ENGINEERING ANALYSIS OF HUMAN-INDUCED ENVIRONMENTAL CONDITIONS AND MOSQUITO BREEDING IN AKURE, NIGERIA

Abstract

In this study, the breeding/occurrence of mosquito, a prominent vector in the transmission of malaria was examined with respect to the human-induced environmental factors that seem to promote its breeding in Akure, Nigeria. It is of interest to note that the environmental indicators considered in the research study were those which were due either to the wrong application of civil engineering principles or the ones where the application of these principles would have made a difference. Data on the human-induced factors such as stagnant water, dumpsites, swamps etc. were collected by direct observation method while data on mosquito occurrence was gathered by using Most Probable Number (MPN) method. Samples were taking randomly at the sites and the number of mosquito larvae in the sample were counted and recorded. This was used to develop the most probable number of mosquito present at each site. Administration of questionnaire was also done to check the awareness of the respondents to the presence of mosquito in their neighbourhood. The study area was divided into four (4) zones comprising five sites each. Visits were made by the researcher to the twenty sites for environmental data acquisition. Six hundred (600) questionnaires were also administered for response, One hundred and fifty (150) copies allocated to each zone. Of these, five hundred (500) were carefully chosen for analysis using modern analytical tools. Microsoft excel was used to calculate the mean and other extended parameters, SPSS was used for the graphical representations while Generalized Linear Models of the SPSS package was used to check for relationships between the environmental indicators and mosquito occurrence in the twenty sites. Result of analysis shows that some indicators contribute massively to the promulgation of mosquito in Akure. Availability of stagnant water bodies around dwellings and the availability of dumpsites are the two indicators that contributed to the multiplication of the mosquito vector in locations throughout Akure. The occurrence of these two indicators was due mostly to the nonoperational condition of a lot of the drainage systems and other systems with water-holding capacity present at most of the sites in Akure. Drainages in many of the sites were discovered to be blocked with refuse and in some other cases, irregularities in design such as inadequate bed slopes which hampers flow at peak times were also observed. Large swamps spanning massive land area were absent in most of the sites. Though the sites where swamps were found were neither drained nor filled which made them probable locations for mosquito breeding especially during the rainy season. It was recommended that the sites with drains should be linked with a suitable watershed that will discharge the drained water into a nearby river or flowing stream. It was also recommended that the drainage pathways be kept free of impediments such as solid wastes.