ABSTRACT
Reliably assessing exposure to mosquitoes carrying malaria parasites continues to be a challenge due to the lack of reliable, highly sensitive diagnostics with high-throughput potential. Here, we describe an approach that meets these requirements by simultaneously measuring immune responses to both disease vector and pathogen, using an electro-chemiluminescence-based multiplex assay platform. While using the same logistical steps as a classic ELISA, this platform allows for the multiplexing of up to ten antigens in a single well. This simple, reproducible, quantitative readout reports the magnitude, incidence, and prevalence of malaria infections in residents of malaria-endemic areas. By reporting exposure to both insect vectors and pathogen, the approach also provides insights into the efficacy of drugs and/or other countermeasures deployed against insect vectors aimed at reducing or eliminating arthropod-borne diseases. The high throughput of the assay enables the quick and efficient screening of sera from individuals for exposure to Plasmodium even if they are taking drug prophylaxis. We applied this assay to samples collected from controlled malaria infection studies, as well as those collected in field studies in malaria-endemic regions in Uganda and Kenya. The assay was sensitive to vector exposure, malaria infection, and endemicity, demonstrating its potential for use in malaria serosurveillance.
ABSTRACT
Among 582 participants in Western Kenya who were retrospectively tested from January through March 2020, 19 (3.3%) had detectable SARS-CoV-2 antibodies. The prevalence of detectable SARS-CoV-2 antibodies was similar between participants with and without HIV (3.1% vs. 4%, Pâ=â0.68). One participant reported a cough in the preceding week but others denied symptoms. These may represent cross-reactivity or asymptomatic infections that predated the first reported COVID-19 cases in Kenya.