Low serological rate of SARS-CoV-2 in cats from military bases in Israel

Abstract

Domestic cats are susceptible to SARS-CoV-2 infection and can transmit the virus to other felines. A high number of COVID-19 human cases within the military personnel and a high density of stray cats living close to soldiers raised the need to perform active animal surveillance. We validated a novel quantitative serological microarray for use in cats, that enables simultaneous detection of IgG and IgM responses; in addition, molecular genetic SARS-CoV-2 detection was performed. Three out of 131 cats analyzed, showed IgG antibodies against SARS-CoV-2 RBD and S2P (2.3 %). None of cats were positive for SARS-CoV-2 RNA by RT-PCR. SARS-CoV-2 infection rate in soldiers ranged from 4.7 % to 16 % (average rate=8.9 %). Further investigations on a larger cohort are necessary, in the light of the emerging new viral variants in other animal species and in humans.

Keywords: COVID-19; Military; One health; SARS-CoV-2; Stray cats.

Fig. 1

COVID-19 cases per month in soldiers in each location. Arrows indicate the month of cat trapping and sampling, and the color shows the location.

Fig. 2

S2P and RBD MFI values of the samples and controls tested in the serological microarray. The red circle indicates the positive control sample of an experimentally infected cat. The yellow circles indicate the positive control samples of naturally infected cats. The purple circles indicate the positive cat samples from the cohort study. The blue circles indicate the negative samples. The parallel axis show the cutoff (LLOQ) of RBD and S2P. The unparallel axis show the trend line.