PT - JOURNAL ARTICLE AU - Kajeguka, Debora Charles AU - Kaaya, Robert TI - PA-153 Use of antibody-based biomarker to assess the risk of human exposure to Aedes mosquito bites and infection of Dengue in North-eastern Tanzania AID - 10.1136/bmjgh-2023-EDC.106 DP - 2023 Dec 01 TA - BMJ Global Health PG - A43--A44 VI - 8 IP - Suppl 10 4099 - http://gh.bmj.com/content/8/Suppl_10/A43.3.short 4100 - http://gh.bmj.com/content/8/Suppl_10/A43.3.full SO - BMJ Global Health2023 Dec 01; 8 AB - Background Global expansion of Arboviral diseases transmitted by Aedes mosquitoes is alarming. As seen by the frequent reports of the emergence and re-emergence of dengue, zika and chikununya infection. There is a growing interest in the use of biomarkers for exposure to mosquito bite, including Aedes Nterm-34 kDa, as a proxy for Aedes-borne diseases risk. The objective of this study was to assess whether IgG antibodies against Nterm-34 kDa peptide was associated with the level of human exposure to Aedes mosquito bites and risk of dengue infection. Methods Three longitudinal surveys were conducted during rainy season (June 2021), dry season (September 2021) and short rainy (January 2022) in three villages in Bondo, Tanga. The study included children aged between 2–10 years and adolescents/adults aged 11–70 years. Face-to-face interviews were conducted. A pre-tested questionnaire was used to collect information regarding demographic characteristics and mosquito bite prevention measures. The developed questionnaire was uploaded in the system and data was collected electronically using Open Data Kit (ODK) application. Collected blood samples were tested for the presence of IgG antibodies against Aedes Nterm-34kDa using ELISA test. Results Results showed that the medians of specific IgG antibodies levels were significantly different in three seasons (p=0.009; Kruskal-Wallis test). Dengue positive participants presented a higher level of anti-salivary IgG compared with dengue negatives (p=0.02; non-parametric Mann-Whitney test). Conclusion Anti-Nterm-34kDa IgG antibodies is important correlate of human exposure to mosquito bite, thus the antibodies are important indicator to measure the risk of dengue infection. Funding: This study is part of the EDCTP2 program supported by the European Union (grant number TMA2019PF-2694-SABOT).