A tropical mosquito researcher in Australia samples 500 mosquitoes. If 18% carry dengue, 22% carry Zika, and 8% carry both, how many carry only one of the two viruses?

Wed, 06 May 2026 11:03:16 +0000

**A tropical mosquito researcher in Australia samples 500 mosquitoes. If 18% carry dengue, 22% carry Zika, and 8% carry both, how many carry only one of the two viruses?**
Active surveillance in tropical regions continues to uncover critical insights about mosquito-borne diseases, especially as climate and travel increase global exposure to arboviruses. For researchers tracking virus transmission risks, understanding co-infection rates is essential. In Australia, where climate conditions support mosquito populations, a recent study on 500 sampled mosquitoes revealed specific infection patterns. If 18% carry dengue, 22% carry Zika, and 8% carry both viruses, many wonder how many are infected with only one. This question cuts to the heart of transmission dynamics—helpful for public health awareness and informed planning by researchers and communities alike. Using basic statistics, the contribution of those carrying only dengue or only Zika comes from careful calculation. To find those with only one virus, subtract those with both from each individual infection rate. For dengue only: 18% minus 8% equals 10%. For Zika only: 22% minus 8% yields 14%. Adding these gives 10% + 14% = 24% of the total sample carry only one virus. With 500 mosquitoes, this translates to 24% of 500—120 mosquitoes—representing approximately 120 individuals likely exposed to just one virus, not both. Why does this data matter beyond academic circles? In an era shaped by climate-driven expansion of mosquito habitats, accurate infection rates guide resource targeting and prevention strategies. For public health practitioners and informed readers, knowing the proportion of individuals with single infections provides clearer insight into localized outbreak risks and data-driven intervention planning. The methodology underpinning this figure combines standard set theory: from the 500 studied, 8% (40 mosquitoes) carry both viruses, reducing effective single infections. Simply, total single infections equal total dengue carriers plus total Zika carriers minus twice those with both (to exclude overlap), then calculating the absolute count. This approach ensures precision aligned with epidemiological convention.