Advancing mosquito blood-feeding rate quantification using micro-CT imaging: an innovative tool for vector-borne disease transmission studies

Mosquito-borne diseases impose significant burdens on global public health, with anthropogenic changes in landscape, socio-economy, and climate further accelerating transmission. However, our ability to quantify the effects of these socio-environmental changes on disease transmission remains limited, impairing our predictions of disease spread and the development of effective intervention strategies. Current field studies primarily rely on vector abundance to assess transmission risk, overlooking the critical role of human-mosquito contact. Mosquito biting rates, a key determinant of pathogen transmission, are difficult to measure accurately in natural settings due to the lack of reliable methods. Thus, despite its importance, field-derived data on mosquito biting rates are scarce, hampering our understanding of how socio- environmental factors influence disease transmission. This study seeks to fill this gap by developing a novel methodology using X-ray micro-computed tomography (micro-CT) to assess key tissue characteristics for quantifying mosquito blood- feeding rates. Building upon a labor-intensive traditional histologic technique, our proof-of-concept study supported that micro-CT imaging offers a non-destructive, high-resolution alternative capable of visualizing bloodmeal separation and ovarian development in Aedes aegypti, a primary vector of many mosquito-borne diseases. By applying this innovative technology, we aim to provide an efficient and scalable approach to quantifying mosquito biting rates more accurately. In Specific Aim 1, we will optimize protocols for sample preparation, micro-CT scanning, and post-imaging processes to balance image clarity and throughput, ensuring cost-effective application. In Specific Aim 2, we will develop image standards and diagnostic keys to assess relevant mosquito midgut and ovarian tissue characteristics important for determining blood-feeding rate, and validate their reliability through blinded validation studies. The adoption of micro-CT imaging technology represents a significant advancement in vector-borne disease research. While micro-CT is well- established for imaging insect morphology, its application to quantify mosquito blood-feeding rates is novel. This project provides a much-needed improvement over traditional histology, simplifying sample preparation and enhancing imaging precision, and will revolutionize how mosquito blood-feeding rates are measured across diverse environments. The 3D imaging technology will also offer deeper insights into mosquito anatomy and physiology, including in blood-engorged midguts—the critical juncture where pathogen infection occurs. The expected outputs include shared protocols, image data, and diagnostic resources that will enable more accurate estimation of mosquito biting rates in the field. By bridging the gap between field data and predictive models, we will enable more precise assessments of disease risk, particularly in the face of rapid socio-environmental change. The results of this research will have far-reaching implications, enhancing global disease prevention efforts and empowering researchers with the tools needed to combat mosquito-borne diseases more effectively. Project Number: 1R03AI193462-01 | Fiscal Year: 2025 | NIH Institute/Center: National Institute of Allergy and Infectious Diseases (NIAID) | Principal Investigator: Panpim Thongsripong | Institution: UNIVERSITY OF FLORIDA, GAINESVILLE, FL | Award Amount: $135,107 | Activity Code: R03 | Study Section: Transmission of Vector-Borne and Zoonotic Diseases Study Section [TVZ] View on NIH RePORTER: https://reporter.nih.gov/project-details/1R03AI19346201