Onderstepoort Journal of Veterinary Research最新文献

Peste des petits ruminants (PPR) is a highly contagious viral disease that mainly affects goats and sheep in Asia, Africa and the Middle East, and threatens Europe [R.E.1]. The disease is endemic on the African continent, particularly in West Africa, and is a major factor driving food insecurity in low-income populations. The aim of this research study was to carry out surveillance, genetic characterisation and isolation of recently circulating PPR viruses (PPRV) in sheep and goats from the six agro-ecological zones of Nigeria. A total of 268 post-mortem tissue samples of lung and mesenteric ganglia were collected from clinically suspected sheep and goats in 18 different states, of which five never previously sampled. The presence of PPRV was confirmed using a reverse-transcription coupled with a polymerase chain reaction (RT-PCR) assay. A total of 72 samples, 17 sheep (6%) and 55 goats (21%), were found to be PPR positive. Positive samples were distributed in almost all states, except Kano, where PPR was detected in previous studies. The PPRV-positive samples were further confirmed by sequencing or virus isolation in areas where the infection had never previously been detected. These results confirm the active circulation of PPRV across all six agro-ecological zones of Nigeria, and consequently, the need for introducing strict measures for the control and prevention of the disease in the country.

Green sea turtles are one of the two species of marine turtles known to nest in the Maldives. The prevalent time of nesting seems to be inconsistent throughout the island nation. In this study, sea turtle nesting activity was monitored on the island of Coco Palm Dhuni Kolhu in Baa Atoll over a period of 12 months. A total of 13 nests were confirmed with a median hatching success rate of 89.58% as ascertained by nest excavation. In one of the nests, a severely deformed hatchling with polycephaly, an opening in the neck area and a lordotic spine was found, and we investigated in detail with radiographic images and a necropsy. Our findings support the importance of consistent nesting activity and nest monitoring efforts in the country as a basis for conservation efforts.

The increasing threat of vector-borne diseases (VBDs) represents a great challenge to those who manage public and animal health. Determining the spatial distribution of arthropod vector species is an essential step in studying the risk of transmission of a vector-borne pathogen (VBP) and in estimating risk levels of VBD. Risk maps allow better targeting surveillance and help in designing control measures. We aimed to study the geographical distribution of Culicoides imicola, the main competent vector of Bluetongue virus (BTV) in sheep in Tunisia. Fifty-three records covering the whole distribution range of C.imicola in Tunisia were obtained during a 2-year field entomological survey (August 2017 - January 2018 and August 2018 - January 2019). The ecological niche of C. imicola is described using ecological-niche factor analysis (ENFA) and Mahalanobis distances factor analysis (MADIFA). An environmental suitability map (ESM) was developed by MaxEnt software to map the optimal habitat under the current climate background. The MaxEnt model was highly accurate with a statistically significant area under curve (AUC) value of 0.941. The location of the potential distribution of C. imicola is predicted in specified regions of Tunisia. Our findings can be applied in various ways such as surveillance and control program of BTV in Tunisia.

The reservoir host of Mokola virus (MOKV), a rabies-related lyssavirus species endemic to Africa, remains unknown. Only sporadic cases of MOKV have been reported since its first discovery in the late 1960s, which subsequently gave rise to various reservoir host hypotheses. One particular hypothesis focusing on non-volant small mammals (e.g. shrews, sengis and rodents) is buttressed by previous MOKV isolations from shrews (Crocidura sp.) and a single rodent (Lophuromys sikapusi). Although these cases were only once-off detections, it provided evidence of the first known lyssavirus species has an association with non-volant small mammals. To investigate further, retrospective surveillance was conducted in 575 small mammals collected from South Africa. Nucleic acid surveillance using a pan-lyssavirus quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay of 329 brain samples did not detect any lyssavirus ribonucleic acid (RNA). Serological surveillance using a micro-neutralisation test of 246 serum samples identified 36 serum samples that were positive for the presence of MOKV neutralising antibodies (VNAs). These serum samples were all collected from Gerbilliscus leucogaster (Bushveld gerbils) rodents from Meletse in Limpopo province (South Africa). Mokola virus infections in Limpopo province have never been reported before, and the high MOKV seropositivity of 87.80% in these gerbils may indicate a potential rodent reservoir.

No abstract available.

No abstract available.