Prophylactic effect of cutaneous leishmaniasis against COVID-19: a case-control field assessment
Mehdi Bamorovat, Iraj Sharifi, Mohammad Reza Aflatoonian, Ali Karamoozian, Amirhossein Tahmouresi, Abdollah Jafarzadeh, Amireh Heshmatkhah, Fatemeh Sharifi, Ehsan Salarkia, Tabandeh Khaleghi, Ahmad Khosravi, Maryam Nooshadokht, Mehdi Borhani Zarandi, Maryam Barghi
Abstract
INTRODUCTION: We assessed the potential relationship between COVID-19 and laboratory-confirmed cutaneous leishmaniasis (CL)-registered cases with a history of scarring, compared with volunteer participants without history of CL. METHODS: This case-control retrospective study was conducted in southeastern Iran with a high anthroponotic cutaneous leishmaniasis (ACL) burden. RESULTS: Overall, n=1010 CL cases (n=479 male, n=531 female) were evaluated for infection with SARS-CoV-2. In the CL case group, 2 men and 1 woman (0.3% in total) had a mild form of COVID-19 disease; none were hospitalized or died. In contrast, of n=2020 participants without history of CL, n=57 (2.9%) contracted laboratory-confirmed COVID-19, including mild (66.7%), hospitalized (26.3%), critical (3.5%) and fatal (3.5%). There was a strong negative association between CL infection and COVID-19. The burden of COVID-19 in CL-cured participants significantly reduced the morbidity (odds ratio: 0.12; CI: 0.03-0.30; P <0.001) and mortality (percentile: -4.10, -0.02). CONCLUSION: Participants with a history of CL scar had significantly reduced incidence of COVID-19 morbidity and mortality. The cross-protection mediated by CL may retard COVID-19 in endemic countries. However, further longitudinal studies are needed to explore the potential profile and duration of this protection offered by CL against COVID-19.