Case Series; Ecological
Study population and setting
The report focuses on two cats from households with suspected or confirmed COVID-19 cases in New York in March and April, 2020.
Summary of Main Findings
One cat (Cat A), a four-year-old male domestic shorthair, developed signs of respiratory illness on March 24. Three of the five members of the household that Cat A lived also had symptoms of respiratory illness but were never tested for SARS-CoV-2. The first illness in human household members started on March 15 — nine days before Cat A became ill. Cat A was reported positive for SARS-CoV-2 on April 14 based on upper respiratory swabs collected at a veterinary clinic on April 1. Follow-up specimens from Cat A taken on April 17 showed that a nasal swab from the cat still tested weakly positive for SARS-CoV-2 and that serum from the cat contained neutralizing antibodies for SARS-CoV-2. The rectal swab collected on April 17 was negative, and the SARS-CoV-2 virus could not be isolated from either the nasal nor rectal swab.
The second cat (Cat B), a five-year-old female Devon Rex, developed signs of respiratory illness similar to Cat A on April 1. The owner of the cat had developed illness consistent with COVID-19 on March 24, eight days before Cat B became ill; the owner tested positive for SARS-CoV-2 on March 26. The owner personally collected specimens that were sent to the lab, which then confirmed that Cat B was positive for SARS-CoV-2 on April 14. Follow-up tests on specimens collected on April 17 showed that Cat B was negative for the virus in nasal and rectal swabs according to PCR and attempted virus isolation. However, serum collected on April 14 contained neutralizing antibodies to SARS-CoV-2.
Compared to other studies of human-to-cat transmission of SARS-CoV-2, the authors were able to confirm the suspected date that cats were exposed based on the development of symptoms in human cases in the same household.
With a very small sample size and only a passive surveillance program at the laboratory where samples were tested, this study cannot determine the overall frequency of human-to-cat transmission of SARS-CoV-2 nor the possibility of cat-to-cat transmission. Additionally, no sequencing analyses were performed on any of the samples from humans or cats to determine if cats were infected with same virus as the sick members in their households.
Similar to reports of SARS-CoV-2 infection in dogs, the study confirms that cats can occasionally become naturally infected with SARS-CoV-2 following exposure in a household setting.
This review was posted on: 4 July 2020