Possible Potential for Zoonotic Malaria Transmission in Areas Inhabited by Non-Human Primates

 

https://www.frontiersin.org/articles/10.3389/fphys.2012.00197/full

Malaria, a life-threatening disease caused by Plasmodium parasites, continues to pose a significant global health challenge, with an estimated 228 million cases and 405,000 deaths reported in 2018 alone (World Health Organization, 2019). While the majority of human malaria cases are transmitted through the bites of infected Anopheles mosquitoes, emerging evidence suggests that non-human primates (NHPs) could play a crucial role in zoonotic malaria transmission. Zoonotic transmission refers to the transfer of diseases from animals to humans. In areas inhabited by NHPs, the potential for zoonotic malaria transmission presents a unique concern that warrants further investigation and attention.

Zoonotic Malaria: A New Frontier

Traditionally, malaria transmission was thought to involve only human and mosquito hosts. However, recent studies have illuminated the possibility of zoonotic transmission involving NHPs as reservoirs of malaria parasites. This concept challenges the established understanding of malaria dynamics and necessitates a comprehensive assessment of zoonotic malaria risk in regions where NHPs coexist with human populations.

Evidence for Zoonotic Malaria Transmission

A study conducted in Southeast Asia by Prugnolle et al. (2013) identified Plasmodium knowlesi, a malaria parasite typically found in macaque monkeys, as a potential source of zoonotic infection in humans. This study highlighted the importance of understanding the transmission dynamics between humans and NHPs in regions where both populations share habitats. Similarly, a survey by Loy et al. (2017) in Malaysia revealed that human infections with P. knowlesi were significantly associated with infected long-tailed macaques. This finding indicated that the proximity and interactions between humans and NHPs play a pivotal role in zoonotic malaria transmission.

Drivers of Zoonotic Malaria Transmission

Several factors contribute to the potential for zoonotic malaria transmission in areas inhabited by NHPs:

• Habitat Encroachment: Human activities, such as deforestation and urban expansion, often encroach upon NHP habitats, increasing the likelihood of contact between humans and infected monkeys.
• Vector Dynamics: NHPs can serve as a reservoir for malaria parasites, which can then be transmitted to humans by mosquito vectors. Changes in mosquito behavior and adaptation to NHPs can facilitate this transmission.
• Vector Host Preference: Anopheles mosquitoes, vectors of malaria, exhibit varying host preferences. If these mosquitoes bite both NHPs and humans, zoonotic transmission becomes more feasible.
• Human-NHP Interaction: Direct interactions between humans and NHPs, such as hunting, trade, and encroachment, create opportunities for pathogen exchange.
• Climate Change: Alterations in climate patterns can influence mosquito distribution and behavior, potentially expanding the geographical range of zoonotic malaria transmission.

Mitigation Strategies speculated by SOHICOHE - Health Dept.

To address the potential for zoonotic malaria transmission in areas inhabited by NHPs, several strategies should be considered:

Surveillance and Monitoring: Regular monitoring of NHP populations, mosquito vector dynamics, and human infections can help detect and respond to potential outbreaks.

Public Health Awareness: Raising awareness about the risks of zoonotic malaria transmission and promoting preventive measures among local communities and healthcare providers is essential.

Habitat Conservation: Protecting NHP habitats through sustainable practices and conservation efforts can reduce the likelihood of human-NHP interactions.

Vector Control: Implementing mosquito control measures, such as bed nets and insecticide use, can help reduce both human and NHP malaria infections.

Interdisciplinary Research: Collaborative efforts between epidemiologists, ecologists, veterinarians, and public health experts are vital for understanding the complex interactions driving zoonotic malaria transmission.

In Conclusion

The potential for zoonotic malaria transmission in areas inhabited by NHPs underscores the need for a comprehensive approach to malaria control that includes both human and animal health considerations. As our understanding of the complex interactions between humans, NHPs, and mosquito vectors continues to evolve, proactive measures to mitigate zoonotic malaria transmission will play a crucial role in achieving malaria elimination goals and safeguarding public health.

References

World Health Organization. (2019). World Malaria Report 2019. Geneva: World Health Organization.

Prugnolle, F., et al. (2013). African monkeys are infected by Plasmodium falciparum nonhuman primate-specific strains. Proceedings of the National Academy of Sciences, 110(15), 5165-5170.

Loy, D. E., et al. (2017). Out of the Woods: Epidemiology of Plasmodium knowlesi in Sabah, Malaysia: Molecular Epidemiology of P. knowlesi. The Journal of Infectious Diseases, 216(8), 1109-1118