Annual Entomology Report for PMI VectorLink in Uganda, 2021

The project aimed to monitor the distribution and behavior of malaria vectors, including Anopheles funestus s.l. and Anopheles gambiae s.l. in six districts: Bugiri, Lira, Otuke, Serere, Tororo, and Wakiso. Longitudinal monitoring was conducted using three collection methods: Pyrethrum Spray Catch (PSC), Human Landing Catch (HLC), and Cone Wall Bioassay Tests. The results showed that Anopheles funestus s.l. was the dominant species in all districts, accounting for 70-90% of the total mosquito collections. Anopheles gambiae s.l. was also present in all districts, but at lower densities. The study found that the mean hourly biting rates (HBRs) of Anopheles funestus s.l. were significantly higher indoors than outdoors, with a mean HBR of 0.35 bites per hour in IRS districts and 0.45 bites per hour in non-IRS districts. In contrast, the mean HBRs of Anopheles gambiae s.l. were similar indoors and outdoors, with a mean HBR of 0.15 bites per hour in IRS districts and 0.20 bites per hour in non-IRS districts. The study also assessed the susceptibility of Anopheles gambiae s.l. to different insecticides using WHO tube tests. The results showed that the Kisumu strain of Anopheles gambiae s.s. was resistant to pyrethroids, with a mortality rate of 20-30% after exposure to 6 insecticides. However, the strain was susceptible to clothianidin and chlorfenapyr, with mortality rates of 90-100% after exposure to these insecticides. The study concluded that the PMI VectorLink Project's entomological surveillance efforts provided valuable insights into the distribution and behavior of malaria vectors in Uganda. The results highlighted the need for continued surveillance and monitoring to inform vector control strategies and evaluate the effectiveness of interventions. The study also identified several challenges and lessons learned during the project. One of the main challenges was the difficulty in collecting mosquitoes using HLCs, particularly in areas with high mosquito densities. The study also highlighted the importance of maintaining high-quality IRS and ensuring that insecticide-treated bed nets are properly used. The study recommended that future entomological surveillance efforts should focus on improving the collection and analysis of mosquito data, as well as enhancing the capacity of local health workers to conduct entomological surveillance. The study also emphasized the need for continued collaboration between national and international partners to develop effective vector control strategies and evaluate their impact on malaria transmission. The study's findings and recommendations have important implications for malaria control efforts in Uganda and other countries in the region. By understanding the distribution and behavior of malaria vectors, policymakers and program managers can develop targeted interventions to reduce malaria transmission and improve public health outcomes.