Dog bite histories and response to incidents in canine rabies-enzootic KwaZulu-Natal, South Africa

The objective of this paper is to report evaluated observations from survey records captured through a cross-sectional observational study regarding canine populations and dog owners in rabies enzootic KwaZulu-Natal province, South Africa. Our aim was to evaluate respondent knowledge of canine rabies and response to dog bite incidents towards improved rabies control. Six communities consisting of three land use types were randomly sampled from September 2009 to January 2011, using a cluster design. A total of 1992 household records were analyzed using descriptive statistics and regression modeling to evaluate source of rabies knowledge, experiences with dog bites, and factors affecting treatment received within respective households that occurred within the 365 day period prior to the surveys. 86% of the population surveyed had heard of rabies. Non-dog owners were 1.6 times more likely to have heard of rabies than dog owners; however, fear of rabies was not a reason for not owning a dog. Government veterinary services were reported most frequently as respondent source of rabies knowledge. Nearly 13% of households had a member bitten by a dog within the year prior to the surveys with 82% of the victims visiting a clinic as a response to the bite. 35% of these clinic visitors received at least one rabies vaccination. Regression modeling determined that the only response variable that significantly reflected the likelihood of a patient receiving rabies vaccination or not was the term for the area surveyed. Overall the survey showed that most respondents have heard of dog associated rabies and seek medical assistance at a clinic in response to a dog bite regardless of offending dog identification. An in-depth study involving factors associated within area clinics may highlight the area dependency for patients receiving rabies post exposure prophylaxis shown by this model.Humane Society International provided $10,000 in 2009 for Dr. Melinda Hergert to condcut this research (www.hsi.org). Bill and Melinda Gates Foundation did not contribute directly to this research but rather indirectly by the researcher piggy-backing onto an existing project (www.gatesfoundation.org).http://www.plosntds.orgam2013mn201

Lyssaviruses and the fatal encephalitic disease rabies

Lyssaviruses cause the disease rabies, which is a fatal encephalitic disease resulting in approximately 59,000 human deaths annually. The prototype species, rabies lyssavirus, is the most prevalent of all lyssaviruses and poses the greatest public health threat. In Africa, six confirmed and one putative species of lyssavirus have been identified. Rabies lyssavirus remains endemic throughout mainland Africa, where the domestic dog is the primary reservoir – resulting in the highest per capita death rate from rabies globally. Rabies is typically transmitted through the injection of virus-laden saliva through a bite or scratch from an infected animal. Due to the inhibition of specific immune responses by multifunctional viral proteins, the virus usually replicates at low levels in the muscle tissue and subsequently enters the peripheral nervous system at the neuromuscular junction. Pathogenic rabies lyssavirus strains inhibit innate immune signaling and induce cellular apoptosis as the virus progresses to the central nervous system and brain using viral protein facilitated retrograde axonal transport. Rabies manifests in two different forms - the encephalitic and the paralytic form - with differing clinical manifestations and survival times. Disease symptoms are thought to be due mitochondrial dysfunction, rather than neuronal apoptosis. While much is known about rabies, there remain many gaps in knowledge about the neuropathology of the disease. It should be emphasized however, that rabies is vaccine preventable and dog-mediated human rabies has been eliminated in various countries. The global elimination of dog-mediated human rabies in the foreseeable future is therefore an entirely feasible goal.http://www.frontiersin.org/Immunologyam2022BiochemistryGeneticsMicrobiology and Plant Patholog

Comparison of pathogenic domains of rabies and African rabies-related lyssaviruses and pathogenicity observed in mice

Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.Scan this QR code with your smart phone or mobile device to read online.W.M. (University of Pretoria) was the project leader, L.H.N. (University of Pretoria) the project co-leader and J.K. (University of Pretoria) performed the experiments. All authors contributed to writing the manuscript.We thank the National Research Foundation, the International Society for Infectious Diseases, the International Foundation for Science and the Poliomyelitis Research Foundation for financial support.http://www.ojvr.orgam201

Molecular phylogeny of Duvenhage virus

The Duvenhage virus (DUVV) constitutes one of the 11 species in the Lyssavirus genus and causes fatal rabies encephalitis. The virus is associated with insectivorous bat species and three human cases have been reported, all of which were linked to contact with bats. Few of these isolates have been studied and thus little is known about the phylogeny and epidemiology of this lyssavirus. Until 2007, when an isolate was made from the East African country of Kenya, all isolations of this virus had been from southern Africa. This discovery led to many questions regarding the spread and diversity of this lyssavirus. Phylogenetic analysis indicated that the DUVV isolates constitute two different lineages, in which the southern African isolates group together to form one lineage and the more recent isolate from Kenya constitutes a new, second lineage. We found that the new isolate has a genetic variation that has not yet been seen for DUVV. Not only is our lack of knowledge regarding the geographical distribution of this uniquely African virus emphasised, but we have also demonstrated the potential diversity within this genotype.http://www.sajs.co.z

Comparison of pathogenic domains of rabies and African rabies-related lyssaviruses and pathogenicity observed in mice

Several lyssavirus species occur in Africa (Rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus), displaying a high sequence diversity between isolates belonging to the same species. There is limited information about comparative pathogenesis of these African lyssaviruses and this precludes authoritative opinion on the potential public and veterinary health impact. In this study, an analysis of representative African lyssaviruses attempted to correlate viral genomic sequence similarities and differences with the corresponding pathogenic profiles observed in mice. The study demonstrated that the virus isolates evaluated could be lethal to mice when introduced intramuscularly and that different isolates of the same lyssavirus species differ in their virulence. Using real-time polymerase chain reaction (PCR), viral RNA was detected in brain tissue, but no viral RNA was detected in the salivary glands or blood of mice that succumbed to infection. Comparison of known pathogenic domains indicated that pathogenicity is likely to be dependent on multiple domains. Cumulatively, our results re-emphasised the realisation that the pathogenicity of a lyssavirus species cannot be deduced based on studies of only a single isolate of the species or a single pathogenic domain.Scan this QR code with your smart phone or mobile device to read online.W.M. (University of Pretoria) was the project leader, L.H.N. (University of Pretoria) the project co-leader and J.K. (University of Pretoria) performed the experiments. All authors contributed to writing the manuscript.We thank the National Research Foundation, the International Society for Infectious Diseases, the International Foundation for Science and the Poliomyelitis Research Foundation for financial support.http://www.ojvr.orgam201

Tollwut bei Kudu-Antilopen (Tragelaphus strepsiceros)

Cycles of terrestrial rabies are associated with carnivores. In non-carnivorous species, rabies typically occurs as a spill-over from the carnivore reservoir and quickly encounters a dead end in such species. One major exception to this scenario has been an ongoing epizootic of rabies in the Greater Kudu, an African antelope. These herbivores are found in high densities in southern Africa, but rabies cycles have only been described from Namibia, a vast country located in the South Western region of Africa. Epizootics were first noted in the late 1970’s and losses of up to 50 000 animals were estimated by 1985. Between 2002 and 2011, Namibian conservancies again estimated kudu losses ranging from 30–70%, resulting in very significant economic losses to the farming and gaming industries of the country. The sheer magnitude of the epizootic, phylogenetic data and experimental evidence of the particular susceptibility of kudu to rabies infection via mucous membranes are factors in support of a hypothesis that suggests horizontal transmission and maintenance of a rabies cycle within this species. It has become critical to investigate pathways for effective rabies control in Namibia – including the development of a strategy to halt and reverse the devastating epizootic of kudu rabies.Die terrestrische Tollwut ist eng mit Karnivoren als Reservoirtiere verbunden. Bei anderen nicht-karnivoren Tierarten stellt die Tollwut typischerweise eine Spillover-Infektion aus dem Fleischfresserreservoir dar, wobei diese Tierarten keinen eigenen Infektionszyklus aufbauen können. Eine große Ausnahme scheint dagegen eine anhaltende Tollwutepidemie beim Großen Kudu, einer afrikanische Antilopenart, zu sein. Obwohl diese Pflanzenfresser in hohen Populationsdichten im südlichen Afrika leben, sind beständige Tollwutinfektionszyklen bislang nur bei Kudus in Namibia im Südwesten Afrikas bekannt. Tollwutepidemien wurden das erste Mal in den späten 1970er Jahren beschrieben, denen bis 1985 schätzungsweise 50 000 Tiere zum Opfer fielen. Zwischen 2002 und 2011 wurden die Verluste bei Kudus durch Namibische Schutzorganisationen auf 30–70 % beziffert mit erheblichen wirtschaftlichen Schäden für die Landwirtschaft und den Jagdtourismus. Das schiere Ausmaß der Epidemie, phylogenetische Daten sowie experimentelle Anhaltspunkte, die eine besonders hohe Empfänglichkeit von Kudus gegenüber Tollwutinfektionen über Schleimhautkontakte belegen, unterstützen die Hypothese einer möglichen horizontalen Übertragung des Tollwutvirus und Aufrechterhaltung des Infektionszyklus in dieser Antilopenart. Daher ist die Suche nach effektiven Wegen der Tollwutbekämpfung in Namibia einschließlich der Entwicklung von Strategien zur Beendigung der verheerenden Epidemien in Kudus eine vordringliche zukünftige Aufgabe.The University of Pretoria and the National Research Foundation (NRF)http://vetline.de/zeitschriften/bmtw/open_access.htmnf201

Characteristics of owned dogs in rabies endemic KwaZulu-Natal province, South Africa

BACKGROUND : Canine rabies has been enzootic in the dog population of the KwaZulu-Natal province of South Africa since the mid-1970s and has been associated with high rates of human exposures and frequent transmissions to other domestic animal species. Several decades of control efforts, consisting primarily of mass vaccination programs, have previously failed to sufficiently curb rabies in the province. Despite this history of canine rabies, the target canine population has never been extensively studied or quantified. For efficient and effective vaccination campaign planning, the target population must be evaluated and understood. This study reports evaluated observations from survey records captured through a cross sectional observational study regarding canine populations and dog owners in rabies enzootic KwaZulu-Natal province, South Africa. The objective of this study was to aid government veterinary services in their current and ongoing efforts to eliminate canine rabies in the province by gaining information about the size and distribution of the owned dog population. RESULTS : Thirty-eight percent of the households owned one or more dogs, with rural areas surveyed containing a significantly higher number of owned dogs than urban areas. The mean dog/person ratio for this study was 1:7.7 (range 1:5.4–1:31). The provincial sex ratio was 1.5:1 male to female, with the percentages for male dogs across the communities ranging from 53 to 61.5%. The age structure of this dog population indicates a high turnover rate. Dogs were kept mostly for guarding homes or livestock. Eighty-four percent of dogs had received a rabies vaccine at some point in their lifetime, almost all during a rabies campaign. CONCLUSIONS : The study indicates the majority of owned dogs can be handled by at least one member of the household, thus can be made readily accessible for rabies vaccination during a campaign. Characteristics of owned dogs in the province were similar to those studied in other African countries; however, there were remarkable differences in age, sex and husbandry practices compared to dogs in eastern or northern Africa. These geographical differences lend credence to the theory that canine populations are heterogeneous; therefore, target populations should be evaluated prior to intervention planning.The University of Pretoria, Onderstepoort and the Humane Society International.https://bmcvetres.biomedcentral.comam2019BiochemistryGeneticsMicrobiology and Plant PathologyParaclinical Science

Reverse transcription recombinase polymerase amplification assay for rapid detection of canine associated rabies virus in Africa

Rabies is a neglected disease mostly affecting the developing world. Accurate and reliable diagnostic and surveillance data forms the foundation for the formulation and monitoring of control strategies. Although various sensitive and specific tests are available for detection of rabies virus, implementation of these tests in low-resource settings are challenging and remains limited. In this study, we describe the developed of a reverse transcription recombinase polymerase amplification assay for the detection of rabies virus. The analytical sensitivity of this assay was determined to be 562 RNA copies and was performed in 20 minutes. The diagnostic sensitivity of the RT-RPA was 100% for detection of rabies virus in field samples. In conclusion, the RT-RPA assay allowed for very quick and sensitive detection of rabies virus and could be adapted for use in low-source settings.Supporting information: S1 Table. Details of rabies virus sequences used for primer and probe design for the RT-RPA assay.S2 Table. Evaluation of the mismatches between the RT-RPA primer and probe set binding regions to rabies-related lyssaviruses.The South African Research Chair initiative of the Department of Science and Technology and National Research Foundation of South Africa and the Poliomyelitis Research Foundation.http://www.plosone.orgpm2020BiochemistryGeneticsMedical VirologyMicrobiology and Plant Patholog

Development of a diagnostic one-tube RT-PCR for the detection of Rift Valley fever virus

Diagnosis of Rift Valley fever (RVF) is based on serology and virus isolation. The disadvantages of the former include poor sensitivity, high cost, risks associated with using infectious virus as antigen, the lengthy duration of ELISA as well as cross-reactivity with other Phleboviruses. We developed, optimised and evaluated a one-tube reverse-transcription-polymerase chain reaction (RT-PCR) for the detection of Rift Valley fever virus (RVFV) in ruminants. The PCR primers for this assay were designed to anneal to a region within the M segment of the virus genome, encoding glycoproteins G1 and G2. A PCR amplicon of 363 bp was obtained. The sensitivity of the assay was determined to be 0.25 TCID₅₀. This test should allow for the early and rapid detection of RVFV in both serum and whole blood. In addition, it could facilitate the quantification of antigen for the manufacture of current vaccines.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Serological survey of bovine viral diarrhoea virus in Namibian and South African kudu (Tragelaphus strepsiceros) and eland (Taurotragus oryx)

Bovine viral diarrhoea virus (BVDV) is a pestivirus that affects members of the order Artiodactyla, including members of the subfamily Bovinae. Little is known about the seroprevalence of BVDV in southern Africa, especially the prevalence in wild ruminant populations such as kudu (Tragelaphus strepsiceros). A handful of random surveys suggested that seroprevalence ranged between 6% and 70% in southern African wild ruminants. The present study aimed to determine the seroprevalence of BVDV amongst kudu and eland (Taurotragus oryx) from Namibia and South Africa. A BVDV-specific enzyme-linked immunosorbent assay was performed on 50 serum samples from kudu and eland from South Africa and Namibia. The seroprevalence of BVDV in South African kudu was 71%, identical to that in Namibian kudu. The seroprevalence in Namibian eland was 40%. The kudu and cattle farming (free ranging) regions in Namibia predominantly overlap in the central regions, ensuring ample opportunity for cross-species transmission of BVDV. It is therefore important to determine the true prevalence of BVDV in southern Africa in both domesticated and wild animals. In addition, a potential link between BVDV incidence and a devastating rabies epidemic in Namibian kudu was proposed and such a notion could be supported or discredited by comparative prevalence data.We would like to thank the University of Pretoria and the National Research Foundation for funding. We would also like to thank all the participating farmers in Namibia, Cruiser Safaris and Thomas Ochsenbein for obtaining blood samples. Publication of this article was sponsored by the Wildlife Group (http://www.vets4wildlife.co.za) of the South African Veterinary Association.http://www.jsava.co.zaam201