In December 2024, Dr. Irina Diekmann, a postdoctoral researcher at Washington University School of Medicine (WashU Med) joined Professor Taniawati Supali and her team at Universitas Indonesia (UI) in Jakarta, Indonesia. Irina travelled with a portable qPCR machine. While the laboratory in Jakarta already had access to real-time PCR equipment, standardization of assays was a problem. Irina’s goal was to quickly transfer standardized assays established at WashU Med to UI and facilitate on-site testing for filarial DNA in mosquitoes.
From 2022 to 2024 Professor Supali’s team collected over 20,000 mosquitoes annually in Belitung district. Belitung island off the coast of Sumatra, was declared by the government to be free of lymphatic filariasis in 2017, after five annual rounds of mass drug administration (MDA) and various WHO-recommended surveys. Two years later routine surveillance revealed infections in adults, raising concerns about the persistence of lymphatic filariasis. In 2023, Professor Supali’s team and Dr. Diekmann collected blood samples from local animals (cats, dogs, and monkeys) and detected larvae of the lymphatic filarial parasite Brugia malayi by microscopy (The Role of Monkeys as a Reservoir for the Lymphatic Filarial Parasite Brugia malayi on Belitung Island, Indonesia).
Molecular data confirmed the presence of an animal reservoir for B. malayi. However, the main mosquito species involved in transmission between animals and humans remained unclear. At UI mosquitoes were pooled by species and DNA was extracted. The portable qPCR machine was used to analyse 150 pooled mosquito samples each day for the presence of B. malayi DNA. Initial findings indicated a high prevalence of pools positive for B. malayi DNA within mosquitoes of the genus Mansonia, that is known to include competent vectors for zoophilic B. malayi. Other mosquito species also tested positive for B. malayi, suggesting involvement in the transmission cycle
The team is currently analysing the remaining samples collected in 2023 and 2024 to observe trends and variations in DNA detection rates after newly initiated mass drug administration of the human population at infection risk. This ongoing research is critical for identifying the local vector species responsible for B. malayi transmission. The project was made possible through the support of the Gates Foundation and the Foundation for Barnes Jewish Hospital. The results will inform strategies to manage lymphatic filariasis in this region and others with zoophilic B. malayi parasites, contributing significantly to the Global Program to Eliminate Lymphatic Filariasis.