Rats And Mice, Oh My

The 2 a.m. call got my blood running. After hearing my pager’s irksome bleep, I groped for the phone and was soon talking to an ER resident.
“The patient says she woke with a rat on her face. But wait, there’s more. The bugger bit her lip.”

“Egad,” was all I could say. “Was she passed out?”

“Yeah, probably,” came the laconic reply. “But she’s conscious now, and has puncture wounds. What antibiotic, doc?”

Aah, the joys of infectious diseases training in Boston. Even though this incident happened long ago, it seems like yesterday.

Back then, we couldn’t fact-check via the Internet of course. Luckily I had been studying for boards and knew my rodent germs.

“Tetracycline should do it,” I mumbled back. “Don’t forget a tetanus booster.”

“Rabies prophylaxis?”

“Er, I’ll check with public health in the morning, but I don’t think so. Unless she confused a rat with a bat, that is.”

We left it there. The ER doc no doubt shared the tale, and here I am, years later, doing the same.

Which brings me today’s earthy topic: rats and mice.

I was inspired by a recent story of corporate damage-control by a restaurant chain. Turns out one of their sites served a salad with an extra ingredient – a well-washed field mouse.

Eeek. Some price to pay for organic greens.

Anyway, the diner survived, the company displayed model remorse, and the mishap got me thinking about little-known rodent-borne infections.

Take Lassa Fever, for example – an African virus shed by mice. Humans are exposed by eating household grains fouled by mice or simply breathing virus-laden air.
Africa is far away, so infections are few and far between here. But did you know we have a U.S. relative also passed in rodent pee? It’s called “lymphocytic choriomeningitis virus” (LCM for short). My first case was another resident of a verminous Boston walkup.

Her illness was less deadly than Lassa, thank God, but she still had prolonged fever, stiff neck, and disabling headache. Eventually, she got better on her own. There’s no specific treatment for LCM (Lassa, in comparison, responds to an anti-viral called ribavirin-if victims can access medical care, that is).

In 1993, Americans learned of a new rodent-borne illness when “Hantavirus pulmonary syndrome” (HPS) erupted in the Southwest. Until then, hantavirus infections in Asia and Russia had caused hemorrhage and renal failure.

Surprisingly, the “Sin Nombre” variant in western states and Latin America targets lungs and triggers shock, often sending patients into ICU.

Despite growing awareness, HPS is still a fearsome disease. Of 560 cases diagnosed in the U.S. through December 2010, 36 percent were fatal.

Back to rats and bacteria and “rat-bite fever” (yes, Virginia, it’s a real disease). The two causative microbes are both killed by penicillin and tetracycline. Hence my middle-of-the-night prescription.

Is there a take-home lesson in this Lemony Snicket litany of unfortunate events? Of course. Minimizing rodent contact in houses, worksites and recreational areas is the key to dodging these diseases. That means sealing holes and gaps, using traps when needed, and securing easily-accessed food.

Also, after handling pet rodents or their “stuff,” don’t forget to wash with soap and water!