RESUMO
Archival swine DNA samples from Indonesia and Mongolia, some of which were previously shown to be positive for African swine fever virus, were screened for the presence of porcine circovirus 2 (PCV-2) and porcine circovirus 3 (PCV-3) by PCR. Samples from both countries were positive for PCV-2 (three from Mongolia and two from Indonesia), while none were positive for PCV-3. The PCV-2 amplicons were sequenced, and phylogenetic analysis revealed that the PCV-2 strains belonged to four different genotypes: PCV-2a (Mongolia), PCV-2b (Mongolia and Indonesia), PCV-2d (Indonesia), and PCV-2g (Mongolia). This is the first report of ASFV/PCV-2 coinfection in pigs and the first report of the presence of PCV-2 in Mongolia.
Assuntos
Vírus da Febre Suína Africana , Infecções por Circoviridae , Circovirus , Coinfecção , Doenças dos Suínos , Vírus da Febre Suína Africana/genética , Animais , Infecções por Circoviridae/veterinária , Circovirus/genética , Coinfecção/veterinária , Filogenia , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
As pig production increases in Africa, it is essential to identify the pathogens that are circulating in the swine population to assess pig welfare and implement targeted control measures. For this reason, DNA samples collected from pigs in Nigeria in the context of African swine fever monitoring were further screened by PCR for porcine circovirus 2 (PCV-2), porcine circovirus 3 (PCV-3), and porcine parvovirus 1 (PPV1). Forty-seven (45%) pigs were positive for two or more pathogens. Sequence analysis identified PCV-2 genotypes a, b, and d, while limited genetic heterogenicity was observed among PCV-3 strains. All except one of the PPV1 sequences were genetically distinct from those previously identified in other countries.
Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Infecções por Circoviridae , Circovirus , Coinfecção , Parvovirus Suíno , Doenças dos Suínos , Suínos , Animais , Circovirus/genética , Parvovirus Suíno/genética , Vírus da Febre Suína Africana/genética , Doenças dos Suínos/epidemiologia , Coinfecção/epidemiologia , Coinfecção/veterinária , Nigéria/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/veterináriaRESUMO
Porcine circovirus 2 (PCV-2) is the causative agent of porcine circovirus diseases (PCVD). A study was undertaken to determine whether PCV-2 was present in samples collected from commercial pigs (n = 46) and warthogs (n = 42) in Namibia between 2019 and 2020. Twenty-three of the collected samples were positive by PCR (13 from pigs and 10 from warthogs), and a phylogenetic analysis of ORF2 identified three genotypes (PCV-2b and PCV-2d in pigs and PCV-2c in warthogs). This is the first time that PCV-2 has been identified in warthogs and in Namibia. It is also the first report of PCV-2c in Africa.
Assuntos
Infecções por Circoviridae/veterinária , Circovirus/genética , Genótipo , Doenças dos Suínos/virologia , Animais , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Namíbia/epidemiologia , Filogenia , Suínos , Doenças dos Suínos/epidemiologiaRESUMO
Introduction: To support African veterinary laboratory services, the Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise puts in place an operational system called "SILAB for Africa" (SILABFA); this is a web application used by a laboratory information management system to support laboratory diagnostic activities and to meet the needs of various African countries. SILABFA was designed to collect and manage all necessary information on samples, tests, and test results.Methods: The system involves the entry of sample data on arrival, the tracking of samples through the various sections of the laboratory, and the collection of test results. It automates the generation of test reports and monitors outbreaks through data interrogation functions and eliminates multiple registrations of the same data on paper records. SILABFA is currently installed in Namibia, Botswana, Zambia, Zimbabwe, Tanzania, Uganda, Kenya, Ethiopia, and Cameroon, and installation in Senegal and Ivory Coast is planned for the next few months. After some years of SILABFA usage, it was natural to want to utilize more and more data collected in a homogeneous and consistent way for epidemiological purposes and to cover informative debts toward ministries and other organizations.Conclusion: To improve the availability of good, detailed, and reliable data, as the epidemiological information, SILABFA has been linked to the local animal identification, registration, and traceability system and other relevant national information systems.
Assuntos
Doenças dos Animais/diagnóstico , Sistemas de Informação em Laboratório Clínico/organização & administração , Laboratórios/organização & administração , Medicina Veterinária/métodos , África , Animais , InternetRESUMO
Between July and August 2018, two outbreaks of infectious laryngotracheitis caused the death of over 116,000 commercial poultry (layers and broilers) near the city of Windhoek, Namibia. A third outbreak occurred in September 2018 in the north of the country approximately 800 km from the original outbreaks. Sample collection and molecular epidemiological analyses revealed that the outbreaks were most likely caused by poor vaccination practices leading to the reversion to virulence of an ILT vaccine strain. The analyses also indicate that inaccurate declarations were made by one of the farms involved and that illegal movement of animals most likely occurred.
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Infecções por Herpesviridae/epidemiologia , Infecções por Herpesviridae/veterinária , Herpesvirus Galináceo 1/imunologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Animais , Galinhas/imunologia , Surtos de Doenças/veterinária , Geografia , Namíbia , Filogenia , Aves Domésticas , Vacinação , Vacinas Virais , VirulênciaRESUMO
Between January and July 2017, lumpy skin disease (LSD) outbreaks were reported in cattle in Namibia. DNA was extracted from skin biopsies taken from 32 cattle, and the RNA polymerase 30 kDa subunit (RPO30) gene of the LSD virus (LSDV) was successfully amplified by PCR. Phylogenetic analysis revealed that the newly sequenced LSDV isolates from Namibia were identical to LSDV isolates identified previously in Burkina Faso, Egypt, Greece, Niger, Serbia and South Africa. Given that only unvaccinated herds were affected by LSD, it is recommended that the current vaccination programmes in Namibia be re-evaluated to allow nationwide coverage.
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DNA Viral/genética , RNA Polimerases Dirigidas por DNA/genética , Surtos de Doenças , Doença Nodular Cutânea/epidemiologia , Vírus da Doença Nodular Cutânea/genética , Proteínas Virais/genética , Animais , Bovinos , Programas de Imunização/organização & administração , Doença Nodular Cutânea/patologia , Doença Nodular Cutânea/virologia , Vírus da Doença Nodular Cutânea/classificação , Vírus da Doença Nodular Cutânea/isolamento & purificação , Namíbia/epidemiologia , Filogenia , Subunidades Proteicas/genéticaRESUMO
The complete sequences of the fusion (F) protein genes of six Newcastle disease virus (NDV) isolates from backyard poultry in Namibia in 2016 have been determined. The F gene cleavage site motif for all of the isolates was 112RRQKRF117, indicating that the viruses are virulent. A phylogenetic analysis using the full F gene sequence revealed that the viruses belong to a novel subgenotype, VIIk. This is the first genetic characterization of NDV isolates from Namibia, and the findings have important implications for Newcastle disease management and control in the region.
Assuntos
Doença de Newcastle/virologia , Vírus da Doença de Newcastle/genética , Vírus da Doença de Newcastle/isolamento & purificação , Doenças das Aves Domésticas/virologia , Proteínas Virais de Fusão/genética , Animais , Sequência de Bases , Genes Virais , Genótipo , Namíbia/epidemiologia , Doença de Newcastle/epidemiologia , Vírus da Doença de Newcastle/classificação , Filogenia , Aves Domésticas , Doenças das Aves Domésticas/epidemiologiaRESUMO
After a May 2011 outbreak of Rift Valley fever among livestock northeast of Etosha National Park, Namibia, wild ruminants in the park were tested for the virus. Antibodies were detected in springbok, wildebeest, and black-faced impala, and viral RNA was detected in springbok. Seroprevalence was high, and immune response was long lasting.
Assuntos
Animais Selvagens/virologia , Gado/virologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift/isolamento & purificação , Animais , Anticorpos Antivirais/imunologia , Surtos de Doenças , Namíbia/epidemiologia , Parques Recreativos , RNA Viral/genética , Febre do Vale de Rift/virologia , Vírus da Febre do Vale do Rift/genética , Estudos SoroepidemiológicosRESUMO
Bovine trichomonosis caused by Tritrichomonas foetus is a significant reproductive disease of cattle. Preputial samples were collected using sheath washing technique in bulls in Namibia. Thirty-six trichomonad cultures were characterized using the TaqMan-probe commercial real-time polymerase chain reaction (PCR) diagnostic assay (VetMAX™-Gold Trich Detection Kit) and CYBR real-time PCR assay based on TFR3/4 primers. Diagnostic real-time PCRs and DNA sequencing of the internal transcribed region confirmed presence of T. foetus in 35 out of 36 samples. Multilocus genotyping using cysteine proteases (CP1, CP2, CP4, CP5, CP6, CP7, CP8, CP9) and malate dehydrogenase (MDH1) gene sequences demonstrate that the T. foetus in Namibia are genetically distinct from those characterized elsewhere. We report the discovery of a novel genotype of T. foetus in Namibian cattle, distinct from other T. foetus genotypes in Europe, South and North America and Australia. We suggest recognition of a 'Southern African' genotype of T. foetus. Identification of the new genotype of T. foetus demonstrates the need for wider global sampling to fully understand the diversity and origin of T. foetus causing disease in cattle or cats.
Assuntos
Doenças dos Bovinos/parasitologia , Infecções Protozoárias em Animais/parasitologia , Tritrichomonas foetus/genética , África Austral/epidemiologia , Animais , Austrália/epidemiologia , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/epidemiologia , Cisteína Proteases/genética , DNA de Protozoário/genética , Europa (Continente)/epidemiologia , Genótipo , Malato Desidrogenase/genética , Namíbia/epidemiologia , América do Norte/epidemiologia , Infecções Protozoárias em Animais/epidemiologia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Análise de Sequência de DNA , Tritrichomonas foetus/isolamento & purificaçãoRESUMO
Pig production is increasing annually in Africa as it is recognized as a significant source of income, livelihood and food security, particularly in rural communities. Understanding the circulating swine pathogens is crucial for the success of this emerging industry. Although there is extensive data available on the African swine fever virus due to its devastating impact on pig production, knowledge about the presence of other viral swine pathogens on the continent is still extremely limited. This review discusses what is currently known about six swine pathogens in Africa: classical swine fever virus, porcine reproductive and respiratory syndrome virus, porcine circovirus-2, porcine circovirus-3, porcine parvovirus-1, and pseudorabies virus. Gaps in our knowledge are identified and topics of future focus discussed.
Assuntos
Animais Selvagens , Circovirus , Doenças dos Suínos , Animais , Suínos , Doenças dos Suínos/virologia , Doenças dos Suínos/epidemiologia , África/epidemiologia , Circovirus/isolamento & purificação , Circovirus/genética , Circovirus/classificação , Animais Selvagens/virologia , Parvovirus Suíno/isolamento & purificação , Parvovirus Suíno/genética , Viroses/veterinária , Viroses/epidemiologia , Viroses/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Febre Suína Africana/isolamento & purificação , Animais Domésticos/virologia , Herpesvirus Suídeo 1/isolamento & purificação , Infecções por Circoviridae/veterinária , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , DomesticaçãoRESUMO
Feline Immunodeficiency Virus (FIV) is one of the most important infectious diseases of cats, with potential implications in wildlife conservation. Unfortunately, FIV screening and surveillance in domestic cats remains limited in several African countries, including Namibia. In this study, 279 blood samples from domestic cats in Namibia were analyzed for FIV diagnosis by PCR. The cats represented various regions and were cared for by people largely from rural areas with limited financial means. Only 1.43 % of the samples tested positive, unexpectedly low given their outdoor lifestyles. The infected cats, primarily adult and unsterilized, showed no typical FIV symptoms, suggesting subclinical infections. Genetic analysis of the detected strains indicated a unique FIV strain cluster in Namibia, although with a certain within-country variability, in the absence of consistent geographical clustering. The present study represents the first detection and genetic characterization of FIV in the Namibian domestic cat population. Although the infection frequency was low, also in the rural free-roaming population, the features of the enrolled population could have biased the estimation, suggesting the need for more extensive surveys involving diseased and older cats as well. Additionally, because of the long-lasting subclinical nature of the infection, frequent monitoring activities should be performed that allow prompt isolation of infected animals and the implementation of appropriate control measures if necessary.
Assuntos
Doenças do Gato , Síndrome de Imunodeficiência Adquirida Felina , Vírus da Imunodeficiência Felina , Humanos , Animais , Gatos , Vírus da Imunodeficiência Felina/genética , Síndrome de Imunodeficiência Adquirida Felina/epidemiologia , Animais Selvagens , Análise por Conglomerados , África , Doenças do Gato/epidemiologiaRESUMO
The present study investigated the seropositivity rate of Hepatitis E virus (HEV) in domestic and working animals in Namibia, which included dogs, cats, horses, and donkeys. HEV poses a growing threat as a significant cause of human hepatitis globally and has several genotypes of varying zoonotic potential. As epidemiological data on the seroprevalence of HEV in Namibia is scarce, a serosurvey was conducted on archived serum samples of 374 dogs, 238 cats, 98 horses, and 60 donkeys collected between 2018 and 2022 from different regions, to assess the potential of these animals as sources of HEV infection. The findings revealed that 10.43% (n = 39/374) canine and 5.88% (n = 14/238) feline samples tested positive for HEV antibodies, whereas no seropositivity was detected in horses and donkeys. The study further examined the risk factors associated with HEV seropositivity, including animal sex, age, and geographical region, and noted a higher prevalence in dogs living in areas with intensive pig farming. Although there is no direct evidence indicating that these animals served as major reservoirs for HEV transmission to humans, the study underscores the importance of preventive measures to minimize contact exposure with pets considering the potential zoonotic risk, especially for susceptible risk groups. Further research is needed to explore the zoonotic potential of domestic animals and the epidemiological links between animal and human HEV transmissions in Namibia.
RESUMO
Since its first identification in 2015, porcine circovirus 3 (PCV-3) has been reported worldwide with a high frequency and in the presence of several clinical conditions, although its impact on pig health and productivity is still debated. Data on the presence of PCV-3 in Africa are, however, limited. A previous study performed on commercial pigs in Namibia failed to identify the pathogen. In the present study, the viral circulation in backyard farms, characterised by lower biosecurity measures and frequent animal exchange between farms, was assessed. The susceptibility of warthogs to PCV-3 infection and their potential epidemiological role were also evaluated. Tonsils from 77 pigs from backyard piggeries and 55 warthogs were collected in different regions of Namibia and tested by PCR. Positive samples were sequenced and compared to PCV-3 strains circulating globally. Forty-two out of 77 pigs (54.54 %) and 12 out of 55 warthogs (21.82 %) tested positive, demonstrating the presence of PCV-3 in the country and suggesting that the high biosecurity measures implemented in the commercial farms that previously tested negative for PCV-3 probably prevented viral introduction. The partial ORF2 gene was successfully sequenced in samples from 27 pigs and 6 warthogs. Genetically, the identified strains were part of 3 distinct groups which included both backyard pigs and warthogs from different regions of Namibia. There is also evidence for the occurrence of multiple introduction events most likely from Asian countries, either directly into Namibia or through other African countries. Considering the strict Namibian regulations on live animal importation, understanding the source of viral introduction is challenging, although semen importation or the habit of feeding backyard pigs with human food waste might have played a role. Pig exchanges between farms for breeding purposes or wildlife movements could also have been involved in PCV-3 dispersal within Namibia. Despite the significant advances in the field, further studies should be undertaken to properly understand PCV-3 epidemiology in Namibia and its impact on pig productivity and wildlife health.
Assuntos
Infecções por Circoviridae , Circovirus , Eliminação de Resíduos , Doenças dos Suínos , Animais , Humanos , Animais Selvagens , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/veterinária , Circovirus/genética , Fazendas , Alimentos , Variação Genética , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/diagnóstico , NamíbiaRESUMO
Objective: Canine distemper virus (CDV) is a highly infectious virus that represents a threat for domestic dogs and several wild species. Despite recognized in several African countries, current knowledge of its molecular epidemiology is scarce and poorly updated. Design: Twenty-two hemagglutinin sequences, obtained from symptomatic Namibian dogs from 2020 to 2023, were analysed through phylogenetic and phylodynamic analysis to characterize the local CDV epidemiology and contextualize it in the international scenario. Results: Two unrelated clades were identified, including strains sampled in different Namibian towns, in the absence of a strong geographical clustering. The ancestors of the two clades were estimated to have originated from South America, likely Brazil, and South Africa, approximately in 2000 and 2006, respectively. While the introduction from South Africa was predictable, the introduction from Brazil was unexpected. The mediation of other African countries, particularly Angola, appears to be the most likely importation pathway. Conclusions: The occurrence of multiple introduction events, likely originating from cross-border illegal animal trade between African countries, and the absence of any geographical clustering within Namibian regions, suggest a need for further investigation into its spreading pattern, as well as improved biosecurity measures to limit foreign viral introduction into the country.
RESUMO
During May-July 2010 in Namibia, outbreaks of Rift Valley fever were reported to the National Veterinary Service. Analysis of animal specimens confirmed virus circulation on 7 farms. Molecular characterization showed that all outbreaks were caused by a strain of Rift Valley fever virus closely related to virus strains responsible for outbreaks in South Africa during 2009-2010.
Assuntos
Surtos de Doenças , Febre do Vale de Rift/veterinária , Vírus da Febre do Vale do Rift/classificação , Vírus da Febre do Vale do Rift/genética , Animais , Linhagem Celular , Geografia Médica , Namíbia/epidemiologia , Filogenia , RNA ViralRESUMO
Thirty swine samples collected from different regions of Namibia between 2019 and 2020 were screened for the presence of porcine parvovirus 1 (PPV1) by PCR. Eleven samples (37%) were positive. Phylogenetic analysis of a partial sequence of the structural protein gene (VP2) identified two distinct clusters, one which contained sequences that were highly similar to PPV1 previously identified in warthogs in Namibia. These results indicate possible PPV1 transmission between warthogs and domestic pigs and highlight the importance of wildlife as sources of pathogens.
Assuntos
Parvovirus Suíno , Doenças dos Suínos , Suínos , Animais , Sus scrofa , Parvovirus Suíno/genética , Filogenia , Namíbia/epidemiologia , Doenças dos Suínos/epidemiologiaRESUMO
In this report, we describe eight complete genome sequences of African horse sickness virus (AHSV) strains belonging to four different serotypes, namely, AHSV-5, AHSV-6, AHSV-8, and AHSV-9. Samples were collected in Namibia and South Africa from infected horses between 2000 and 2011. As expected, phylogenetic analyses of the variable outer capsid protein VP2 genomic sequences of AHSV-6 and AHSV-8 show higher nucleotide identity between the isolated viruses than that of the relevant reference strains. The full-genome sequence of AHSV will provide useful information on its geographical origin, and it will also be instrumental for comparing the distribution of the Namibian isolate with that of global isolates.
RESUMO
The commercial farming and trading of parrots and ornamental birds as companion animals are important economic activities in many countries. Some of the bird species farmed/traded are captured from the wild or are closely related to wild birds and therefore represent a risk of pathogen exchange/introduction. Beak and feather disease virus (BFDV) and avian poliomavirus (APV) are among the viruses with the biggest impact on companion bird populations and have been detected in different hosts worldwide. Despite their relevance for both domesticated and wild birds, our knowledge of BFDV and APV epidemiology remains limited in several African countries. In the present study, 143 cloacal swabs were collected from companion birds in Windhoek, Namibia, and tested by polymerase chain reaction for BFDV and APV. Of the samples tested, 35/143 (24.48%) tested positive for BFDV; 11/143 (7.69%) were positive for APV; and 6/143 (4.2%) tested positive for both pathogens. Positive amplicons, consisting of segments of the ORF1 and VP1 genes, were sequenced and compared with sequences from viruses identified in other countries. Four Namibian-only clades of BFDV were identified, loosely related to foreign strains, which suggest the occurrence of multiple introduction events in the past, potentially from South Africa, followed by local, independent evolution. In contrast, the Namibian APV sequences were identical to each other and form a single clade. In both instances, no correlation was observed between the sampling host and the viral phylogeny, suggesting the absence of host-specific adaptation and a remarkable, unconstrained viral circulation within Namibian borders. Therefore, while regulations and control measures developed against foreign strain introduction have proven to be effective over time, the spread of BFDV and APV within Namibia's borders appears undeterred. Additional resources should be dedicated to limit strain circulation in commercial farming facilities, markets and small-scale traders.
Assuntos
Doenças das Aves , Infecções por Circoviridae , Circovirus , Papagaios , Polyomavirus , Animais , Circovirus/genética , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/veterinária , Namíbia/epidemiologia , Polyomavirus/genética , Análise de Sequência , Doenças das Aves/epidemiologia , FilogeniaRESUMO
West Nile virus (WNV) is an important zoonotic Flavivirus responsible for mild fever to severe neurological disease in humans and horses. Despite the occurrence of major previous outbreaks in Namibia and the likelihood of the current endemicity of the virus, only limited investigations and monitoring activities of WNV have been performed in the country. The use of animal sentinels is a valuable approach toward investigating the infection presence in an area and to predict the potential occurrence of human outbreaks. Serological investigations in dogs hold several advantages, considering their infection susceptibility, the ease of sample handling, and the evaluation of risk factors of pet owners that share the same habit with their pets. To evaluate the usefulness of such a sero-epidemiological investigation in Namibia, a broad serosurvey was performed in 2022 that included 426 archived domestic dog samples from eight Namibian regions. Although the ELISA prevalence, indicative of Flavivirus infection, was relatively high (16.43%; 95 CI: 13.10-20.39%), the virus neutralization test confirmed only a minority of cases, highlighting a prevalence of 2.82% (95 CI: 1.47-4.90%), significantly lower than in Namibian donkeys and reports from other countries. Variables that could explain the recorded differences remain to be explored, including animal exposure, variable vector presence, distribution, and feeding preferences. The study results suggest the limited usefulness of dogs as sentinels for WNV monitoring in Namibia.
RESUMO
Canine circovirus (CanineCV) is a DNA virus affecting domestic dogs and other wild carnivore species. Despite the potential implications for dogs' health and wildlife conservation, data on CanineCV presence, epidemiology and genetic features from Africa is still poor. In the present study, biological specimens collected between 2020 and 2022 from a total of 32 jackals and 575 domestic dogs were tested for the presence of CanineCV DNA to evaluate its frequency. Furthermore, sequencing was conducted on positive samples to characterize the strains and compare them with publicly available sequences through phylogenetic analysis. A high CanineCV prevalence was observed both in jackals (43.75%; 95 CI: 28.17% - 60.67%) and domestic dogs (27.13%; 95 CI: 23.66% - 30.91%). All aside from one Namibian strain formed an independent clade, suggestive of extremely rare introduction events, followed by local persistence, circulation, and evolution. Remarkably, different recombination events were observed involving strains from both jackals and domestic dogs, which testify to the likely strain exchange between these populations. Distinctive amino acid residues were also observed in jackals. The limitations of the considered host populations however prevent a definitive conclusion on host adaptation, biological, and clinical features. Further studies should be performed to expand our current knowledge of the CanineCV disease scenario in Namibia, other African regions, and associated host species in Africa.