Alice Fincato

Background: Q fever is a zoonotic disease caused by the intracellular bacterium Coxiella (C.) burnetii. In ruminants, it mainly leads to reproductive disorders. In humans, transmission typically occurs through direct contact with infected animals or inhalation of contaminated aerosols. Although it is a notifiable disease in the European Union for both humans and certain animal species, the actual incidence is likely underestimated due to the non-specific nature of clinical symptoms. Domestic ruminants are considered the main reservoirs of C. burnetii, placing farmers and veterinarians at increased occupational risk of infection. Objectives: This study aimed to assess the risk of Q fever infection in northern Italy by comparing the seroprevalence rates between professionally exposed individuals and not professionally exposed people. Methods: A total of 209 serum samples were analysed: 117 from exposed professionals (veterinarians, biologists, agronomists, laboratory technicians) and 92 from professionally unexposed people (control group). Serum samples were tested with a commercial enzyme-linked immunosorbent assay to detect the presence of IgG against C. burnetii. Positive and doubtful samples were further investigated with a commercial immunofluorescence assay for detection of IgM and IgG. Epidemiological data were also collected to explore potential risk factors. Results: In total, 10 of the 117 exposed individuals tested positive, yielding a seroprevalence of 8.6%, while only 1 of the 92 control subjects tested positive (1.1%). These findings indicate a significantly higher occupational risk of C. burnetii infection among exposed professionals compared to the general population. Conclusions: The results highlight the need for preventive measures and surveillance in at-risk occupational groups.

Leptospirosis is a worldwide zoonosis frequently responsible for clinical disease in dogs and rarely reported in human people. The risk of human exposure to Leptospira has been investigated in a sample population working in the northeast of Italy, a geographical area with high endemicity of canine leptospirosis. Two-hundred twenty-one human serum samples were analyzed for Leptospira microagglutination test (MAT): 112 clinical freelance small animal practitioners (exposed subjects) and 109 people not occupationally exposed to Leptospira-infected animals (unexposed subjects) were voluntarily enrolled. Despite the previously reported serological detection of antibodies vs. Leptospira in people in different Italian regions, this study did not detect any reactivity in the investigated population. This study shows that veterinarians do not appear to be at a greater risk of leptospirosis than the reference population. This may be due to both veterinarian awareness of the Leptospira zoonotic risk and the efficiency of the preventive measures and management of patients. Moreover, it could be the result of the relatively low excretion of Leptospira in symptomatic dogs, which can be considered as an environmental sentinel for Leptospira presence rather than a vehicle of transmission.

Despite the reported increase in SARS-CoV-2-infected pets, the description of the clinical features from natural infection and the medical follow up in symptomatic pets is still not sufficiently documented. This study reports the case of an indoor cat that displayed respiratory signs and a gastrointestinal syndrome, following the COVID-19 diagnosis of his owners. Thoracic radiographies were suggestive of bronchial pneumonia, while blood tests were indicative of a mild inflammatory process. Nasal and oropharyngeal swabs tested positive through RT-qPCR assays targeting SARS-CoV-2 genes 14 days after his owners tested positive for the virus. Nasal swabs persisted to be RT-qPCR positive after 31 days. Serology confirmed the presence of antibodies through ELISA, electrochemiluminescence analysis and plaque reduction neutralization test, recording a high antibody titre after 31 days. The cat improved after medical treatment and clinically recovered. This study suggests that exposure to SARS-CoV-2 could lead to a natural infection with bronchial pneumonia in cats along with a possible prolonged persistence of SARS-CoV-2 RNA in the upper airways, albeit at a low level. The cat developed neutralizing antibodies, reaching a high titre after 31 days. Further descriptions of SARS-CoV-2 naturally infected pets, their medical management and diagnostic findings would be useful to enhance knowledge about COVID-19 in susceptible animals.