Tuesday, May 3, 2011

Wiping Out Sleeping Sickness

The incidence of sleeping disease, trypanossomiasis (try saying that quickly!) is decreasing in the most contaminated areas of Angola, most notably the seven endemic provinces: Malanje, Kwanza Norte, Kwanza Sul, Uíge, Zaire, Bengo and Luanda. Sleeping sickness threatens one third of the Angolan population and recent screenings carried out revealed a sharp decrease in positive cases. 

The disease is mostly transmitted through the bite of an infected tsetse fly but there are other ways in which people are infected with sleeping sickness; mother-to-child infection through the placenta and through mechanical transmission through other blood sucking insects,

In the first stage, the trypanosomes multiply in subcutaneous tissues, blood and lymph. This is known as a haemolymphatic phase, which entails bouts of fever, headaches, joint pains and itching.

In the second stage the parasites cross the blood-brain barrier to infect the central nervous system. This is known as the neurological phase. In general this is when more obvious signs and symptoms of the disease appear: changes of behaviour, confusion, sensory disturbances and poor coordination. Disturbance of the sleep cycle, which gives the disease its name, is an important feature of the second stage of the disease. Without treatment, sleeping sickness is considered fatal.

Sleeping sickness threatens millions of people in 36 countries in sub-Saharan Africa. Many of the affected populations live in remote areas with limited access to adequate health services, which hampers the surveillance and therefore the diagnosis and treatment of cases. In addition, displacement of populations, war and poverty are important factors leading to increased transmission and this alters the distribution of the disease due to weakened or non-existent health systems. In 2009, after continued control efforts, the number of cases reported has dropped below 10,000 (9878) for first time in 50 years. The estimated number of actual cases in sub-Saharan Africa is currently 30,000. (WHO Report 2011)

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