Innovative Digital Counting Enhances Mosquito Surveillance Accuracy

In a significant advancement for public health and vector control, researchers from the Salt Lake City Mosquito Abatement District (SLCMAD) have developed a digitized optical counting method that markedly improves the accuracy and efficiency of mosquito surveillance. Their findings, published in June 2025 in the Journal of Insect Science, highlight how this new technique outperforms traditional mass and volume measurement methods, which have long been challenged by inaccuracies and labor-intensive processes.

The motivation for this research stems from the necessity of effective mosquito surveillance in mitigating the spread of vector-borne diseases such as West Nile virus, dengue, and Zika virus. As noted by John P. Roche, Ph.D., a contributing author and biologist, "Accurate mosquito counting is critical for municipalities to estimate risk and formulate control strategies effectively. Delays or errors in data processing can lead to public health threats or unnecessary expenditure on control measures."

The study involved extensive fieldwork, with researchers collecting mosquito samples from over 40 sites spanning a 285 square-kilometer area near Salt Lake City. Over a span of 26 weeks, they accumulated more than 2 million mosquitoes, of which over 500,000 were used for detailed analysis. The researchers employed three different estimation techniques: mass measurement, volume measurement, and the innovative digitized optical counting method utilizing ImageJ software.

Mass and volume methods, while traditionally used, exhibited notable limitations. For instance, mass measurements tended to overestimate mosquito counts, while volume measurements frequently underestimated them, particularly as mosquito populations fluctuated in size throughout the season. Conversely, the digitized optical counting method maintained consistent accuracy, even as conditions changed, thus proving more reliable under various sampling scenarios.

Ayla Faraji, one of the lead researchers, explained, "Our findings suggest that the decline in accuracy observed with mass and volume methods during the latter half of the sampling period may correlate with seasonal changes in mosquito size. This highlights a critical advantage of our digital method, which remains robust regardless of such variations."

The implications of this research extend beyond local applications. According to the World Health Organization (WHO), vector-borne diseases pose a substantial global health burden, with millions infected annually. The European Centre for Disease Prevention and Control reported over 1.4 million cases of dengue fever globally in early 2025, emphasizing the need for effective surveillance in regions heavily affected by such diseases.

Christopher Bibbs, Ph.D., laboratory director at SLCMAD and senior author of the study, articulated the potential of the digital counting technique, stating, "This method can significantly enhance the rapid response capabilities of mosquito control agencies, particularly during peak outbreak periods. It also opens avenues for similar applications in counting other insect populations."

The researchers concluded that the digitized optical counting technique not only offers an efficient alternative for mosquito surveillance but also holds promise for broader applications in entomological research and pest management. With the increasing threat of vector-borne diseases worldwide, such innovations could play a crucial role in public health strategies, potentially reducing the incidence of disease transmission in vulnerable populations.

Looking forward, the adoption of such technologies is anticipated to improve the efficacy of mosquito control programs globally, particularly in regions where mosquito-borne diseases are endemic. Continued research and development in this area remain essential to bolster public health efforts and combat the challenges posed by these persistent vectors.

This study underscores the importance of integrating modern technology into public health practices, paving the way for smarter, more effective mosquito surveillance and management strategies. Future work will focus on refining the digital counting method and exploring its applications across different species and ecological contexts.