Climate change and global warming have become a big issue worldwide; where one of the consequences is the spread of mosquito-borne diseases, as the activities of mosquitoes are dependent on temperature: the warmer the environment, the more active the insect.

In addition to dengue fever, malaria, which is discussed in CUSA2013 Great Discoveries in Biomedical Sciences, is another disease transmitted by mosquitoes. Malaria is an infectious disease caused by a parasite called plasmodium, resulting in the damage of red blood cells. Based on the literature available, there are over 3,000 species of mosquitoes, where around 40 are known to transmit malaria.

According to a survey, the most important species of mosquitoes causing malaria in the world are not found in Hong Kong; where a local record shows that there are only two species known to transmit malaria here in Hong Kong. They are namely Anopheles jeyporiensis and Anopheles minimus. With reference to the Centre for Health Protection, the chance for An. jeyporiensis to proliferate in the urban area is low. It is not commonly found elsewhere in the world either. For An. minimus, however, it is a species found in Asia. This species used to be common in the countryside, but it was last identified in Hong Kong dated back to 2002. Yet, studies showed that this mosquito remained active in Southeast Asian region, such as Vietnam, Thailand, and Cambodia. In Asia, for example, Anopheles farauti is another important species of mosquito responsible for the spread of malaria.

When we compare the transmission of malaria with dengue fever, although both diseases rely on mosquitoes, malaria is transmitted by An. minimus or An. farauti in Asia; whereas, dengue fever is transmitted by different species, such as Aedes albopictus, which is better adapted to the urbanized environment, such as Hong Kong.