Uncorrected Proof Arch Clin Infect Dis. 2021 August; 16(4):e118047. Published online 2021 December 6. doi: 10.5812/archcid.118047. Research Article The Importance of Screening Strongyloides stercoralis Infection in Solid Organ Transplant Donors and Recipients Sara Abolghasemi 1 , Farnaz Zolfaghari 2, * , Shahnaz Sali 1 , Abdollah Ghaffari 3 and Mehran Noori 1 1 Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Department of Infectious Diseases and Tropical Medicine, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Gholhak Laboratory, Tehran, Iran * Corresponding author: Department of Infectious Diseases and Tropical Medicine, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Email: zolfaghari83@yahoo.com Received 2021 August 15; Revised 2021 November 13; Accepted 2021 November 14. Abstract Background: Strongyloides stercoralis is an intestinal nematode with worldwide distribution which is endemic in tropical and sub- tropical areas. It is unique in its ability to complete its entire life cycle and reinfect its human host via a phenomenon called autoin- fection. The majority of infections are clinically asymptomatic or can manifest with gastrointestinal symptoms, such as heartburn, bloating, diarrhea, abdominal discomfort, gastroesophageal reflux disease (GERD), or symptoms related to the penetration of lar- vae through skin, including dermatitis and eosinophilia. Immunosuppressed patients, such as solid organ transplant patients with untreated strongyloidiasis are at great risk of hyperinfection, dissemination syndromes, and often fatal conditions associated with strongyloidiasis. Methods: In this retrospective single-center cross-sectional study, we evaluated 157 cases (131 heart, lung, and kidney transplant re- cipients and 26 kidney donors) in Tehran, Iran, from March 2020 to April 2021. Demographic information including age, gender, place of birth, place of residence, underlying disease, being the donor or recipient, history of previous transplant and type of trans- plant, travel history to endemic regions, and seropositivity for S. stercoralis were evaluated. Results: Among 157 cases with a mean age of 38.9 years, 40 (25.5%) cases tested positive for S. stercoralis antibodies. Out of 26 donors, eight cases were seropositive, and among 131 recipients, 32 cases were seropositive. There was no significant correlation between birth place and place of residence in endemic areas and seropositivity for S. stercoralis. None of the cases showed hypereosinophilia, hyperinfection, or disseminated syndrome. Also, we found no significant correlation between the type and time of transplant, his- tory of previous transplants, and S. stercoralis infection. Conclusions: Universal screening for S. stercoralis latent infection is important in immunosuppressed patients, especially in solid organ transplants because of the high risk of hyperinfection and disseminated syndrome, which may culminate in death. Fur- thermore, screening for latent strongyloides infection in donors seems to be necessary because of the possibility of strongyloides infection being transmitted from donors to recipients. Keywords: Strongyloides stercoralis, Solid Organ Transplant, Disseminated Syndrome, ELISA, Serology 1. Background Strongyloides stercoralis is an intestinal nematode with worldwide distribution which is endemic in tropical and subtropical areas. Approximately 100 million people are infected, while billions are at risk of infection. S. stercoralis is unique in its ability to complete its entire life cycle and reinfect its human host, which is known as autoinfection (1). The majority of infections are clinically asymptomatic or can manifest with gastrointestinal symptoms such as heartburn, bloating, diarrhea or abdominal discomfort, gastroesophageal reflux disease (GERD), or via the pene- tration of skin by larvae with dermatitis and eosinophilia. Strongyloides infection occurs through skin contact with contaminated soil (1). Immunosuppressed patients such as solid organ trans- plant patients with untreated strongyloidiasis are at a great risk of hyperinfection and dissemination syndromes and often fatal conditions associated with strongyloidia- sis. This process can lead to a high risk of death, with mor- tality estimates ranging from 35 to 100% (1). Therefore, early diagnosis and screening for S. sterco- Copyright © 2021, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.