The United Nations World Health Organization (WHO) says it is still investigating the possible origin of an outbreak of a mystery illness that has forced at least 370 people to seek hospital treatment in Angola.
The symptoms include extreme drowsiness and loss of muscle control, WHO said in a statement issued yesterday, and although most patients recover slowly over a number of days many are still unable to walk without assistance. Children suffer the most extreme symptoms.
WHO said that while a toxicological cause is suspected, a series of tests on patients for 300 organic solvents and 800 compounds have proven negative and tests for cadmium, lead, manganese and mercury have shown levels within the normal range.
Health officials are still awaiting the results of environmental samples and tests of food and drinking water in Cacuaco municipality in the suburbs of the capital, Luanda, where the outbreak was first reported on 2 October.
WHO said it fears that the number of people affected by the disease may be more than reporter as some patients prefer to receive treatment from traditional healers or remain at home rather than visit a hospital.