A visit by a bat is no joke

Kasey Riemer thought her friend would find the tale amusing: Chasing a bat around the house in the middle of the night, her cats and dogs woke up the family.

Her friend, a nurse, wasn't amused.

She informed Riemer that she, her husband, and two daughters needed to get to an emergency room pronto to get rabies treatment.

"I didn't think the bat bit anyone, so I thought we'd be fine," said Riemer, 51, who lives in Wayne.

After a few calls to doctors and even one to the Centers for Disease Control and Prevention, Riemer took her friend's advice, and the family headed off to Bryn Mawr Hospital.

The Riemers have had plenty of company.

In August, 348 patients were treated at three Main Line Health System facilities - Bryn Mawr, Lankenau, and Paoli Hospitals - for bat-related incidents, according to Bridget Therriault, director of communications at Bryn Mawr Hospital. While regionwide data were wanting, the Main Line numbers represented a 40 percent increase over August 2013.

Officials say they aren't sure why those numbers might be spiking upward, but one factor might be increased rabies awareness, said Lawrence Livornese, an infectious-disease specialist and chairman of Main Line Health's department of medicine.

Ironically, the increases come as a blight known as white-nose syndrome has been wiping out millions of bats in Pennsylvania, New Jersey, Delaware, Maryland, and more than 20 other states. And, as a further irony, white-nose concerns indirectly contributed to the plight of the Riemers.

It is known that late summer and early autumn constitute the active season for the juvenile bats who are just taking wing. They are the ones that tend to blunder into houses and become potential dangers to humans.

While most bats are healthy, a small percentage might carry the rabies virus, a possibility that should be taken with the utmost seriousness, Livornese said.

Those who discover that they had been in the presence of a bat while sleeping, drunk, or otherwise not conscious should "assume to be bitten," he said. Bat bites aren't always felt.

Livornese said that anyone aware of having been bitten should immediately wash the wound with soap and water, and treatment should begin as soon as possible. Rabies can develop days to more than a year after exposure.

When a person is bitten, the virus is in the tissue and eventually makes its way to a nerve and then to the brain, he said.

The shots are not as onerous as they once were. On the first visit, patients receive doses of both a human rabies immune globulin and the rabies vaccine, followed by three more visits for the rabies vaccine.

Worldwide, about 55,000 people die each year from rabies, mostly in Asia and Africa, according to the World Health Organization. In the United States, the death rate is far lower, with the CDC reporting 49 fatal cases between 1995 and 2011.

Pennsylvania does not monitor rabies in the general bat population but does selective sampling of bats that are found.

In recent years in the state, the percentage of cases of rabies in bats submitted by humans for testing has nearly doubled, from 3.6 percent in 2010, to 6.9 percent last year. But because of the small sample size - 1,101 in 2013 - that increase might not be statistically significant, said Greg Turner, a state wildlife biologist.

However, New Jersey also showed a 38 percent increase in 2013 compared with the previous four years. Nationally, the increase was 8 percent in 2012, compared with the average for the previous four years, according to the Journal of the American Veterinary Medical Association.

As for the bats themselves, white-nose, a fungal infection, is a far greater threat than rabies. It has been blamed for killing more than five million bats since 2007, wiping out almost all of the hibernating species. Those species constitute about half of all bat species in the nation, according to the U.S. Fish and Wildlife Service.

Greg Turner, a state wildlife biologist, said the bats do appear to be rallying. The population decline has stabilized, and scientists are starting to see a slight increase in the number of juvenile bats surviving the winter.

As for the bats who wind up indoors, most likely they are juveniles.

"They get themselves in trouble and end up getting trapped in homes," Turner said.

In spring, female bats seek out places to give birth and raise their young. While that can be trees or railroad tunnels, attics provide an ideal and consistently warm environment, said Turner.

The older homes - such as the Riemers' Victorian - have crevices that bats naturally seek.

Seitz Wildlife Services, in Drexel Hill, is getting about 10 to 20 calls a day to remove bats, said Terry Seitz. The winged creatures - the world's only flying mammals - most often found in area homes are the "little brown bats" and, another species, "big brown bats," said Seitz.

Seitz said they look for gaps or cracks near the roof for entry points.

"Whether it is one bat or 100, the work is the same for us. We have to seal the opening," Seitz said. Workers install a one-way door to let bats out, she said.

Riemer said the bat encounter was a case of no good deed goes unpunished for her family.

Her husband, Mike McBride, had trapped the bat in a laundry basket and then released it. He had heard about the declining bat population and didn't want to injure this one. The upshot: Rounds of rabies shots for everyone.

"Now we are happily protected for the next couple of years if another one comes around," Riemer said.

mschaefer@phillynews.com

610-313-8111 @MariSchaefer