SARS-CoV-2 infection in synanthropic rats from Guayaquil city (Ecuador) during COVID-19 pandemic: A proxy to prevent wild reservoirs in the tropics.

Human-to-animal reverse transmission of SARS-CoV-2 is a risk for new reservoirs' emergence and new variants' evolution. SARS-CoV-2 infection of synanthropic rodents in urban settings has been reported during COVID-19 in New York and Mexico cities. In this study, we addressed the potential transmission of SARS-CoV-2 to synanthropic rats in the city of Guayaquil (Ecuador) during the COVID-19 pandemic. A total number of 234 rats were collected and analyzed for SARS-CoV-2 detection by RT-qPCR. A positivity rate of 6 % (14 rats) was found, and SARS-CoV-2 infection was confirmed by Sanger sequencing of the viral genome. Our results confirm the potential risk of synanthropic rats as reservoirs for SARS-CoV-2 infection. This is worrisome for low and middle income countries like Ecuador, where pest and waste control in urban settings is challenging. Moreover, the risk of spillover to wild fauna is a concern in Guayaquil, where synanthropic fauna includes raccoons or coatis and forest patches with a wild population of felids or primates existing within the city limits. In this context, SARS-CoV-2 sentinel surveillance of synanthropic rodents could serve as a proxy for a One Health approach to prevent the emergence of new wild reservoirs.

SARS-CoV-2 transmission from infected owner to household dogs and cats is associated with food sharing.

OBJECTIVES: Several cases of reverse transmission of SARS-CoV-2 from human to pets were reported during the first year of the COVID-19 pandemic. Accordingly, the World Organization for Animal Health has recommended to improve SARS-CoV-2 surveillance on household animals to assess the risk of transmission between species. After such recommendation, we studied the potential SARS-CoV-2 infection in household dogs and cats in the city of Guayaquil, the most populated city in Ecuador. METHODS: Oral and nasal swab samples were collected from dogs and cats within 10 days of a positive SARS-CoV-2 test result of their owners. Total ribonucleic acid was extracted and detection of viral gene targets N and ORF1ab was performed by quantitative reverse transcription polymerase chain reaction. RESULTS: From the 50 cats and dogs tested, 12 were SARS-CoV-2 positive, giving a total positivity rate of 24%. A total of 1 of 8 cats tested positive, whereas 11 of 42 dogs were positive, yielding a positivity rate of 12.5% and 26.2%, respectively. SARS-CoV-2 was confirmed by whole genome sequencing. In addition, we also found a statistically significant association between SARS-CoV-2 pet positivity and food sharing with infected owners. CONCLUSION: This study is the second active surveillance of SARS-CoV-2 in household dogs and cats in Latin America. Moreover, it is the first study to address the risk factors associated with potential anthropogenic SARS-CoV-2 transmission to domestic cats and dogs. Given the high presence of free-roaming dogs and cats in rural and urban areas in Latin American countries and the high capacity shown by coronaviruses for interspecies transmission, our findings support the view that SARS-CoV-2 surveillance in pets is necessary to better understand the role that pet-human interaction plays in the COVID-19 spread.