Background: Schistosomiasis and Malaria are among the most prevalent afflictions of humans who live in areas of poverty in the developing world. The present study was aimed at determining the socio demographic characteristics and prevalence of schistosomiasis and malaria in children living in Suburb of Malentouen Health District and analyzing the effect of co-infection on haemoglobin level, mean corpuscular volume and platelet count. Methods: Questionnaires were distributed to parents or guardians of children attending public primary school in the area. A total of 429 pupils aged 6-15 years old were screened for urinary schistosomiasis and 228 out of the 429 were tested for. Prevalences of the two parasites were calculated; Haemoglobin level, Mean Corpuscular Volume and platelets count of the 228 participants were recorded. Results: The prevalence of malaria was 26.75%, where as that of schistosomiasis was 43.82%. 31(13.60%) of the participants were co-infected with the two parasites. Mean haemoglobin level obtained was 11.01± 1.19 G/dL, that of MCV was 84.50±5.31/fl and the mean platelet count was 255.13±96.99/µl. In malaria single infected and co-infected participants, low haemoglobin level (c2 = 50.315, p = .000), low MCV (c2 = 27.448, p = .000) and low platelets count (c2 = 37.253, p = .000) were observed with significant variations. Conclusions: The three haematological parameters analysed in this study (Hb, MCV, Platelets count), showed low level or amount in malaria and malaria-schistosomiasis infected participants. Moreover, thrombocytopenia in children in this endemic area may be useful as supportive diagnostic criteria for malaria in case with low level of parasite number.

Background: Botanicals are generally assumed to be more biodegradable, leading to less environmental problems. Combination of botanicals could enhance biological activity against insect pests. Hence, the amount of botanical used for the control of stored grain pests may be minimised. In this study, the bioassay was carried out on Sitophilus zeamais to assess the effectiveness of binary combinations of Hymenocardia acida wood ash and Plectranthus glandulosus leaf powder. The quantities of mixed products were added to maize grains to constitute the contents of 5, 10, 20 and 40 g/kg. Then, the bioassays on toxicity within 1, 3, 7 and 14 days exposure, progeny production, population increase, grain damage and germination ability of protected grains were carried out. Results:The major compounds (pinene, α-pinene, α-terpineol, thymol, β-myrcene and 3-carene) of P. glandulosus leaf powder were monoterpenes. The major non-monoterpenic constituent was an oxygenated sesquiterpene, β caryophyllene oxide. The chemical analysis of H. acida ash showed that calcium (5800 mg/kg) and phosphorus (2782 mg/kg) recorded higher content than the other minerals. Plectranthus glandulosus leaf powder, H. acida wood ash and their binary combinations significantly induced mortality of S. zeamais adult (P < 0.0001). The higher mortality rate was achieved by the highest content within 14 days of exposure. The combinations of P. glandulosus leaf powder with H. acida at different proportions produced different interactions. The mixture of 75% P. glandulosus and 25% H. acida produced synergistic effect, whereas the mixture of 50:50 had antagonistic effect in weevil mortality. The three combinations of H. acida and P. glandulosus significantly reduced the production of the progeny compared to the control. From the application of 5 g/kg (lowest content), the number of emerging adults was highly reduced. The combination 25PG75HA revealed to be more effective than the two other against F 1 production. The grain damage and population growth were significantly reduced. In general, the non-infested maize grain had a good germination rate than the infested ones. The treatment did not have negative effect on seed germination. Conclusions:From our results, the two powders and their binary combinations could be used to reduce grain infestation by insect while taking into account the proportions of insecticidal powders implied in the combination.

Laboratory tests were conducted in order to assess the potential insecticidal effect of hexane, acetone and methanol fractionated extracts from Hemizygia welwitschii leaves against Sitophilus zeamais Motschulsky, important stored maize pest. The three extracts used individually were applied at four different concentrations (2, 4, 6 and 10 g/kg of maize) against the weevil. The efficacy of the treatment was evaluated by recording adult mortality after 1, 3, 7 and 14 days of infestation, and the F1 progeny emergence. Population increase, grain damage, and seeds germination were also assessed after three months of storage. The results showed that, among the three fractionated extracts, hexane extract was the most effective with 100% mortality recorded within 14 days after infestation at the concentration of 10 g/kg of maize, followed by acetone extract with 83.75% and methanol extract with 79.21% of mortality. The LC50 values decrease with the increase of exposure periods. The 14-day LC50 values were 0.78 g/kg, 1.58 g/kg and 3.10 g/kg respectively for hexane, acetone and methanol extract. The three extracts achieved significant inhibition of F1 progeny at all the concentrations. Among them, the hexane and methanol extracts induced complete inhibition of F1 progeny emergence at 10 g/kg of maize, acetone extract recorded 82.33% of inhibition. Significant reductions of insect population growth and percentage of seed damage were recorded after three months of storage on the maize treated with each extract at all the concentrations compared to negative control. Furthermore, no alive insects was recorded in maize seeds treated with the three extracts at the concentration of 10 g/kg. It is noticed that, percentage of gain damage were similar (0.15%) in maize treated with hexane and methanol extracts at 10 g/kg, while acetone extract recorded 0.76% of grain damage. In general, these extracts had no negative effect on the germination capacity of maize grains at the end of storage. Overall, the results obtained indicate that the use of these fractionated extracts could serve as an alternative to synthetic insecticides.

Malaria interventions-vector control using long-lasting insecticidal nets (LLINs) or indoor residual spraying, chemoprevention and case management including diagnosis and treatment of infections-are highly effective and affordable. These interventions have led to a significant reduction in malaria prevalence, and a marked decline in morbidity and mortality associated. Despite these increasing control efforts, this parasitic disease is still persisting in most African countries. The aim of this study was to investigate the risk factors associated with malaria infection in the Obang Valley (North Western Cameroon) in order to identify potential bottlenecks in the malaria elimination procedure. A structured questionnaire was administered to a random sample of 100 individuals visiting the Mbakong Health Centre or attending the Obang Government High School. Association between malaria infection and individual household or environmental risk factors was investigated using logistic regression models. Malaria infection was not significantly associated with LLIN possession (p = 0.999) since 97% of interviewees received them free of charge. The age and habits (having each bed cover by a LLIN, time when doors and windows are closed or antimalarial medicine used) of study participants were however significantly associated with malaria infection (p < 0.033). These findings suggest that although the interventions recommended by the World Health Organization may help in reducing malaria prevalence and burden, it is of prime importance to also tackle associated risk factors which are mostly related to individual habits.

The control of soil-transmitted helminthiasis (STH) in Cameroon is focused on large-scale deworming through annual mass drug administration (MDA) of albendazole or mebendazole to at-risk groups, principally pre-school and school-age children. After a decade of intervention, prevalence and intensity of infection have been significantly lowered, encouraging the paradigm shift from control to elimination. However, STH eggs are extremely resistant to environmental stressors and may survive for years in soils. It therefore appeared important to assess whether the risk of transmission was still prevailing, especially in a context where transmission of soil-transmitted helminths in the human population had almost been interrupted. A retrospective and a prospective cross-sectional surveys were conducted in five Health Areas of the Mifi Health District (West Region, Cameroon) to: (i) assess the trends in infestation rates over three-years (2018–2020) using health facility registers, and (ii) investigate, in 2020, the contamination rates of the environment by dissemination stages of soil-transmitted helminths using the sucrose centrifugal flotation method. The overall soil-transmitted helminth infestation rate was 4.9% (95% CI: 4.3–5.6), significantly lower than the overall soil contamination rate (12.0%; 95% CI: 8.2–17.2). These results are supportive of the low endemicity level of STHs in the Mifi Health District, but environmental pollution by dissemination stages of the parasites outlines that the risk of transmission is still persistent. It therefore appears compulsory to account for the environment when considering policy/recommendations for transmission interruption and stopping MDA, as it is in the case with vector-borne diseases.