RESUMO
In May 2017, high mortality of chickens and Muscovy ducks due to the H5N8 highly pathogenic avian influenza virus (HPAIV) was reported in the Democratic Republic of Congo (DR Congo). In this study, we assessed the molecular, antigenic, and pathogenic features in poultry of the H5N8 HPAIV from the 2017 Congolese outbreaks. Phylogenetic analysis of the eight viral gene segments revealed that all 12 DR Congo isolates clustered in clade 2.3.4.4B together with other H5N8 HPAIVs isolated in Africa and Eurasia, suggesting a possible common origin of these viruses. Antigenically, a slight difference was observed between the Congolese isolates and a representative virus from group C in the same clade. After intranasal inoculation with a representative DR Congo virus, high pathogenicity was observed in chickens and Muscovy ducks but not in Pekin ducks. Viral replication was higher in chickens than in Muscovy duck and Pekin duck organs; however, neurotropism was pronounced in Muscovy ducks. Our data confirmed the high pathogenicity of the DR Congo virus in chickens and Muscovy ducks, as observed in the field. National awareness and strengthening surveillance in the region are needed to better control HPAIVs.
Assuntos
Antígenos Virais/metabolismo , Vírus da Influenza A Subtipo H5N8/classificação , Vírus da Influenza A Subtipo H5N8/patogenicidade , Influenza Aviária/imunologia , Doenças das Aves Domésticas/virologia , África , Animais , Ásia , Galinhas , República Democrática do Congo , Patos/classificação , Patos/virologia , Europa (Continente) , Sequenciamento de Nucleotídeos em Larga Escala , Vírus da Influenza A Subtipo H5N8/genética , Vírus da Influenza A Subtipo H5N8/isolamento & purificação , Influenza Aviária/virologia , Filogenia , Filogeografia , Doenças das Aves Domésticas/imunologia , Especificidade da Espécie , Replicação ViralRESUMO
Although rabies is enzootic in the Democratic Republic of the Congo, there is very little molecular epidemiological information about the viruses circulating in animals. In this study, a fragment of the rabies virus (RABV) nucleoprotein gene was amplified and sequenced from 21 animal brain samples collected in two western provinces of the country between 2008 and 2017. The samples tested were from cat (n = 1), dog (n = 17), goat (n = 2), and sheep (n = 1). Phylogenetic analysis revealed that the sequences generated were highly similar to each other and belonged to lineage Africa 1b clustering with a single sample identified in a canine in the Republic of Congo in 2014. This is the first molecular epidemiological study of RABV in the DRC and the data generated will assist authorities in the development of effective control strategies for rabies in the country.
Assuntos
Vírus da Raiva , Raiva , Animais , Gatos , República Democrática do Congo/epidemiologia , Cães , Cabras , Proteínas do Nucleocapsídeo/genética , Filogenia , RNA Viral/genética , Raiva/epidemiologia , Raiva/veterinária , Raiva/virologia , Vírus da Raiva/classificação , Vírus da Raiva/genética , Vírus da Raiva/isolamento & purificação , OvinosRESUMO
This study aimed at assessing the serological and virological status of Rift Valley fever virus (RVFV) in cattle from four climatically diverse zones of the Democratic Republic of the Congo (DRC). A total of 1675 sera samples collected between 2014 and 2015 from cattle without clinical manifestation of RVF infection were tested using competitive and capture enzyme ELISA to detect both IgG and IgM. RT-PCR was used for the detection of nucleic acid of RVFV. Out of the 1675 cattle sera tested, 203 were found to be IgG-positive, giving an overall true seroprevalence of 12.37% (95% CI 10.86-14.05). This seroprevalence varied between the four zones with a seroprevalence of 16.16% (95% CI 12.86-20.12), 14.70% (95% CI 11.72-18.29), 10.82% (95% CI 7.19-14.19), and 7.34% (95% CI 5.13-10.41) recorded in cattle sampled in the mountainous, humid savannah, dry savannah, and forest zones, respectively (p < 0.05, χ2 = 17.26). A higher true seroprevalence of 14.58% (95% CI 9.3-22.13) was found in animals aged 1 year compared to 10.43% (95% CI 8.12-13.30) and 13.16% (95% CI 11.19-15.42) in groups aged between 2-3 and > 3 years, respectively, although the difference was not statistically significant (p > 0.05, χ2 = 2.95). Similarly, no statistically significant difference (p > 0.05, χ2 = 0.04) was found between the sexes of the animals. Among the IgG-positive samples screened for anti-RVFV IgM, only 1.47% (3/203) was IgM-positive. One of the IgM-positive samples was positive by RT-PCR. These findings reveal country-wide distribution of RVF in the DRC for the first time.
Assuntos
Doenças dos Bovinos/virologia , Febre do Vale de Rift/epidemiologia , Vírus da Febre do Vale do Rift , Animais , Anticorpos Antivirais/sangue , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , República Democrática do Congo/epidemiologia , Ensaio de Imunoadsorção Enzimática , Febre do Vale de Rift/sangue , Estudos SoroepidemiológicosRESUMO
BACKGROUND: Worldwide, the highest malaria mortality is due to Plasmodium falciparum infection. However, other species of Plasmodium (Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, and Plasmodium knowlesi) can also cause malaria. Therefore, accurate identification of malaria species is crucial for patient management and epidemiological surveillance. This study aimed to determine the different Plasmodium species causing malaria in children under 5 years old in two provinces (Kinshasa and North Kivu) of the Democratic Republic of Congo (DRC). METHODS: From October to December 2015, a health-facility based cross-sectional study was conducted in General Reference Hospitals in Kinshasa and North Kivu. Four hundred and seven blood samples were collected from febrile children aged ≤ 5 years. Nested polymerase chain reaction assays were performed for Plasmodium species identification. RESULTS: Out of 407 children, 142 (34.9%) were infected with Plasmodium spp. and P. falciparum was the most prevalent species (99.2%). Among those infected children, 124 had a mono infection with P. falciparum and one with P. malariae. Mixed infections with P. falciparum/P. malariae and P. falciparum/P. vivax were observed in 6 (1.5%) and 8 (2.0%) children, respectively. The prevalence of infection was higher in females (64.8%) than in males (35.2%), p < 0.001. The age-specific distribution of infection showed that children of less than 2 years old were less infected (18.4%) compared to those aged above 2 years (81.6%), p < 0.001. CONCLUSION: Although this study showed clearly that the most prevalent species identified was P. falciparum, the findings demonstrate the existence of non-falciparum malaria, especially P. malariae and P. vivax among children aged ≤ 5 years living both Kinshasa and North Kivu Provinces in DRC.
Assuntos
Malária/diagnóstico , Malária/parasitologia , Técnicas de Diagnóstico Molecular/métodos , Plasmodium/classificação , Plasmodium/genética , Reação em Cadeia da Polimerase/métodos , Sangue/parasitologia , Pré-Escolar , Coinfecção/diagnóstico , Coinfecção/epidemiologia , Coinfecção/parasitologia , Estudos Transversais , República Democrática do Congo/epidemiologia , Feminino , Humanos , Lactente , Malária/epidemiologia , Masculino , Plasmodium/isolamento & purificação , PrevalênciaRESUMO
The latest outbreak of Ebola virus disease (EVD) in West Africa has highlighted the urgent need for the development of rapid and reliable diagnostic assays. We used monoclonal antibodies specific to the ebolavirus nucleoprotein to develop an immunochromatography (IC) assay (QuickNavi-Ebola) for rapid diagnosis of EVD. The IC assay was first evaluated with tissue culture supernatants of infected Vero E6 cells and found to be capable of detecting 103-104 focus-forming units/mL of ebolaviruses. Using serum samples from experimentally infected nonhuman primates, we confirmed that the assay could detect the viral antigen shortly after disease onset. It was also noted that multiple species of ebolaviruses could be detected by the IC assay. Owing to the simplicity of the assay procedure and absence of requirements for special equipment and training, QuickNavi-Ebola is expected to be a useful tool for rapid diagnosis of EVD.
Assuntos
Anticorpos Monoclonais/imunologia , Antígenos Virais/imunologia , Cromatografia de Afinidade/métodos , Surtos de Doenças , Ebolavirus/imunologia , Doença pelo Vírus Ebola/diagnóstico , África Ocidental/epidemiologia , Animais , Anticorpos Antivirais/sangue , Ebolavirus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Nucleoproteínas/imunologiaRESUMO
Among the many challenges to health, infectious diseases stand out for their ability to have a profound impact on humans and animals. The recent years have witnessed an increasing number of novel infectious diseases. The numerous examples of infections which originated from animals suggest that the zoonotic pool is an important and potentially rich source of emerging diseases. Since emergence and re-emergence of pathogens, and particularly zoonotic agents, occur at unpredictable rates in animal and human populations, infectious diseases will constitute a significant challenge for the public health and animal health communities in the twenty-first century. The African continent suffers from one of the highest burdens of infectious diseases of humans and animals in the world but has the least capacity for their detection, identification and monitoring. Lessons learnt from recent zoonotic epidemics in Africa and elsewhere clearly indicate the need for coordinated research, interdisciplinary centres, response systems and infrastructures, integrated surveillance systems and workforce development strategies. More and stronger partnerships across national and international sectors (human health, animal health, environment) and disciplines (natural and social sciences) involving public, academic and private organisations and institutions will be required to meet the present and future challenges of infectious diseases. In order to strengthen the efficiency of early warning systems, monitoring trends and disease prediction and timely outbreak interventions for the benefit of the national and international community, it is essential that each nation improves its own capacity in disease recognition and laboratory competence. The SACIDS, a One Health African initiative linking southern African academic and research institutions in smart partnership with centres of science excellence in industrialised countries as well as international research centres, strives to strengthen Africa's capacity to detect, identify and monitor infectious diseases of humans and animals, to better manage health and socio-economic risks posed by them, and to improve research capacity in investigating the biologic, socio-economic, ecologic and anthropogenic factors responsible for emergence and re-emergence of infectious diseases.
Assuntos
Controle de Doenças Transmissíveis/métodos , Doenças Transmissíveis Emergentes/prevenção & controle , Saúde Global , Zoonoses/prevenção & controle , Animais , Comportamento Cooperativo , Surtos de Doenças/prevenção & controle , Abastecimento de Alimentos , Humanos , África do SulRESUMO
BACKGROUND: Bas-Congo virus (BASV), an emerging tibrovirus, was associated with an outbreak of acute haemorrhagic fever in Mangala, Democratic Republic of the Congo, in 2009. In 2012, neutralising antibodies to BASV were detected in the lone survivor and one of his close contacts. However, subsequent serological and molecular surveys were unsuccessful as neither BASV antibodies nor its RNA were detected. In this study, we determined the seroprevalence of BASV infection in Mangala 13 years after the initial outbreak. METHODS: We conducted a population-based serological survey from Jan 17 to Jan 23, 2022. Consenting individuals at least 5 years of age, living in Mangala for at least 4 weeks, and who had no contraindication to venepuncture were enrolled. Participants were interviewed using a pre-tested questionnaire for sociodemographic and clinical characteristics. We supplemented the collected serum samples with 284 archived samples from Matadi and Kinshasa. All samples were tested for antibodies to BASV and other tibroviruses using a pseudovirus-based neutralisation test. FINDINGS: Among the 267 individuals from Mangala, the prevalence of BASV antibodies was 55% (95% CI 49-61; n=147). BASV seropositivity odds significantly increased with age (5·2 [95% CI 2·1-12·9] to 83·9 [20·8-337·7] times higher in participants aged 20 years or older than participants aged 5-19 years). Some occupational categories (eg, farmer or public servant) were associated with seropositivity. Only nine (6%) of 160 samples from Matadi and one (<1%) of 124 samples from Kinshasa had neutralising antibodies to BASV. Moreover, we also detected neutralising antibodies to other tibroviruses-Ekpoma virus 1, Ekpoma virus 2, and Mundri virus-in 84 (31%), 251 (94%), and 219 (82%) of 267 Mangala samples; 14 (9%), 62 (39%), and 120 (75%) of 160 Matadi samples; and six (5%), five (4%), and 33 (27%) of 124 Kinshasa samples, respectively. INTERPRETATION: Human infection with BASV and other tibroviruses seems common in Mangala, although no deadly outbreak has been reported since 2009. Exposure to BASV might be highly restricted to Mangala and the increasing prevalence of neutralising antibodies with age suggests regular contact with the virus in this city. Altogether, our findings suggest that human infection with tibroviruses could be common in the study areas and not associated with deadly haemorrhagic or debilitating syndromes. FUNDING: Japan Agency for Medical Research and Development (AMED) and Japan International Cooperation Agency (JICA) under the Science and Technology Research Partnership for Sustainable Development (SATREPS) and Japan Program for Infectious Diseases Research and Infrastructure from AMED.
Assuntos
Anticorpos Antivirais , Humanos , República Democrática do Congo/epidemiologia , Masculino , Estudos Soroepidemiológicos , Adulto , Estudos Transversais , Adolescente , Feminino , Pessoa de Meia-Idade , Criança , Adulto Jovem , Anticorpos Antivirais/sangue , Pré-Escolar , Anticorpos Neutralizantes/sangue , Idoso , Surtos de DoençasRESUMO
Taenia hydatigena is a non-zoonotic worm that has dogs and wild canids as definitive hosts. Its presence induces cross reactions in certain diagnostic tests for porcine cysticercosis caused by T. solium, the occurrence of which has a considerable public health and economic impact. In the Democratic Republic of the Congo (DR Congo), T. solium is considered endemic, however, the prevalence of T. hydatigena has not been estimated yet. The objective of the study was therefore to estimate the prevalence of T. hydatigena cysticercosis by serological and molecular diagnostic tools in pigs slaughtered in DR Congo. A total of 480 pigs slaughtered in 6 slaughter slabs in Kinshasa, DR Congo, were examined. The thoracal and abdominal cavity organs were inspected for cysts, which were analyzed using PCR-RFLP. Furthermore, 480 sera were collected, and analyzed for the presence of circulating Taenia spp. cysticercus antigens, using the B158/B60 Ag-ELISA. Upon inspection of the carcass, 41 cysts suspected to be metacestodes of Taenia spp. were collected, from the following viscera: spleen (24/41, 59%), liver (13/41, 32%), intestine (3/41, 7%) and lung (1/41, 2%). Molecular analyses revealed a T. hydatigena prevalence of 0.2% (95% CI: 0.0001-0.0116), based on a single lesion (1/480), taken from the spleen. Out of the 480 sera collected, the presence of circulating Taenia spp. cysticerci antigens was detected in 32 (6.7%; 95% CI: 4.5-11.2). The results of this study revealed that T. hydatigena is present in pigs sold in markets in the city of Kinshasa in DR Congo, albeit at a very low prevalence, thus the impact on the interpretation of the B158/B60 seems low in this setting. Detection of circulating antigens in porcine sera by Ag-ELISA, shows that pigs slaughtered in Kinshasa, DR Congo, were infected with viable cysticerci of Taenia spp. which in turn can infect humans.
Assuntos
Cisticercose , Cistos , Doenças do Cão , Doenças dos Suínos , Taenia , Humanos , Suínos , Animais , Cães , Prevalência , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/diagnóstico , República Democrática do Congo/epidemiologia , Cisticercose/epidemiologia , Cisticercose/veterinária , Cisticercose/diagnóstico , Cysticercus , Cistos/veterináriaRESUMO
Crimean-Congo hemorrhagic fever virus (CCHFV), a nairovirus, is a tick-borne zoonotic virus that causes hemorrhagic fever in humans. The CCHFV nucleoprotein (NP) is the antigen most used for serological screening of CCHFV infection in animals and humans. To gain insights into antibody epitopes on the NP molecule, we produced recombinant chimeric NPs between CCHFV and Nairobi sheep disease virus (NSDV), which is another nairovirus, and tested rabbit and mouse antisera/immune ascites, anti-NP monoclonal antibodies, and CCHFV-infected animal/human sera for their reactivities to the NP antigens. We found that the amino acids at positions 161-320 might include dominant epitopes recognized by anti-CCHFV IgG antibodies, whereas cross-reactivity between anti-CCHFV and anti-NSDV antibodies was limited. Their binding capacities were further tested using a series of synthetic peptides whose sequences were derived from CCHFV NP. IgG antibodies in CCHFV-infected monkeys and patients were reactive to some of the synthetic peptide antigens (e.g., amino acid residues at positions 131-150 and 211-230). Only a few peptides were recognized by IgG antibodies in the anti-NSDV serum. These results provide useful information to improve NP-based antibody detection assays as well as antigen detection tests relying on anti-NP monoclonal antibodies.
Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo , Febre Hemorrágica da Crimeia , Animais , Anticorpos Monoclonais , Anticorpos Antivirais , Epitopos , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Febre Hemorrágica da Crimeia/diagnóstico , Humanos , Imunoglobulina G , Camundongos , Nucleoproteínas , Coelhos , OvinosRESUMO
BACKGROUND: Detection of spliced leader (SL)-RNA allows sensitive diagnosis of gambiense human African trypanosomiasis (HAT). We investigated its diagnostic performance for treatment outcome assessment. METHODS: Blood and cerebrospinal fluid (CSF) from a consecutive series of 97 HAT patients, originating from the Democratic Republic of the Congo, were prospectively collected before treatment with acoziborole, and during 18 months of longitudinal follow-up after treatment. For treatment outcome assessment, SL-RNA detection was compared with microscopic trypanosome detection and CSF white blood cell count. The trial was registered under NCT03112655 in clinicaltrials.gov. FINDINGS: Before treatment, respectively 94.9% (92/97; CI 88.5-97.8%) and 67.7% (65/96; CI 57.8-76.2%) HAT patients were SL-RNA positive in blood or CSF. During follow-up, one patient relapsed with trypanosomes observed at 18 months, and was SL-RNA positive in blood and CSF at 12 months, and CSF positive at 18 months. Among cured patients, one individual tested SL-RNA positive in blood at month 12 (Specificity 98.9%; 90/91; CI 94.0-99.8%) and 18 (Specificity 98.9%; 88/89; CI 93.9-99.8%). INTERPRETATION: SL-RNA detection for HAT treatment outcome assessment shows ≥98.9% specificity in blood and 100% in CSF, and may detect relapses without lumbar puncture. FUNDING: The DiTECT-HAT project is part of the EDCTP2 programme, supported by Horizon 2020, the European Union Funding for Research and Innovation (grant number DRIA-2014-306-DiTECT-HAT).
Assuntos
Antiprotozoários , Trypanosoma , Tripanossomíase Africana , Animais , Humanos , Antiprotozoários/uso terapêutico , Seguimentos , RNA Líder para Processamento , Resultado do Tratamento , Trypanosoma brucei gambiense/genética , Tripanossomíase Africana/diagnóstico , Tripanossomíase Africana/tratamento farmacológicoRESUMO
Newcastle disease (ND) is a highly transmissible and devastating disease that affects poultry and wild birds worldwide. Comprehensive knowledge regarding the characteristics and epidemiological factors of the ND virus (NDV) is critical for the control and prevention of ND. Effective vaccinations can prevent and control the spread of the NDV in poultry populations. For decades, the Democratic Republic of the Congo (DRC) has reported the impacts of ND on commercial and traditional poultry farming systems. The reports were preliminary clinical observations, and few cases were confirmed in the laboratory. However, data on the phylogenetic, genetic, and virological characteristics of NDVs circulating in the DRC are not available. In this study, the whole-genome sequences of three NDV isolates obtained using the next-generation sequencing method revealed two isolates that were a new variant of NDV, and one isolate that was clustered in the subgenotype VII.2. All DRC isolates were velogenic and were antigenically closely related to the vaccine strains. Our findings reveal that despite the circulation of the new variant, ND can be controlled in the DRC using the current vaccine. However, epidemiological studies should be conducted to elucidate the endemicity of the disease so that better control strategies can be implemented.
Assuntos
Doença de Newcastle/epidemiologia , Doença de Newcastle/virologia , Vírus da Doença de Newcastle/classificação , Vírus da Doença de Newcastle/genética , Doenças das Aves Domésticas/virologia , Animais , República Democrática do Congo/epidemiologia , Genótipo , Vírus da Doença de Newcastle/isolamento & purificação , Filogenia , Aves Domésticas/virologia , Doenças das Aves Domésticas/epidemiologia , RNA Viral/genética , Proteínas Virais/genética , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: Spliced Leader (SL) trypanosome RNA is detectable only in the presence of live trypanosomes, is abundant and the Trypanozoon subgenus has a unique sequence. As previously shown in blood from Guinean human African trypanosomiasis (HAT) patients, SL-RNA is an accurate target for diagnosis. Detection of SL-RNA in the cerebrospinal fluid (CSF) has never been attempted. In a large group of Congolese gambiense HAT patients, the present study aims i) to confirm the sensitivity of SL-RNA detection in the blood and; ii) to assess the diagnostic performance of SL-RNA compared to trypanosome detection in CSF. METHODOLOGY/PRINCIPAL FINDINGS: Blood and CSF from 97 confirmed gambiense HAT patients from the Democratic Republic of Congo were collected using PAXgene blood RNA Tubes. Before RNA extraction, specimens were supplemented with internal extraction control RNA to monitor the extraction, which was performed with a PAXgene Blood RNA Kit. SL-RNA qPCR was carried out with and without reverse transcriptase to monitor DNA contamination. In blood, 92/97 (94.8%) HAT patients tested SL-RNA positive, which was significantly more than combined trypanosome detection in lymph and blood (78/97 positive, 80.4%, p = 0.001). Of 96 CSF RNA specimens, 65 (67.7%) were SL-RNA positive, but there was no significant difference between sensitivity of SL-RNA and trypanosome detection in CSF. The contribution of DNA to the Cq values was negligible. In CSF with normal cell counts, a fraction of SL-RNA might have been lost during extraction as indicated by higher internal extraction control Cq values. CONCLUSIONS/SIGNIFICANCE: Detection of SL-RNA in blood and CSF allows sensitive demonstration of active gambiense HAT infection, even if trypanosomes remain undetectable in blood or lymph. As this condition often occurs in treatment failures, SL-RNA detection in blood and CSF for early detection of relapses after treatment deserves further investigation. TRIAL REGISTRATION: This study was an integral part of the diagnostic trial "New Diagnostic Tools for Elimination of Sleeping Sickness and Clinical Trials: Early tests of Cure" (DiTECT-HAT-WP4, ClinicalTrials.gov Identifier: NCT03112655).
Assuntos
RNA de Protozoário/genética , RNA de Protozoário/isolamento & purificação , Trypanosoma brucei gambiense , Tripanossomíase Africana/parasitologia , República Democrática do Congo/epidemiologia , Humanos , RNA de Protozoário/sangue , RNA de Protozoário/líquido cefalorraquidiano , Tripanossomíase Africana/sangue , Tripanossomíase Africana/líquido cefalorraquidiano , Tripanossomíase Africana/epidemiologiaRESUMO
Crimean-Congo hemorrhagic fever virus (CCHFV) causes a zoonotic disease, Crimean-Congo hemorrhagic fever (CCHF) endemic in Africa, Asia, the Middle East, and Southeastern Europe. However, the prevalence of CCHF is not monitored in most of the endemic countries due to limited availability of diagnostic assays and biosafety regulations required for handling infectious CCHFV. In this study, we established a protocol to purify the recombinant CCHFV nucleoprotein (NP), which is antigenically highly conserved among multiple lineages/clades of CCHFVs and investigated its utility in an enzyme-linked immunosorbent assay (ELISA) to detect CCHFV-specific antibodies. The NP gene was cloned into the pCAGGS mammalian expression plasmid and human embryonic kidney 293 T cells were transfected with the plasmid. The expressed NP molecule was purified from the cell lysate using cesium-chloride gradient centrifugation. Purified NP was used as the antigen for the ELISA to detect anti-CCHFV IgG. Using the CCHFV NP-based ELISA, we efficiently detected CCHFV-specific IgG in anti-NP rabbit antiserum and CCHFV-infected monkey serum. When compared to the commercially available Blackbox CCHFV IgG ELISA kit, our assay showed equivalent performance in detecting CCHFV-specific IgG in human sera. These results demonstrate the usefulness of our CCHFV NP-based ELISA for seroepidemiological studies.
Assuntos
Febre Hemorrágica da Crimeia/metabolismo , Nucleoproteínas/metabolismo , Ensaio de Imunoadsorção Enzimática , Células HEK293 , Febre Hemorrágica da Crimeia/sangue , Febre Hemorrágica da Crimeia/genética , Humanos , Nucleoproteínas/sangue , Nucleoproteínas/genética , Plasmídeos/genética , Estudos SoroepidemiológicosRESUMO
Two groups of Trypanosoma congolense isolates collected from cattle in 1996 (n=39) and 2003 (n=38) in the Eastern Province of Zambia were analyzed by BclI-PCR-RFLP to assess the evolution of diminazene aceturate (DA) resistance over a period of seven years. The results show a significant increase of DA resistance in this relatively short period of time. In 1996, among the 39 isolates, 61.5% were found sensitive, 12.8% resistant and 25.7% had a mixed BclI-PCR-RFLP profile. In 2004, among the 38 isolates, 10.5% were found sensitive, 63.2% were resistant and 26.3% showed a mixed BclI-PCR-RFLP profile. In vivo tests in mice showed that isolates with a sensitive or mixed RFLP profile were sensitive to DA whereas isolates with a resistant RFLP profile were resistant. Since there are no indications that the drug pressure has increased between 1996 and 2003, it is suggested that genetic exchange of resistance genes might explain the increased frequency of resistance to DA.
Assuntos
Doenças dos Bovinos/parasitologia , Diminazena/análogos & derivados , Resistência a Medicamentos/efeitos dos fármacos , Tripanossomicidas/uso terapêutico , Trypanosoma congolense/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , DNA de Protozoário/genética , Diminazena/administração & dosagem , Diminazena/farmacologia , Diminazena/uso terapêutico , Relação Dose-Resposta a Droga , Resistência a Medicamentos/genética , Camundongos , Camundongos Endogâmicos , Polimorfismo de Fragmento de Restrição , Tripanossomicidas/administração & dosagem , Tripanossomicidas/farmacologia , Trypanosoma congolense/genética , Trypanosoma congolense/isolamento & purificação , Tripanossomíase Africana/parasitologia , Tripanossomíase Africana/veterinária , ZâmbiaRESUMO
In the Democratic Republic of Congo (DRC), where state-driven animal vaccination campaigns are organized only in response to epidemics, the organization of a permanent animal vaccination service is urgently needed. A non-governmental organization has set up an experimental paid vaccination service for village chickens against Newcastle Disease (ND) in the Kongo Central province. This mixed-method study presents a participatory assessment of this experiment, identifying socio-economic factors that influence the decision of chicken keepers to adopt vaccination. The study was conducted in four territories of the province. Qualitative and quantitative data were collected through 12 focus group discussions (FGDs) with professionals of animal health and chicken keepers and 160 semi-structured interviews with chicken keepers, sampled by snowball technique. This participatory process has resulted in the design of a grid for assessing animal vaccination service's performance. Here translating the narratives into a preliminary structured assessment, this grid is an output of the study, to be mobilized for future rapid assessments of the vaccination service in a quantitative prospect. The grid consisted of nine criteria, further composed by 16 items, translated into questions to be asked to chicken keepers and vaccinators. In our study area, fieldworkers enumerated four animal vaccination campaigns during a period of 21 years (except those subject to the present assessment). Around 13% of chicken keepers of our sample had participated in ND vaccination programs. Almost 96% of interviewed chicken keepers expressed their willingness to pay for ND vaccination, and 87% of chicken keepers that vaccinated their chickens perceived the vaccine as effective. Vaccinators estimated that 56% of the chicken keepers who were contacted had actually paid for the vaccination of their chickens. The assessment grid highlighted four points in favor of the sustainability of this service, i.e. the general interest of chickens keepers, vaccine efficacy, vaccine availability and ease of use of the vaccine. Two weak points were identified, viz. the poor access of chicken keepers to information and the weak motivation of vaccinators. The vaccine coverage was calculated within the sample at 13.1%. Paid vaccination campaign for village chicken in Kongo Central obtained a performance score of 62.8%, with the highest score in Kwilu-Ngongo (73.1%) and the lowest in Kasangulu (52.4%). Two factors of adoption of vaccination were identified as statistically significant, i.e. chicken housing and territory. Significant differences appeared between territories in access to information for chicken keepers and in vaccinators motivation. The priorities for the improvement of this service appear to be awareness raising among chicken keepers and increasing vaccinators' motivation.
Assuntos
Galinhas , Programas de Imunização/estatística & dados numéricos , Doença de Newcastle/prevenção & controle , Vírus da Doença de Newcastle/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Criação de Animais Domésticos , Animais , República Democrática do Congo , Programas de Imunização/economia , Vacinação/economia , Vacinação/estatística & dados numéricosRESUMO
Understanding the molecular epidemiology and evolution of peste des petits ruminants virus (PPRV), the causative agent of Peste des petits ruminants, can assist in the control of the transboundary spread of this economically important disease. To date, despite having been reported in the majority of northern and central African countries, no molecular epidemiological data on PPRVs are available for the Democratic Republic of the Congo (DRC). This study reports the collection and analysis of 11 samples collected from three provinces of the DRC in 2016 and 2018. Sequence analysis identified two (i.e. II and III) of the four known lineages of PPRV in the country providing important information that will assist in the global eradication of PPR.
Assuntos
Peste dos Pequenos Ruminantes/virologia , Vírus da Peste dos Pequenos Ruminantes/classificação , Animais , Sequência de Bases , República Democrática do Congo/epidemiologia , Erradicação de Doenças , Epidemiologia Molecular , Peste dos Pequenos Ruminantes/epidemiologia , Peste dos Pequenos Ruminantes/prevenção & controle , Vírus da Peste dos Pequenos Ruminantes/genética , RNA Viral/química , RNA Viral/genéticaRESUMO
The recent large outbreaks of Ebola virus disease (EVD) in West Africa and the Democratic Republic of the Congo (DRC) have highlighted the need for rapid diagnostic tests to control this disease. In this study, we clinically evaluated a previously developed immunochromatography-based kit, QuickNaviTM-Ebola. During the 2018 outbreaks in DRC, 928 blood samples from EVD-suspected cases were tested with QuickNaviTM-Ebola and the WHO-approved GeneXpert. The sensitivity and specificity of QuickNaviTM-Ebola, estimated by comparing it to GeneXpert-confirmed cases, were 85% (68/80) and 99.8% (846/848), respectively. These results indicate the practical reliability of QuickNaviTM-Ebola for point-of-care diagnosis of EVD.
Assuntos
Cromatografia de Afinidade/métodos , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , República Democrática do Congo/epidemiologia , Surtos de Doenças , Ebolavirus/genética , Doença pelo Vírus Ebola/virologia , Humanos , Kit de Reagentes para Diagnóstico , Sensibilidade e EspecificidadeRESUMO
Trypanosoma brucei gambiense causes human African trypanosomiasis (HAT). Between 1990 and 2015, almost 440000 cases were reported. Large-scale screening of populations at risk, drug donations, and efforts by national and international stakeholders have brought the epidemic under control with <2200 cases in 2016. The World Health Organization (WHO) has set the goals of gambiense-HAT elimination as a public health problem for 2020, and of interruption of transmission to humans for 2030. Latent human infections and possible animal reservoirs may challenge these goals. It remains largely unknown whether, and to what extend, they have an impact on gambiense-HAT transmission. We argue that a better understanding of the contribution of human and putative animal reservoirs to gambiense-HAT epidemiology is mandatory to inform elimination strategies.
Assuntos
Erradicação de Doenças , Reservatórios de Doenças , Tripanossomíase Africana/prevenção & controle , Tripanossomíase Africana/transmissão , Animais , Humanos , Fatores de Risco , Trypanosoma brucei gambiense/fisiologia , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/parasitologiaRESUMO
Rabies is a preventable fatal disease that causes about 61,000 human deaths annually around the world, mostly in developing countries. In Africa, several studies have shown that vaccination of pets is effective in controlling the disease. An annual vaccination coverage of 70% is recommended by the World Health Organization as a control threshold. The effective control of rabies requires vaccination coverage of owned dogs. Identification of the factors determining dog owners' choice to vaccinate is necessary for evidence-based policy-making. However, for the Democratic Republic of Congo (DRC), the limited data on rabies vaccination coverage makes it difficult for its control and formulation of appropriate policies. A cross-sectional study was conducted in Kinshasa (Lemba commune) with dog-owning households and owned dogs as study populations. The association between dog vaccination and independent factors (household socio-demographics characteristics, dog characteristics, knowledge of rabies and location of veterinary offices/clinics) was performed with Epi-info 7. The Odds Ratio (OR) and p-value < 0.05 were used to determine levels of significance. A total of 166 households owning dogs and 218 owned dogs were investigated. 47% of the dogs had been vaccinated within one year preceding the survey which is higher than the critical coverage (25 to 40%) necessary to interrupt rabies transmission but below the 70% threshold recommended by WHO for control. The determinants of vaccination included socio-economic level of the household (OR = 2.9, p<0.05), formal education level of the dog owner (OR = 4, p<0.05), type of residence (OR = 4.6, p<0.05), knowledge of rabies disease (OR = 8.0, p<0.05), knowledge of location of veterinary offices/clinics (OR = 3.4, p<0.05), dog gender (OR = 1.6, p<0.05) and dog breed (OR = 2.1, p<0.05). This study shows that the vaccination coverage in this area can easily reach the WHO threshold if supplemented by mass vaccination campaigns.