Effects of environmental factors and storage conditions on the performance of Olyset® Plus against sand flies in WHO cone bioassays

Abstract

Background: Leishmaniasis, visceral and cutaneous, is seen in Turkey and has both public and veterinary importance. So far, four Leishmania species and their vectors have been detected in Turkey. Vector control is essential in endemic areas and several personal protection methods are available including long-lasting insecticidal nets (LLINs). In this study, we aimed to measure the effects of usage and storage conditions on LLINs in a village-scale study.

Methods: Olyset(®) Plus bed nets were set up in different climatic conditions (rain, exposed to sunlight and humidity) and collected after 6 months. The effectiveness of bed nets were tested by WHO's cone test method using wild-caught sand flies.

Results: Bed nets, which were placed directly exposed to sunlight (A1, A2) showed lower (17.2%) knock down effect compared to bed nets placed indoors (A3, B1). Twenty-four hour mortality was 100% for the five study groups (A2, A3, B1, C1, C2) whereas group A1 was found to have a lower mortality rate (44.4%).

Conclusion: Bed nets need to avoid direct exposure to sunlight. When used and stored in appropriate conditions (cool, well-ventilated place away from sunlight) they can be used as an effective vector control tool in endemic areas.

Keywords: Bed net efficacy; Environmental effects; Leishmaniasis; Olyset Plus; Sand flies; Turkey.