Despite significant advancements in malaria elimination tools, extensive financial investments, and the development of two new vaccines, malaria remains a formidable threat, claiming a minimum of 608,000 lives annually.
But why does this persist?
Dr. Bernard Ogutu, the chief research officer at the Kenya Medical Research Institute (Kemri), sheds light on this issue. Despite progress that has led to a 35% reduction in malaria cases over the past two decades, the most effective means of prevention still lies in avoiding mosquito bites.
“Mosquitoes have adapted, becoming more elusive and strategic, with some species now preferring to bite during daylight hours,” notes Dr. Ogutu.
He underscores the significant role of climate change in exacerbating this global health challenge. Rising temperatures extend the malaria transmission season in many endemic regions, heightening the risk to populations. Moreover, even slight temperature increases in cooler regions can create optimal breeding conditions for mosquitoes, potentially introducing malaria to new areas lacking immunity and robust healthcare systems.
The climate crisis exacerbates the situation further, with increased flooding and heavy rainfall creating stagnant water bodies ideal for mosquito breeding. Dr. Ogutu also highlights how droughts can contribute to standing water formation by disrupting river and stream flow.
Additionally, the emergence of resistance among mosquitoes and parasites poses a grave threat to malaria prevention and treatment efforts. The World Health Organization (WHO) has identified four critical areas of concern in its 2023 strategy to combat antimalarial drug resistance in Africa. Partial resistance to artemisinin, a key component of malaria treatment, has been observed in several regions, leading to delayed parasite clearance and decreasing cure rates below WHO’s recommended threshold.
Furthermore, rising resistance to insecticides, particularly pyrethroids used in insecticide-treated nets, poses a significant challenge. Between 2010 and 2020, 78 countries reported mosquito resistance to at least one class of insecticide, with Western Africa bearing the brunt of this issue. Genetic mutations hindering malaria diagnosis, such as pfHRP2/3 deletions, further complicate efforts to detect and treat the disease effectively.
Moreover, the spread of zoonotic malaria, particularly Plasmodium knowlesi, which has a human fatality rate of one to two percent and rapid onset, adds to the disease’s complexity. Zoonotic malaria infections in humans have been increasing in many Southeast Asian countries, even in those nearing the elimination of human-only malaria transmission.
In summary, despite remarkable progress and investments, malaria’s persistence underscores the multifaceted challenges posed by climate change, drug resistance, insecticide resistance, genetic mutations, and zoonotic transmission. Addressing these interconnected issues is imperative for effective malaria control and eventual elimination.
