The Epidemiological Implications of Deer Fly Nuisance Biting and Transmission of Loiasis in an Endemic Area in Southeastern Nigeria

Abstract

This work was aimed at determining the epidemiological implications of deer fly biting in Southeastern Nigeria and ascertaining the circadian and monthly biting pattern and the transmission potential of Chrysops in the area. Human-landing catches were carried out for 52 weeks by a catching team of four. A total of 930 female Chrysops sp. was caught; biting peaked during the months of June through August. The highest monthly biting rate (MBR) was 353 bites per person per month in July 2006. The annual biting rate (ABR) was 3,317 bites per person per year. The overall infective rate was 3.8%. A total of 314 L3s was recorded with a mean of 9.8 L3s per infective Chrysops. The highest monthly transmission potential (MTP) was 389 infective bites per month observed in July 2006. The annual transmission potential (ATP) was 1,265 infective bites per person per year. Parous rate was 29.3% and was higher during dry months of October through February. The circadian biting activities showed two peaks: between 07:00 and 10:00 hours and between 15:00 and 17:00 hours. The epidemiological implications of deer fly biting in the area are multifaceted. Resources must not be spared in bringing an end to their menace.