The Food and Drug Administration and national Centers for Disease Control and Prevention issued an interim final rule in November establishing new restrictions and modifying others to prevent transmission of monkeypox, a rare viral disease.

Published in the Nov. 4 Federal Register, the rule affects the import, capture, transport, sale, barter, exchange, distribution, and release of African rodents, North American prairie dogs, and certain other animals in the United States.

Earlier this year, an outbreak of monkeypox linked to exotic animals caused 37 confirmed, 12 probable, and 22 suspect human cases in the United States.

Monkeypox is a communicable, viral disease that occurs primarily in rainforest regions of central and west Africa. Monkeypox was first reported in prairie dogs and humans in the United States in May 2003. Individuals contracted monkeypox primarily as a result of contact with prairie dogs that became infected with monkeypox virus from diseased, imported African rodents.

Investigations implicated a shipment of animals from Ghana that arrived in Texas on April 9, 2003. This shipment contained approximately 800 small mammals of nine species, including six genera of African rodents that came in contact with prairie dogs.

In June, the CDC implemented an immediate embargo on the importation of all rodents from Africa. The FDA and CDC prohibited prairie dogs and certain rodents from Africa from being transported in interstate commerce, sold, or offered for sale or commercial or public distribution, including release into the environment. The rodents from Africa are tree squirrels, rope squirrels, dormice, Gambian giant pouched rats, brush-tailed porcupines, and striped mice.

This interim rule is intended to prevent possible transmission of monkeypox from imported animals and from those currently in the United States that may have become infected.

As outlined in the interim rule, the CDC will restrict importation of these animals, and the FDA will restrict their domestic interstate and intrastate movement, with exemption procedures to accommodate special circumstances.

Comments on the interim final rule must be submitted by Jan. 20, 2004. Written statements can be submitted to the FDA at Dockets Management Branch (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Room 1061, Rockville, MD 20852. Comments can also be submitted electronically through www.fda.gov/dockets/ecomments.