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Summer 2003 - Article 4

From the Lab
Monkeypox Virus

Monkeypox is a rare viral disease that occurs mostly in Central and Western Africa. It is called "monkeypox" because it was first discovered in 1958 in laboratory monkeys (first reported in humans in 1970). Blood tests of animals in Africa later found that other species of animals had monkeypox too. Scientists also recovered the virus from an African squirrel. These types of squirrels may be the common host for the disease. Rats, mice and rabbits can get monkeypox too.

In early June of this year, monkeypox was reported among several people in the United States. Most of these people became sick after having contact with pet prairie dogs that were sick with monkeypox. This is the first reported and confirmed outbreak in the United States.

Investigators have traced the possible source back to a common distributor of exotic pets where prairie dogs and Gambian rats were housed together in Illinois. The Gambia rats were shipped to the U.S. from Ghana. The shipment contained a large number of other small mammals that may have been the actual source of monkeypox (still being investigated).

The virus responsible for monkeypox is related to the virus that causes smallpox. Vaccination against smallpox (no longer necessary) also gave protection against monkeypox. Before the eradication of smallpox, vaccination was widely practiced against both diseases. However, children born after 1980 have not been vaccinated against smallpox and are likely to be more susceptible to monkeypox than older members of the population. The mortality rate from monkeypox is highest in children, reaching about 10%.

The monkeypox virus is transmitted to humans through an infected animal if they are bitten or if they touch the animal's blood, body fluids or its rash. About 12 days after people are infected, they will get a fever, headache, muscle aches and backache; their lymph nodes will swell and they will feel tired. A rash will then appear one to three days after the fever starts. This rash develops into raised bumps filled with fluid and often starts on the face and spreads. The bumps go through several appearance stages before falling off. The illness can last from two to four weeks.

There are currently no EPA-approved protocols, including surrogates for testing disinfectants against monkeypox, so no products make the claim. As always, good housekeeping that includes the proper use of disinfectants is the best defense against pathogenic organisms.