Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.(AU)

Persistent SARS-CoV-2 antigen presence in multiple organs of a naturally infected cat from Brazil

Abstract Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of the disease coronavirus 2019 (COVID-19) in humans. SARS-CoV-2 has been identified in cats with or without clinical signs. Case presentation: We describe the pathological and molecular findings in a six-month-old asymptomatic cat with SARS-CoV-2 infection from Brazil, belonging to a human family with COVID-19 cases. The pool of nasopharynx and oropharynx swabs at day zero tested positive by RT-qPCR for SARS-CoV-2. No amplification resulted from molecular testing performed on days 7 and 14. The cat was hit by a car and died 43 days after the molecular diagnosis. Immunohistochemistry at post-mortem examination demonstrated nucleocapsid protein in samples from the lungs, kidneys, nasal conchae, trachea, intestine, brain and spleen. Conclusion: The present study has highlighted the possibility that viral antigens can be detected by immunohistochemistry in multiple organs six weeks after infection, although the same tissues tested negative by RT-PCR.

Occurrence of antibodies anti-Toxoplasma gondii among sheltered and free-roaming cats within a university campus / Ocorrência de anticorpos anti-Toxoplasma gondii entre gatos de abrigo e de vida livre dentro de um campus universitário

The present study aimed to assess anti-T. gondii antibodies in sheltered and free-roaming cats within a university campus that has an overlapping population of humans and livestock. A total of 51 cats were tested for anti-T. gondii antibodies using the indirect immunofluorescent antibody test. Overall, 8/51 cats (15.7%) were seropositive. Cats were more likely to be seropositive when free-roaming (p= 0.008) and with presence of skin lesions (p= 0.042), and less likely with < 1 year of age (p= 0.021), probably due to higher environmental exposure and infected prey consumption. The presence of seropositive free-roaming cats whose areas overlapped those occupied by humans and livestock may suggest an increased on-campus chance of T. gondii occurrence.

O presente estudo teve por objetivo acessar anticorpos anti-Toxoplasma gondii em gatos de abrigo e gatos de vida livre dentro de um campus universitário que tem uma população sobreposta de seres humanos e animais de produção. Um total de 51 gatos foram testados para anticorpos anti- T. gondii usando o teste de imunofluorescência indireta. No geral, 8/51 (15.7%) gatos foram soropositivos. Os gatos foram mais propensos a ser soropositivos quando em vida livre (p = 0,008) e com lesões de pele (p = 0.042), e menos prováveis com menos de 1 ano de idade (p = 0,021), provavelmente devido à maior exposição ambiental e consumo de presas infectadas. A presença de gatos errantes soropositivos cujas áreas se sobrepõem àquelas ocupadas por seres humanos e animais pode sugerir um risco aumentado de ocorrência de T. gondii no campus.

Occurrence of antibodies anti-Toxoplasma gondii among sheltered and free-roaming cats within a university campus / Ocorrência de anticorpos anti-Toxoplasma gondii entre gatos de abrigo e de vida livre dentro de um campus universitário

The present study aimed to assess anti-T. gondii antibodies in sheltered and free-roaming cats within a university campus that has an overlapping population of humans and livestock. A total of 51 cats were tested for anti-T. gondii antibodies using the indirect immunofluorescent antibody test. Overall, 8/51 cats (15.7%) were seropositive. Cats were more likely to be seropositive when free-roaming (p= 0.008) and with presence of skin lesions (p= 0.042), and less likely with < 1 year of age (p= 0.021), probably due to higher environmental exposure and infected prey consumption. The presence of seropositive free-roaming cats whose areas overlapped those occupied by humans and livestock may suggest an increased on-campus chance of T. gondii occurrence.(AU)

O presente estudo teve por objetivo acessar anticorpos anti-Toxoplasma gondii em gatos de abrigo e gatos de vida livre dentro de um campus universitário que tem uma população sobreposta de seres humanos e animais de produção. Um total de 51 gatos foram testados para anticorpos anti- T. gondii usando o teste de imunofluorescência indireta. No geral, 8/51 (15.7%) gatos foram soropositivos. Os gatos foram mais propensos a ser soropositivos quando em vida livre (p = 0,008) e com lesões de pele (p = 0.042), e menos prováveis com menos de 1 ano de idade (p = 0,021), provavelmente devido à maior exposição ambiental e consumo de presas infectadas. A presença de gatos errantes soropositivos cujas áreas se sobrepõem àquelas ocupadas por seres humanos e animais pode sugerir um risco aumentado de ocorrência de T. gondii no campus.(AU)

Serosurvey of Rickettsia spp. in cats from a Brazilian spotted fever-endemic area / Soroprevalência de Rickettsia spp. em gatos de uma área endêmica para a Febre Maculosa Brasileira

Rickettsia spp. bacteria are responsible for tick-borne diseases worldwide, mostly maintained by rickettsial amplifiers capybaras in Brazilian endemic areas. The campus of the University of São Paulo, in southeastern Brazil, is an area endemic for Brazilian spotted fever (BSF), with high density of capybaras and Amblyomma spp., along with confirmed human cases. Besides capybaras, the university has also an in-campus high population of sheltered and free-roaming cats. Accordingly, the aim of this study was to determine the prevalence and characteristics associated with Rickettsia rickettsii, Rickettsia parkeri and Rickettsia felis exposure among cats in a BSF-endemic area. Out of 51 cats sampled, 23/35 shelter (65.7%) and 5/16 free-roaming (31.2%) were positive (titers 64) for at least one Rickettsia species. Ticks species were present in 3/16 free-roaming cats (18.8%), consisting of Amblyomma spp., nymphs of Amblyomma sculptum and adult Rhipicephalus sanguineus sensu lato. Despite sharing the capybaras environment, the seropositivity among the free-roaming and shelter cats was lower than owned cats in other endemic areas. Whether equally or less exposed to rickettsial infection, compared with owned cats in endemic areas, free-roaming and shelter cats may be used as environmental sentinels for human exposure to rickettsiae in such areas.(AU)

Espécies de Rickettsia têm sido responsáveis por doenças transmitidas por carrapatos no mundo, a maioria mantida por hospedeiros amplificadores, como as capivaras em áreas endêmicas no Brasil. A Universidade de São Paulo, em Piracicaba, no sudeste do Brasil, é uma área endêmica para a Febre Maculosa Brasileira (FMB), com alta densidade de capivaras e Amblyomma spp., e com casos humanos confirmados. Além de capivaras, a universidade também possui gatos em um abrigo e de vida livre. Assim, o objetivo deste estudo foi determinar a prevalência e as características associadas com exposição à Rickettsia rickettsii, Rickettsia parkeri e Rickettsia felis em gatos de área endêmica para a FMB. Dos 51 gatos amostrados, 23/35 (65,7%) do abrigo e 5/16 (31,2%) de vida livre foram positivos (títulos 64) para pelo menos uma Rickettsia spp. Carrapatos estiveram presentes em 3/16 (18,8%) gatos de vida livre, representados por Amblyomma spp., ninfas de Amblyomma sculptum e adultos de Rhipicephalus sanguineus sensu lato. Apesar de compartilharem o ambiente com capivaras, os gatos amostrados foram igualmente ou menos expostos à infecção riquetsial do que os gatos com proprietário em outras áreas endêmicas, podendo ser usados como sentinelas para exposição humana à riquétsias nessas áreas.(AU)