Does Variation in Malaria Vector Collection Methods Significantly Affect Entomologic Inoculation Rates?

摘要

Background: Entomologic Inoculation Rate (EIR), the product of vector biting rate and the sporozoites rate or the proportion of mosquitoes with sporozoites in the salivary glands has been strongly correlated with malaria prevalence. This study was undertaken to determine whether mosquito collection method significantly affected EIR estimates. Method: Study was conducted in 7 local Government Areas (LGAs) of Bayelsa State, across 3 eco-vegetational zones (fresh water forest, brackish water swamp forest, mangrove coastal water forest). Three methods were used for mosquito collections: Pyrethrum Spray Catch (SPC), Human Bait Catch (HBC) (Indoor), Human Bait Catch (Outdoor). EIR was calculated as per standard method. Results: EIR means obtained by PSC and HBC (Outdoor) methods were not significantly different (F=4.989; df=2; p<0.05), but significant differences were obtained between PSC and HBC (Indoor) estimates. These differences were also significantly influenced by eco-vegetational zones (F=3.92; df=2’ p<0.05). Conclusions: It is advisable to compare EIRs obtained by the same mosquito collection methods as indices of malaria prevalence.