EClinicalMedicine (Sep 2021)

Effect of co-infection with intestinal parasites on COVID-19 severity: A prospective observational cohort study

  • Dawit Wolday,
  • Teklay Gebrecherkos,
  • Zekarias Gessesse Arefaine,
  • Yazezew Kebede Kiros,
  • Atsbeha Gebreegzabher,
  • Geremew Tasew,
  • Mahmud Abdulkader,
  • Hiluf Ebuy Abraha,
  • Abraham Aregay Desta,
  • Ataklti Hailu,
  • Getachew Tollera,
  • Saro Abdella,
  • Masresha Tesema,
  • Ebba Abate,
  • Kidist Lakew Endarge,
  • Tsegaye Gebreyes Hundie,
  • Frehiwot Kassahun Miteku,
  • Britta C. Urban,
  • Henk H.D.F. Schallig,
  • Vanessa C. Harris,
  • Tobias F. Rinke de Wit

Journal volume & issue
Vol. 39
p. 101054

Abstract

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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in a spectrum of clinical presentations. Evidence from Africa indicates that significantly less COVID-19 patients suffer from serious symptoms than in the industrialized world. We and others previously postulated a partial explanation for this phenomenon, being a different, more activated immune system due to parasite infections. Here, we aimed to test this hypothesis by investigating a potential correlation of co-infection with parasites with COVID-19 severity in an endemic area in Africa.Methods: Ethiopian COVID-19 patients were enrolled and screened for intestinal parasites, between July 2020 and March 2021. The primary outcome was the proportion of patients with severe COVID-19. Ordinal logistic regression models were used to estimate the association between parasite infection, and COVID-19 severity. Models were adjusted for sex, age, residence, education level, occupation, body mass index, and comorbidities.Findings: 751 SARS-CoV-2 infected patients were enrolled, of whom 284 (37.8%) had intestinal parasitic infection. Only 27/255 (10.6%) severe COVID-19 patients were co-infected with intestinal parasites, while 257/496 (51.8%) non-severe COVID-19 patients were parasite positive (p<0.0001). Patients co-infected with parasites had lower odds of developing severe COVID-19, with an adjusted odds ratio (aOR) of 0.23 (95% CI 0.17–0.30; p<0.0001) for all parasites, aOR 0.37 ([95% CI 0.26–0.51]; p<0.0001) for protozoa, and aOR 0.26 ([95% CI 0.19–0.35]; p<0.0001) for helminths. When stratified by species, co-infection with Entamoeba spp., Hymenolepis nana, Schistosoma mansoni, and Trichuris trichiura implied lower probability of developing severe COVID-19. There were 11 deaths (1.5%), and all were among patients without parasites (p = 0.009).Interpretation: Parasite co-infection is associated with a reduced risk of severe COVID-19 in African patients. Parasite-driven immunomodulatory responses may mute hyper-inflammation associated with severe COVID-19.Funding: European and Developing Countries Clinical Trials Partnership (EDCTP) – European Union, and Joep Lange Institute (JLI), The Netherlands.Trial registration: Clinicaltrials.gov: NCT04473365

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