Leishmania infantum Specific Humoral and Cellular Immune Responses in Cats and Dogs: A Comparative Cross-Sectional Study.

Dogs are the main reservoir of Leishmania infantum and display different immunological patterns correlating with the progression of infection to disease. Data about feline L. infantum adaptive immune response are scant. This study aimed to compare the prevalence and immune response in cats and dogs from the same endemic area of canine leishmaniosis. Stray cats (109) and rescued dogs (59) from Córdoba (Spain) were enrolled. Data about their exposure to L. infantum were analyzed by detection of parasite DNA, measurements of Leishmania-specific interferon-γ (whole blood assay in 57 cats and 29 dogs), and antibodies (enzyme-linked immunosorbent assay and immunofluorescence antibody test). An overall L. infantum prevalence of 30.5% in dogs and 30% in cats were found according to serology and PCR tests. Prevalence was 44.8% in dogs and 35.1% in cats tested also for interferon-γ production. Dogs showed higher anti-L. infantum antibody levels compared to cats. More than one-third of cats had contact with or were infected by L. infantum and they may contribute to the endemicity of leishmaniosis in the investigated region. The immunopathogenesis of feline L. infantum infection has similarities with dogs but cats show a lower level of adaptive immune response compared to dogs.

Transmission of toxigenic Clostridiodes difficile between a pet dog with diarrhea and a 10-month-old infant.

We describe a case of interspecies transmission of toxigenic Clostridioides difficile involving a female and her dog, both with diarrhea without another diagnosis. Genomic analysis showed that isolates were grouped into MLST clade I, closely related to ribotype 020 and shared identical genotypes.

Serological and molecular survey of hepatitis E virus in cats and dogs in Spain.

Hepatitis E virus (HEV) is an emerging zoonotic pathogen that is currently recognized as one of the major causes of acute human hepatitis worldwide. In Europe, the increasing number of hepatitis E cases is mainly associated with the consumption of animal food products or contact with infected animals. Dogs and cats have been suggested as a zoonotic source of HEV infection. The aim of this study was to assess Orthohepevirus circulation, including HEV-A, HEV-B and HEV-C species, in sympatric urban cats and dogs in southern Spain. Between 2017 and 2020, blood samples were collected from 144 stray cats and 152 dogs, both strays and pets. The presence of antibodies against HEV were tested using a double-antigen sandwich ELISA and seropositive samples were further analysed by western blot. A RT-PCR was performed to detect RNA of Orthohepevirus species (HEV-A, HEV-B and HEV-C). A total of 19 (6.4%; 95%CI: 3.6-9.2) of the 296 animals tested showed anti-HEV antibodies by ELISA. Seropositivity was significantly higher in dogs (9.9%; 15/152; 95%CI: 5.1-14.6) than in cats (2.8%; 4/144; 95%CI: 0.1-5.5). Ten of the 18 ELISA-positive animals that could be further analysed by western blot, reacted against HEV-3 and/or HEV-C1 antigens, which suggest circulation of both genotypes in urban cats and dogs in the study area. However, HEV-A, HEV-B and HEV-C RNA were not detected in any of the tested sera. This is the first study to assess HEV circulation in both stray cats and dogs in Europe. Our results provide evidence of HEV exposure in sympatric urban cat and dog populations in southern Spain. Further studies are needed to determine the role of these species in the epidemiology of HEV.

Serosurvey of pandemic H1N1 influenza A virus in dogs in Andalusia (southern Spain).

In April 2009, a new influenza A virus (IAV) subtype (A(H1N1)pdm09) spread worldwide and triggered the first human influenza pandemic of the 21st century. Since then, exposure to the pandemic H1N1 IAV has been confirmed in different animal species. Serological evidence and clinical infection with A(H1N1)pdm09 have been reported in canines, but the information available about the role of dogs in the epidemiology of this IAV subtype is still very limited in Europe. A cross-sectional study was carried out to determine the seroprevalence of A(H1N1)pdm09 in dogs in southern Spain, a region with endemic seasonal circulation in human. Sera from 750 companion dogs were collected during the period 2013-2016. Antibodies against pandemic H1N1 IAV were analysed using the haemagglutination inhibition test. Positive samples were also tested by single radial haemolysis assay. Seropositivity was only confirmed by both methods in one (0.13%; 95% CI: 0.00-0.38) adult animal sampled in 2013. To the best of the authors' knowledge, this is the first report of A(H1N1)pdm09 exposure in dogs in Spain. The low seroprevalence obtained indicates a limited exposure history to A(H1N1)pdm09 IAV in dogs in this country and suggests a low risk of transmission of this zoonotic IAV subtype between humans and dogs.

Surveillance of influenza viruses in waterfowl used as decoys in Andalusia, Spain.

A longitudinal study was carried out to determine the seroprevalence of avian influenza viruses (AIVs) in waterfowl used as decoys in Andalusia, southern Spain. A total of 2319 aquatic birds from 193 flocks were analyzed before and after the hunting season 2011-2012. In the first sampling, 403 out of 2319 (18.0%, CI95%: 15.8-19.0) decoys showed antibodies against AIVs by ELISA. The AI seroprevalence was significantly higher in geese (21.0%) than in ducks (11.7%) (P<0.001). Besides, the spatial distribution of AIVs was not homogeneous as significant differences among regions were observed. The prevalence of antibodies against AIVs subtypes H5 and H7 were 1.1% and 0.3%, respectively, using hemagglutination inhibition test (HI). The overall and H5 seroprevalences slightly increased after the hunting period (to 19.2% and 1.4%, respectively), while the H7 seroprevalence remained at the same level (0.3%). The proportion of flocks infected by AIVs was 65.3%, while 11.2% and 4.9% of flocks were positive for H5 and H7, respectively. Viral shedding was not detected in any of the 47 samples positive by both ELISA and HI, tested by RRT-PCR. The individual incidence after the hunting season was 3.4%. The fact that 57 animals seroconverted, 15 of which were confirmed by HI (12 H5 and 3 H7), was indication of contact with AIVs during the hunting period. The results indicate that waterfowl used as decoys are frequently exposed to AIVs and may be potentially useful as sentinels for AIVs monitoring. The seroprevalence detected and the seropositivity against AIVs H5 and H7, suggest that decoys can act as reservoirs of AIVs, which may be of animal and public health concern.