We have been tackling COVID-19 in our daily lives and pondering over other forms of contagions such as the plague, sins, memes, information, beliefs, syphilis, family values, memories, influenza, AIDS, and even fictional diseases like the Shen fever every Monday and Wednesday morning. However, our discussions have been concerned about how humans are affected by and react to these contagions. Through this short post, I want to introduce you to a different perspective on contagion through the example of chytridiomycosis, an infectious disease discovered around 20 years ago that is known to have caused the decline of hundreds of amphibian species, including 90 presumed extinctions (Scheele et al. 2019).
Chytridiomycosis is a fungal infection caused by the spread of Bd/Bsal (Batrachochytrium dendrobatidis/Batrachochytrium salamandrivorans) fungi through contact with spore-infected water or other infected hosts. The fungus replicates rapidly on the skin of the host and kills it off by blocking their breathing metabolism (most amphibians breathe through their skin). The contagious nature of the disease thus leads to mass die-offs in certain regions, and has been wreaking havoc on amphibians throughout the past half-century. Similar to COVID-19, Chytridiomycosis is also hard to detect without testing and thus in the absence of proper testing, the global trade network has also led to its spread across the continents. So while humans initially might not have been directly responsible for this plague on amphibians, the trade of animals without realizing its consequences has certainly exacerbated the problem.
Taxonomic distribution of chytridiomycosis-associated amphibian declines: Each bar represents one species, and color denotes the severity of its decline. Concentric circles indicate, from inner to outer, order (Caudata or Anura), family, and genus. (Scheele et al. 2019)
Most prevention and detection efforts for Chytridiomycosis are currently being led by researchers (funding for which is also quite scarce, since the issue is quite low priority among governments) who test the amphibians for Bd/Bsal in suspected habitats. The results take 2-3 days to be processed in a lab and till then the tested individuals are kept isolated from their natural habitat in containers (quite similar to the practice of quarantine until COVID-19 test results come), which is quite undesirable (I think we all agree about that from our quarantine experiences). Finally, based on the results, the amphibians are released or treated for the disease using medicated baths and further measures are taken to prevent the spread of the disease from the area tested.
To aid the efforts to fight against this disease, the NYUAD iGEM team (which I am also a part of hehe!) has also been developing a diagnostic device that can be used in the field itself to give rapid and accurate results about the presence of Bd/Bsal. This will not only eliminate the need for isolating the animals for days, it will also encourage more testing, especially at trading ports, so that the disease can be prevented from spreading. Our progress this year has been slow due to restricted lab access, but the pandemic has also provided us with the opportunity to learn from some great (and still ongoing) rapid diagnostics research that was prompted by COVID-19. We are hopeful that we will be finishing the device soon and achieve our goals! I will leave you now with our 2-min project description video that illustrates most of what I have talked about quite well:
I loved this post. Super informative and exciting! no more long quarantine for froggies 🙂 btw additional question is there any way to treat places that are contaminated or reduce the spread of Bd/Bsal?
Thanks Maryam! So from what I know, it is not possible to treat a whole place because the current treatment is to use fungicides and the areas contaminated are quite large to be sprayed with a fungicide as a whole. Most approaches have used individual treatment instead to stop the infection from spreading.