U.S. Tries to Curb Monkeypox on Several Fronts

Health officials recommend smallpox shots, ban imports of African rodents

(HealthDay is the new name for HealthScoutNews.)

WEDNESDAY, June 11, 2003 (HealthDayNews) -- U.S. health officials moved aggressively Wednesday to contain the first monkeypox outbreak in the Western hemisphere, as the number of suspected cases and the number of affected states rose dramatically.

The U.S. Centers for Disease Control and Prevention recommended immediate smallpox shots for a small group of people who were -- or may have been -- exposed to the virus, which was apparently transmitted by infected prairie dogs that have been sold as pets.

At the same time, the Department of Health and Human Services instituted an immediate ban on the importation of rodents from Africa and also banned the commercial transportation and sale of African rodents and prairie dogs within the United States.

The actions came as the number of suspected monkeypox cases rose to 54. There are nine cases in four states -- Wisconsin, Indiana, Illinois, and New Jersey. But the Associated Press reported that the probe has expanded to 11 other states: Kentucky, Florida, Tennessee, Mississippi, Massachusetts, Michigan, New York, Pennsylvania, Texas, Ohio, and South Carolina.

The AP, citing the U.S. government, said that an Illinois dealer of exotic pets may have sold infected prairie dogs to "numerous buyers" in these states since mid-April.

CDC officials said the decision to recommend the controversial and dangerous smallpox vaccine, which is not approved for monkeypox, was made with the backing of the U.S. Food and Drug Administration, which allowed its emergency use in this case.

"The smallpox vaccine is about 85 percent effective in preventing monkeypox," Dr. David Fleming, the CDC's deputy director, told a news conference Wednesday. "Experts have advised that it was prudent to go ahead and recommend vaccination to people who have been exposed or potentially exposed."

This is the first time the exotic disease, which is related to smallpox, has been seen in the United States. It is more common in Africa, where it has a 1 percent to 10 percent mortality rate in humans. The disease is not easily passed from person to person, though it is easily transmitted from animal to animal and from animal to human.

However, Fleming warned that the United States should be anticipating a similar mortality rate in this country.

"There are lots of reasons why things may be different here, including improved medical treatment and better nutrition, but we do need to be prepared that monkeypox can be a fatal disease," he said.

Generally, monkeypox causes fever, headache, dry cough, chills, sweats, and, later, a rash consisting of pus-filled blisters.

Since the disease surfaced in the Midwest this past weekend, health officials at all levels of government have been engaged in a concerted dog-and-rodent hunt.

An initial group of prairie dogs in the Midwest that fell ill has now been traced back to a distribution center in Texas. That distribution center also handled one shipment from Africa of Gambian rats, which has now become a prime suspect in the genesis of the disease. The disease, however, has not yet been confirmed in any of the rodents.

"A likely candidate is the Gambian rat, but at this point we do not have definitive confirmation," Fleming said.

Officials are now trying to determine how many animals might have been exposed to the initial suspects.

Knowing which animals have been exposed will help to determine who should be inoculated. Right now, this "limited" group includes public health officials out in the field, health-care workers who may be treating sick people, family and close household contacts of people who are sick, or people who have had contact with a sick animal.

While Fleming said he anticipated that only a "modest number" of people would be vaccinated, this group would potentially include pregnant women and children, two groups that normally would not receive the vaccine because of various risks involved.

"The targeted vaccination recommendation is different in that we're not dealing with a potential risk in the future but the reality that these people have been exposed," Fleming said. "In that context, the risk-benefit changes. We're taking a more aggressive approach to who should receive vaccination in this focused group. We felt that the risk of disease is sufficient to make that recommendation to pregnant women and children."

The smallpox vaccine has been known to kill people and to result in various side effects, including brain infection and severe skin rashes.

Vaccinations will be carried out by state and local health departments and will use stockpiles already accumulated for bioterrorism purposes.

In the meantime, the CDC asks that people who have been exposed to an exotic rodent or prairie dog be on the watch for such symptoms as respiratory disease and rash.

People who have acquired prairie dogs or small rodents since April 15 should also be watching their animals for signs of illness, including cold-like symptoms, running or oozing eyes, respiratory disease, and a rash. Anyone who notices any of these signs in a pet should contact the state or local health department and/or a veterinarian.

The CDC emphasizes that sick pets should not be released outside. The agency also urges people to contact a vet before taking the animal in, so the vet can take appropriate precaution.

"We have moved quickly to develop interim orders, which we feel are appropriate steps to prevent the spread of this outbreak," Fleming said. "I'm confident that everything that can be done is being done to prevent further spread of the disease."

More information

The CDC and Stanford University have information on monkeypox.

SOURCES: News conference with David Fleming, M.D., deputy director, Centers for Disease Control and Prevention, Atlanta; Associated Press; CDC Web site; CDC news release
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