Episode 129 Lymphatic Filariasis: Hiding in plain sight

With a history extending back millennia, with a biology that leads to permanent disability for tens of millions of people globally, and with a bacterial endosymbiont that may prove to be its Achilles heel, the filarial parasites that cause lymphatic filariasis are quite the complex creatures. In this episode, we explore the intricacies of this neglected tropical disease – also known as elephantiasis. We start by examining its complicated ecology involving many mosquito and parasite species, before moving on to its tricky biology where we finally answer the age-old question, “What is the lymphatic system anyway?”. Next, we move on to the convoluted history of lymphatic filariasis, where it holds the distinction of being the first disease recognized as mosquito-borne. We wrap up the episode with a look at its present global status, grappling with some current figures on the tremendous global burden of this disease and investigating some exciting treatment developments that will hopefully bring relief to the hundreds of millions of people at risk of developing this debilitating disease.

HistoryBiology
Hoerauf, Achim, and Ramakrishna U. Rao, eds. Wolbachia: a bug’s life in another bug. Vol. 5. Karger Medical and Scientific Publishers, 2007.Babu, S. and Nutman, T.B., 2014. Immunology of lymphatic filariasis. Parasite immunology, 36(8), pp.338-346. 
Addiss, D. G., et al., eds. Lymphatic filariasis. Vol. 1. World Scientific, 2000.Lourens, G.B. and Ferrell, D.K., 2019. Lymphatic filariasis. Nursing Clinics, 54(2), pp.181-192. 
Kenneth, F. Kiple. “The Cambridge world history of human disease.” Cambridge: Cambridge University Press 197 (1993): 9-23.World Health Organization, 2001. Lymphatic filariasis. Weekly Epidemiological Record= Relevé épidémiologique hebdomadaire, 76(20), pp.149-154. 
Bain, Odile. “Evolutionary relationships among filarial nematodes.” The Filaria (2002): 21-29.Taylor, M.J., Hoerauf, A. and Bockarie, M., 2010. Lymphatic filariasis and onchocerciasis. The Lancet, 376(9747), pp.1175-1185. 
Bertwistle, A. P., and A. L. Gregg. “Elephantiasis.” Brit. J. Surgery 16.62 (1928).Turner, H.C., Ottesen, E.A. and Bradley, M.H., 2022. A refined and updated health impact assessment of the Global Programme to Eliminate Lymphatic Filariasis (2000–2020). Parasites & Vectors, 15(1), pp.1-9. 
Bouchery, T., et al. “The symbiotic role of Wolbachia in Onchocercidae and its impact on filariasis.” Clinical Microbiology and Infection 19.2 (2013): 131-140.World Health Organization, 2022. Global programme to eliminate lymphatic filariasis: progress report, 2021– Weekly Epidemiological Record, 97(41), pp.513-524. 
Brown, Amanda MV, et al. “Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts.” Scientific reports 6.1 (2016): 34955.Kalyanasundaram, R., Khatri, V. and Chauhan, N., 2020. Advances in vaccine development for human lymphatic filariasis. Trends in parasitology, 36(2), pp.195-205. 
Charlat, Sylvain, Gregory DD Hurst, and Hervé Merçot. “Evolutionary consequences of Wolbachia infections.” TRENDS in Genetics 19.4 (2003): 217-223.Cromwell, E.A., Schmidt, C.A., Kwong, K.T., Pigott, D.M., Mupfasoni, D., Biswas, G., Shirude, S., Hill, E., Donkers, K.M., Abdoli, A. and Abrigo, M.R., 2020. The global distribution of lymphatic filariasis, 2000–18: a geospatial analysis. The Lancet Global Health, 8(9), pp.e1186-e1194. 
Ferri, Emanuele, et al. “New insights into the evolution of Wolbachia infections in filarial nematodes inferred from a large range of screened species.” PloS one 6.6 (2011): e20843.Mathew, C.G., Bettis, A.A., Chu, B.K., English, M., Ottesen, E.A., Bradley, M.H. and Turner, H.C., 2020. The health and economic burdens of lymphatic filariasis prior to mass drug administration programs. Clinical Infectious Diseases, 70(12), pp.2561-2567. 
Gerth, Michael, et al. “Phylogenomic analyses uncover origin and spread of the Wolbachia pandemic.” Nature communications 5.1 (2014): 5117.
Kaur, Rupinder, et al. “Living in the endosymbiotic world of Wolbachia: a centennial review.” Cell host & microbe 29.6 (2021): 879-893.
LePage, Daniel, and Seth R. Bordenstein. “Wolbachia: can we save lives with a great pandemic?.” Trends in parasitology 29.8 (2013): 385-393.
McNulty, Samantha N., et al. “Inter and intra-specific diversity of parasites that cause lymphatic filariasis.” Infection, Genetics and Evolution 14 (2013): 137-146.
Quek, Shannon, et al. “Wolbachia depletion blocks transmission of lymphatic filariasis by preventing chitinase-dependent parasite exsheathment.” Proceedings of the National Academy of Sciences 119.15 (2022): e2120003119.
Routh, H. B., and K. R. Bhowmik. “History of elephantiasis.” International Journal of Dermatology 32.12 (1993): 913-916.
Samuels, Tristan. “Undoing the Hottentoting of “the Queen of Punt” A Jamaican Afronography on the Kemetiu Depiction of Ati of Punt.” Journal of Black Studies 52.1 (2021): 3-23.
Small, Scott T., Daniel J. Tisch, and Peter A. Zimmerman. “Molecular epidemiology, phylogeny and evolution of the filarial nematode Wuchereria bancrofti.” Infection, Genetics and Evolution 28 (2014): 33-43.
Taylor, Mark J., Claudio Bandi, and Achim Hoerauf. “Wolbachia. Bacterial endosymbionts of filarial nematodes.” Advances in parasitology 60 (2005): 245-284.
Werren, John H., Laura Baldo, and Michael E. Clark. “Wolbachia: master manipulators of invertebrate biology.” Nature Reviews Microbiology 6.10 (2008): 741-751.
Firsthand Account: Living with Complications from Lymphatic Filariasis by The Carter Center. Link to Carter Center page on Lymphatic Filariasis Elimination Program

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