Loaisis in Edo State, Nigeria

A study to determine the prevalence of loaisis was carried out in Edo State, Nigeria for a period of one year beginning from February 1999 to January 2000. A total of thirteen thousand, two hundred samples were examined. Nine samples (0.07%) were positive for Loa loa. The parasite had limited distribution in Edo State. It was observed in only six local government areas namely Uhunmwode, Ikpoba Okha, Igueben, Etsako East, Akoko-Edo and Owan East. The pattern of infection in the various age groups showed clearly that maximum exposure occurred from the third to fifth decade of life. All the positive samples were from males. The prevalence of infection was higher during the rainy (wet) season than in the dry season. The inaccessibility of the arthropod vector to humans could be advanced for the low prevalence of the disease in the state. The socio-cultural and economic factors, which predisposed to infection, were discussed as part of control measures. © CMS UNIBEN JMBR 2006; 5(1): 12-17 INTRODUCTION Loaisis is an infection caused by the filarial worm Loa loa. The clinical manifestations as well as the pathology particularly in the production of subcutaneous swellings, pains and conjunctivitis have been very elaborately described. Loaisis is common in developing tropical countries where conditions are suitable for the breeding of the arthropod vectors Chrysops species. These flies are canopy lovers and there are lots of warm humid canopy forests in Edo State, which provide ideal breeding habitats for the Chrysops species. Here in Edo State there is need to estimate the prevalence of loaisis. The estimate of the infection is of importance in the surveillance of the disease in the state. Despite the fact that community studies in some parts of the state have been done, the actual pattern of infection among the population through epidemiological studies of the community is not known for the greater part of the state. The paucity of information currently available as regards loaisis in Edo state necessitated this study. There is need to know the pattern of transmission, distribution and prevalence. Hospital reports are the main source of information on loaisis in the state. Hospital reports are, however, on referred patients and cannot be used to determine pattern of transmission, distribution and prevalence. Again the hospital reports, which are available in the epidemiological unit, State Ministry of