ORIGINAL RESEARCH

 

Evidence for a host switching in the maintenance of canid rabies variant in two wild carnivore species in the Northern Cape Province, South Africa

 

 

CE Ngoepe^I; W Shumba^II; C Sabeta^I

^IWOAH Rabies Reference Laboratory, Agricultural Research Council, Onderstepoort Veterinary Research, South Africa
^IIEpidemiology and Laboratory Services, Northern Cape Department of Agriculture, Environmental Affairs, Rural Development and Land Reform, South Africa
^IIIDepartment of Veterinary Tropical Diseases, University of Pretoria, South Africa

Correspondence

 

 

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ABSTRACT

Rabies is a zoonotic infectious disease that causes at least 59 000 human deaths worldwide annually, with 95% of the cases occurring in the developing countries of Asia and Africa. There are two Lyssavirus rabies (RABV) variants circulating in South Africa, notably the canid and mongoose RABV biotypes. The canid RABV biotype is maintained in the domestic dog and two wild carnivore species, the black-backed jackal (Canis mesomelas) and the bat-eared fox (Otocyon megalotis). The yellow mongoose, a member of the Herpestidae family, is a reservoir and vector species for the mongoose RABV biotype. Rabies trends showed an increase in rabies-positive cases in aardwolves between 2011 and 2016 surpassing the bat-eared fox as the most rabies-affected wild carnivore in the Northern Cape Province of South Africa. The aim of the study was to establish the genetic relationships amongst rabies viruses recovered from both the aardwolves and bat-eared foxes. A partial region of the glycoprotein gene and the variable G-L intergenic region of the viral genome were analysed using nucleotide sequences generated from PCR amplicons. The rabies viruses recovered from the aardwolves between the year 2015 and 2017 were 100% nucleotide sequence identical, suggesting a single or common source and possible evidence for a host shift. Furthermore, the phylogenetic reconstruction demonstrated that the rabies viruses obtained from the two wild carnivore species from the Northern Cape Province clustered independently of each other with 96% nucleotide sequence identity, suggesting that the aardwolf may be able to maintain the canid RABV variant in this geographical area.

Keywords: rabies, wildlife, aardwolf, phylogenetic analysis, Northern Cape Province

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Introduction

Rabies is a neglected zoonotic and fatal disease of warm-blooded vertebrates including humans. Death is inevitable as soon as clinical signs develop. Rabies remains a significant public and veterinary health problem causing at least 59 000 human deaths annually and primarily affecting developing countries in Asia and Africa (Hampson et al. 2015). The causative agent of the disease is a viral species of the Lyssavirus genus currently composed of 17 confirmed viral species (Walker et al. 2020). Recently, putative and unclassified lyssaviruses named Kotalahti bat lyssavirus (KBLV) that were isolated from a Brandt's bat (Myotis brandtii) in Finland (Nokireki et al. 2018), and Matlo bat lyssavirus isolated from Natal long-fingered bat (Miniopterus natalensis) in South Africa (Coertse et al. 2020), both await formal inclusion into the genus. At least four members of the Lyssavirus genus have been identified and confirmed in terrestrial and Chiropteran host species in South Africa, including the classical Lyssavirus rabies (RABV), Lyssavirus Lagos (LBV), Lyssavirus mokola (MOKV) and Lyssavirus duvenhage (DUVV) (Walker et al. 2022).

Epidemiologically, RABV is distributed globally with the exception of some nation islands (such as Solomon Islands, Marshall Islands, Papua New Guinea, etc. (World Health Organization 2022). This highly neurotropic pathogen has a wide host range including terrestrial mammals and several bat species (Badrane & Tordo 2001). In southern Africa, RABV occurs as two distinct variants adapted to Carnivora and Herpestidae families, and these are referred to as the canid and mongoose RABV biotypes respectively (King et al. 1993; von Teichman et al. 1995). The canid RABV biotype is highly adapted and transmitted primarily by domestic dogs and is also maintained by wild carnivore species such as the black-backed jackal (Canis mesomelas) and bat-eared fox (Otocyon megalotis), whereas the mongoose RABV biotype is transmitted by members of the Herpestidae family, especially the yellow mongoose (Cynictis penicillata). It has been shown that black-backed jackals are able to maintain and transmit RABV in the north-western regions of South Africa (Zulu et al. 2007) where ecological conditions are favourable and support the growth of the vector populations. On the other hand, bat-eared foxes maintain and transmit the RABV in the western and drier regions of the country, including the Northern and Western Cape provinces respectively (Sabeta et al. 2007).

The aardwolf (Proteles cristatus) is a member of the Hyaenidae family that weighs 8-12 kg, and thrives on termites (Skinner & Chimimba 2005). This wild carnivore species is generally found in the semi-arid areas of southern Africa (Koehler & Richardson 1990) and its distribution is influenced primarily by the availability of termites of the genus Trinervitermes, which constitute its main diet (Cooper & Skinner 1979; Richardson 1987). Aardwolves escape the thermal stresses of the environment they occupy by making extensive use of underground dens during the inactive periods of the colder months (Anderson 1994; Richardson 1987). It is believed that during the summer and winter months, aardwolves spend more than half a day in underground dens (Anderson 2004). Furthermore, during the colder months, aardwolves switch to diurnal feeding on a different termite species, Hodotermes mossambicus (Richardson 1987), which is the primary food source for the bat-eared fox (Sillero-Zuberi 2009). Dens are also important for the aardwolves especially during the rearing of the young cubs and act as a refuge for the young cubs from predators such as black-backed jackals (Richardson 1985). Aardwolves frequently relocate to new dens when they have young cubs (every 2-5 days), a behaviour believed to be an anti-predatory strategy for protecting their young cubs (Richardson 1985).

Historically, rabies in the Northern Cape Province has been mainly confirmed in the bat-eared fox and members of the Herpestidae family, especially the yellow mongoose (ARC-OVR, unpublished records). The sporadic cases of rabies were recorded in bat-eared foxes from 1955, and since 1980 onwards there have been up to 24 confirmed cases each year (Swanepoel et al. 1993). The epidemiological and surveillance data showed a steady increase in the number of rabies-positive cases reported in aardwolves in the Northern Cape Province, South Africa. Furthermore, surveillance data showed that the number of positive rabies cases reported in aardwolves has surpassed those obtained from the bat-eared fox from 2011 (ARC-OVR, unpublished records). The rabies virus is a multi-host pathogen, to which all mammals are susceptible. Cross-species transmission or spill-over events occur when the rabies virus, which has adapted to a specific animal reservoir species is transmitted to a non-reservoir species (Wallace et al. 2014). Most cross-species transmission events do not lead to successful onward transmissions or infections within a non-reservoir population and are referred to as dead-end infections (Guerra et al. 2003; Kim et al. 2013). The rabies virus maintenance cycle in a particular host species represents a cross-species transmission event that occurred in the past and has established transmission in a novel host species (Mollentze et al. 2020). Elsewhere, it has been shown that repeated cross-species transmission from bats to skunks (Mephitis mephitis) and grey foxes (Urocyon cinereoargenteus) in northern Arizona resulted in a focal region of sustained bat rabies variant transmission within these terrestrial mammals (Kuzmin et al. 2012; Wallace et al. 2014).

The cytoplasmic domain of glycoprotein gene and G-L intergenic region is the most genetically divergent portion of the RABV genome (Sacramento et al. 1991) and its relevance in monitoring epidemiological changes in the evolution of RABVs has been investigated and routinely used globally, including in South Africa (Von Teichman et al. 1995; Ngoepe et al. 2009). Our primary objective was to establish the genetic relationships of the RABV isolates originating from aardwolves with those obtained from bat-eared foxes. Secondly, to establish the origin of the rabies epizootic in the aardwolf population. In this way, we attempted to clarify whether rabies in aardwolves is indeed part of a new and independent rabies epidemiological cycle.

 

Materials and methods

Viruses

A cohort of 52 RABV isolates collected from aardwolves between 1994 and 2017 were selected from the rabies repository at the Agricultural Research Council, Onderstepoort Veterinary Research (ARC-OVR) (Pretoria, South Africa) (Table I) for this study. The state veterinarians submit rabies-suspected cases to the laboratory for confirmation as part of the national and rabies passive surveillance programme in South Africa. The specimens were initially shown to contain lyssavirus antigen by the direct fluorescent antibody test (dFAT) (Rupprecht et al. 2018) prior to genetic characterisation. The rabies viruses collected between 1994 and 1998 were passaged once in suckling mice and subsequently stored as 20% lyophilised mouse-infected brain tissues. Viruses collected after 1998 were stored as original brain tissues at -70 ^oC. An additional nine rabies viruses obtained from bat-eared foxes collected between 2016 and 2017 were included in the study as well as previously published nucleotide sequences of rabies viruses obtained from the Northern and Western Cape Provinces of South Africa (Table I). Microsoft Excel version 2019 (Microsoft Corporation, 2018) was used for data management and descriptive statistics.

Viral RNA extraction, RT-PCR and sequencing

Total viral RNA was extracted from either the original infected brain tissues or 20% lyophilised mouse brain tissues using Tri-Reagent (Sigma Aldrich, USA) followed by Directzol^TM RNA miniprep kit (Zymo Research, USA) according to the manufacturer's instructions. The extracted RNA was stored at -80 ^oC until required. A reverse transcription polymerase chain reaction (RT-PCR) was performed using the G (+) and L (-) primer set targeting an 860 bp region inclusive of the cytoplasmic domain of the glycoprotein and the G-L intergenic region of the viral genome (Sacramento et al. 1991). The PCR products were electrophoresed in 1% agarose gels and subsequently purified using the PCR purification kit (Qiagen, Germany) according to the manufacturer's protocol. The purified PCR amplicons were sequenced in both directions using the G (+) and L (-) primers as in the PCR reactions with the BigDye^(R) Terminator v3.1 sequencing reaction kit (Applied Biosystems, USA) on an ABI 3100 automated sequencer (Applied Biosystems, USA).

Phylogenetic analysis

The phylogenetic analysis included the nucleotide sequences described in this study and other previously characterised rabies virus sequences in bat-eared foxes originating from the Northern Cape Province and the neighbouring Western Cape Province (Table I). Nucleotide sequences (n = 87) from both the Northern Cape and Western Cape provinces were aligned using ClustalW subroutine of MEGA X software package (Kumar et al. 2018) and the best fitting nucleotide substitution model was found to be symmetrical model plus Gamma (SYM + G) using the Akaike's information criterion (AIC) subroutine of the j-Model test software package (version 2.1.10). The phylogenetic analysis was undertaken using a Bayesian Markov Chain Monte Carlo (MCMC) method in the BEAST software package (version 2.5.0) using a relaxed exponential clock (Bouckaert et al. 2019).

The phylogenetic analysis relied on three independent Markov chains sampled for 10 million states and a sampling frequency of 10 000 was combined after discarding at least 10% of burn-in. The posterior distributions were subsequently inspected using the Tracer software (version 1.7.1) and the results were summarised as a maximum clade credibility tree and visualised using FigTree software (version 1.4.4). In addition, the pairwise mean evolutionary distances were calculated using Kimura-2 parameter distance model with a bootstrap of 1 000 replicates subroutine of MEGA X software package (Nei & Kumar 2000).

 

Results

Rabies statistics and trends in selected study species from 1994-2017

The epidemiological and historical surveillance data at the World Organization for Animal Health (WOAH) Rabies Reference Laboratory showed a steady increase in rabies-positive cases reported in aardwolves from 2011 until 2017 from the Northern Cape Province in South Africa (Figure 1). The rabies-positive cases diagnosed in bat-eared foxes and aardwolves between 1994 and 2017 represented 36% (n = 195) and 12% (n = 67) positivity rates respectively (Figure 1). In addition, the trends analyses demonstrated that the rabies-positive cases in bat-eared foxes were six times higher than the rabies-positive cases recorded in aardwolves between 1994 and 2010 (Figure 1). Additionally, the data demonstrated that from 2011 until 2016 aardwolves were the most affected wildlife carnivore species infected with the rabies virus as compared to bat-eared foxes (Figure 1). In addition, the passive surveillance data revealed that rabies-positive cases in aardwolves increased during the dry winter season, peaking in July on average (Figure 2).

Spatial distribution of rabies in aardwolves and bat-eared foxes in the Northern Cape between 1994 and 2017

Similarly, spatial analysis of the rabies-positive cases in aardwolves revealed 64% (n = 19) more cases clustered in the western region of the Northern Cape Province with the majority of cases being confirmed between 2011 and 2017 (Figure 3).

Furthermore, other areas reported 36% (n = 11) rabies-positive cases in the aardwolf between 2011 and 2017.

Molecular analysis and inferences on the viruses isolated from bat-eared foxes and aardwolves during the study period

All the selected rabies viruses were successfully amplified and yielded an expected amplicon of approximately 850 bp in size (data not shown). The phylogenetic analysis revealed three main distinct viral clades (A, B and C) supported by a high posterior probability of 1 (Figure 4). Clade A comprised of rabies viruses obtained from both aardwolves (n = 9) and bat-eared foxes (n = 6) originating from different geographical areas in the eastern and northern regions of the Northern Cape Province indicating a single epidemiological rabies cycle (Figure 4, Table I). The pairwise mean distance of the viruses within Clade A was 98% nucleotide sequence similarity (Table I). The viral isolates were obtained between the year 1994 and 2017 (Table I). Clade B consisted of 18 RABV from central and eastern regions of the Northern Cape Province as compared to Clade A. At least 67% (n = 12) of viral isolates were obtained from the aardwolves and 33% (n = 6) were obtained from the bat-eared foxes. The data further shows that the viruses had 98% nucleotide sequence similarity on average (Table I). Clade C consisted of 50 RABV sequences obtained mainly from the western region of the Northern Cape Province (n = 38) and neighbouring Western Cape Province (n = 12) in the south. The data revealed that the viral isolates had 98% sequence identity, which indicate that they are from a single source of infection. Furthermore, Clade C could be delineated into Sub-clades C I and II with each sub-clade supported by a high posterior probability of 1 (Figure 4). The Sub-clade C I consisted of viral isolates mainly obtained from the aardwolves with the exception of single isolate (676/16) obtained from the bat-eared foxes in 2016 (Figure 4). The data analysis showed that the viral sequences in this Sub-clade C I had 99% sequence similarity on average indicating a single source of infection (Table I). The data analysis further showed that the most recent viral isolates obtained between 2015 and 2017 from the aardwolves had 100% nucleotide sequence identity. On the other hand, Sub-clade C II consisted of viral isolates obtained from the bat-eared foxes from the Western Cape Province (Figure 4). The pairwise mean distances of the viruses within Sub-clade C II showed 99% sequence identity on average (Table I). The data analysis showed that the pairwise distance between Sub-clades C I and II had a 98% sequence identity on average (Table I).

 

Discussion and conclusion

We investigated the molecular epidemiology of rabies in two wildlife species, the aardwolf and the bat-eared fox, both found in the dry and ecologically common areas of the Northern Cape Province of South Africa. The data presented here suggest two rabies virus (RABV) epidemiological cycles occurring within the aardwolf population perpetuated by the aardwolf-to-aardwolf and aardwolf-to-bat-eared fox transmissions and vice versa. In particular, the phylogenetic data demonstrated that the RABV isolates from the aardwolf clustered independently from those obtained from the bat-eared fox, especially those originating from the western region of the Northern Cape Province. The heterogeneous clustering of the rabies viruses obtained from the aardwolf indicates that the RABV canid variant has been circulating in the aardwolf population for some time and, therefore, it appears to be well adapted to this wildlife species. A previous study demonstrated that the RABV was maintained by the Namibian kudu (Tragelaphus strepsiceros) population independently from the black-backed jackal species in similar temporal and ecological conditions (Scott et al. 2013). Another study reported an unusually high transmission of the raccoon (Procyon lotor) rabies variant to skunks (Mephitis spp), demonstrating that the virus had already undergone a host shift into the skunk population (Wallace et al. 2014). Even though spillover events from RABV maintenance host species into other species are common, most do not result in ongoing transmission or host shifts (Mollentze et al. 2020). Furthermore, the study suggested that the RABV transmission into new species with a warmer body temperature than the current maintenance host is more likely to become established as ongoing transmissions and/or maintenance host species (Mollentze et al. 2020).

The data presented suggest a common source of RABV infection in the aardwolf population especially for the viruses obtained between 2015 and 2017 in the western region of the Northern Cape Province. The data revealed that the monophyletic clade from the viral isolates from the western region of the Northern Cape Province shared a common and recent ancestor with the RABV isolates from the bat-eared fox from the Western Cape Province, which suggests cross species transmission events between the two species. A similar phenomenon was observed in Namibia where kudu rabies resulted from spillover infection from black-backed jackals and established itself as an independent rabies epidemiological cycle within the kudu population (Scott et al. 2013). Therefore, it appears that the aardwolf has been instrumental in maintaining and transmitting the RABV canid variant infection in this geographical area of the country. Our data suggest the aardwolf-associated RABV canid variant has most likely evolved in an independent epidemiological cycle originating from the bat-eared fox probably during long-term repeated infection in this part of the country. This could have resulted from sharing of limited dietary resources by these insectivorous carnivores particularly during the dry winter season and/or use of the same dens, as aardwolves tend to use dens of similar sized carnivores (Anderson 1994; Richardson 1987). It is evident that there is an ease of exchange of the RABV canid variant amongst the wild insectivorous carnivores in the Western Cape and Northern Cape Provinces, which warrants further investigation. We do not have a plausible explanation for the decline in the number of recorded rabies-positive cases in aardwolves between 2016 and 2017 and this may warrant field studies and further investigation. In the Caribbean Islands, domestic dogs and mongooses maintain the same dog-derived RABV and both act as maintenance hosts (Nadin-Davies et al. 2008; Velasco Villa et al. 2017). The presence of multiple maintenance host species could have an impact on the control measures and re-emergence of the disease in a particular geographic area. Therefore, understanding the involvement of various maintenance host species in the epidemiology of rabies can add value to the formulation of a rabies control strategy in the region.

The recent passive surveillance data showed that aardwolves accounted for the majority of rabies-positive cases in the Northern Cape Province (ARC-OVR, unpublished records) and this observation, together with phylogenetic analysis undertaken here, lends support to a maintenance and transmission role of the RABV canid variant in this species. Similar observations from epidemiological and surveillance data in south-east China suggested that ferret badger (Melogale moschata)-associated rabies has likely formed as an independent cycle originating from dogs during the long-term rabies infection (Liu et al. 2010). However, passive surveillance programmes only rely on samples submitted to the laboratory for confirmation, which may result in a significant bias (i.e. not all suspected rabies samples are submitted to the laboratory for confirmation). On the contrary, implementation of passive surveillance in Brazil resulted in an increase in the number of samples submitted for rabies testing and the frequency of positive samples significantly (Duarte et al. 2020). It was found that the majority of the aardwolf-associated rabies virus cases occurred in the sheep and goat farming areas of the Northern Cape Province where one farmer alerted the veterinary officials to the deaths occurring in this species. Since the aardwolves do not prey on livestock, most farmers are not concerned about their presence on their farms and consequently do not report any morbidities and mortalities from this species occurring on their respective farms (personal communication with a farmer). Therefore, such behaviour would result in a substantial underestimation of the actual incidence of the aardwolf-associated rabies virus cases in this area and elsewhere in the country.

The passive surveillance data reported in this study revealed that the majority of rabies-positive cases occurred in the colder months peaking in July and a similar pattern was observed in the bat-eared foxes, which peaked during the dry season (Thomson & Meredith 1993). A previous study demonstrated that during winter months the food sources for the aardwolf become scarce and this wildlife carnivore species switches to a different diet, a termite species called Hodotermes mossambicus, which makes up 90% of the bat-eared fox diet (Richardson 1985). It could, therefore, be speculated that during the winter periods, scarcity of food could potentially lead to possible intra- or inter-species contacts, as these wildlife hosts search for food or food competition, which can promote cross-species rabies virus transmission between the two species. Aggressive interaction during the territorial defense and breeding season could also create an ideal opportunity for intra- or inter-species transmission of the rabies virus amongst the population in the area. It was reported that bite wounds sustained through African wild dog (Lycaon pictus) fights with other pack members and excessive licking of wounds by sick animals could enhance the direct transmission of RABV infections within a population (Canning et al. 2019). Furthermore, the wide-ranging movement of these wild animals together with sharing of food sources during colder months might facilitate close contact between remote individuals in the population (McKenzie 1993).

The existence of rabies epidemiological cycles involving both the aardwolf and the bat-eared fox demonstrates that the RABV is easily exchanged between the two species especially in the eastern region of the Northern Cape Province. Findings from a previous study showed that the bat-eared fox is responsible for the maintenance and transmission of the rabies virus in this region of South Africa (Sabeta et al. 2007) and the data presented here suggest that a cross-species transmission event occurred from the bat-eared foxes into the aardwolf population. Such phenomena of cross-species transmission events result in enhancing the diversity of RABVs and increase the chance of virus transmission between different canid groups (Carnieli Jr 2006). This study provides some evidence that the aardwolves are capable of sustaining RABV infection cycles independent of the bat-eared foxes in this geographical area of South Africa. Despite a general lack of population statistics for the aardwolf, it is believed that this species has a stable population in the region (Green 2015) and this may allow the RABV infection to be maintained in this population. Surveillance data of the aardwolf-associated rabies virus cases in the Northern Cape Province over the last two decades together with a detailed phylogenetic analysis presented here demonstrates a RABV host shift from the bat-eared fox and the spread of the RABV in the aardwolf population. The RABV transmission dynamics are poorly understood in wildlife populations in South Africa. These results may be useful and contribute to future wildlife rabies control strategies in the Northern Cape Province. Understanding the role of different species in the transmission of multi-host pathogens, such as RABV, is vital for effective control strategies. Improved wildlife rabies virus surveillance and control strategies are required to ensure effective control of rabies in the relevant territories.

Acknowledgments

The authors would like to thank Dr Antoinette van Schalkwyk for critically reviewing the manuscript and Dr Mohamed Sirdar for generating the maps.

Conflict of interest

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Funding source

This research was funded by European Virus Archive global (EVAg), a project that has received funding from the European Union's Horizon 2020 research and innovation programme, grant number 871029.

ORCID

CE Ngoepe https://orcid.org/0000-0002-3272-9547

C Sabeta https://orcid.org/0000-0001 -7842-7985

 

References

Anderson, M.D., 1994, The influence of seasonality and quality of diet on the metabolism of the aardwolf, Proteles cristatus (Sparrman 1783), Unpublished M.Sc. Dissertation, University of Pretoria, Pretoria.         [ Links ]

Anderson, M.D., 2004, Aardwolf adaptations: a review, Transactions of the Royal Society of South Africa 59(2), 73-78. https://doi.org/10.1080/00359190409519168.         [ Links ]

Badrane, H., Tordo, N., 2001, Host switching in Lyssavirus history from the Chiroptera to the Carnivora orders, Journal of Virology 75, 8096-8104. https://doi.org/10.1128/JVI.75.17.8096-8104.2001.         [ Links ]

Bouckaert, R., Vaughan, T.G., Barido-Sottani, J., et al., 2019, BEAST 2.5: An advanced software platform for Bayesian evolutionary analysis, PLOS Computational Biology 15(4), e1006650. https://doi.org/10.1371/journal.pcbi.1006650.         [ Links ]

Canning, G., Camphor, H., Schroder, B., 2019, Rabies outbreak in African Wild Dogs (Lycaon pictus) in the Tuli region, Botswana: Interventions and management mitigation recommendations., Journal for Nature Conservation 48, 71-76. https://doi.org/10.1016/j.jnc.2019.02.001.         [ Links ]

Carnieli Jr., P., Brandão, P.E., Carrieri, M.L., et al., 2006, Molecular epidemiology of rabies virus strains isolated from wild canids in North-eastern Brazil, Virus Research 120, 1 13-120. https://doi.org/10.1016/j.virusres.2006.02.007.         [ Links ]

Coertse, J., Grobler, C.S., Sabeta, C.T., et al., 2020, Lyssaviruses in insectivorous bats, South Africa, 2003-2018, Emerging Infectious Diseases 26(12), 3056-3060. https://doi.org/10.3201/eid2612.203592.         [ Links ]

Cooper, R.L., Skinner, J.D., 1979, Importance of termites in the diet of the aardwolf, Proteles cristatus, in southern Africa, South African Journal of Zoology 14, 5-8. https://doi.org/10.1080/02541858.1979.11447640.         [ Links ]

Duarte, N.F.H., Alencar, C.H, Cavalcante, K.K.D.S., et al., 2020, Increased detection of rabies virus in bats in Ceará State (Northeast Brazil) after implementation of a passive surveillance programme, Zoonoses Public Health 67, 186-192. https://doi.org/10.1111/zph.12670.         [ Links ]

Green, D.S., 2015, Proteles cristata, The IUCN Red List of threatened species 2015: e.T18372A45195681.         [ Links ]

Guerra, M.A., Curna, A.T., Rupprecht, C.E., et al., 2003, Skunk and raccoon rabies in the eastern United States: temporal and spatial analysis, Emerging Infectious Diseases 9, 1143-1150. https://doi.org/10.3201/eid0909.020608.         [ Links ]

Hampson, K., Coudeville, L., Lembo, T., et al., 2015, Estimating the global burden of endemic canine rabies, PLOS Neglected Tropical Disease 9, e0003709. https://doi.org/10.1371/journal.pntd.0003709.         [ Links ]

Kim, B.I., Blanton, J.D., Gilbert, A., et al., 2013, A conceptual model for the impact of climate change on fox rabies in Alaska, 1980-2010, Zonooses Public Health.https://doi.org/10.1111/zph.12044.         [ Links ]

King, A.A., Meredith, C.D., Thomson, G.R., 1993, Canid and viverrid rabies viruses in South Africa, Onderstepoort Journal of Veterinary Research 60, 295-299.         [ Links ]

Koehler, C.E., Richardson, P.R.K., 1990, Proteles cristatus, Mammalian Species 363, 1-6. https://doi.org/10.2307/3504197.         [ Links ]

Kumar, S., Stecher, G., Li, M., et al., 2018, MEGA X: Molecular evolutionary genetics analysis across computing platforms, Molecular Biology and Evolution 35(6), 1547-1549. https://doi.org/10.1093/molbev/msy096.         [ Links ]

Kuzmin, I.V., Shi, M., Orciari, L.A., et al., 2012, Molecular inferences suggest multiple host shifts of rabies viruses from bats to mesocarnivores in Arizona during 2001-2009, PLoS Pathogens 8, e1002786. https://doi.org/10.1371/journal.ppat.1002786.         [ Links ]

Liu, Y., Zhang, S., Wu, X., et al., 2010, Ferret badger rabies origin and its revisited importance as potential source of rabies transmission in Southeast China, BMC Infectious Diseases 10, 234. https://doi.org/10.1186/1471-2334-10-234.         [ Links ]

McKenzie, A.A., 1993, Biology of the black-backed jackal (Canis mesomelas) with reference to rabies, Onderstepoort Journal of Veterinary Research 60, 367-371.         [ Links ]

Microsoft Corporation, 2018, Microsoft Excel. Retrieved from: https://office.microsoft.com/excel.         [ Links ]

Mollentze, N., Streicker, D.G., Murcia, P.R., et al., 2020, Virulence mismatches in index hosts shape the outcomes of cross-species transmission, Proceedings of the National Academy of Sciences 117(46), 28859-28866. https://doi.org/10.1073/pnas.2006778117.         [ Links ]

Nadin-Davis, S.A., Velez, J., Malaga, C., et al., 2008, A molecular epidemiological study of rabies in Puerto Rico, Virus Research 131(1), 8-15. https://doi.org/10.1016/j.virusres.2007.08.002.         [ Links ]

Nei, M., Kumar, S., 2000, Molecular evolution and phylogenetics. Oxford University Press, New York. Page 37.         [ Links ]

Ngoepe, C.E., Sabeta, C., Nel, L., 2009, The spread of canine rabies into Free State province of South Africa: A molecular epidemiological characterization.,Virus Research 142(1-2), 175-180. https://doi.org/10.1016/j.virusres.2009.02.012.         [ Links ]

Nokireki, T., Tammiranta, N., Kokkonen, U-M, et al., 2018, Tentative novel lyssavirus in a bat in Finland, Transboundary and Emerging Diseases 65, 593-596. https://doi.org/10.1111/tbed.12833.         [ Links ]

Redlands, C.E.S.R.I., 2011, ArcGIS Desktop: Release 10.         [ Links ]

Richardson, P.R.K., 1985, The social behaviour and ecology of the aardwolf, Proteles cristatus (Sparrman, 1783) in relation to its food resources, Unpublished D. Phil. thesis, University of Oxford, Oxford.         [ Links ]

Richardson, P.R.K., 1987, Food consumption and seasonal variation in the diet of the aardwolf Proteles cristatus in south-ern Africa, Zeitskrift für Säugetierkunde 52, 307-325.         [ Links ]

Rupprecht, C.E., Fooks, A.R., Abela-Ridder, B., editors., 2018, Laboratory techniques in rabies, Geneva: World Health Organization 5(1), 108-129.         [ Links ]

Sabeta, C.T., Mansfield, K.L., McElhiney, L.M., et al., 2007, Molecular epidemiology of rabies in bat-eared foxes (Otocyon megalotis) in South Africa, Virus Research 129, 1-10. https://doi.org/10.1016/j.virusres.2007.04.024.         [ Links ]

Sacramento D., Bourhy H., Tordo, N., 1991, PCR techniques as an alternative method for diagnosis and molecular epidemiology of rabies virus, Molecular and Cellular Probes 5, 229-240. https://doi.org/10.1016/0890-8508(91)90045-L.         [ Links ]

Schepers, C., 2018, Molecular epidemiology of rabies in domestic and wildlife in South Africa. Unpublished data.         [ Links ]

Scott, T.P., Fischer, M., Khaiseb, S., et al., 2013, Complete genome and molecular epidemiological data infer the maintenance of rabies among kudu (Tragelaphus strepsiceros) in Namibia, PLoS ONE 8(3), e58739. https://doi.org/10.1371/journal.pone.0058739.         [ Links ]

Sillero-Zuberi, C., 2009, Bat eared fox (Otocyon megalotis). In D.E. Wilson & R. A. Mittermeir (Eds). Handbook of the mammals of the world volume 1: Carnivores (pp 435-436). Barcelona, Spain. Lynx Edicions.         [ Links ]

Skinner, J.D., Chimimba, C.T. Eds., 2005, The Mammals of the Southern African Sub-region. Cambridge. https://doi.org/10.1017/CBO9781107340992.         [ Links ]

Swanepoel, R., Barnard, B.J.H., Meredith, C.D., et al., 1993., Rabies in southern Africa Onderstepoort Journal of Veterinary Research 60, 325-325.         [ Links ]

Thomson, G.R., Meredith, C.D., 1993, Rabies in bat eared foxes in South Africa, Onderstepoort Journal of Veterinary Research 60(4), 399-403.         [ Links ]

Velasco-Villa, A., Escobar, L.E., Sanchez, A., et al., 2017, Successful strategies implemented towards the elimination of canine rabies in the Western Hemisphere, Antiviral Research 143, 1-2. https://doi.org/10.1016/j.antiviral.2017.03.023.         [ Links ]

Von Teichman, B.F., Thomson, G.R., Meredith, C.D., et al., 1995, Molecular epidemiology of rabies virus in South Africa: evidence of two distinct virus groups, Journal of General Virology 76, 73-82. https://doi.org/10.1099/0022-1317-76-1-73.         [ Links ]

Walker, P.J., Siddell, S.G., Lefkowitz, E.J., et al., 2020, Changes to virus taxonomy and the statutes ratified by the International Committee on Taxonomy of Viruses, Archives of Virology 165(1 1), 2737-2748. https://doi.org/10.1007/s00705-020-04752-x.         [ Links ]

Walker, P.J., Siddell, S.G., Lefkowitz, E.J., et al., 2022, Recent changes to virus taxonomy ratified by the International Committee on Taxonomy of Viruses (2022), Archives of Virology 167(11), 2429-2440. https://doi.org/10.1007/s00705-022-05516-5.         [ Links ]

Wallace, R.M., Gilbert, A., Slate, D., et al., 2014, Right place, wrong species: a 20-year review of rabies virus cross species transmission among terrestrial mammals in the United States, PloS One 9(10), e107539. https://doi.org/10.1371/journal.pone.0107539        [ Links ]

World Health Organization, 2022, Rabies. In: Neglected tropical diseases. Available from: https://www.who.int/data/gho/data/themes/topics/rabies.         [ Links ]

Zulu, G.C., Sabeta, C.T., Nel, L.H., 2007, Molecular epidemiology of rabies: Focus on domestic dogs (Canis familiaris) and black-backed jackals (Canis mesomelas) from northern South Africa, Virus Research 140, 71-78. https://doi.org/10.1016/j.virusres.2008.11.004.         [ Links ]

 

 

Correspondence:
email: Ngoepee@arc.agric.za