Mosquito bite risk linked to blood type, CO2 and scent cues

Scientific studies have shown that mosquito attraction depends on a mixture of chemical, physical and visual signals. Research published in the Journal of Medical Entomology found that the tiger mosquito (Aedes albopictus) prefers people with blood type O over type A, though blood type alone does not determine bite risk.

Carbon dioxide exhaled by humans acts as a long‑range beacon, making individuals with higher metabolism, larger body size, pregnancy or vigorous activity more noticeable. Once mosquitoes detect CO₂, they rely on skin odors – such as lactic acid and ammonia produced by the skin microbiome – and body heat to locate a host. A meta‑analysis of over 15,000 data points confirmed that different mosquito species show distinct feeding preferences, with Culex mosquitoes being generalists, Aedes more selective for humans, and Anopheles showing the strongest preference for humans among a limited range of species. Climate change may also affect these feeding patterns.