Monitoring Natural SARS-CoV-2 Infection in Lions (Panthera leo) at the Barcelona Zoo: Viral Dynamics and Host Responses

Abstract

To date, no evidence supports the fact that animals play a role in the epidemiology of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus infectious disease 2019 (COVID-19). However, several animal species are naturally susceptible to SARS-CoV-2 infection. Besides pets (cats, dogs, Syrian hamsters, and ferrets) and farm animals (minks), different zoo animal species have tested positive for SARS-CoV-2 (large felids and non-human primates). After the summer of 2020, a second wave of SARS-CoV-2 infection occurred in Barcelona (Spain), reaching a peak of positive cases in November. During that period, four lions (Panthera leo) at the Barcelona Zoo and three caretakers developed respiratory signs and tested positive for the SARS-CoV-2 antigen. Lion infection was monitored for several weeks and nasal, fecal, saliva, and blood samples were taken at different time-points. SARS-CoV-2 RNA was detected in nasal samples from all studied lions and the viral RNA was detected up to two weeks after the initial viral positive test in three out of four animals. The SARS-CoV-2 genome was also detected in the feces of animals at different times. Virus isolation was successful only from respiratory samples of two lions at an early time-point. The four animals developed neutralizing antibodies after the infection that were detectable four months after the initial diagnosis. The partial SARS-CoV-2 genome sequence from one animal caretaker was identical to the sequences obtained from lions. Chronology of the events, the viral dynamics, and the genomic data support human-to-lion transmission as the origin of infection.

First Detection of SARS-CoV-2 Delta (B.1.617.2) Variant of Concern in a Dog with Clinical Signs in Spain

“…A replicating-virus neutralization assay of the Se2 sample was performed as previously described [15]. The inactivated serum sample was first diluted at 1:10 and then 2-fold serially diluted in DMEM.…”

“…Since the beginning of the pandemic, several domestic and wild animals have shown to be susceptible to SARS-CoV-2 infection [12,13]. Moreover, reverse zoonosis episodes have been documented on farms, in zoos and in familiar households [14][15][16][17]. Recently, by infecting wild-type mice, it has been shown that some SARS-CoV-2 variants display an increased virulence in humanized ACE2 transgenic mice and a broadened host range [18,19].…”

Experimental and natural infections of severe acute respiratory syndrome-related coronavirus 2 in pets and wild and farm animals

“…Indeed, the spread of this virus among humans and many animals has been reported widely. These animals include domestic cats [23][24][25][26][27][28][51][52][53][54][55], dogs [23,26,28,52,54,55], and wild Felidae families, such as tigers [29,65,66], lions [29,[62][63][64], snow leopards [60,61] and cougars [59], as well as gorilla [91]. It was confirmed that the animals acquired viral infection from humans infected with SARS-CoV-2.…”

“…In addition, there has been evidence of natural infections in various animals from several countries, including China, which was the first country in which human infections were found, and in other countries in Asia, Europe, Australia, Africa, and the Americas. Some studies conducted to challenge animals against SARS-CoV-2 infection are presented in Table-1 [22,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50], whereas natural infections in animals, including domestic animals, farm animals, and wild animals, are listed in Table-2 [23][24][25][26][27][28][29]31,34,35,[51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66], and natural infections in the USA are listed in Table-3 . Experimental infections and natural cases with the presumed sources of infection and their transmission are summarized in Figure-1 [4,5,…”

Emerging Trends in the Epidemiology of COVID-19: The Croatian ‘One Health’ Perspective

“…The zoonotic potential adds another dimension in understanding the epidemiology of coronaviruses and successful surveillance. It is now known that SARS-CoV-2 can infect several wild and domestic animals [8][9][10]. However, the role of animals in the epidemiology of COVID-19 and the influence of SARS-CoV-2 on animal health have not been fully understood.…”