( Human African trypanosomiasis more com...)Resistance and genetic sensitivity to sleeping sickness

Human African trypanosomiasis, more commonly called sleeping sickness, is induced by a parasite, the trypanosome, transmitted to humans by the bite of an insect, the glossinid tse-tse fly. There has been a resurgence of this disease over the past 20 years in Sub-Saharan Africa. The World Health Organization (WHO) in a 1998 report estimated the number of people infected to be about 300 000. Awareness of the seriousness of the situation led to an increase in screening and treatment operations over the past five years, allowing a substantial fall in the number of subjects infected.

Sleeping sickness classically manifests itself in two forms, corresponding to two parasite subspecies. The chronic form, encountered in Central and West African countries, is caused by Trypanosoma brucei gambiense (T.b. gambiense). Its development cycle in the host vaires greatly, from a few months to several years. The acute form of the disease is brought on by Trypanosoma brucei rhodesiense (T.b. rhodesiense), in southern and eastern African countries. The infection it induces takes effect after a few weeks. More virulent than the chronic form, its development cycle is also more rapid and, consequently, clinical detection can be made earlier.

However, it is increasingly recognized that the existence of these two forms, the chronic one due to T. b. gambiense and the acute one provoked by T. b. rhodesiense, only partly reflect the real mechanisms at work. Concerning the Gambian form, the screening and treatment teams indicates the occurrence of several categories of subjects infected: some show Glossina fuscipes gorged with blood affected by classical chronic forms of the disease; others bear severe rapidly developing forms; still other people show no symptoms of human African trypanosomiasis, in spite of a long period of infection. This diversity in host clinical presentation in reaction to infection can have several sources: the host's ability to respond to infection, the
'"/>

Source:Institut de Recherche Pour le D茅veloppement

Page: 1 2 3
Related biology news :

1. To Stop Evolution: New Way Of Fighting Antibiotic Resistance Demonstrated By Scripps Scientists
2. Large-scale Computer Simulations Reveal New Insights Into Antibiotic Resistance
3. Resistance to anti-HIV drugs in Uganda developed due to drug supply problems
4. Its not all genetic: Common epigenetic problem doubles cancer risk in mice
5. Scientists detect probable genetic cause of some Parkinsons disease cases
6. Mouse brain tumors mimic those in human genetic disorder
7. Scientists identify genetic pathways essential to RNA interference
8. Researchers trace evolution to relatively simple genetic changes
9. Key mechanism in genetic inheritance during cell division identified
10. Scientists identify genetic pathways essential to RNA interference
11. MUHC scientists describe genetic resistance to rampant virus