One Health Investigation of SARS-CoV-2 Infection and Seropositivity among Pets in Households with Confirmed Human COVID-19 Cases-Utah and Wisconsin, 2020

Abstract

Approximately 67% of U.S. households have pets. Limited data are available on SARS-CoV-2 in pets. We assessed SARS-CoV-2 infection in pets during a COVID-19 household transmission investigation. Pets from households with ≥1 person with laboratory-confirmed COVID-19 were eligible for inclusion from April-May 2020. We enrolled 37 dogs and 19 cats from 34 households. All oropharyngeal, nasal, and rectal swabs tested negative by rRT-PCR; one dog's fur swabs (2%) tested positive by rRT-PCR at the first sampling. Among 47 pets with serological results, eight (17%) pets (four dogs, four cats) from 6/30 (20%) households had detectable SARS-CoV-2 neutralizing antibodies. In households with a seropositive pet, the proportion of people with laboratory-confirmed COVID-19 was greater (median 79%; range: 40-100%) compared to households with no seropositive pet (median 37%; range: 13-100%) (p = 0.01). Thirty-three pets with serologic results had frequent daily contact (≥1 h) with the index patient before the person's COVID-19 diagnosis. Of these 33 pets, 14 (42%) had decreased contact with the index patient after diagnosis and none were seropositive; of the 19 (58%) pets with continued contact, four (21%) were seropositive. Seropositive pets likely acquired infection after contact with people with COVID-19. People with COVID-19 should restrict contact with pets and other animals.

Keywords: COVID-19; SARS-CoV-2; cat; dog; household transmission; pets; transmission; zoonoses.

Figure 1

COVID-19 diagnostic testing and symptom duration among humans and animals in households with a seropositive pet, One Health COVID-19 Household Transmission Investigation, April–May 2020. Symptom durations are shown only for humans. Pets with clinical signs are denoted with an *.

Figure 2

Timeline and phylogenetic analysis of human and dog testing in one household in Utah with SARS-CoV-2 RNA detected on the dog’s fur, One Health COVID-19 Household Transmission Investigation, April–May 2020. (A) Timeline of human and dog testing in one household in Utah with six persons with laboratory-confirmed COVID-19 and SARS-CoV-2 RNA detected on the dog’s fur. The timeline indicates dates of reported symptoms and results of nasopharyngeal swab testing by rRT-PCR in human COVID-19 cases and samples collected from the dog in the household. Diagnostic samples * from the dog included oral, nasal, and rectal swabs and stool, which all tested negative by rRT-PCR, and a blood sample which was negative by virus neutralization. (B) Enhanced view of branch-tip from comprehensive phylogram (Figure S2), depicting here the seven study sequences (red) alongside selected Utah complete genome sequences available from Global Initiative on Sharing All Influenza Data. Branch length is by divergence. See Figure S2 for zoomed-out dendrogram depicting additional available sequences from Utah.

Figure 3

(A) Reported duration of interaction per day and (B) types of interactions between human index patients and pets in each household before and after human index patient diagnosis, by pet serostatus—One Health COVID-19 Household Transmission Investigation, April–May 2020.