SARS-CoV-2 RNA in Swabbed Samples from Latrines and Flushing Toilets: A Case–Control Study in a Rural Latin American Setting

Del Brutto, Oscar H.; Costa, Aldo F.; Mera, Robertino M.; Andrade-Molina, Derly; Recalde, Bettsy Y.; García, Héctor H.; Fernández-Cadena, Juan C.

Information about factors potentially favoring the spread of SARS-CoV-2 in rural settings is limited. Following a case–control study design in a rural Ecuadorian village that was severely struck by the pandemic, SARS-CoV-2 RNA were detected by real-time PCR in swabs obtained from inner and upper walls in 24/48 randomly selected latrines from case-houses and in 12/48 flushing toilets from paired control-houses (P = 0.014; McNemar’s test). This association persisted in a conditional logistic regression model adjusted for relevant covariates (OR: 4.82; 95% CI: 1.38–16.8; P = 0.014). In addition, SARS-CoV-2–seropositive subjects were more often identified among those living in houses with a latrine (P = 0.002). Latrines have almost five times the odds of containing SARS-CoV-2 RNA than their paired flushing toilets. Latrines are reservoirs of SARS-CoV-2 RNA, and it cannot be ruled out that latrines could contribute to viral transmission in rural settings. Frequent disinfection of latrines should be recommended to reduce the likelihood of fecal contamination.