The World Health Organisation said on Thursday it was investigating reports of suspected cases of the previously eradicated disease smallpox in eastern Uganda, according to Reuters. Smallpox is an acute contagious disease and was one of the world's most feared sicknesses until it was officially declared eradicated worldwide in 1979. "WHO takes any report of smallpox seriously," Gregory Hartl, a spokesman for the Geneva-based United Nations health agency, told Reuters via email. "WHO is aware of the reports coming out of Uganda and is taking all the necessary measures to investigate and verify." He added that the WHO had received reports before of smallpox cases, but they had turned out to be false alarms. "In the past, these cases have always turned out not to be smallpox and were, usually, either chickenpox or monkeypox cases," he said, stressing that the reports had been of suspected cases. Smallpox was eradicated by a collaborative global vaccination programme launched by the WHO in 1967, but a rise in global terrorist activity means governments around the world have become concerned terrorists might use smallpox as a weapon. The United States and other countries have built up stockpiles of vaccine to deal with any threat. The last known natural case of smallpox was in Somalia in 1977. Since then, the only known cases were caused by a laboratory accident in 1978 in Birmingham, England, which killed one person and caused a limited outbreak. Makers of smallpox vaccine include Sanofi Pasteur, the vaccines division of Sanofi-Aventis, and Denmark's Bavarian Nordic. Smallpox, which is believed to have originated more than 3,000 years ago in India or Egypt, is described by the WHO as "one of the most devastating diseases known to humanity". The incubation period usually lasts from 12 to 14 days, followed by the sudden onset of flu-like symptoms including fever, headache, severe back pain, abdominal pain and vomiting. Two to three days later pox, or lesions, start to appear first on the face, hands and arms and then on the trunk. The pox ulcerate quickly, releasing large amounts of virus into the mouth and throat. The most severe cases involve haemorrhage, or bleeding, into the mucous membranes and skin. Smallpox can sometimes be confused with chickenpox, a worldwide infection of children that is very rarely dangerous. Chickenpox produces much more superficial lesions which tend to appear more on the trunk than the face or hands.
