houseguest, this particular guest was the best possible victim — because just a few years earlier she’d had a similar bad bat experience, although that time there was a visible bite. (Because that bat encounter took place in dreamy Italy, we felt a little less guilty about our slightly scruffy summer rental.)
The guest’s prior encounter meant she not only knew the CDC protocol but had a head start on treatment. Because a bat’s bite can be imperceptible, she wrote me, “anyone who has been unconscious or is unable to speak for themselves — baby, old person, drunk person, sleeping person — who has been in a room with a bat or where the possibility exists that there was contact with a bat and the person did not know it or can’t say it, must be immunized for rabies.”
The treatment, known as post-exposure prophylaxis or PEP, is always effective when given within 10 days of exposure and when given correctly: several shots of human rabies immunoglobulin to start disabling rabies virus particles; along with a course of rabies vaccines to stimulate the body’s own immune reaction. Because the houseguest’s prior treatment had occurred within five years, she could forgo the immunoglobulin and, instead of the prescribed five rabies vaccinations at recommended intervals over 28 days, needed only four shots over two weeks. (Reports on the exact number of shots vary, and the CDC protocol should be reviewed by anyone seeking treatment.) Side effects from both sets of injections include aches, fever, nausea and nightmares, but this regimen is a far cry from the 20 injections with a large needle through the abdominal wall used until the 1980s.
A final boon of the houseguest’s prior experience: knowing that the treatment could cost thousands of dollars. Calling her insurance to find a local provider, she learned that “an animal bite (even a theoretical one in this case) is considered an accident and as long as I sought treatment within the first 72 hours I’m fully covered.” The CDC estimates 40,000 to 50,000 people in the U.S. receive PEP each year, costing an average of $3,000 per person — but fees can run higher than $7,000.
With an actual bite — which can feel like a sharp needle going in — the advice is to wash thoroughly with soap and water and, if available, apply an anti-viral such as Betadine. Bite wounds can injure nerves, lacerate tendons and cause local and systemic infection.
Rabies from animals is spread through direct contact with saliva, although rare cases have occurred from air-borne exposure in bat caves. Among humans, though, rabies can be spread in saliva and tears before symptoms occur, and later in respiratory tract secretions from coughing or sneezing.
Since 2011 two people have died from rabies contracted from bats in the bedroom after which they received faulty information about the need for treatment. Just this year, a Wyoming woman woke to find a bat on her neck, swatted it away, and then consulted a local agricultural expert, who did not give her the proper warnings. When she finally made it to the hospital, she had experienced five days of progressive weakness, could no longer stand alone and had slurred speech. By the time of her death, she had exposed 15 family members and 100 health care workers both locally and at a referral hospital.
Although rabid bats have been documented in all 49 continental United States, only one to three human cases of rabies occur here each year — and some of these infections were contracted outside the U.S., for example, from dogs in Guatemala and Brazil. People planning to spend long periods of time in Latin America, Africa or India are advised to get rabies vaccines before traveling.
Without preventive treatment, symptoms of rabies begin during the disease’s incubation period, which can last three weeks or more. Brain infection or encephalitis causes the familiar fears of water and bright light as well as muscle weakness and dementia. The disease is almost always fatal, with death due to respiratory failure within a week after symptoms start.
Before 1960, the majority of U.S. rabies cases occurred in domestic animals, whereas now more than 90% are seen in wild carnivores and bats. Most of the domestic animal cases now seen each year — fewer than 100 dogs, and more than 300 cats — were in unvaccinated animals infected by wildlife.
Of the top four wild animal sources of rabies in 2014, the lowest incidence occurred among foxes, while at least 2,000 cases were reported each for skunks, bats and raccoons. In the Eastern U.S., raccoons have the highest incidence after bats.
Of human rabies cases in the U.S., 90% are caused by bats —though “of all weak and sick bats captured and tested for the disease, only about 6% have the virus,” according to the Washington Post. In recent years, more wild animals have been brought in for testing, and more rabid bats have been found in the Chicago area and in Pennsylvania than in previous years.
The presence of bats does have benefits. They voraciously consume insects, saving Americans billions of dollars each year in pest control services. Like bees, nectar-eating bats pollinate over 700 plants, spurring the creation of fruits and seeds. And while flying squirrels are restricted to gliding, bats are the only mammals that can fly — that is, in control of their flights.
— Mary Carpenter
Mary Carpenter is the well-being editor of MyLittleBird. Her last post was “Addicted to Shopping.”