Wild animal densities as predictors of cattle disease risks and breed types in southwestern Uganda.

BACKGROUND: This study investigated the spatial distribution of wild ungulates that pastoralist communities perceive as culprits in the transmission of cattle diseases outside protected areas in southwestern Uganda. Diseases are hypothesized as having influence on pastoralists' choice of cattle breed types. Until now, there have been no studies conducted on spatial patterns of wild animal species association with cattle breeds reared in Lake Mburo Conservation Area (LMCA), and how diseases transmitted therein potentially influence cattle breed herd sizes. METHODS: Animal population survey was carried out on cattle and wild ungulate species along transect lines laid perpendicular to the northern boundary of Lake Mburo National Park (LMNP). Data on the costs of cattle mortality and disease control were gathered using face-to-face interviews. We used SPSS version 17 for descriptive statistics to summarize unit cost of disease control at herd level, whereas chi-square (χ2) tests of goodness-of-fit were used to analyze observations on frequency of wild animal sightings, whose association with spatial distribution patterns of cattle breeds was examined using Pearson correlation test. RESULTS: Our results show inverse association of distance away from LMNP with wild animal populations and the cost of cattle disease control. The mean population of exotic cattle significantly increased as that of indigenous cattle decreased with increasing distance from LMNP. In a similar way, the cost of disease control and cattle abortion incidences were much lower in rangelands far away from LMNP (R2 = 0.965, p < 0.001). CONCLUSION: Spatial distribution of wild ungulates was significantly associated with reported cattle mortality, disease, and cost of disease control. Diseases and their costs of control potentially influenced spatial patterns of cattle breeds and breed herd sizes in LMCA, which in turn could affect range resource use for conserving different species of wild animals outside protected area.

Serological surveillance for wild rodent infection with SARS-CoV-2 in Europe

We report serological surveillance for exposure to SARS-CoV-2 in 1,237 wild rodents and other small mammals across Europe. All samples were negative with the possible exception of one. Given the ongoing circulation of this virus in humans and potential host jumps, we suggest such surveillance be continued.

SARS-CoV-2 surveillance in Norway rats (Rattus norvergicus) from Antwerp sewer system, Belgium

BackgroundSARS-CoV-2 human-to-animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans. AimWe tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS-CoV-2 following a local COVID-19 epidemic peak. In addition, we discuss the use and interpretation of SARS-CoV-2 serological tests on non-human samples. MethodsBetween November and December 2020, Norway rat oral swabs, feces and tissues from the sewer system of Antwerp were collected to be tested by RT-qPCR for the presence of SARS-CoV-2. Serum samples were screened for the presence of anti-SARS-CoV-2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT). ResultsThe serum of 35 rats was tested by MIA showing 3 potentially positive sera that were later shown to be negative by cVNT. All tissue samples of 39 rats analyzed tested negative for SARS-CoV-2 RNA. ConclusionThis is the first study that evaluates SARS-CoV-2 infection in urban rats. We can conclude that the sample of 39 rats had never been infected with SARS-CoV-2. We show that diagnostic serology tests can give misleading results when applied on non-human samples. SARS-CoV-2 monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents.