Written by Kerre Ann Willsher, PhD
Do you miss the croaking of frogs on summer nights? I know that I do. When I was a child there were thousands of frogs on the creek across the road, and they carried on all night. But they kept the mosquitos down. We know that anopheles mosquitos spread malaria, but not everyone gets the connection with frogs. It is of concern that frogs in many areas of the World, especially, Central and South America, are now critically endangered or extinct. In many cases, the die-off of frogs is due to a fungal infection called chytridiomycosis which coats the skin so it is unable to breathe (Springborn et al., 2022). The fungus may have spread via globalized trade ventures including the pet trade, along with the destruction of habitat (Springborn et al., 2022).
The spread of chytridiomycosis was a catastrophe leading to a worldwide, decades-long destruction of amphibians according to Springborn et al (2022). There has been a mobile wave of frog destruction across Costa Rica and Panama from the 1980s to the present day (Cunningham, 2022). The examination of local ecological surveys, public health records, and satellite imagery supports the link between the loss of amphibians and an increase in malaria cases in Central America (Springborn et al., 2022). Nonetheless, there was a drop in malaria cases worldwide from 2010 until 2019 which is attributed to improved health care, the work of the World Health Organization, and organizations such as Rotarians Against Malaria (Burkot & Gilbert, 2021; World Health Organization, 2019). A holistic approach that examines the impacts of environmental health on human well-being is essential for the elimination of malaria.
BUT FROGS MAY NOT HAVE “CROAKED IT”, THEY ARE FIGHTING BACK
In some areas of the world, frog populations are being rediscovered after being thought to be extinct. This is due to genetic changes resulting in an increasing number of frogs developing immunity against chytridiomycosis which has remained as virulent as ever (Rodriguez & Voyles, 2021; Rosa et al., 2022). Environmental ecology needs to be managed so that mosquito populations are minimized, and there are fewer cases of malaria. Amphibians have an important role in the elimination of malaria.
Burkot, C., & Gilbert, K. (2021). Eliminating again, for the last time: A case study of donor support for malaria in Solomon Islands. Asia & the Pacific Policy Studies, 8(2), 189-207. https://doi.org/https://doi.org/10.1002/app5.320
Cunningham, A. (2022, October 5, 2022). Losing amphibians may be tied to spikes in human malaria cases. https://www.sciencenews.org/article/amphibian-loss-human-malaria-cases-mosquitoes
Rodriguez , K. M., & Voyles, J. (2021). The amphibian complement system and chytridiomycosis. Journal of Experimental Zoology Part A Ecological and Integrative Physiology ·, 333(10), 706-719. Retrieved November 11, 2022, from https://onlinelibrary.wiley.com/doi/full/10.1002/jez.2419
Rosa, G. M., Perez, R., Richards, L. A., ., Richards-Zawacki, C. L., Smilanich, A. M., Reinert, L. K., ., Rollins-Smith, L. A., Wetzel, D. P., ., & Voyles, J. (2022). Seasonality of host immunity in a tropical disease system. Ecosphere, 13(7), e4158. https://doi.org/https://doi.org/10.1002/ecs2.4158
Springborn, M. R., Weill, J. A., Lips, K. R., Ibáñez, R., & Ghosh1, A. (2022). Amphibian collapses increased malaria incidence in Central America*. Environmental Research Letters, 17(10). https://iopscience.iop.org/article/10.1088/1748-9326/ac8e1d
World Health Organization. (2019). World Malaria Report 2019 United Nations. https://www.who.int/publications/i/item/9789241565721