Ivermectin Effect in COVID-19 Varies With Strongyloidiasis Prevalence

Ivermectin, 3 mg tablet, as sold in the USA. Brand name: Stromectol, manufactured by Edenbridge Pharmaceuticals. It is also sold under brand names Heartgard and Sklice. Ivermectin is a broad-spectrum antiparasitic agent, traditionally against parasitic worms. It is mainly used in humans in the treatment of onchocerciasis (river blindness), but is also effective against other worm infestations (such as strongyloidiasis, ascariasis, trichuriasis, filariasis and enterobiasis), and some epidermal parasitic skin diseases, including scabies. From Wikipedia: Ivermectin is currently being used to help eliminate river blindness (onchocerciasis) in the Americas, and to stop transmission of lymphatic filariasis and onchocerciasis around the world in programs sponsored by the Carter Center using ivermectin donated by Merck. The disease is endemic in 30 African countries, six Latin American countries, and Yemen, according to studies conducted by the World Health Organization. The drug rapidly kills microfilariae, but not the adult worms. A single oral dose of ivermectin, taken annually for the 10- to 15-year lifespan of the adult worms, is all that is needed to protect the individual from onchocerciasis.
In trials of ivermectin as a treatment for COVID-19, the relative risk of mortality varies with strongyloidiasis prevalence.

HealthDay News — In trials of ivermectin as a treatment for COVID-19, the relative risk of mortality varies with strongyloidiasis prevalence, according to research published online March 21 in JAMA Network Open.

Avi Bitterman, M.D., from the Icahn School of Medicine at Mount Sinai in New York City, and colleagues examined the association between regional prevalence of strongyloidiasis and ivermectin trial results for the outcome of mortality in a meta-analysis of randomized clinical trials using ivermectin as a treatment for COVID-19. Data were included from 12 trials, with 3,901 patients: four and eight trials took place in regions of high and low strongyloidiasis prevalence, respectively.

The researchers found that there was no significantly decreased risk of mortality in ivermectin trials that took place in areas of low regional strongyloidiasis prevalence (relative risk, 0.84; 95 percent confidence interval, 0.60 to 1.18; P = 0.31). In contrast, a significantly decreased risk of mortality was seen in ivermectin trials that took place in areas of high regional strongyloidiasis prevalence (relative risk, 0.25; 95 percent confidence interval, 0.09 to 0.70; P = 0.008). The difference between the results of groups with low and high strongyloidiasis prevalence was significant. For each 5 percent increase in strongyloidiasis prevalence, meta-regression analysis revealed a decrease of 38.83 percent in relative risk.

“Results of ivermectin trials in strongyloidiasis-endemic regions may not extrapolate to strongyloidiasis-nonendemic regions,” the authors write. “Future trials in nonendemic regions may provide insight into the true effect of ivermectin in this context. In the interim, we strongly caution against extrapolation for patients not at increased risk for strongyloidiasis.”

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