Field trials of low dose Bayluscide on snail hosts of schistosome and selected non-target organisms in sahelian Cameroon

More than 85 percent of all cases of schistosomiasis in Cameroon occur in the northern sahelian half of the country representing 20 percent of the population. Several workers have advocated the integrated approach to schistosomiasis control, including snail control, but the death and decay of aquatic organisms, and fish kill that often follows Bayluscide application at the dose of 1g/m³ decrease its acceptability. The present study was designed to assess the effect of lower Bayluscide doses on snail host and non-target fish, frog, the tadpole kill. Bayluscide was applied to study ponds at concentrations of 0, 0.25, 0.5, and 1 g/m³ (ppm). Pre and post application assessment of snails hosts of schistosomes, fish, frog, and tadpole kill were carried out. All 0.25, 0.5, and 1 g/m³ Bayluscide concentrations reduced snail population significantly. Bayluscide concentration of 0.50 g/m³ applied in two rounds of 0.25 g/m³ resulted in high snail mortality and low lethality to fish, frogs, and tadpoles. Further studies are needed to assess the cost-effectiveness of Bayluscide in the control of schistosomiasis following the simplified approach.

Hematuria and Dysuria in the Self-Diagnosis of Urinary Schistosomiasis among School-Children in Northern Cameroon

The present study was designed to assess the value of self reported hematuria and dysuria in the diagnosis of urinary schistosomiasis at the individual level. A sample of 964 school children of grade 5 and 6 from 15 schools of the French speaking educational system in the Sudano-sahelian zone of northern Cameroon were submitted to a questionnaire related to hematuria and dysuria; and provided a urine sample each. The urine samples were processed using the dip stick and sedimentation methods; and the degree of microhematuria and oviuria determined. In all 964 questionnaires were collected; 843 urine samples examined for microhematuria and 871 for oviuria. The percentage of children reporting hematuria increased with the degree of microhematuria and the intensity of infection. Among the various indicators of urinary schistosome infection; microhematuria had the highest sensitivity (76); followed by self reported hematuria or dysuria (65); and dysuria (52). The specificity was highest for self reported hematuria; and lowest for self reported hematuria or dysuria. The efficiency of self reported hematuria or dysuria increased with the intensity of infection and was highest (100) for heavy infections ( 400 eggs/ml g urine). We advocate the use of self reported hematuria or dysuria for the assessment of S. haematobium at the individual level

Incidence ecologique du futur barrage de Memv'ele (Cameroun) sur les vecteurs des maladies transmissibles

Les amenagements en eau presentent un atout pour la croissance economique. Cependant ils peuvent etre a l'origine de divers problemes sanitaires si leur gestion n'est pas rationalisee. L'objectif de la presente etude etait d'evaluer l'etat actuel de la distribution des vecteurs et hotes intermediaires des maladies transmissibles dans le site du futur barrage hydroelectrique de Memve'ele. Il resulte des prospections entomologiques que les principaux vecteurs sont Anopheles gambiae et A. nili pour le paludisme; Simulium damnosum pour l'onchocercose; Glossina palpalis pour la trypanosomiase; Chrysops dimidiata et C. silacea pour la loase. Sur le plan malacologique; aucun hote intermediaire de schistosomiase n'a ete recolte. Le risque d'introduction de l'onchocercose; de la trypanosomiase et autres maladies vectorielles dans la region est discute en fonction des donnees ecologiques qui suivront la construction et la mise en eau du barrage. Des mesures visant a reduire les impacts negatifs sur la sante des populations sont preconisees

Impact des effluents d'un complexe agro-industriel sucrier sur la distribution des mollusques dulcaquicoles a Mbandjock (Cameroun)

Des prospections malacologiques ont ete entreprises dans la zone sucriere de Mbandjock (Cameroun). La discussion des mollusques est discutee suivant les types d'habitat. L'incidence des effluents du complexe agro-industriel (SOSUCAM) sur la faune malacogique est evaluee. En general; un faible degre de pollution est favorable a la faune malacologique alors qu'une forte pollution lui est nuisible. La presence de bulinus globosus est mise en evidence. Ce mollusque; hote intermediaire de schistosoma haematobium; etait absent lors des prospections anterieures. L'extension de bulinus globosus dans la localite devrait faire l'objet d'une surveillance a long terme

Determinants de la transmission de la bilharziose en zones amenagees dans les monts Mandara (Cameroun) : facteurs botaniques et malacologiques

Une etude de la transmission de la bilharziose a ete entreprise dans l'Extreme Nord du Cameroun. Les barrages de Ouro tada; de Douvar-Oudahay et de Ouazan ont ete etudies. Les facteurs malacologiques et botaniques ont ete evalues. Une polarisation des activites en fonction de la pente des berges de la retenue a ete observee. Les zones de faible pente sont les plus utilisees et correspondent aux sites privilegies par les plantes supportant les colonies de mollusques hotes intermediaires de schistosomiase. D'autres aspects de l'interaction homme-plantes aquatiques sont discutes