Zoonotic Dis., Volume 2, Issue 1 (March 2022) – 5 articles

Previous studies have highlighted the potential role of Mycobacterium avium subspecies paratuberculosis (MAP) and human endogenous retrovirus W (HERV-W) in the pathogenesis of type 1 diabetes (T1DM) among Sardinian subjects. To better understand how antibody responses evolve during disease progression, a serological evaluation of IgG antibodies was performed in Sardinian children with T1DM collected at different time-points following the onset of the disease. It is known that anti-PI and anti-insulin (IAA) autoantibodies are the first to appear before the clinical onset of T1DM. In order to investigate the humoral responses, 69 children with T1DM were enrolled in the study, including 25 with new onset, 25 with T1DM at 1–5 years since diagnosis and 19 with T1DM at 6–12 years since diagnosis. Serum samples were tested for the presence of antibodies (Abs) against PI_46–61, three MAP epitopes (including MAP 2404c, which has a homologous sequence with PI) and two HERV-W-derived epitopes via indirect enzyme-linked immunosorbent assay (ELISA). The data obtained from the analysis showed significantly higher IgG responses against all peptides detected in the new onset group compared to longer suffering (1–5 and 6–12 years) T1DM patients, also showing a robust correlation between the proinsulin autoantibody and anti-MAP/HERV antibodies, characterized by a progressive decline the first year after onset. Taken together, these findings support the hypothesis that MAP and HERV could act as risk factors for T1DM, suggesting that they may serve as potential biomarkers of disease progression in early-stage T1DM. Full article

Recent global outbreaks of highly pathogenic avian influenza viruses (HPAIVs) of the H5N8 subtype in poultry and wild birds have raised concerns about animal and human health, particularly after its first evidence of zoonotic transmission from birds to humans. Here, we report a lethal infection with the H5N8 HPAIV in a mandarin duck that had previously demonstrated resistance to the H5N8 HPAIV infection. In addition, we revealed that the isolated virus was a genetic reassortant between the existing H5N8 HPAIV and LPAIV(s). Although further studies are warranted to assess the impact of the genetic reassortment on virus pathogenicity, the potential role of mandarin ducks in HPAIV dissemination should be re-evaluated. Full article

Phlebotomine sandflies are important vectors of Leishmania spp. and phleboviruses causing disease in animals and humans. Morphological identification of phlebotomine sandflies to the species level is challenging, requiring microscopical examination of the genitalia, which is demanding and time consuming. Molecular sandfly species identification can be a practical solution to save resources since it enables further molecular studies capable of generating data, such as biting preferences by blood meal analysis. In this study, resorting to a sandfly dataset collected between 2014 and 2018 across Portuguese territory under active mosquito surveillance and sandfly specific surveys, we used molecular methods to explore the genetic diversity and spatial distribution, further exploring ecological co-variants of four sandfly species—Phlebotomus ariasi, P. perniciosus, P. sergenti, and Sergentomyia minuta—all of which are of public health importance. Sandflies were collected from Spring to Autumn (May–November) following local temperature patterns. P. perniciosus was the most widespread detected species, with a nationwide distribution. All studied species clustered together with known samples from the Iberian Peninsula. Further monitoring studies of sandfly species diversity, distribution, and seasonality are essential for surveillance and control of sandfly-borne pathogens both nationally and globally. Full article

Hepatitis E virus (HEV) is the main cause of enterically transmitted hepatitis in humans worldwide. Among HEV, genotypes 3 and 4 are considered zoonotic agents associated with domestic pigs and wild boars, showing an increasing trend in Europe. The aim of this study is to contribute data on the prevalence of HEV in wild boars in Southwest Germany and to present a time and cost-effective two-step laboratory diagnostic approach for serological monitoring of blood samples. This method uses enzyme-linked immunosorbent assay (ELISA), followed by testing for HEV RNA by reverse transcription real-time PCR (RT-qPCR). A total of 2295 blood samples were collected in 234 municipalities in 12 counties in the period from 2016 to 2020. There was an overall seroprevalence of 10.8%, ranging from 3.6% to 17.5% per county and 7.5% to 14% per year. Retesting of these blood samples for HEV RNA revealed 15.7% viremic wild boars originating from 30 municipalities in 11 counties. Viremic wild boars were found in seven regional clusters, including 84% of the animals that tested positive for HEV. Seropositive animals <1 year of age were significantly more likely to be viremic than those >1 year. Further characterization of HEV RNA resulted in the identification of genotype 3. Altogether, serological monitoring of the blood samples, complemented by successive and targeted investigations into the presence of HEV RNA based on blood samples, provide reliable information on the seroprevalence and virus load in wild boars, which proved to be a relevant and persistent sylvatic reservoir for HEV. Full article

Rabies, a zoonotic encephalitis due to transmission of a lyssavirus, such as rabies virus (RABV), has the highest case fatality of any infectious disease. A global program for the elimination of human rabies caused by dogs is proposed for realization by 2030. Sensitive, specific, and inexpensive diagnostic tests are necessary for enhanced surveillance to detect infection, inform public health and veterinary professionals during risk assessments of exposure, and support overall programmatic goals. Multiple laboratory techniques are used to confirm a suspect case of rabies. One method for the detection of lyssavirus antigens within the brain is the direct rapid immunohistochemical test (dRIT), using light microscopy, and suitable for use under field conditions. Besides dogs, other major RABV reservoirs reside among mammalian mesocarnivores and bats. To date, use of the dRIT has been applied primarily for the diagnosis of RABV in suspect mesocarnivores. The purpose of this study was to assess the usefulness of the dRIT to the diagnosis of rabies in bats, compared to the gold-standard, the direct fluorescent antibody test (DFAT). Brains of 264 suspect bats, consisting of 21 species from Arizona and Texas, were used in the evaluation of the dRIT. The overall sensitivity of the dRIT was 100% (0.969–1.0, 95% CI) and the specificity was 94.6% (0.896–0.976, 95% CI), comparable to the DFAT. This preliminary study demonstrated the utility of the dRIT in the confirmation of RABV infection in bats. Future studies should include additional geographic, lyssavirus, and mammalian species representations for broader application during enhanced rabies surveillance, with incorporation of any potential adjustments to standard protocols, as needed. Full article