Effect of Co-Infection with Intestinal Parasites on COVID-19 Severity: A Prospective Observational Cohort Study

Background: COVID-19 symptomatology in Africa appears significantly less serious than the industrialized world. We and others previously postulated a partial explanation for this phenomenon, being different, more activated immune system due to parasite infections. investigated hypothesis an endemic area Africa. Methods: Ethiopian patients were enrolled screened intestinal parasites. The primary outcome was proportion of with severe COVID-19. Logistic regression models used estimate association between infection, severity. Models adjusted sex, age, residence, comorbidities. Findings: 751 SARS-CoV-2 infected enrolled, whom 284 (37·8%) had parasitic infection. Only 27/255 (10·6%) co-infected parasites, while 257/496 (51·8%) non-severe appeared positive (p<0.0001). Patients parasites lower odds developing COVID-19, ratio (aOR) 0·14 (95% CI 0·09–0·24; p<0·0001) all aOR 0·20 ([95% 0·11–0·38]; protozoa, 0·13 0·07–0·26]; helminths. When stratified by species, co-infection Entamoeba spp. , Hymenolopis nana, Schistosoma mansoni implied probability There 11 deaths (1·5%), among without (p=0·009). Interpretation: Parasite is associated reduced risk African patients. Parasite-driven immunomodulatory responses may mute hyper-inflammation Funding: European Developing Countries Clinical Trials Partnership (EDCTP) Joep-Lange Institute. Declaration Interests: declare no competing interests. Ethics Approval Statement: study protocol reviewed approved Health Research Ethics Review Committee Mekelle University College Sciences (No.: ERC 1769/2020), Public Institute (No: EPHI 6.13/814), Eka Kotebe General Hospital EK/150/5/32). Written informed consent obtained participants, or their guardians, participation study.