Why there is a surge in mosquitoes in Nairobi - Expert analysis

Nairobi residents have recently raised concerns over a noticeable surge in mosquito activity across several estates, particularly in fast-growing urban areas.

Social media platforms have been flooded with speculation, with some users linking the rise to conspiracy theories involving genetically modified insects.

However, medical experts and scientific evidence point to more natural and environmental causes behind the increase.

Dr Reign, a medical professional, addressed the issue in a public post, seeking to dispel misinformation and offer scientific insight into the phenomenon.

According to him, a combination of weather patterns, urban expansion and rapid breeding cycles is largely responsible for the growing mosquito population in the city.

Temperature plays a crucial role in mosquito reproduction and survival. While some Nairobi residents have described recent weather conditions as a heat wave, Dr Reign notes that meteorological data does not fully support this claim.

Nonetheless, he explains that warm temperatures alone can significantly accelerate mosquito breeding.

Warmer environments create ideal conditions for mosquito larvae to develop faster, shortening breeding cycles and allowing populations to expand rapidly.

Mosquitoes are known to lay eggs in stagnant water, and under warm conditions, the eggs can hatch and mature into adult mosquitoes in as little as one to two weeks.

Dr Reign highlights this rapid cycle, explaining that they are larvae hatching and replicating within seven to 14 days. That’s why the population is increasing.

Beyond weather conditions, Nairobi’s rapid urban growth is also contributing to the mosquito surge.

The city has experienced an increase in construction activities, many of which leave behind stagnant water in building foundations, drainage systems and unused containers. These areas create ideal breeding grounds for mosquitoes.

Dr Reign links the problem to urban planning challenges, suggesting that some developments may unintentionally support mosquito reproduction.

He points out that a lot of these construction sites are becoming breeding sites for a lot of mosquitoes, adding that when combined with warm weather and climate shifts, the result is a significant rise in mosquito populations.

While the growing number of mosquitoes has raised fears about malaria outbreaks, Dr Reign reassures residents that the dominant species currently being observed in Nairobi is not typically associated with malaria transmission.

He explains that the mosquito population is the Culex mosquito, not the Anopheles mosquito that is known to spread malaria.

The Culex mosquito is commonly associated with nuisance bites rather than severe disease transmission.

However, it is known for its loud buzzing and irritating bites, which can cause allergic reactions in some individuals.

The increase in mosquito numbers has also fuelled online misinformation, including claims that international organisations have released genetically modified mosquitoes.

Dr Reign strongly dismisses such theories, emphasising that scientific evidence supports environmental explanations instead.

“As much as people want to blame certain things, such as the Gates Foundation for releasing lab-grown genetically modified mosquitoes, that is absolutely false. The science is telling us something else,” he says.

Although the current mosquito surge may not pose a major malaria threat, experts warn that it remains a public health concern due to allergic reactions, sleep disruption and overall discomfort.