Navigation Links
Understanding Sleeping Sickness

Sleeping sickness or Human African trypanosomiasis is caused by the bite of an insect , called the glossinid tse-tse fly//, which passes on the parasite called the trypanosome, to human beings through the bite. There has been a come-back of this disease over the past two decades in Sub-Saharan Africa. The World Health Organization (WHO) has tried to collect the data of the number of people suffering this sickness, which is about 300,000, as mentioned in a 1998 communiqué. Evolved screening and treatment measures have indeed resulted in a considerable decline in the infection rates of this disease.

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 r espond to infection, the degree of parasite virulence or pathogenicity and the environment.

An IRD team focused particularly on the role of host genetic diversity in response to T. b. gambiense infection (whether or not the disease develops). As human experimentation is excluded, genetic, epidemiological and statistical methods, all brought under the term genetic epidemiology, were developed in order to identify the chromosome regions and/or DNA mutations involved in the development of the disease. The researchers used association techniques in order to determine the influence of certain mutations on the DNA of genes coding for particular immune system proteins (cytokines) in manifestation of the disease. This type of study consists in comparing the frequency of a mutation in subjects with symptoms and in healthy individuals. When the frequency of a mutation is significantly higher in the sick subjects than in the healthy ones, this mutation is associated with an enhanced risk of developing the disease. Conversely, a significantly lower frequency is an expression of a protective effect conferred by the mutation.

The two studies conducted in two distinct foci of the disease, respectively at Sinfra in the Ivory Coast and at Bandundu in the Democratic Republic of Congo (1), revealed evidence of three associations between a DNA mutation and the development of the disease. Depending on their position on certain cytokines genes, the mutations investigated were shown to be capable of inducing in the subject carrying them an increased risk of developing this human trypanosomiasis, or conversely a higher chance of a protector effect (2).

The associations brought out between these mutations and the disease necessitate work to confirm this in different populations and environments. New investigations, particularly in genetic epidemiology, are currently being put into operation in order to check up on possible effects of genetic predisposition already observed. The results obtained will help improve our knowledge about host-parasite interactions, by means of identifying genetic markers signalling risk. That should open the way in the long term to possible development of innovative control strategies against sleeping sickness.



Source-Eurekalert
'"/>




Related medicine news :

1. Understanding The Predictors Of Prostate Cancer
2. Understanding Restless Legs Syndrome
3. Understanding Lung Cancer Metastasis
4. Understanding The Link Between Hormone Replacement and Respiratory Disease
5. Understanding The Risks Of Hormone Therapy
6. Understanding The Link Between Metabolic Syndrome And Drinking Patterns
7. A Better Understanding Of The Brain Network
8. Understanding The Predictor’s Of Alzheimer’s Diseae
9. Understanding The Harmful Effects Of Radiation Exposure
10. Understanding The Origin Of Tumors
11. Understanding Insulin Resistance
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/26/2016)... ... June 26, 2016 , ... Pixel Film Studios Released ProSlice ... "Film editors can give their videos a whole new perspective by using the ... of Pixel Film Studios. , ProSlice Levels contains over 30 Different presets to ...
(Date:6/25/2016)... , ... June 25, 2016 , ... ... policy issues and applications at AcademyHealth’s Annual Research Meeting June 26-28, 2016, at ... on several important health care topics including advance care planning, healthcare costs and ...
(Date:6/25/2016)... , ... June 25, 2016 , ... First Choice ... States, named Dr. Sesan Ogunleye, as the Medical Director of its new Mesquite-Samuell Farm ... Medical Director of our new Mesquite location,” said Dr. James M. Muzzarelli, Executive Medical ...
(Date:6/25/2016)... Canada (PRWEB) , ... June 25, 2016 , ... Conventional ... pursuit of success. In terms of the latter, setting the bar too high can ... risk more than just slow progress toward their goal. , Research from ...
(Date:6/24/2016)... ... ... Marcy was in a crisis. Her son James, eight, was out of control. Prone to ... , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If there ... my other children and say he was going to kill them. If we were ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... -- MedSource announced today that it has selected Datatrial,s ... choice.  This latest decision demonstrates MedSource,s commitment to ... by offering a state-of-the-art electronic data capture (EDC) ... the EDC platform of choice in exchange for ... long been a preferred EDC platform by our ...
(Date:6/23/2016)... , June 23, 2016  In a startling report released ... failing their residents by lacking a comprehensive, proven plan to eliminate ... a definitive ranking of how states are tackling the worst drug ... only four states – Kentucky , ... Vermont . Of the 28 failing states, three – ...
(Date:6/23/2016)... , June 23, 2016 Research and ... News Issue 52" report to their offering. ... influenza treatment creates a favourable commercial environment for MedImmune to ... patient base that will serve to drive considerable growth for ... would serve to cap sales considerably, but development is still ...
Breaking Medicine Technology: