Seasonal Transmitting Potential of Malaria Vectors in Six Communities in Ekiti State, Nigeria

Abstract

Malaria vectors are found virtually in all communities of Nigeria. Understanding the transmitting potential of these vectors in relationship with the malaria parasite (MP) infection is essential to design a sustainable community base control programme. This study aimed at determining this relationship in six communities in Ekiti State, Nigeria. The communities were randomly selected through a multistage sampling. Blood samples were screened for MPinfection among human volunteers during dry and rainy seasons in each community. Adult mosquitoes were collected indoors for twelve months in the communities using light traps. Female Anopheles mosquitoes collected were characterized by Polymerase Chain Reactions and circumsporozoite proteins of the infected mosquitoes were detected by Enzyme-Linked Immunosorbent Assay. Prevalence of MP infection, human biting rates (HBR), sporozoite rates and entomological inoculation rates (EIRs) were determined using appropriate formulae. Overall prevalence of MPinfection was 26% in dry season and 38% in rainy season (P=0.001). Female Anopheles mosquitoes collected were 428. Strong relationship existed between HBR and MP infection in rainy season (R2 = 0.671) but the relationship was weak (R2 = 0.209) in dry season. Sporozoites were detected in 2.3% of the female Anopheles mosquitoes collected. EIRs were between 0.100 - 0.252 infective bites/person/night. Transmission of malaria parasites occurred throughout the year particularly during rainy season when there were recorded EIRs. Malaria control interventions will be more appropriate during raining season in this region.
 Keywords: Anophelesmosquitoes, Nigeria, transmission, malaria, season

Attitudinal exposure to mosquito bites in two rural suburb communities of Ado-Ekiti, Nigeria

“…Even though, majority of the people in the study area claimed to be sleeping under bed nets, this might not be absolutely true. This is because majority of people who claimed to be sleeping under bed nets in the past studies were observed to be highly infected with malaria parasite infection [23,24] and further investigations revealed that they only owned bed nets but were not regular users [23]. As regard the number of houses that were without window screened nets in the study area which were few could be connected with the socioeconomic status of the people in the area being rural communities.…”

“…One of the factors that contribute to the spread of these diseases is the entomological inoculation rates (EIRs) of mosquitoes. EIR depends on the rate at which infected mosquitoes bite in a specific area [8,9]. Another factor that contributes to the spread of MBDs is the attitude and practice of people that could predispose them to infectious mosquito bites [10].…”

Malaria cases and its trend among the outpatients who attended some hospitals and health centres in four towns in Ekiti State, Nigeria

“…However, a particular species P. knowlesi which infects monkeys has been reported in the recent times to infect humans [5]. Plasmodium is transmitted by female Anopheles mosquitoes [6,7] which are readily available in most habitats of Ekiti State in Nigeria [8,9]. Among the species of Anopheles mosquitoes found in Ekiti State include An.…”

“…funestus and one notorious species, An. gambiae gambiae [9] that have been incriminated to be very effective in transmitting malaria parasites to humans [10]. However, the attitude and practice of most community people in Ekiti State enhance malaria transmission [11].…”

“…gambiae gambiae [9] that have been incriminated to be very effective in transmitting malaria parasites to humans [10]. However, the attitude and practice of most community people in Ekiti State enhance malaria transmission [11]. This has been one of the major reasons why most community people in Ekiti State are infected with malaria parasites thereby necessitating their visiting to the hospitals and health centres.…”