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Chemistry still has a role in the management of malaria, alongside the mosquito netting soaked in insecticide that is used increasingly, as we continue to await the long anticipated vaccine. During its cycle, the hematozoon parasite develops through three major periods. The first, malarial infection, corresponds to the intrahepatic development of infective forms from the mosquito vector; this period is not sensitive to treatment and is often asymptomatic. The period of erythrocytic schizogony is the most urgent, and treatment activity is primordial. Finally, the phase of sexual reproduction, when gametocytes develop within the erythrocytes ensures the perpetuation of the species when these reach the blood-feeding female anopheles mosquitoes. The aim of our work was to study the effect on gametocytes of drugs known to be effective on the asexual blood forms of the protozoan and thus the potential repercussions on malaria transmission. This experimental study was conducted with an animal model whose parasite cycle and modes of transmission are close to those of human malaria: Plasmodium yoelii, maintained on Swiss mice, with the Anopheles stephensi vector (maintained in an animal facility at the National Museum of Natural History in Paris). Two drugs were tested: ferroquine (a chloroquine derivative with a ferrocene molecule at the lateral carbon chain that restores its efficacy against chloroquine-resistant strains) and artesunate (a derivative of artemisinin, from ginghao, a Chinese plant also known as artemisia annua, or sweet wormwood), a treatment of choice in the combined therapies recommended by WHO. The efficacy of these drugs, prescribed at doses subcurative for the asexual forms, were tested against gametocyte production, quantitatively by counting them in the blood and qualitatively by counting the quantity of oocysts developed on the mosquito's midgut, which are indicators of gametocyte activity. The mice that were parasite-infected and then treated served as their own controls: lots of 30 mosquitoes fed on each mouse before treatment and then 90  minutes and 5  hours after treatment. Quantitatively, the comparison of the blood parasite level and the gametocyte index shows that treated mice had a higher level of circulating gametocytes than untreated parasite infested mice, regardless of drug or dose (5 or 10  mg/kg). For artesunate at 5  mg/kg, we noted that the blood gametocyte level was almost double that of the controls. On the other hand, qualitatively, the first results obtained with optical and electronic microscopy showed morphologic alterations of the circulating gametocytes (pigment clumping and lateralisation within red blood cells) and reduced infectivity of the gametocytes for the mosquitoes that fed at 1 and 5  hours after treatment. We were able to demonstrate statistically that the infectivity of gametocytes, measured by the quantity of oocysts counted in the mosquito midgut, was reduced by 70% for those treated with ferroquine and by 85% for those from mice treated by artesunate. Complementary studies will seek to specify the populations (age) of gametocytes damaged by treatment and the importance and nature of their morphologic alterations.

Distomatoses due to Fasciola spp. and Fasciolopsis buski are very common in the developing countries of Southeast Asia. The flukes in Laos have not yet been completely studied and described, however. In 2004, we began screening for these two distomatoses in the province of Savannakhet, in southern Laos. Our initial results showed that the causal agent of fascioliasis in humans and animals is Fasciola gigantica. The infestation rate of fascioliasis in cattle in slaughterhouses ranged from 17 to 57%, with higher percentages in buffalo (75-100%) than in cows (0-25%). In Laotian villages, the prevalence of human fascioliasis reached 2.4 % after a stool examination and 13.8 % after systematic serology testing. The prevalence of intestinal distomatosis from F. buski was 33.7%. The rate of villagers with hepatobiliary and intestinal events exceeded 2% but the involvement of these two forms of distomatosis varied highly, ranging from 1.7% (stool diagnosis) to 16.4% (serodiagnosis) for F. gigantica and 11.2% for F. buski. We have described the first cases of fascioliasis and intestinal distomatosis from F. buski in Laos.

Sowda skin lesions are of medical and social importance in Yemen. Ivermectin (Mectizan) chose as a control strategy plan in onchocerciasis is active during 3 months for the less on clinical and histological data. After a short increase of itching and oedematous skin aspects clinical signs decrease. Some patients notice an itching rebound after 90 days. Histologically, localized ingratiates, presence of mononuclear cells and melenin loaded histiocytes and eosinophils decreased. The rythm cure has to be studied on a longer period but 3 to 6 months repetition between oral treatment with 200 micrograms/kg dose during two years could be effective.

During the last 25 years, 64 cases of chromoblastomycosis were diagnosed in Gabon. They came from the entire territory, where living in rural zones men as well as women were affected. The evolution of the disease has lasted for more than 10 years for the majority of the cases. The preferential location is the lower limb for 78.5% of the patients, with a double localization for one case and an exceptional malignant transformation for another case. Two clinical aspects emerged, despite an apparent polymorphism: extensive patches and warty nodules, spread apart from or adjacent to the others. The histological images were classical and the fumagoid cells, sometimes budding and filamentous, were easily detected during examination of the squama and scabs. Fonsecaea pedrosoï was the only identified species. The 5-fluorocytosine treatment constantly led to an improvement of the lesions. The major problem for these destitute patients is economic, concerning the cost of the therapy.

A 27 month epidemiological survey of cryptosporidiosis in stools was conducted in 288 Gabonese children aged between 0 and 2 years (mean 10.2 months). By at least one of two staining techniques, acid-fast and direct immunofluorescence, the rate of infection was determined to be 24%. The rate was 28% in cases of acute diarrhea, in striking contrast with the low prevalence of 14.8% in uninjured gastroenteritus subjects (p < 0.05). The notion of asymptomatic carriers was clearly demonstrated. The maximum of 34.4% was observed for infants aged between 6 and 12 months (p < 0.02). In cases of malnutrition, this rate increased to 31.8%, whereas it was 16.8% in eutrophic children (p < 0.01). For the rainy and dry seasons, it was 31.7% and 19.4%, respectively (p < 0.02). Water is emerging as an important vehicle for the transmission and spread of Cryptosporidium sp. in tropical areas.

We report specific dyslipidemia in Gabonese children aged 18 months to 4 years old treated with Halfan for malaria. This is observed in addition to the hypoglycemia typically associated with malaria. C-HDL (high density lipoprotein) fell on day 0 (D0), then increased during the treatment. Triglycerides (TG), total cholesterol (TC) and non-esterified fatty acids (NEFA) rose on D0. CT continued to rise evenly throughout the treatment, whereas TG declined. The differences with respect to normal values are significantly different as assessed by the Student test. We report metabolic variation and tolerance to Halfan.