PLOS Neglected Tropical Diseases announces the launch of a new collection focusing on the human parasitic roundworm Strongyloides stercoralis (S. stercoralis). Containing nearly twenty research articles by nematode experts from across the globe, the collection kicks off with new Viewpoints and Review articles that highlight the need for sustained action to fight this disease.
While recognized by the World Health Organization officially as an NTD, the nematode S. stercoralis has fallen under the radar of many campaigns for control of soil-transmitted helminths despite threatening hundreds of millions and killing thousands every year worldwide.
Dr. Zeno Bisoffi and colleagues open this collection with a Viewpoints article titled “Strongyloides stercoralis: a Plea for Action” in which they argue that the true infection rates of this parasite are severely underestimated. “If we refer to the current estimate of 740 million people infected with hookworm globally [Bungiro and Cappello 2011], a prevalence of at least 370 million people infected with S. stercoralis worldwide seems a more reasonable (and probably still conservative) figure,” says Bisoffi.
Due to the difficulty in detecting S. stercoralis it’s likely to remain a silent menace even after many other parasites have been controlled by regional pushes for elevated medical treatment and hygiene improvement.
Strongyloides is unique among soil transmitted helminths (STH) due to differences in life cycle, diagnostic strategies, therapeutic drugs and even therapeutic outcome measurements. However, Dr. Alejandro Krolewiecki, author of “A Public Health Response against Strongyloides stercoralis: Time to Look at Soil-Transmitted Helminthiasis in Full,” asserts that strongyloides “is as much an STH [as ascariasis, hookworm and tricuriasis] by its standard definition” and therefore should be controlled in an integrated manner because it affects the same populations as other STH.
Thankfully, an effective drug to treat strongyloides is already available: ivermectin. This drug, often donated by its producers, is currently being used in several countries for control/elimination of onchocerciasis and lymphatic filariasis. There are indications that the prevalence of strongyloides is virtually zero in areas where ivermectin is/has been repeatedly used for mass treatment of adults and children, though more studies are necessary.
With the burden of disease, risk factors, best diagnostic approach and most effective regimen with ivermectin still to be defined, there are significant research questions in search of practical operational answers. We hope that this collection will serve as motivation and a rallying point to further pull back the curtain from strongyloides in order to locate an effective treatment strategy. If one thing is certain, it’s that we know enough to call for action now.
We invite you to view the full strongyloides collection here.