Community Knowledge, Attitude and Practices on Malaria Vector Control Strategies in Lagos State, South-West Nigeria

Pyrethroid Susceptibility in Culex quinquefasciatus Say. (Diptera: Culicidae) Populations from Delta State, Niger-Delta Region, Nigeria

The development of insecticide resistance in different species of mosquitoes to Pyrethroids is a major challenge for vector-borne diseases transmitted by mosquitoes. Failure of Pyrethroids in control of mosquitoes would impact negatively on the gains recorded in control of mosquito-borne diseases in previous years. In anticipation of a country-wide deployment of Pyrethroid-treated nets for control of mosquito-borne diseases in Nigeria, this study assessed susceptibility of Culex quinquefasciatus Say. (Diptera: Culicidae) to Pyrethroids in Owhelogbo, Ejeme and Oria-Abraka communities in Delta State, Niger-Delta, Nigeria. Three to five day old Cx. quinquefasciatus were exposed to Deltamethrin (0.05%), Permethrin (0.75%), and Alphacypermethrin (0.05%) using World Health Organization bioassay method. Polymerase chain reaction (PCR) was employed in characterization of species and knockdown mutation. Results revealed that Cx. quinquefasciatus were generally susceptible (98-100%) to Deltamethrin, Permethrin, and Alphacypermethrin in the three communities with the exception of Owhelogbo where resistance to Deltamethrin (97%) was suspected. Knockdown time to Deltamethrin (11.51, 11.23, and 12.68 min), Permethrin (28.75, 13.26, and 14.49 min), and Alphacypermethrin (15.07, 12.50, and 13.03 min) were considerably low for Owhelogbo, Ejeme, and Oria-Abraka Cx. quinquefasciatus populations, respectively. Species identification result showed that all amplified samples were Cx. quinquefasciatus; however, no kdr allele was found in the three populations. Deployment of pyrethroid-treated nets for control of mosquito-borne diseases in Niger-Delta region of Nigeria is capable of reducing burden of diseases transmitted by Cx. quinquefasciatus as well as addressing nuisance value of the vector; however, caution must be entertained so as not to increase selection pressure thereby aiding resistance development.

Multiple insecticide resistance mechanisms in urban population of Anopheles coluzzii (Diptera: culicidae) from Lagos, South-West Nigeria

Malaria is a major public health challenge in Africa with Nigeria accounting for the highest burden of the disease in the world. Vector control has proved to be a highly effective component of malaria control, however, the development and spread of insecticide resistance in major vectors of malaria have been a major challenge. This study assessed resistance mechanisms in Anopheles coluzzii populations from Kosofe, Lagos mainland and Ojo Local Government Areas in Lagos, Nigeria where An. gambiae s.l is resistant to DDT and Permethrin. WHO susceptibility bioassay test was used in determining resistance status of An. coluzzii to discriminating doses of DDT and Permethrin while synergist assay was used to assess the involvement of monooxygenases in resistance development. Sub-species of An. gambiae s.l (An. gambiae and An. coluzzii) were identified using polymerase chain reaction (PCR) and Restriction Fragment Length Polymorphism (PCR-RFLP) while Allele-Specific Polymerase Chain Reaction (AS-PCR) assay was used to detect knockdown mutation (kdr-West; L1014F). Biochemical assays were used in determining the activities of metabolic enzymes. High DDT resistance was recorded in An. coluzzii populations from the three sites. Mortality rate of mosquitoes exposed confirmed Permethrin resistance in Kosofe (50%) and Lagos mainland (48%) but resistance was suspected in Ojo (96%). All specimens tested were confirmed as An. coluzzii with low kdr frequency; 11.6%, 16.4% and 6.7% in Kosofe, Lagos mainland and Ojo respectively. Pre-exposure to synergist (PBO) before exposure to Permethrin led to increased mortality in all populations. Esterase activity was insignificantly overexpressed in Kosofe (p = 0.849) and Lagos mainland (p = 0.229) populations. In contrast, GST activity was significantly lower in populations from Lagos mainland (63.650 ± 9.861; p = 0.007) and Ojo (91.765 ± 4.959; p = 0.042) than Kisumu susceptible strains (120.250 ± 13.972). Monooxygenase activity was higher in Lagos mainland (2.371 ± 0.261) and Ojo (1.361 ± 0.067) populations, albeit significantly in Lagos mainland (p = 0.007) only. Presence of target-site mutation in all populations, increased mortality with pre-exposure to PBO and elevated monooxygenase in Lagos mainland population were confirmed. Multiple resistance mechanisms in some urban populations of An. coluzzii from Lagos, Nigeria calls for appropriate resistance management strategies.

Analysis of Residents’ Preparedness Protocols during Ebola Pandemic in Urban Environment

Background: The study provided empirical analysis of the change in hygiene behavioural practices among community in Ogun and Lagos State with respect to Ebola outbreak in Nigeria. Methods: The data were extracted from a 2015 Cross-Sectional Survey on wellness, knowledge, attitude and practices towards the control and prevention of Ebola virus disease (EVD). Out of 1093 respondents selected in the main survey through simple random sampling technique within two enumeration areas (EAs), only 933 data cases were analyzable, leaving an attrition rate of 14.6%. The EAs represents the sampling points within the local government areas selected for the interviewed. Descriptive and inferential statistical techniques were both employed in the data analysis. Results: The results revealed high level of knowledge of EVD but over 70% were not aware of centre for treatment of EVD; 60.2% believed they cannot be susceptible to EVD. There were changes in certain practices that were canvassed and earlier adhered to during the outbreak. The practice of handshaking reduced, eating of hunted animals decreased only marginally by 6.9% and washing with soap increased by 4%. Conclusion: The study provides helpful insights for public health policy on possible mitigating strategies, especially in terms of behavioral risk factors that are prone to Ebola virus infections or other communicable diseases. The study emphasises that regular hand washing with soap and the use of sanitising agents including availability of treatment centres would be helpful in preventing the occurrence or re-occurrence of pandemic. The protocols identified in this study could be relevant to both medical personnel and the community for adoption especially as the unlikelihood of Ebola (or other pandemic) re-emergence have not been established.