African Sleeping Sickness: What is it and What is Being Done To Stop it?
African Trypanosomiasis, or African Sleeping Sickness, is a vector borne parasitic disease. The disease is transmitted by an infected Tsetse fly. As the infected fly takes a blood meal from its mammalian host, parasites enter the host through the lymphatic system and into the bloodstream. Once inside the bloodstream, the parasite turns into trypomastigotes, which are then carried throughout the rest of the body and reach other vital bodily fluids. During this whole process, the trypomastigotes are continuously multiplying by binary fission. The whole life cycle of the tsetse fly can be seen in figure 1 (CDC, 2015).
Once infected, there are two stages that a person goes through with the disease. Stage 1 (haemolymphatic stage) is when non-specific symptoms such as headaches and fevers begin to present themselves. During this stage, the disease is very easy to treat, but very difficult to diagnose so many cases go undiagnosed, allowing for the parasite to invade the person’s central nervous system, which leads to stage 2. In stage 2 (neurological phase), the parasite has reached the central nervous system of its host. During this stage, specific symptoms start to appear including convulsions, confusion, violent behavior, and the most notable symptom- inability to sleep at night and extreme sleepiness during the day (Doctors Without Borders, 2015).
There are 36 African countries consider endemic for sleeping sickness, but of these 36, 7 countries are responsible for 97% of all reported cases. This disease is most present in very poor, rural countries where there is difficulty to diagnose the disease, political instability, and lack of proper health surveillance. All of these factors make diagnosing and treating the disease more difficult, but they also leave uncertainty of the accurate number of cases prevalent each year (DNDI, 2012). The Democratic Republic of Congo has the highest rate of infection, reporting 1000 new cases each year and accounting for roughly 85% of all cases (WHO, 2016). The distribution of the disease can be seen in figure 2.
Currently, the WHO has noted that elimination of the disease is feasible, and they have even set a target date for elimination as the year 2030. To make this possible, surveillance of the disease is going to need to increase in many afflicted countries. Many of the health care facilities and resources in the endemic countries are weak and poorly staffed. Increased support and external assistance is necessary to ensure the surveillance of the disease and early diagnosis. Additionally, environmental changes can affect the disease. Given the changing climate and the massive population growth in Africa, some areas may be affected worse than before, or areas that were endemic may have the relief of a smaller fly population. Drought and increased temperatures can drive flies away. Although this can be good for some countries, other countries that were not endemic may notice an increase in the disease. All of this is dependent upon population growth and climate change, so constant surveillance of those issues and predictions for the future will need to occur to ensure control over the disease (Franco et al., 2014).
Fig 1: life cycle of the tsetse fly
Fig 2: distribution of the disease throughout Africa
Works Cited:
“Trypanosomiasis, Human African (sleeping Sickness).” World Health Organization. World Health Organization, Feb. 2016. Web. 06 Nov. 2016.
“Biology.” Centers for Disease Control and Prevention. Centers for Disease Control and Prevention, 16 Mar. 2015. Web. 06 Nov. 2016.
“Sleeping Sickness.” MSF USA. N.p., 25 Mar. 2016. Web. 06 Nov. 2016.
“About Sleeping Sickness.” DNDi. N.p., 2012. Web. 06 Nov. 2016.
Franco, Jose R., Pere P. Simarro, Abdoulaye Diarra, and Jean G. Jannin. “Epidemiology of Human African Trypanosomiasis.” Clinical Epidemiology. Dove Medical Press, 6 Aug. 2014. Web. 06 Nov. 2016.
