Updates-By Carol A. Kemper, MD, FACP

Show-and-Tell: Look! My Dog has Rabies!

Source: ProMED-mail, March 2 and 5, 2001. Promed@promedmail.org.

A 9-week-old border collie subsequently diagnosed with rabies exposed more than 50 adults and small children in Mecklenburg County, North Carolina, this spring, many of whom required postexposure prophylaxis. The puppy was adopted by a couple with 2 small children in early February, and then attended 2 birthday parties and visited a local preschool for show-and-tell. Four days later, the puppy began showing increasing signs of illness and was euthanized. In retrospect, the puppy’s behavior at the preschool was erratic—he had snapped and snarled at a couple of kids and then would run and hide—not exactly puppy behavior. DFA confirmed rabies; the strain appeared to be raccoon in origin.

Parents of 26 children at the preschool and the preschool staff, as well as 25 people from the birthday parties were requesting postexposure prophylaxis. Neither the breeder nor the family recalled seeing the puppy in association with wild animals or bats, and all of the other puppies in the litter were apparently without disease.

While cases of rabies in domestic animals have significantly decreased in past years, rabies among wild animals, especially raccoons, has increased ~20% since 1996 (Kuritzky L. Infectious Disease Alert. 2000;20:8). The only case of rabies in a domestic animal in the Bay Area in recent years occurred in an adopted stray cat, which unfortunately bit the family’s 2-year-old child—the cat had likely been exposed to a rabid raccoon or skunk. Even in our neighborhood only 4 miles down the road from Stanford, raccoons and skunks make their nightly foray across the back deck, the coyotes are howling down in the canyon—and the cats are in and out all day—a perfect scenario for rabies transmission. Fortunately, rabies in domestic animals remains uncommon.

Kids Pick Up Salmonella from Owl Droppings

Source: http://www.salon.com/mwt/ wire/2001/06/07/salmonella_outbreak. June 7, 2001.

Dozens of elementary school children in Washington County, Minnesota, developed salmonellosis after participating in a school project to learn what an owl eats. Apparently dissecting owl "pellets"—regurgitated food—is a great way for kids to learn more about owls and their prey. Owls typically dine on small rodents and mammals such as mice, voles, and shrews, although occasionally they will eat other animals like squirrels, snakes, frogs, birds, and skunks. A hungry owl will often swallow his prey whole. While the soft tissues are dissolved by gastric juices, the indigestible parts are packaged together as pellets and regurgitated several hours later. If you find an owl roost, you can often find the characteristic pellets on the ground beneath. The pellets typically contain bones, fur, and feathers and—often—whole skulls (http:// www.conservation.state.mo.us/conmag/1998).

Like small detectives armed with zoology texts, kids can identify which animal met its fate by dissecting the pellets. This outbreak of salmonellosis was traced to an owl at a local nature center that provided droppings for the class project. One dissection apparently occurred in the cafeteria just before lunch—and the lunch table had not been immediately disinfected. Molecular studies subsequently confirmed that the salmonella isolated from the children matched an isolate obtained from the owl.

Feral Cats Transmit Plague

Source: ProMED-mail, June 26-28, 2001. Promed@promedmail.org.

Similar to other wild animals such as foxes and coyotes, cats and dogs are vulnerable to Yersinia pestis infection, which may be transmitted to humans. Once thought to be unusual, New Mexico, for example, has identified 294 cases of feline plague since 1977. The disease can be overlooked in cats as the swollen and draining buboes can easily be mistaken for typical cat-bite abscesses (Kemper CA. Infectious Disease Alert. 2000;19:176).

After identification of 2 feral cats with plague, Clark County Health District officials in Nevada have issued an alert to visitors and residents in the area (where 4 foxes and a coyote developed plague last year). And, authorities in Santa Fe County, New Mexico, where 3 cats with plague have been identified thus far this year, confirmed that a 21-year-old man is the first person to contract plague in the state this year. It is not clear if the man had contact with any infected cats.

Cats have been identified as the source of at least 15 cases of human plague infection in the United States. Y pestis can be transmitted to humans through the bite of an infected flea, the bite of an infected animal, or contact with draining buboes or inhalation of droplets from an infected animal (Gage K, et al. Clin Infect Dis. 2000;30:893-900). Transmission risk can be reduced by keeping your cats indoors, limiting their hunting of rodents, and good flea control.