Questions and answers on the monkeypox outbreak

WASHINGTON -- Public health authorities are scrambling to combat the nation's first outbreak of monkeypox -- including a controversial recommendation of smallpox vaccinations for people who may have been exposed.

Several cases of monkeypox have been confirmed in the United States, with more than 50 possible cases, apparently spread by infected pets.

Some questions and answers about the disease, based on information from the federal Centers for Disease Control and Prevention.

Q: What is monkeypox?

A: It is similar to smallpox in people, but milder. The incubation period is about 12 days. It begins with fever, headache, muscle aches, backache, swollen lymph nodes and general discomfort. After the fever, the patient develops a rash that later crusts over. The disease lasts two weeks to four weeks. In Africa, it can kill between 1 percent and 10 percent of victims.

Q: What causes it?

A: The monkeypox virus, a relative of smallpox and cowpox.

Q: Is there a treatment?

A: The CDC says there is no proven safe treatment for monkeypox.

Q: Can it be prevented?

A: Smallpox vaccine has been reported to reduce the chance of getting the disease.

Q: What action is recommended?

A: People investigating the outbreak or caring for patients or animals with the disease should get a smallpox vaccination, the CDC recommends. Vaccinations also are recommended for people who have had close personal contact with infected people or animals. They can be vaccinated up to 14 days after exposure to the disease. The smallpox vaccine is widely available because of concerns about potential bioterrorism.

Q: Aren't there risks from the smallpox vaccine?

A: Based on studies from the 1960s, experts estimate that 15 out of every million people vaccinated for the first time will face life-threatening complications, and one or two will die. If everyone in the country were to be vaccinated, that would include approximately 130 million Americans never inoculated before. Experts would expect nearly 2,000 from that group to face life-threatening complications and 125 to 250 of them to die. Of the 158 million people being revaccinated, nearly 800 would face life-threatening complications and about 40 would die.

The most common serious reaction comes when vaccinia escapes from the inoculation site, often because people touch the site and then themselves or someone else. For instance, the virus transferred to the eye can cause blindness. More deadly is encephalitis, which can cause paralysis or permanent neurologic damage. Also fatal though very rare is progressive vaccinia, where the vaccination site does not heal and the virus spreads, eating away at flesh, bone and gut. Typical minor reactions include sore arms, fever and swollen glands.

Q: Have these problems been occurring among people getting the smallpox vaccine?

A: Three people have died of heart attacks, but they were at risk for heart problems before they were vaccinated. Two people have reported cases of angina, or chest pain. It is possible that the vaccine is triggering heart problems in people who are already prone to difficulty; it also is possible the vaccine is unrelated.

Q: Who is at greatest risk?

A: People with weak immune systems -- those with HIV, cancer and transplanted organs, and pregnant women. People with eczema risk a serious, permanent rash. Officials administering the vaccine will ask detailed questions to try to screen out such people. The CDC is recommending vaccinations, even for pregnant women, children and people with eczema, if they have been exposed to infected animals.

Q: Why give a risky vaccine to people to prevent a mostly nondeadly disease?

A: Dr. Joanne Cono, an epidemiologist at the CDC, said "there is concern that we don't know enough about the disease yet, and about person-to-person transmission." A CDC committee concluded that "the risk from the disease outweighed the risk from the vaccine for most people," she said.

Q: How do you persuade people to take the vaccine when there has been such resistance for a preventive against smallpox threat?

A: Cono pointed out that in the case of smallpox, there is no case of the disease occurring. As for monkeypox, "We're in the middle of an outbreak, and that's where the risk and benefit changes," she said.

That is why a wide range of people were told not to get the smallpox vaccine -- such people with weakened immune systems. But now many of those people are urged to get the vaccine if exposed to monkeypox.