Lassa fever is a severe hemorrhagic fever with devastating consequences that is transmitted via a virus from the Mastomys rat which breed around human residences, to man. An alternate hypothesis is that household characteristics—like housing quality and hygiene—are associated with the occurrence of Lassa fever.
Aims: Assessment and comparison of housing quality and hygiene in two peri-urban settlements differentiated by the annual incidence of Lassa fever. The study also assessed awareness and family history of Lassa fever in the preceding year of the study.
Methodology: This was a descriptive cross sectional study carried out in two peri-urban settlements (Eguare and Ikekogbe) in Irrua town of Edo State in 2012. Both communities are similar in terms of ethnicity and socioeconomic developments but differ in the incidence of Lassa fever: Eguare had 6-10 cases of Lassa fever per year while Ikekogbe had 0-1 case of Lassa fever per year. Eguare has an estimated population of 911 and Ikekogbe 517. The sample size was obtained using the formula for comparing two proportions. The minimum sample size for this study using this formula is 155 although a total population survey was conducted. Information was obtained by Interviewer administered questionnaire with the head of each household and in their absence; any household member above the age of 18years was interviewed. A checklist was used to elicit information on quality and hygienic state of houses and its surrounding. One questionnaire and checklist per household was administered.
Results: 7.7% of the households in Eguare reported a case of Lassa fever in the preceding year as against 1% in Ikekogbe (x 2 =5.01, df=1, p=0.03). There was no difference in the housing quality between the two settlements (X 2 =6.469, df=2, P=0.091), however there was a difference in hygienic state in the two settlements. 20.5% and 54.5% of households in Eguare had good and poor hygiene respectively while 56% and 15.4% of households in Ikekogbe has good and poor hygiene respectively(X 2 =43.796, df=2, P<0.000). This may account for the higher incidence of Lassa fever in Eguare. Houses that had brick walls and ill-fitted roofs had higher risk of reporting cases of lassa fever with odds 2.212 (CI 10.766-6.383), P=0.142 when compared to houses with brick walls and well-fitted roofs. Surrounding with foliage over growth had higher risk of reporting cases of lassa fever with odds 1.455 (CI 0.532-3.980), p=0.465 well compared to houses with clean surroundings. Houses that had household equipments, appliances, tools heaped up in the premises had higher risk of reporting cases of lassa fever with odds 4.969 (CI 1.663-14.848), P=0.004 when compared to houses that had their tools neatly arranged within the premises. The use of buildings for both residential and commercial purposes had higher risk of reporting cases of lassa fever odds 11.425 (CI 3.080-42.371), p=0.000 compared to buildings that are purely residential. Houses that had poor grade on the hygiene scores had higher risk of reporting cases of lassa fever 50.645 (13.718-186.973), p=0.000 compared to houses that had good grade on the hygiene scores.
Conclusion: Poor hygiene and use of buildings for both residential and commercial purposes are likely risk factors for transmission of Lassa virus in households. Cleaning up houses and surroundings should be seen as a way of controlling the disease.
