Background Effective malaria control relies on evidence-based interventions. Anopheline behaviour and Plasmodium infections were investigated in North Cameroon, following long-lasting insecticidal net (LLIN) distribution in 2010. Methods During four consecutive years from 2011 to 2014, adult mosquitoes were collected indoors, outdoors and in exit traps across 38 locations in the Garoua, Pitoa and Mayo-Oulo health districts. Anophelines were morphologically and molecularly identified, then analysed for blood meal origins and Plasmodium falciparum circumsporozoite protein ( Pf -CSP). Blood from children under 5 years-old using LLINs was examined for Plasmodium infections. Results Overall, 9376 anophelines belonging to 14 species/sibling species were recorded. Anopheles gambiae ( s.l. ) [ An. arabiensis (73.3%), An. coluzzii (17.6%) and An. gambiae ( s.s. ) (9.1%)] was predominant (72%), followed by An. funestus ( s.l. ) (20.5%) and An. rufipes (6.5%). The recorded blood meals were mainly from humans (28%), cattle (15.6%) and sheep (11.6%) or mixed (45%). Pf -CSP rates were higher indoors (3.2–5.4%) versus outdoors (0.8–2.0%), and increased yearly ( χ 2 < 18, df = 10, P < 0.03). Malaria prevalence in children under 5 years-old, in households using LLINs was 30% (924/3088). Conclusions The present study revealed the variability of malaria vector resting and feeding behaviour, and the persistence of Plasmodium infections regardless the use of LLINs. Supplementary interventions to LLINs are therefore needed to sustain malaria prevention in North Cameroon.

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BackgroundThe effectiveness of Long-Lasting Insecticidal Nets and Indoor Residual Spraying in malaria vector control is threatened by vector resistance to insecticides. Knowledge of mosquito habitats and patterns of insecticide resistance would facilitate the development of appropriate vector control strategies. Therefore, we investigated An. coluzzii larval habitats and resistance to insecticides in the Manoka rural island area compared with the Youpwe suburban inland area, in Douala VI and II districts respectively.MethodsAnopheline larvae and pupae were collected from open water bodies in December 2013 and April 2014 and reared until adult emergence. Two to four day old emerging females were morphologically identified as belonging to the An. gambiae complex and used for WHO susceptibility tests with 4 % DDT, 0.75 % permethrin, and 0.05 % deltamethrin, with or without piperonyl butoxide (PBO) synergist. Control and surviving specimens were identified down to the species using a PCR-RFLP method. Survivors were genotyped for kdr L1014 mutations using Hot Oligonucleotide Ligation Assay.ResultsIn both study sites, ponds, residual puddles, boats, and drains were identified as the major An. gambiae s.l. larval habitats. A total of 1397 females, including 784 specimens from Manoka and 613 from Youpwe, were used for resistance testing. The two mosquito populations displayed resistance to DDT, permethrin and deltamethrin, with variable mortality rates from 1 % to 90 %. The knock-down times were also significantly increased (at least 2.8 fold). Pre-exposure of mosquitoes to PBO did not impact on their mortality to DDT, conversely the mortality rates to permethrin and deltamethrin were significantly increased (7.56 ≤ X2 ≤ 48.63, df = 1, p < 0.01), suggesting involvement of P450 oxidases in pyrethroid resistance. A subsample of 400 An. gambiae s.l. specimens including 280 control and 120 survivors from bioassays were all found to be An. coluzzii species. Only the kdr 1014 F mutation was found in survivors, with 88.5 % (N = 76) and 75 % (N = 44) frequencies in Youpwe and Manoka respectively.ConclusionThis is the first report of An. coluzzii resistance to insecticides in an insular area in Cameroon. Since permanent larval habitats have been identified, larval source management strategies may be trialed in this area as complementary vector control interventions.

Malaria vectors control is essentially based on the use of insecticides against adult mosquitoes. However because of the development of resistance to insecticides, there is now a renewed interest in the management of larval sources. The aim of the present study was to map and characterize the breeding sites of Anopheles coluzzii in the Wouri river estuary in Cameroon. Larval surveys were carried out between December 2013 and August 2014 in rural areas on the island of Manoka and urban area in Youpwe at Douala. Culicidae breeding sites identified were georeferenced and mapped. Their larval productivity was evaluated by the method of "dipping" and their physicochemical parameters measured by spectrophotometry and oximetry. Culicidae collected larvae were reared in the insectarium to the adult stage. Adult mosquitoes were subjected to morphological identification and those belonging to the Anopheles gambiae complex have subsequently been subjected to molecular identification by the PCR-RFLP technique. A total of 240 breeding sites were geo-referenced in the two sites, including 10 types. Abandoned containers and pools were the most frequent breeding sites respectively in Manoka and in Youpwe. After morphological and molecular identification, eleven mosquito species have been identified. Anopheles coluzzii and Culex quinquefasciatus were the most frequent species respectively in Manoka and in Youpwe. Mosquito density was higher in managed gutters and canoes respectively in Manoka and in Youpwe. Culex and Aedes genus were more frequent in the hollow palm and water wells respectively in Manoka and Youpwe. The productivity of breeding sites varied according to the physicochemical parameters. Species richness varied according to the type of breeding site. Anopheles coluzzii was observed for the first time in Cameroon in water storage containers, tires, discarded containers and canoes. This study highlighted diversity in the type of breeding site of An. coluzzii in the Wouri estuary, suggesting the adaptation of this species in its environment. These results could be used to develop an antilarval control strategy in Manoka and in Youpwe.

Objectif : La mise en œuvre d’une stratégie de lutte efficiente et réussie requiert une évaluation récurrente des rapports qu’entretiennent les populations locales avec la maladie. L’objectif de cette étude était d’évaluer les connaissances, les attitudes et les pratiques (CAP) sur le traitement et la prévention du paludisme. Méthodologie et résultats : L’étude a été réalisée du 7 au 14 février 2019 auprès de 509 chefs de ménage des localités de Bafang et Bakassa dans la région de l’ouest-Cameroun à l’aide d’un questionnaire standard administré aux enquêtés. Les enquêtés associaient la transmission du paludisme à des piqûres de moustiques dans 76,5% de cas à Bafang (n= 305) contre 67% à Bakassa (n=59). En cas de crise du paludisme, 36,3% des enquêtés de la ville de Bafang (n = 151) et 48,4% des enquêtés de la localité de Bakassa (n = 45) se rendaient à l’hôpital. La tranche de la population restante pratiquait soit la médecine traditionnelle, soit l’automédication, s’approvisionnant en médicaments de pharmacie ou de rue. Pour le traitement et la prévention contre le paludisme, chaque foyer dépensait mensuellement en moyenne 8640 FCFA (13,17 €) à Bafang et 7300 FCFA (11,13€) à Bakassa. Les taux d’utilisation des moustiquaires imprégnées d’insecticides (MII) par les enquêtés de Bafang et Bakassa étaient de 68,7% et 65,6% respectivement. Toutefois, d’autres moyens de prévention étaient pratiqués dans les 2 localités : l’assainissement de l’environnement, l’usage des sprays et les couvertures/rideaux. Conclusion et application des résultats : Les populations des localités d’étude ont un niveau acceptable de la connaissance du paludisme, des pratiques de lutte et de prise en charge des cas. Cependant le taux d’utilisation des MII reste en deçà de celui préconisé par l’OMS. Les programmes de sensibilisation des populations devraient améliorer cette situation. Mots clés : Paludisme, Connaissance, Attitude, Pratique, Bafang, Bakassa, Ouest-Cameroun Enama et al., J. Appl. Biosci. 2020 Le paludisme : connaissances, attitudes et pratiques des chefs de ménage de la region de l’ouest-Cameroun 15118 Malaria: Knowledge, Attitudes and Practices of Household Heads in the Western-Cameroon Region. ABSTRACT Objective: The implementation of an efficient and successful control strategy requires a recurrent evaluation of the relationship between local populations and the disease. The objective of this study was to assess knowledge, attitudes and practices (KAP) on the treatment and prevention of malaria. Methodology and results: The study was carried out from 7 to 14 February 2019 among 509 heads of household in the localities of Bafang and Bakassa in the western region of Cameroon using a standard survey. The respondents associated the transmission of malaria with mosquito bites in 76.5% of cases in Bafang (n = 305) against 67% in Bakassa (n = 59). In case of a malaria crisis, 36.3% of the respondents in the city of Bafang (n = 151) and 48.4% of the respondents in the locality of Bakassa (n = 45) went to the hospital. The remaining part of the population practiced either traditional medicine or self-medication, purchasing drugs from pharmacy or street. For treatment and prevention against malaria, each household spent an average of 8640 FCFA (13.17 €) in Bafang and 7300 FCFA (11.13 €) in Bakassa. The rates of use of insecticide-treated nets (ITNs) by respondents in Bafang and Bakassa were 68.7% and 65.6% respectively. However, other means of prevention were practiced in the two localities: environmental sanitation, the use of sprays and blankets/curtains. Conclusion and Application of Results: Populations in study areas have an acceptable level of knowledge of malaria, control practices, and case management. However, the ITN utilization rate remains below that recommended by WHO. Outreach programs should improve this situation. Keywords: Malaria, Knowledge, Attitude, Practice, Bafang, Bakassa, West Cameroon