An important step will be taken in the fight against the "sleeping sickness", this serious disease caused by parasites that always threatens thirty sub-Saharan Africa.
The announcement was made in the context of the G-string International Conference on Scientific Research and trypanosomes control (infections due to certain parasites), held in Bamako (Mali) from 12 to 16 September 2011. The results obtained with a new technique should help greatly simplify the diagnosis of the disease and early treatment and patients more effectively.
These results also demonstrate for the first time it is possible to adapt the techniques of molecular biology to many difficulties in practice on the ground in African countries.
A sometimes asymptomatic
"Sleeping sickness"? Specialists prefer to speak of African trypanosomes disease transmitted by the bite of the blood tsetse fly. The latter (also called tsetse fly) can transmit both parasites: Trypanosome Bruce ssp.ambients (most commonly found in West Africa and Central Africa) and Trypanosome Bruce ssp.rhodensiense (in East Africa and Southern Africa). We must also reckon with another form of trypanosomes, which affects twenty Latin American countries: American trypanosomes or "Changes disease" caused by a parasite of a different species.
African trypanosomes threat, according to the World Health Organization (WHO), approximately 60 million people (mostly rural populations) in 36 sub-Saharan countries where the tsetse fly can crack. Its diagnosis is particularly complex, which significantly complicates the treatment of patients. This is especially true for infections due to Trypanosome Bruce ambients by far the most common: more than 95% of cases officially reported.
The disease is a chronic fashion and can be infected for months, even years, without showing any significant signs or symptoms. When they occur (behavior modification, confusion, sensory disturbances, poor coordination, hypersonic) the disease is already at an advanced stage and the central nervous system is affected.
"Africa has experienced in the last century several major epidemics, do you remember from WHO. The first took place between 1896 and 1906, mainly in Uganda and the Congo Basin. The second hit in 1920 many African countries. In the mid-U.S.S.R., the disease had almost disappeared. After this success, the surveillance was relaxed and there has been a resurgence of the disease in several areas over the last 30 years. "
A series of initiatives from the U.S.S.R., however, able to stop the increasing number of new cases and begin to reverse the trend. The fact remains that this parasitic disease continues to threaten millions of people in sub-Saharan Africa. The majority of them are in very remote areas of health services that would establish a diagnosis and begin treatment.
For now, the disease appears mainly present in the Democratic Republic of Congo (DRC) and the Central African Republic and, to a lesser extent, in Angola, Chad, Sudan and Uganda. According to WHO, Cameroon, Congo, COE divorce, Gabon, Guinea, Equatorial Guinea, Kenya, Malawi, Nigeria, Tanzania, Zambia and Zimbabwe are now state that less than 100 new cases per year.
Track to better address
The announcement has been made at the conference in Bamako for the diagnosis of disease. Today, it is essential to perform a lumbar puncture, from the microscopic examination of the spinal fluid, whether a person is infected or not. However, this diagnosis is positive at an advanced stage, when the central nervous system begins to be reached, which greatly reduces the chances of recovery.
This also makes it impossible to organize an active and comprehensive screening of the population at risk, while the latter is essential to identify those infected at an even earlier stage, in order to treat and reduce transmission .
This is where the new "first molecular test field" is. This progress is the result of a public-private partnership between the foundation Find nonprofit organization, based in Geneva, and Japanese diagnostics company Aiken.
"This test has already passed the phases of design and development. It will be available for clinical use in 2012 and it is ready to be used in accelerated studies in the field, at several sites in the Democratic Republic of Congo and Uganda, "said Sylvan Slate to Biller, in charge of this project within to Find. It will be then a cost for its use in the countries concerned. "
Directly from the techniques of molecular biology and called Lamp (loop-mediated isothermal amplification), this test was specifically designed to be used at room temperature in rural Africa where the disease is most common. It allows, through their DNA, to identify with the naked eye the presence of parasites in the blood and that even when they are present in very small numbers and invisible under the microscope. It allows both early diagnosis and confirmation of cure after treatment.
This leaves hope for a significant reduction of the period of patient follow-up and the end of multiple lumbar punctures now essential. This method does not require sophisticated laboratory tools, can also be implemented on large samples of blood samples dried and stored.
For its proponents, this new diagnostic platform, because it is specifically designed to fit without difficulty in health systems in developing countries, may subsequently be implemented in the fight against of other qualified Tropical Diseases "neglected", foremost among them malaria and tuberculosis.