RESUMEN
This study analyses the basic reproductive biology of the schistosonie-vector snail Bulinus forskalli. This hermaphroditic species can self-fertilize. Variation of the mating system was analysed in two populations from Cameroon in a three-step experiment. (i) The fecundity (number of eggs and of egg capsules) of isolated virgin individuals from both populations was followed over a month, as well as the survival of offspring from these individuals. Estimates of these parameters were intermediate. Our results also indicate that inbreeding depression has a maximum value of about one-half in both populations. No difference was observed between populations for both the overall fecundity of adults and survival of offspring. (ii) Individuals were then paired either within, or between populations over three successive days, and the number of copulations recorded. Copulations were observed in all situations, including between-population pairs. No significant dlifference in the number of copulations per pair was detected. However, this value decreased with time, and reciprocal copulations were significantly less numerous between than within populations. (iii) Individuals that successfully copulated as female in (ii) were isolated, and their fecundity was followed over 3 weeks. The fecundity of individuals that had been maintained isolated over the whole experiment served as a control. No significant difference was on the whole detected. Our results collectively suggest that the individuals from the two populations studied are rather selfers, confirming that B. forskalii is a preferentially selfing species. There is also some pre-zygotic isolation against crosses between populations.
Asunto(s)
Bulinus/fisiología , Trastornos del Desarrollo Sexual/veterinaria , Endogamia , Conducta Sexual Animal/fisiología , Animales , Camerún , Femenino , Fertilidad , Agua Dulce , MasculinoRESUMEN
A comparative study in vivo of amodiaquine efficacy (35 mg/kg over 3 d) and chloroquine (25 mg/kg over 3 d) was conducted in 1991 and 1992 in Cameroon and Congo in 123 patients with uncomplicated Plasmodium falciparum malaria. Amodiaquine was more effective than chloroquine, with parasite clearance by day 7 in 79.7% of the patients compared with 59.4%. Sixteen of 32 (50%) P. falciparum isolates tested in vitro were resistant to chloroquine and only 3 of 34 (9%) were resistant to amodiaquine. 5.3% of patients treated with amodiaquine complained of pruritus and 18.7% of nausea, compared with 15.7% and 5% respectively of those treated with chloroquine.
Asunto(s)
Amodiaquina/uso terapéutico , Antimaláricos/uso terapéutico , Cloroquina/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Adolescente , Adulto , Amodiaquina/efectos adversos , Animales , Antimaláricos/efectos adversos , Camerún , Niño , Preescolar , Cloroquina/efectos adversos , Congo , Resistencia a Medicamentos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Plasmodium falciparum/efectos de los fármacos , Prurito/inducido químicamenteRESUMEN
The epidemiological study of onchocerciasis performed in the area, where a certain number of dams are already build, shows that the prevalence of the disease varies in the different villages. The variations observed are probably in relation with the distance separating the villages from the temporary breeding sites of S. damnosum. The onchocerciasis is of the savannah type. The visual acuity is low and blinds are frequently seen in the villages where the prevalence of the disease is high.