US health officials keeping an eye on potential bubonic plague exposure : LUSENET : Grassroots Information Coordination Center (GICC) : One Thread

Thursday, June 21 8:45 AM SGT

US health officials keeping an eye on potential bubonic plague exposure

DENVER, Colorado, June 20 (AFP) -

Colorado health officials are carefully examining reports of possible human exposure to bubonic plague that has killed a sizable portion of a nearby prairie dog colony.

While health officials have confirmed the prairie dogs do carry the deadly but treatable disease, they are unsure if colony neighbors -- including a unidentified man who died of plague-like symptoms Monday -- have contracted the disease, said Tisha Dowe, director of the El Paso County Department of Health and Environment.

"Right now, we're out checking other prairie dog colonies, too," Dowe said. "In the meantime, I've alerted doctors in the area to watch for symptoms just in case." As a precaution, the humans are being treated with antibiotics while health officials investigate whether there is a connection with the rodents, Dowe said.

The county began spraying the colony to kill infected fleas which transmit the disease to humans. Health officials were alerted to the incident after a number of the rodents were found dead in the past week.

Bubonic plague, which killed an estimated 25 million people in Europe in the 14th century, is a disease carried by rodents that is normally transmitted to humans through bites from infected fleas, said John Pape, a Colorado Department of Health and Environment epidemiologist who specializes in animal-borne illnesses.

The plague produces flu-like symptoms, including high fever, chills, headaches, severe fatigue, vomiting and tender or swollen lymph glands that appear two days to a week after exposure, Pape said. "This is not the kind of flu that, when you get it, you wonder if you should go to the doctor," Pape said. "When you get it, you know it. It hits you that hard."

While the threat of a widespread epidemic is minimal, Pape and other health officials have issued warnings alerting the public and their pets to stay away from the rodents. Pets, more likely to pick up the unwanted fleas as passengers, have transmitted the disease to more than half of the humans reported to have contracted the disease, Pape said.

"We get reports of rodent die-offs every year throughout the west, but it rarely makes the jump to humans," Pape said, "The last time a human contracted it from another human in the United States was in 1924. Unlike 14th-century Europe, we don't have infected rats in our homes."

Earlier this month, Colorado health officials confirmed other cases of plagued animals in the southern city of Pueblo and the Denver metropolitan area, but no human victims were reported. Last year, one human was treated for the disease on the state's Western Slope.

The last confirmed bubonic plague death in the state was in 1999, one of three human cases in the state that year, Pape said.

-- Swissrose (, June 21, 2001


It's never clear to me why certain plague cases get jumped on by the media, while others don't.

The western United States has roughly *a dozen cases* of human plague *every year*, and this has been going on for most of the (previous) century. For general info see:

and mores specifically for a map of U.S. counties reporting plague in the past couple decades, see:

Note this: "Wild rodents in certain areas around the world are infected with plague. Outbreaks in people still occur in rural communities or in cities. They are usually associated with infected rats and rat fleas that live in the home. In the United States, the last urban plague epidemic occurred in Los Angeles in 1924-25. Since then, human plague in the United States has occurred as mostly scattered cases in rural areas (an average of 10 to 15 persons each year)..."

It's certainly a very scary dramatic disease, and can kill if not immediately treated appropriately. The good news is that human-to- human transmission is *extremely* rare in the U.S.; as the article notes, it hasn't happened here in 75+ years. Partly this is due to modern "chemical quarantine" (a fancy way of saying, "treatment with antibiotics as a method to eliminate contagiousness") and modern standards of infection control, but also due to the rarity of the pneumonic (lung) form of the disease, which poses the major risk of further tranmission.

The article notes: "While the threat of a widespread epidemic is minimal..." Based on actual U.S. epidemiologic experience since the 1920s, plus the appropriate public health actions to control fleas and to notify public and clinicians, I'd say the threat is indeed quite "minimal." At least from a natural outbreak...deliberate release is a whole different matter, but that's a seperate discussion.

-- Andre Weltman, M.D. (, June 22, 2001.

Here's a little follow-up information on one aspect of North American plague epidemiology/epizoology:


From: ProMED-mail

Subject: PRO/AH/EDR> Plague, cats - USA (New Mexico)


A ProMED-mail post

ProMED-mail, a program of the International Society for Infectious Diseases

[see also:

Plague, cats - USA (Nevada): alert 20010627.1225

Plague - USA (New Mexico) 20010630.1246 1999

Plague, cats - USA (New Mexico) 19990531.0912

Plague, cats & dogs to humans 19990619.1045]

Date: 28 Jun 2001

From: Pam Reynolds

Subject: Feline Plague in New Mexico

New Mexico has reported a total of 294 feline plague cases from 1977 through the present. 3 cases have been identified this year, all in Santa Fe County. The first human plague case of the year has just been confirmed from the same area as the cat cases (the human case was flea bite acquired).

In the last post on feline plague [Plague, cats - USA (Nevada): alert 20010627.1225], the moderator commented it was not known if the increase in cat plague cases was due to an increase in infection, improved surveillance, or increased awareness by veterinarians. The first 2 cases of reported feline plague (in 1977, in Arizona and New Mexico) were recognized because they resulted in human plague cases.

It certainly appeared the increase in report of cases after that, at least through the 1980s, was probably due to improved surveillance and increased awareness by veterinarians. A great deal of effort has been expended by the New Mexico Department of Health to educate physicians and veterinarians on the symptoms and treatment of plague. In the last 10 years or so, the incidence of reported feline plague in New Mexico has more closely reflected the level of plague activity in rodents.

For a more recent summary of all cat-associated human plague cases, see "Cases of Cat-Associated Human Plague in the Western U.S., 1977- 1998" by Kenneth Gage, et al, Clinical Infectious Diseases 2000; 30:893-900.

- -- Pamela J. Reynolds Environmental Specialist Vector Control Program New Mexico Environment Department Santa Fe, NM

[In addition to the programs New Mexico has instituted to raise awareness of the situation, there has also been the advent of specialized cat practice. 20 or more years ago, the speciality of a cat-only veterinary practice was rare, now it is common place.

-- Moderator MHJ/TG]


-- Andre Weltman, M.D. (, July 03, 2001.

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