Medecine tropicale : revue du Corps de sante colonial最新文献

A major chikungunya outbreak concerned 38% of people living in Reunion Island in 2005-2006. Chikungunya is an arthropod-born-virus disease conveyed by mosquitoes called Aedes albopictus. The health agency in Indian Ocean is responsible for vector control. Previously, in the early 40s, vector control concerned only malaria prophylaxis in La Réunion. Then, during the chikungunya outbreak, a new vector control team was installed and learned from this epidemic. The lessons drawn from chikungunya outbreak in La Réunion are about global executive management and organization linked the local partners and population. The lessons also concern technical topics such as the need of scientific research about vectors and vector-control methods. Finally, the regional cooperation in Indian Ocean (Réunion, Maurice, Seychelles, Comoros, Madagascar) has to be developed to share epidemiologic and entomologic data in order to prevent new chikungunya or dengue outbreak.

The chikungunya virus epidemic that occurred on Reunion Island from May 2005 to the end of 2006 affected 30% of the population (more than 250 000 people). As a result of its major clinical impact, this outbreak allowed better documentation of the acute phase of the disease. The disease generally has a slowly self-limiting course over a period of several months with rheumatic manifestations. For practitioners, these symptoms raise numerous questions at several levels, i.e., i) role of the virus in pain, ii) most appropriate treatment, and iii) prevention of development of chronic symptoms. This study in two patient cohorts on Reunion Island was carried out in an attempt to improve understanding and management of chronic rheumatic manifestations following chikungunya virus infection. Findings in 360 patients presenting painful manifestations following chikungunya virus infection showed that the risk of developing inflammatory polyarthritis was higher if the initial acute phase lasted longer than 3 weeks. Based on this observation, it is recommended that these patients undergo rheumatologic evaluation at 3 months to assess the need for possible immunosuppressor treatment (methotrexate).

Settlement of medical malpractice claims was radically changed by the Kouchner Law that set up a rapid, effective system of indemnification. Victims can choose between conventional court proceedings and a non-judicial conciliation procedure. Choice between the two processes depends on the circumstances of the case.

During the chikungunya outbreak of 2005 - 2006, the only laboratory facilities available in Mauritius were virus isolation in cell culture tubes and serology. The laboratory was submerged with large numbers of blood samples. Comparative isolation was made in human embryonic lung (HEL) and VERO cells grown in 96-well plate. Culture on HEL cells was found to be more sensitive and presence of cytopathic effect (CPE) was observed earlier than in VERO cells. Out of the 18 300 blood samples inoculated on HEL, 11 165 were positive. This virus isolation method was of great help for the surveillance and control of the vectors. In cases of an outbreak a cheap, rapid and simple method of isolating chikungunya virus is described.

Since mid 2005 pediatricians of the Groupe hospitalier Sud Reunion de Saint-Pierre have observed a self-imposed requirement to test for mother-to-child transmission of chikungunya. Sanitary authorities refuse to consider such testing as necessary. The risk of mother-to-child transmission was not mentioned in literature of the time.

Sterile insect technique (SIT) is a method of disease vector control technique that consists of releasing overwhelming numbers of sterile males. This method provides an environmentally friendly alternative to insecticides. Another advantage of SIT in comparison with other methods is to provide a targeted species-specific approach. In Reunion Island, SIT has been proposed as a basis for developing a viable method of vector control against Aedes albopictus and Anopheles arabiensis. The technique has already been successfully tested on fly and mosquito species for more than 40 years. The CRVOI (Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien) is carrying out studies to determine the feasibility of SIT for control of Anopheles arabiensis (vector of malaria) and Aedes albopictus (vector of chikungunya and dengue) on Reunion Island and other islands in the Indian Ocean region.

In 2005-2006 the Chikungunya caused a major sanitary crisis in Reunion for which neither the authorities, nor the healthcare professionals were prepared, as the symptoms were poorly defined, the treatment not validated and the sequels underestimated. General practioners described "in vivo" clinical and therapeutic facts and help conducted three ground studies. They were indeed the doctors of first recourse for painful and feverish patients. Have we drawn all lessons of this sanitary crisis that struck nearly the third of the population? Are we better prepared to face the acute and the chronic forms of a forthcoming epidemic? Efforts and indisputable institutional progress were made, but "Everything" still remains to be made combining all health professional efforts with a better consideration of the professionals of ground.

Chronic arthritis following chikungunya infection has no specific treatment. Studies on mice have confirmed involvement of fibroblasts and myoblasts as target cells replicating the virus and shown that macrophages play a key role in the innate immune response involving multiple cytokines and chimiokines. Paradoxically, TH1 and TH2 cytokine levels do not increase significantly during the acute and chronic phases, with the exception of interferon-gamma and IL12 that rise dramatically during the acute phase. The level of IL12 returns to normal in patients who recover. In contrast, patients who develop chronic arthritis show persistently high IL12 levels along with IFN-alpha within PBMC. Histologic examination of synovia reveals joint inflammation due to macrophages containing viral material. Metallo-protease (MMP2) also contributes to tissue damage. Chikungunya virus leads to apoptosis by both the intrinsic and extrinsic pathways.