Recent data on the prevalence of intestinal parasites in N’Djamena, Chad Republic

This cross sectional study assessed the prevalence of intestinal protozoan and helminth infections in N’Djamena, Chad Republic, and determined the main  epidemiological transmission factors of these pathogens in order to develop efficient control strategies of intestinal parasites. Four hundred and sixty two  randomly selected persons, from eight quarters (administrative districts), of age less than one year to seventy six years old of both sexes, were examined in  N’Djamena town. Out of the 462 samples, 235 (51%) were found to harbour at least one parasite species. The prevalences of the eight (8) parasite species detected were: Entamoeba histolytica (30%), Hymenolepis nana (13%), Ascaris  lumbricoides (10%), Trichomonas hominis (6%), Giardia intestinalis (3%),  hookworm (0.5%), and Schistosoma mansoni (0.2%). These pathogens appeared mostly in single infections. The quarters with higher infection indices were those that experienced floods (Abena and Chagoua) and where people do not use latrines (Naga and Goudji). The population customs and the environmental conditions in N’Djamena still favour high faecal- oral transmission of intestinal parasites.Key words: Prevalence, Intestinal Parasites, Protozoans, Helminths, N’Djamena, Chad

Hemipyrellia fernandica (Macquart, 1855) and Hemipyrellia sp. (Print)

Abstract Carcasses of laboratory-bred red rats (Rattus rattus, Berkenhout, 1769 var Wistar) were exposed in wooden cages on the campus of the University of Yaounde I (Cameroon) to take a census and identify insects of forensic importance. Amongst the 1613 insects obtained from the emergence of maggots reared in the laboratory under ambient air temperature, the family Calliphoridae (Diptera) represents 72% (1161). The species were distributed betwee

Pesticides use in cocoa sector in Cameroon: characterization of supply source, nature of actives ingredients, fashion and reasons for their utilization

The chemical control is the widely control method applied in Cameroon for pests and diseases by all the cocoa producers without technical suitable assistance by the State as before 1980’S. However, it is known that farmers have less knowledge on the good pesticides use for the control of a specific pest. The objective of this study was to provide insight in current pesticide use in the cocoa sector in Cameroon. A stratified sampling scheme was used. A total of 251 cocoa farmers, 20 post-harvest cocoa traders and 37 chemical retailers were randomly selected and interviewed. The study showed that 35 different chemicals were marketed in Cameroon for use in cocoa: 4 herbicides, 11 fungicides and 20 insecticides. Of 251 farmers consulted, 96.8% said that they use pesticides on their farms while 3.2% did not. Fungicides were used most often by farmers 61.8%) followed by insecticides (38.2%). Eight active ingredients although, officially banned, were still being used on cocoa farms. Over 77% of farmers do not respect the official spray recommendations for chemicals. Moreover, 64% do not respect recommended doses. Two main pesticide-supply-pathways exist in Cameroon: a legal and illegal supply chain, which provides 51% of pesticides to cocoa farmers, resulting in an estimated loss of value added tax for the Cameroonian government of about 550 000 to 2.4 million Euros per year. These results suggest that improved pests and diseases control by the State and raising farmer awareness about pesticide use in cocoa could greatly attribute to more sustainable cocoa economy in Cameroon.Keywords : Cocoa, pesticides, insecticides, fungicides, Cameroon

In vitro activities of acetonic extracts from leaves of three forage legumes (Calliandra calotyrsus, Gliricidia sepium and Leucaena diversifolia) on Haemonchus contortus

AbstractObjectiveTo assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, Calliandra calotyrsus (C. calotyrsus), Gliricidia sepium (G. sepium) and Leucaena diversifolia (L. diversifolia) in vitro on Haemonchus contortus (H. contortus).MethodsEggs were exposed for 24 hours to five different concentrations (0.075, 0.15, 0.3, 0.6 and 1.25 mg/mL) of acetonic extracts at room temperature (24 °C). Distilled water and 0.4% Tween were used in the bioassay as negative controls.ResultsThe later did not affect embryonation and egg hatching of H. contortus. Conversively, significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL). The acetonic extract of G. sepium was found to be more active (2.9% and 0.0% for embryonation and egg hatching, respectively) than the other substances 16.5% and 33.5%, respectively for C. calothyrsus, 33.7% and 33.3%, respectively for L. diversifolia.ConclusionsThese results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out

In vitro comparative effect of extracts of the seeds of Embelia rowlandii (Myrsinaceae) on the eggs and L1 and L2 larval stages of the parasitic nematode Heligmosomoides bakeri (Nematoda; Heligmosomatidae)

In vitro ovicidal and larvicidal activities of extracts of the seeds of Embelia rowlandii were investigated on unembryonated and embryonated eggs, first and second stage larvae of Heligmosomoides bakeri. Three different extracts were prepared with distilled water (DW) and 95% ethanol. The organic extract was first diluted with 3% Tween and then distilled water added to obtain five different concentrations (625, 1250, 2500, 3750 and 5000 μg/ml). These concentrations were put in contact with eggs and larvae of H. bakeri. One milliliter of each extract at different concentrations and controls were added to 1 ml solution containing 30 to 40 eggs or 10 to 15 larvae (L<sub>1</sub> and L<sub>2</sub> larvae) and distributed in different Petri dishes. Both eggs and larvae were incubated at 24°C and exposure time was 48 h for fresh (unembryonated) eggs, 6 h for embryonated eggs, 24 h for L<sub>1</sub> and L<sub>2</sub> larvae, respectively. Distilled water and 3% Tween were used as negative controls in the bioassay. These placebos neither affected egg development, hatching nor larval survival. A significant effect was obtained with cold water extract (CWE), hot water extract (HWE) and ethanolic extract (EtE) and differences were observed depending on the parasitic stage. CWE, HWE and EtE inhibited embryonic development (60.5, 82.5 and 46.9%) and hatching (85.8, 74.1 and 41.0%), respectively at 5000 μg/ml. All the three extracts killed both L<sub>1</sub> larvae (84.5, 86.0 and 61.2%) and L<sub>2</sub> larvae (65.2, 83.7 and 33.3%) respectively at 5000 μg/ml. These in vitro results suggest that extracts of E. rowlandii possess ovicidal and larvicidal properties.Keywords: Embelia rowlandii, Heligmosomoides bakeri, plant extractsAfrican Journal of Biotechnology Vol. 12(2), pp. 205-21