At least seven counties in New Mexico have seen a spike in cases of plague and the bacterial infection tularemia in pets, diseases that can be deadly, the state Department of Health said Monday.
Ten cases of plague in dogs and cats have been confirmed in Santa Fe, Los Alamos, Taos, Sandoval, Rio Arriba and Torrance counties, according to the department. Pets have also tested positive in 19 cases of tularemia in Sandoval, Bernalillo, Santa Fe and Los Alamos counties.
Flea bites can transmit the diseases, and the department advised residents that fever and lethargy can be symptoms in themselves and in their pets. It says pets shouldn’t be allowed to roam or hunt, lessening the chance of disease spreading from infected rodents to pets and humans.
“The concern, of course, is that once you see cases in dogs and cats, you may then start to see cases in people,” said Dr. Paul Ettestad, a veterinarian with the Department of Health.
New Mexico typically accounts for a significant percentage of the reported cases of plague in the United States each year, about four of some 10 annual human deaths nationwide.
“It’s a high number this early in the year,” Ettestad said. “It is telling us there is an increase in activity in both of these diseases going on right now.”
Plague is believed to be more common in New Mexico because of the large diversity of fleas and animals here, ranging from rats to prairie dogs, Ettestad said.
Oropsylla montana fleas, prolific in the Rocky Mountain high desert region, are one of the more common carriers. The minuscule parasite, about a millimeter in size, resembles a multilimbed cockroach beneath a microscope and is drawn into the nests of rodents. They live off the mammals’ blood and, if infected with plague, will transmit the disease to their host as they feed.
Ettestad calls this “the blood meal.”
Because fleas are attracted indiscriminately to a warm body, Ettestad said, they can wantonly jump from rodent to rodent or from rodent to human to feed and infect. This is how cases of human plague in New Mexico usually occur, he said. Too often a pet owner will allow his dog or cat to roam and hunt around the neighborhood, he said, only to return to the home and join its owner in bed, allowing plague-infected fleas to bite humans while they sleep.
Plague and tularemia affects household animals in a way similar to a severe flu. Fever, lethargic behavior, loss of appetite and swelling beneath an infected animal’s jaw are some symptoms.
In humans, the bacterial infection appears similarly, with a sudden high fever, chills, headache and weakness. This is accompanied by painful swelling in the lymph nodes, as the bacteria multiplies, and can form large bulges visible through the skin surface in underarm, neck and groin areas.
Ettestad said a lab test is required to determine if either bacteria has been contracted, but the state has just one lab able to analyze the blood results. It is in Albuquerque.
From the time of infection, it takes two to eight days for the fever to set in, at which point Ettestad said it is crucial to get to a doctor immediately to receive antibiotic treatment. Deaths have occurred when the doctor visit was delayed or the illness was misdiagnosed. Pet owners whose animals contract the disease may be put on a prophylactic course of antibiotics.
Though fleas are a common carrier, the plague can also be transmitted through bites by horse flies. Once the bacteria gets into human lungs, it forms the notorious black cloud that led to the disease’s nickname of “black death.” It can be transmitted through a hacking cough.
“In New Mexico, 7 to 10 percent of people who come down with plague actually die from it,” Ettestad said. “It is a serious disease, but if you take precautions, you can reduce your risk.”