A study was conducted to investigate the seroprevalence and associated risk factors of Rift Valley fever (RVF) infection in cattle and some selected wildlife species at selected interface areas at the periphery of the Great Limpopo Transfrontier Conservation Area in Zimbabwe. Three study sites were selected based on the type of livestock–wildlife interface: porous livestock–wildlife interface (unrestricted); non-porous livestock–wildlife interface (restricted by fencing) and livestock–wildlife non-interface (totally absent contact or control). Sera were collected from cattle aged ≥ 2 years representing both female and intact male. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda Pools (non-interface) areas of the Gonarezhou National Park. Sera were tested for antibodies to Rift Valley fever virus (RVFV) using a competitive enzyme-linked immunosorbent assay (ELISA) test. AX2 test was used to assess differences between categories, and p 0.05 was considered as significant. In cattle, the overall seroprevalence was 1.7% (17/1011) (95% confidence interval [CI]: 1.01–2.7). The porous interface recorded a seroprevalence of 2.3% (95% CI: 1.2–4.3), the non-porous interface recorded a prevalence of 1.8% (95% CI: 0.7–4.3) and the non-interface area recorded a seroprevalence of 0.4% (955 CI: 0.02–2.5), but the difference in seroprevalence according to site was not significant (p 0.05). All impala and kudu samples tested negative. The overall seroprevalence in buffaloes was 11.7% (95% CI: 6.6–19.5), and there was no significant (p = 0.38) difference between the sites (Mabalauta, 4.4% [95% CI: 0.2–24] vs. Chipinda, 13.6% [95% CI: 7.6–23]). The overall seroprevalence in buffaloes (11.7%, 13/111) was significantly (p 0.0001) higher than in cattle (1.7%, 17/1011). The results established the presence of RVFV in cattle and selected wildlife and that sylvatic infections may be present in buffalo populations. Further studies are required to investigate if the virus is circulating between cattle and wildlife.

International audience | A study was conducted to investigate the seroprevalence and associated risk factors of Rift Valley fever (RVF) infection in cattle and some selected wildlife species at selected interface areas at the periphery of the Great Limpopo Transfrontier Conservation Area in Zimbabwe. Three study sites were selected based on the type of livestock-wildlife interface: porous livestock-wildlife interface (unrestricted); non-porous livestock-wildlife interface (restricted by fencing) and livestock-wildlife non-interface (totally absent contact or control). Sera were collected from cattle aged >= 2 years representing both female and intact male. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda Pools (non-interface) areas of the Gonarezhou National Park. Sera were tested for antibodies to Rift Valley fever virus (RVFV) using a competitive enzyme-linked immunosorbent assay (ELISA) test. AX2 test was used to assess differences between categories, and p < 0.05 was considered as significant. In cattle, the overall seroprevalence was 1.7% (17/1011) (95% confidence interval [CI]: 1.01-2.7). The porous interface recorded a seroprevalence of 2.3% (95% CI: 1.2-4.3), the non-porous interface recorded a prevalence of 1.8% (95% CI: 0.7-4.3) and the non-interface area recorded a seroprevalence of 0.4% (955 CI: 0.02-2.5), but the difference in seroprevalence according to site was not significant (p > 0.05). All impala and kudu samples tested negative. The overall seroprevalence in buffaloes was 11.7% (95% CI: 6.6-19.5), and there was no significant (p = 0.38) difference between the sites (Mabalauta, 4.4% [95% CI: 0.2-24] vs. Chipinda, 13.6% [95% CI: 7.6-23]). The overall seroprevalence in buffaloes (11.7%, 13/111) was significantly (p < 0.0001) higher than in cattle (1.7%, 17/1011). The results established the presence of RVFV in cattle and selected wildlife and that sylvatic infections may be present in buffalo populations. Further studies are required to investigate if the virus is circulating between cattle and wildlife.

A study was conducted to investigate the seroprevalence and associated risk factors of Rift Valley fever (RVF) infection in cattle and some selected wildlife species at selected interface areas at the periphery of the Great Limpopo Transfrontier Conservation Area in Zimbabwe. Three study sites were selected based on the type of livestock–wildlife interface: porous livestock–wildlife interface (unrestricted); non-porous livestock–wildlife interface (restricted by fencing) and livestock–wildlife non-interface (totally absent contact or control). Sera were collected from cattle aged ≥ 2 years representing both female and intact male. Sera were also collected from selected wild ungulates from Mabalauta (porous interface) and Chipinda Pools (non-interface) areas of the Gonarezhou National Park. Sera were tested for antibodies to Rift Valley fever virus (RVFV) using a competitive enzyme-linked immunosorbent assay (ELISA) test. AX2 test was used to assess differences between categories, and p < 0.05 was considered as significant. In cattle, the overall seroprevalence was 1.7% (17/1011) (95% confidence interval [CI]: 1.01–2.7). The porous interface recorded a seroprevalence of 2.3% (95% CI: 1.2–4.3), the non-porous interface recorded a prevalence of 1.8% (95% CI: 0.7–4.3) and the non-interface area recorded a seroprevalence of 0.4% (955 CI: 0.02–2.5), but the difference in seroprevalence according to site was not significant (p > 0.05). All impala and kudu samples tested negative. The overall seroprevalence in buffaloes was 11.7% (95% CI: 6.6–19.5), and there was no significant (p = 0.38) difference between the sites (Mabalauta, 4.4% [95% CI: 0.2–24] vs. Chipinda, 13.6% [95% CI: 7.6–23]). The overall seroprevalence in buffaloes (11.7%, 13/111) was significantly (p < 0.0001) higher than in cattle (1.7%, 17/1011). The results established the presence of RVFV in cattle and selected wildlife and that sylvatic infections may be present in buffalo populations. Further studies are required to investigate if the virus is circulating between cattle and wildlife.

The first known severe disease caused by a coronavirus (CoV) in humans emerged with the severe acute respiratory syndrome (SARS) epidemic in China, which killed 774 people during its 2002/2003 outbreak. The Middle East respiratory syndrome (MERS) was the second human fatal disease, which started in 2012 in Saudi Arabia and resulted in 858 fatalities. In December 2019, a new virus, SARS-CoV-2 (COVID-19), originating from China, began generating headlines worldwide because of the unprecedented speed of its transmission; 5.2 million people were infected and 338 480 had been reported dead from December 2019 to May 2020. These human coronaviruses are believed to have an animal origin and had reached humans through species jump. Coronaviruses are well known for their high frequency of recombination and high mutation rates, allowing them to adapt to new hosts and ecological niches. This review summarises existing information on what is currently known on the role of wild and domesticated animals and discussions on whether they are the natural reservoir/amplifiers hosts or incidental hosts of CoVs. Results of experimental infection and transmission using different wild, domesticated and pet animals are also reviewed. The need for a One Health approach in implementing measures and practices is highlighted to improve human health and reduce the emergence of pandemics from these zoonotic viruses.

The first known severe disease caused by a coronavirus (CoV) in humans emerged with the severe acute respiratory syndrome (SARS) epidemic in China, which killed 774 people during its 2002/2003 outbreak. The Middle East respiratory syndrome (MERS) was the second human fatal disease, which started in 2012 in Saudi Arabia and resulted in 858 fatalities. In December 2019, a new virus, SARS-CoV-2 (COVID-19), originating from China, began generating headlines worldwide because of the unprecedented speed of its transmission; 5.2 million people were infected and 338 480 had been reported dead from December 2019 to May 2020. These human coronaviruses are believed to have an animal origin and had reached humans through species jump. Coronaviruses are well known for their high frequency of recombination and high mutation rates, allowing them to adapt to new hosts and ecological niches. This review summarises existing information on what is currently known on the role of wild and domesticated animals and discussions on whether they are the natural reservoir/amplifiers hosts or incidental hosts of CoVs. Results of experimental infection and transmission using different wild, domesticated and pet animals are also reviewed. The need for a One Health approach in implementing measures and practices is highlighted to improve human health and reduce the emergence of pandemics from these zoonotic viruses.

All effects taken together, bovine tuberculosis (bTB) has a long-term detrimental effect on bovine herds and many wildlife species in South Africa. The disease is not only found in domestic cattle but also in African buffaloes and has to date been diagnosed in 21 wildlife species, including several rare and endangered species, thus having a potentially serious effect on conservation and biodiversity. In cattle, bTB is mostly characterised by sporadic outbreaks, but bovine herds chronically infected with the clinical disease are not uncommon. Presently, the recognised bTB control strategy in South Africa is based on ‘test and slaughter’, using the intradermal tuberculin test, followed by the slaughter of animals that have tested positive. Affected herds are placed under veterinary quarantine with movement restrictions until the outbreak is eradicated; this can take several years or last indefinitely if the outbreak cannot be eradicated. The same measures apply to infected buffalo populations, often with no prospect of ever being eradicated. This strategy is neither practical nor viable in the context of a communal farming system and becomes unethical when dealing with valuable wildlife reservoir hosts. Transmission of bTB between wildlife and cattle has been demonstrated and emphasises the need for an effective, affordable and culturally acceptable control strategy to curb the spread of bTB in South Africa. In countries with similar challenges, vaccination has been used and found to be promising for treating wild and domestic reservoir species and may hence be of value as a complementary tool for bTB control in South Africa.

All effects taken together, bovine tuberculosis (bTB) has a long-term detrimental effect on bovine herds and many wildlife species in South Africa. The disease is not only found in domestic cattle but also in African buffaloes and has to date been diagnosed in 21 wildlife species, including several rare and endangered species, thus having a potentially serious effect on conservation and biodiversity. In cattle, bTB is mostly characterised by sporadic outbreaks, but bovine herds chronically infected with the clinical disease are not uncommon. Presently, the recognised bTB control strategy in South Africa is based on ‘test and slaughter’, using the intradermal tuberculin test, followed by the slaughter of animals that have tested positive. Affected herds are placed under veterinary quarantine with movement restrictions until the outbreak is eradicated; this can take several years or last indefinitely if the outbreak cannot be eradicated. The same measures apply to infected buffalo populations, often with no prospect of ever being eradicated. This strategy is neither practical nor viable in the context of a communal farming system and becomes unethical when dealing with valuable wildlife reservoir hosts. Transmission of bTB between wildlife and cattle has been demonstrated and emphasises the need for an effective, affordable and culturally acceptable control strategy to curb the spread of bTB in South Africa. In countries with similar challenges, vaccination has been used and found to be promising for treating wild and domestic reservoir species and may hence be of value as a complementary tool for bTB control in South Africa.

Bluetongue (BT) is a vector-borne disease of ruminants caused by Bluetongue virus (BTV). Twenty-nine different serotypes of BTV are currently reported throughout the world. The main objective of this study is the development of a subunit vaccine model that could potentially be adapted to provide broad spectrum protection against multiple BTV serotypes, which the conventional vaccines fail to address. To this end, three different BTV proteins (conserved region of viral protein [VP]2, VP5 and NS1) were expressed and purified in an Escherichia coli expression system. The immunogenicity of these proteins was tested in murine models using the MontanideTM ISA 201 VG adjuvant. BALB/c mice were immunised thrice (with individual proteins and a mixture of three proteins) at two-week intervals and were monitored until Day 40 post-infection/vaccination. Protein-specific antibodies directed against the recombinant proteins were detected by indirect enzyme-linked immunosorbent assay. Neutralising antibody (Nab) titres and cross-neutralisation against a range of BTV serotypes (BTV-1, -2, -4, -5, -9, -10, -12, -16, -21, -23 and -24) were determined by serum neutralisation test. The recombinant proteins elicited higher Nab titres compared with the inactivated vaccine group, except for BTV-1, where the inactivated vaccine group elicited higher Nab titres. Additive effect of the three proteins was not observed as the Nab titres generated with a combination of conserved VP2, VP5 and NS1 was similar to those of the individual protein groups. Whilst BTV-12 could only be neutralised by serum raised against the inactivated vaccine group, BTV-5 and -24 could not be neutralised by any of the groups tested. Our cumulative data suggest that the conserved regions of VP2 (cVP2), VP5 and NS1 could play an important part in the novel vaccine design against multiple BTV serotypes. Importantly, given that VP2 was already known to elicit a serotype-specific immune response against BT, we report, for the first time, that the conserved region of VP2 has the ability to induce cross-protective immune response.

Bluetongue (BT) is a vector-borne disease of ruminants caused by Bluetongue virus (BTV). Twenty-nine different serotypes of BTV are currently reported throughout the world. The main objective of this study is the development of a subunit vaccine model that could potentially be adapted to provide broad spectrum protection against multiple BTV serotypes, which the conventional vaccines fail to address. To this end, three different BTV proteins (conserved region of viral protein [VP]2, VP5 and NS1) were expressed and purified in an Escherichia coli expression system. The immunogenicity of these proteins was tested in murine models using the MontanideTM ISA 201 VG adjuvant. BALB/c mice were immunised thrice (with individual proteins and a mixture of three proteins) at two-week intervals and were monitored until Day 40 post-infection/vaccination. Protein-specific antibodies directed against the recombinant proteins were detected by indirect enzyme-linked immunosorbent assay. Neutralising antibody (Nab) titres and cross-neutralisation against a range of BTV serotypes (BTV-1, -2, -4, -5, -9, -10, -12, -16, -21, -23 and -24) were determined by serum neutralisation test. The recombinant proteins elicited higher Nab titres compared with the inactivated vaccine group, except for BTV-1, where the inactivated vaccine group elicited higher Nab titres. Additive effect of the three proteins was not observed as the Nab titres generated with a combination of conserved VP2, VP5 and NS1 was similar to those of the individual protein groups. Whilst BTV-12 could only be neutralised by serum raised against the inactivated vaccine group, BTV-5 and -24 could not be neutralised by any of the groups tested. Our cumulative data suggest that the conserved regions of VP2 (cVP2), VP5 and NS1 could play an important part in the novel vaccine design against multiple BTV serotypes. Importantly, given that VP2 was already known to elicit a serotype-specific immune response against BT, we report, for the first time, that the conserved region of VP2 has the ability to induce cross-protective immune response.

The non-invasive monitoring of physiological stress can provide conservation and wildlife managers with an invaluable tool for assessing animal welfare and psychological health of captive and free-ranging populations. A significant decrease in free-ranging primate populations globally and an increase in captive-housed primates have led to a need to monitor the stress and general welfare of these animals. We examined the suitability of three enzyme immunoassays (EIAs) for monitoring stress-related physiological responses in the samango monkey, Cercopithecus albogularis erythrarchus. We conducted an adrenocorticotropic hormone (ACTH) challenge on a male and female at the National Zoological Garden, Pretoria, South Africa. Individual faecal samples were collected 8 days pre- and post-ACTH administration and subsequently analysed for faecal glucocorticoid metabolite (fGCM) concentrations. During the study, biological stressors occurred for both the male and female. Two of the three EIAs tested (11-oxoetiocholanolone I and II) were able to reliably monitor fGCM alterations throughout the study period in both sexes. The 11-oxoetiocholanolone I EIA, however, had the lowest mean deviation from the calculated baseline value and was thus chosen as the preferred assay. Both the physiological activation of the stress response and the biological response to a stressor could be monitored with the chosen assay. The successful establishment of a reliable, non-invasive method for monitoring adrenocortical activity in C. albogularis erythrarchus will now allow conservationists, scientific researchers and wildlife managers to evaluate the level of stress experienced, and general welfare, by animals in captivity as well as free-ranging populations.

The non-invasive monitoring of physiological stress can provide conservation and wildlife managers with an invaluable tool for assessing animal welfare and psychological health of captive and free-ranging populations. A significant decrease in free-ranging primate populations globally and an increase in captive-housed primates have led to a need to monitor the stress and general welfare of these animals. We examined the suitability of three enzyme immunoassays (EIAs) for monitoring stress-related physiological responses in the samango monkey, Cercopithecus albogularis erythrarchus. We conducted an adrenocorticotropic hormone (ACTH) challenge on a male and female at the National Zoological Garden, Pretoria, South Africa. Individual faecal samples were collected 8 days pre- and post-ACTH administration and subsequently analysed for faecal glucocorticoid metabolite (fGCM) concentrations. During the study, biological stressors occurred for both the male and female. Two of the three EIAs tested (11-oxoetiocholanolone I and II) were able to reliably monitor fGCM alterations throughout the study period in both sexes. The 11-oxoetiocholanolone I EIA, however, had the lowest mean deviation from the calculated baseline value and was thus chosen as the preferred assay. Both the physiological activation of the stress response and the biological response to a stressor could be monitored with the chosen assay. The successful establishment of a reliable, non-invasive method for monitoring adrenocortical activity in C. albogularis erythrarchus will now allow conservationists, scientific researchers and wildlife managers to evaluate the level of stress experienced, and general welfare, by animals in captivity as well as free-ranging populations.

Bovine brucellosis in South Africa is caused mainly by Brucella abortus biovar (bv.) 1 and less frequently by B. abortus bv. 2. Bacterial isolation is regarded as the gold standard for diagnosis of Brucella species; however, it is not very sensitive. The aim of this study was to determine the selective medium with optimum antibiotic composition that will allow the growth of Brucella species (spp.) while inhibiting moulds, yeast and most, if not all, Gram-negative contaminants in South Africa. In the controlled experiment, modified Agrifood Research and Technology Center of Aragon (CITA) medium (mCITA) seemed to be the optimum selective medium for isolation of Brucella spp. as compared with Farrell’s medium (FM) and modified Thayer Martin (mTM), while FM inhibited the growth of most fungal and bacterial contaminants. Mean comparison between the three media used to culture B. abortus resulted in lower mean difference ranging from 0 to 2.33. In case of Brucella ovis, high mean difference was obtained when comparing FM with mCITA (10.33) and mTM (12). However, the mean differences of 0.67 and 1.67 were obtained when comparing mCITA and mTM media used to, respectively, culture pasteurised and raw milk spiked with B. ovis. Further optimisation at the Agricultural Research Council – Onderstepoort Veterinary Research Institute resulted in a comparable performance between FM and mCITA; however, mCITA allowed optimal growth of the fastidious B. ovis, which is generally inhibited on FM. Generally, mCITA seemed to be the optimum selective medium for isolation of Brucella spp., while FM inhibits the growth of most fungal and bacterial contaminants. Thus, veterinary laboratories can use mCITA and/or FM but should take into consideration the detection of factious Brucella isolated in the country or region.

Bovine brucellosis in South Africa is caused mainly by Brucella abortus biovar (bv.) 1 and less frequently by B. abortus bv. 2. Bacterial isolation is regarded as the gold standard for diagnosis of Brucella species; however, it is not very sensitive. The aim of this study was to determine the selective medium with optimum antibiotic composition that will allow the growth of Brucella species (spp.) while inhibiting moulds, yeast and most, if not all, Gram-negative contaminants in South Africa. In the controlled experiment, modified Agrifood Research and Technology Center of Aragon (CITA) medium (mCITA) seemed to be the optimum selective medium for isolation of Brucella spp. as compared with Farrell’s medium (FM) and modified Thayer Martin (mTM), while FM inhibited the growth of most fungal and bacterial contaminants. Mean comparison between the three media used to culture B. abortus resulted in lower mean difference ranging from 0 to 2.33. In case of Brucella ovis, high mean difference was obtained when comparing FM with mCITA (10.33) and mTM (12). However, the mean differences of 0.67 and 1.67 were obtained when comparing mCITA and mTM media used to, respectively, culture pasteurised and raw milk spiked with B. ovis. Further optimisation at the Agricultural Research Council – Onderstepoort Veterinary Research Institute resulted in a comparable performance between FM and mCITA; however, mCITA allowed optimal growth of the fastidious B. ovis, which is generally inhibited on FM. Generally, mCITA seemed to be the optimum selective medium for isolation of Brucella spp., while FM inhibits the growth of most fungal and bacterial contaminants. Thus, veterinary laboratories can use mCITA and/or FM but should take into consideration the detection of factious Brucella isolated in the country or region.

This study was conducted from January to October 2018 with the objective to determine the prevalence and genetic diversity of Eimeria species in broiler and free-range chickens in KwaZulu-Natal province, South Africa. A total of 342 faecal samples were collected from 12 randomly selected healthy broiler chicken farms and 40 free-range chickens from 10 different locations. Faecal samples were screened for the presence of Eimeria oocysts using a standard flotation method. The species of Eimeria isolates were confirmed by amplification of the internal transcribed spacer 1 (ITS-1) partial region and sequences analysis. Among broiler and free-ranging chickens, 19 out of 41 pens (46.3%) and 25 out of 42 faecal samples (59.5%) were positive for Eimeria infection. Molecular detection revealed the following species: Eimeria maxima, Eimeria tenella, Eimeria acervulina, Eimeria brunetti and Eimeria mitis in all the samples screened. Similarly, polymerase chain reaction assays specific for three cryptic Eimeria operational taxonomic units were negative for all the samples. Phylogenetic analysis of the ITS-1 sequences supported species identity with the greatest variation detected for E. mitis. This study provides information on the range and identity of Eimeria species, and their genetic relatedness, circulating in commercially reared broilers and free-ranging chickens from different locations in KwaZulu-Natal province.

This study was conducted from January to October 2018 with the objective to determine the prevalence and genetic diversity of Eimeria species in broiler and free-range chickens in KwaZulu-Natal province, South Africa. A total of 342 faecal samples were collected from 12 randomly selected healthy broiler chicken farms and 40 free-range chickens from 10 different locations. Faecal samples were screened for the presence of Eimeria oocysts using a standard flotation method. The species of Eimeria isolates were confirmed by amplification of the internal transcribed spacer 1 (ITS-1) partial region and sequences analysis. Among broiler and free-ranging chickens, 19 out of 41 pens (46.3%) and 25 out of 42 faecal samples (59.5%) were positive for Eimeria infection. Molecular detection revealed the following species: Eimeria maxima, Eimeria tenella, Eimeria acervulina, Eimeria brunetti and Eimeria mitis in all the samples screened. Similarly, polymerase chain reaction assays specific for three cryptic Eimeria operational taxonomic units were negative for all the samples. Phylogenetic analysis of the ITS-1 sequences supported species identity with the greatest variation detected for E. mitis. This study provides information on the range and identity of Eimeria species, and their genetic relatedness, circulating in commercially reared broilers and free-ranging chickens from different locations in KwaZulu-Natal province.