RESUMEN
Canine distemper virus (CDV) is responsible for a highly contagious and often fatal neurological disease that affects various carnivores, including domestic dogs. In Nepal, recent reports of CDV exposure and illness in leopards (Panthera pardus) have raised concerns about the transmission of the virus among domestic dogs and wild carnivores. To investigate the genetic lineage and spread of CDV, our study utilized archived post-mortem samples from four leopards that exhibited clinical signs suggestive of canine distemper infection. These leopards were rescued in the Palpa, Dolakha, Kathmandu, and Parbat districts. Our phylogenetic analysis revealed that the CDV strains circulating among the leopards belong to the Asia-5 lineage, which is also prevalent among dogs and wild carnivores in Nepal and neighboring India. The genetic relatedness between the leopard CDV sequences and those from both dogs and other carnivores within the Asia-5 lineage suggests that leopards in Nepal may have acquired the virus from multiple sources, potentially facilitated by their generalist dietary habits preying on dogs and even mesocarnivores. Furthermore, we inspected specific amino acid substitution in the hemagglutinin gene of leopard CDV, which also suggests possible transmission from both domestic dogs and non-canid hosts, although further research is needed to draw definitive conclusions. Given the vulnerable state of the leopard population in Nepal, already threatened by poaching and retaliatory killing, the emergence of CDV as a potential novel threat is deeply concerning. Comprehensive surveillance studies are essential to understand the dynamics of CDV spillover and to develop informed interventions. Urgent measures, including vaccination programs and effective control of the dog population, are needed to mitigate the impact of this disease and safeguard the future of Nepal's leopards and other wild carnivores.
RESUMEN
From wild dogs (Lycaon pictus) in the Serengeti to tigers (Panthera tigris altaica) in the Russian Far East, canine distemper virus (CDV) has been repeatedly identified as a threat to wild carnivores. Between 2020 and 2022, six Indian leopards (P. pardus fusca) presented to Nepali authorities with fatal neurological disease, consistent with CDV. Here, we report the findings of a serosurvey of wild felids from Nepal. A total of 48 serum samples were tested, comprising 28 Bengal tigers (P. t. tigris) and 20 Indian leopards. Neutralizing antibodies were identified in three tigers and six leopards, equating to seroprevalences of 11% (CI: 2.8-29.3%, n = 28) and 30% (CI: 12.8-54.3%, n = 20), respectively. More than one-third of seropositive animals were symptomatic, and three died within a week of being sampled. The predation of domestic dogs (Canis lupus familiaris) has been posited as a potential route of infection. A comparison of existing diet studies revealed that while leopards in Nepal frequently predate on dogs, tigers do not, potentially supporting this hypothesis. However, further work, including molecular analyses, would be needed to confirm this.
RESUMEN
This report describes the genome sequences of two Mycobacterium tuberculosis isolates, S1 and S3, recovered from Asian elephants in Nepal. These genome sequences will enhance our understanding of the genomic epidemiology of Mycobacterium tuberculosis in Asian elephants.
RESUMEN
We conducted a tuberculosis (TB) serosurveillance program of captive elephants in Nepal and compared hematology and biochemistry parameters between seropositive and seronegative elephants. A total of 153 elephants (male=20, female=133) from four national parks were tested for TB using the ElephantTB STAT-PAK® Assay (ChemBio Diagnostic Systems, Inc., Medford, NY, USA). The mean reported age for 138 elephants was 38.5 years (range 2-71 years). Seroprevalence for TB was 21.56% (33/153). The majority of seropositive elephants were female (n=30) and from Chitwan National Park (n=29). The occurrence of TB seropositive cases in other more remote national parks suggests TB may be widespread among the captive elephant population of Nepal. Hematology and biochemistry analyses were performed on 13 and 22 seropositive elephants, respectively and, nine elephants from a seronegative TB herd for comparison. Hematology parameters (hemoglobin, packed cell volume, platelet, white blood cells, and erythrocyte sedimentation rate) were comparable between the two groups. Total protein, globulin, and lactate dehydrogenase were significantly higher in seronegative elephants, and bilirubin was significantly higher in seropositive elephants whereas blood urea nitrogen, creatinine, glutamic oxaloacetic transaminase/aspartate aminotransferase (GOT/AST), glutamic pyruvic transaminase/alanine aminotransferase (GPT/ALT), gamma glutamyl transferase (GT), and albumin were not significantly different. The range of biochemical parameters that were significantly different between seropositive and seronegative elephants had narrow ranges. Thus, the potential of these parameters as a direct biomarker for TB diagnosis is limited based on the findings in this study. We recommend including blood parameters in future TB surveillance studies.
