RESUMEN
The anthrax-causing bacterium Bacillus anthracis comprises the genetic clades A, B, and C. In the northernmost part (Pafuri) of Kruger National Park (KNP), South Africa, both the common A and rare B strains clades occur. The B clade strains were reported to be dominant in Pafuri before 1991, while A clade strains occurred towards the central parts of KNP. The prevalence of B clade strains is currently much lower as only A clade strains have been isolated from 1992 onwards in KNP. In this study 319 B. anthracis strains were characterized with 31-loci multiple-locus variable-number tandem repeat analysis (MLVA-31). B clade strains from soil (n = 9) and a Tragelaphus strepsiceros carcass (n = 1) were further characterised by whole genome sequencing and compared to publicly available genomes. The KNP strains clustered in the B clade before 1991 into two dominant genotypes. South African strains cluster into a dominant genotype A.Br.005/006 consisting of KNP as well as the other anthrax endemic region, Northern Cape Province (NCP), South Africa. A few A.Br.001/002 strains from both endemic areas were also identified. Subclade A.Br.101 belonging to the A.Br.Aust94 lineage was reported in the NCP. The B-clade strains seems to be vanishing, while outbreaks in South Africa are caused mainly by the A.Br.005/006 genotypes as well as a few minor clades such as A.Br.001/002 and A.Br.101 present in NCP. This work confirmed the existence of the rare and vanishing B-clade strains that group in B.Br.001 branch with KrugerB and A0991 KNP strains.
Asunto(s)
Carbunco , Bacillus anthracis , Filogenia , Bacillus anthracis/genética , Bacillus anthracis/clasificación , Bacillus anthracis/aislamiento & purificación , Sudáfrica , Carbunco/microbiología , Carbunco/epidemiología , Carbunco/veterinaria , Genotipo , Genoma Bacteriano , Microbiología del Suelo , Secuenciación Completa del GenomaRESUMEN
BACKGROUND: Anthrax is the most prioritized zoonotic disease in Kazakhstan due to its threatening potential to the public health and agricultural sector. Sporadic anthrax outbreaks are being reported annually among human and livestock populations throughout the country, with the highest frequency occurring in West Kazakhstan. METHODS: A cross-sectional study was conducted using a survey-based face-to-face interview. From January to May 2022, 489 randomly selected participants were surveyed in 6 districts of the Baiterek province in West Kazakhstan oblast to evaluate the knowledge, attitude and practice (KAP) regarding anthrax among community members. This is the first KAP study conducted relating to outbreaks of anthrax in Kazakhstan. RESULTS: In this study, most participants (74%) surveyed were males, and 40% of respondents had a secondary level education. Overall, 91% of the community respondents were engaged in agriculture and livestock rearing. Among these community members, cattle rearing was the most common (67%) occupation compared to other livestock species. Additionally, over a 50% of the population studied had no knowledge about the zoonotic nature of the disease, and about 82% and 87% of respondents were unaware of any animal and human anthrax symptoms, respectively. About 70% of the respondents were interested in vaccinating their livestock against anthrax. Individuals aged 45-54 displayed notably higher animal vaccination rates (45%; 95% CI: 38.4-52.0; p < 0.025) compared to those aged 25-34 and 65-74. Respondents residing in the Beles district (20%; 95% CI: 17.1-24.7; p < 0.005) exhibited a significantly higher level of awareness concerning the fatality of anthrax in contrast to participants from Bolashak. Roughly 61% of respondents held the belief that anthrax is a lethal disease. An overwhelming majority of the survey participants (99%) affirmed their non-participation in the slaughter of infected animals. CONCLUSION: The findings of this study indicate that KAP among community members relating to anthrax is low and requires swift implementation of education programmes in building awareness of anthrax under the One Health approach, especially in anthrax prone regions.
Asunto(s)
Carbunco , Agricultores , Conocimientos, Actitudes y Práctica en Salud , Ganado , Carbunco/veterinaria , Carbunco/epidemiología , Carbunco/prevención & control , Masculino , Estudios Transversales , Kazajstán/epidemiología , Femenino , Humanos , Animales , Adulto , Agricultores/psicología , Agricultores/estadística & datos numéricos , Persona de Mediana Edad , Adulto Joven , Zoonosis , Anciano , Crianza de Animales Domésticos/métodos , AdolescenteRESUMEN
Objective: To analyze the multiple locus variable number tandem repeat analysis (MLVA) genotype polymorphism of Bacillus (B.) anthracis and establish a MLVA genotype database of B. anthracis in China. Methods: B. anthracis strains isolated from different sources in China since 1947 were collected. Genotype identification was carried out using the MLVA15 genotyping protocol based on 15 variable number tandem repeat loci. The genotypes were uniformly numbered and named. The distribution characteristics of the MLVA genotypes of strains were analyzed. Software Bionumerics was used to construct clustering diagrams to analyze the genetic relationships. Results: The MLVA15 clustering analysis subdivided the isolates into 4 major groups and 91 genotypes, 54 of which were unique to China. The genotypes from MLVA15-CHN1 to MLVA15-CHN6 were widely distributed throughout China and in all eras, while other genotypes were restricted to certain regions or eras. Conclusions: This study established a MLVA genotype database of B. anthracis, which provides basis for the understanding of MLVA genetic polymorphisms and the control and molecular source tracing of the anthrax outbreaks in China.
Asunto(s)
Bacillus anthracis , Genotipo , Repeticiones de Minisatélite , Polimorfismo Genético , Bacillus anthracis/genética , China/epidemiología , Filogenia , Carbunco/microbiología , Carbunco/epidemiología , Tipificación de Secuencias Multilocus , Análisis por ConglomeradosRESUMEN
OBJECTIVES: Bacillus anthracis clinical breakpoints, representing a systematic approach to guide clinicians in selecting the most appropriate antimicrobial treatments, are not part of the guidance from the European Committee on Antimicrobial Susceptibility Testing (EUCAST). This is because defined distributions of MIC values and of epidemiological cut-off values (ECOFFs) have been lacking. In this study, a Europe-wide network of laboratories in collaboration with EUCAST, aimed at establishing standardized antimicrobial susceptibility testing methods, wild-type MIC distributions, and ECOFFs for ten therapeutically relevant antimicrobials. METHODS: About 335 B. anthracis isolates were tested by broth microdilution and disc diffusion methodologies. MIC and inhibition zone diameters were curated according to EUCAST SOP 10.2 and the results were submitted to EUCAST for ECOFFs and clinical breakpoint determination. RESULTS: Broth microdilution and disc diffusion data distributions revealed putative wild-type distributions for the tested agents. For each antimicrobial agent, ECOFFs were defined. Three highly resistant strains with MIC values of 32 mg/L benzylpenicillin were found. MIC values slightly above the defined ECOFFs were observed in a few isolates, indicating the presence of resistance mechanisms to doxycycline, tetracycline, and amoxicillin. DISCUSSION: B. anthracis antimicrobial susceptibility testing results were used by EUCAST to determine ECOFFs for ten antimicrobial agents. The MIC distributions were used in the process of determining clinical breakpoints. The ECOFFs can be used for the sensitive detection of isolates with resistance mechanisms, and for monitoring resistance development. Genetic changes causing phenotypic shifts in isolates displaying slightly elevated MICs remain to be investigated.
Asunto(s)
Antibacterianos , Bacillus anthracis , Pruebas de Sensibilidad Microbiana , Antibacterianos/farmacología , Bacillus anthracis/efectos de los fármacos , Bacillus anthracis/genética , Bacillus anthracis/aislamiento & purificación , Humanos , Europa (Continente)/epidemiología , Carbunco/microbiología , Carbunco/epidemiología , Farmacorresistencia BacterianaRESUMEN
Anthrax is a zoonotic disease caused by a spore-forming gram-positive bacterium, Bacillus anthracis. Increased anthropogenic factors inside wildlife-protected areas may worsen the spillover of the disease at the interface. Consequently, environmental suitability prediction for B. anthracis spore survival to locate a high-risk area is urgent. Here, we identified a potentially suitable habitat and a high-risk area for appropriate control measures. Our result revealed that a relatively largest segment of Omo National Park, about 23.7% (1,218 square kilometers) of the total area; 36.6% (711 square kilometers) of Mago National Park, and 29.4% (489 square kilometers) of Tama wildlife Reserve predicted as a high-risk area for the anthrax occurrence in the current situation. Therefore, the findings of this study provide the priority area to focus on and allocate resources for effective surveillance, prevention, and control of anthrax before it causes devastating effects on wildlife.
Asunto(s)
Animales Salvajes , Carbunco , Bacillus anthracis , Animales , Carbunco/epidemiología , Carbunco/veterinaria , Carbunco/prevención & control , Bacillus anthracis/aislamiento & purificación , Animales Salvajes/microbiología , Etiopía/epidemiología , Conservación de los Recursos Naturales , EcosistemaRESUMEN
The One Health approach calls for collaboration across various sectors and different scales to improve understanding of complex health issues. Regarding epidemiological surveillance, this implies the development of integrated systems that link several surveillance components operating in different domains (human, domestic animals, environment) and involving several actor networks. However, surveillance continues to operate in a very compartmentalized way, with little interaction between sectoral institutions and with the community for the governance and operation of surveillance activities. This is partly explained by the insufficient consideration of the local context and the late involvement of national stakeholders when developing programmes that aimed at strengthening the integration of surveillance. In low- and middle-income countries in particular, there is a strong influence of external partners on the development of intersectoral programmes, including surveillance systems. In this context, we developed and implemented a participatory planning process to support stakeholders of the surveillance system of anthrax in Burkina Faso, in the definition of the One Health surveillance system they wish for and of the pathway to reach it. The workshop produced an action plan that reflects the views and perspectives of representatives of the different categories of stakeholders and beneficiaries of surveillance. In addition, the participation of stakeholders in this participatory co-construction process has also improved their knowledge and mutual understanding, fostering a climate of trust conducive to further collaboration for surveillance activities. However, the quality of the participation raises some questions over the results, and contextual factors may have influenced the process. This underlines the need to include a monitoring and evaluation plan in the process to assess its implementation and ability to produce One Health surveillance modalities that are appropriate, accepted and applied over the long term.
Asunto(s)
Carbunco , Salud Única , Burkina Faso/epidemiología , Humanos , Carbunco/epidemiología , Carbunco/prevención & control , Vigilancia de la Población/métodos , Monitoreo Epidemiológico , AnimalesRESUMEN
BACKGROUND: Since 2019, the incidence of anthrax in the Ningxia Hui Autonomous Region has increased significantly compared with previous years, so in this situation the anthrax in the Ningxia region not only had a detrimental impact on public health, but also inflicted significant economic repercussions. Therefore, we conducted a molecular epidemiological study of 20 strains from 2019-2023 isolates. This study investigated the origin of Bacillus anthracis and its genetic diversity. METHODS: We conducted canonical single-nucleotide polymorphisms (CanSNPs) typing and whole genome sequencing based on the extracted nucleic acid of Bacillus anthracis. Based on the whole genome drafts, we studied the genomic characteristics of 20 isolates. Meanwhile, we performed phylogenetic studies based on genome-wide core single-nucleotide polymorphisms (SNPs) using MEGA's Maximum Likelihood (ML) method and core-genome-based multilocus sequence typing (cgMLST) of the core genomes of these strains using BioNumerics' minimum spanning tree (MST) model. RESULTS: The 20 isolates were categorized into sub-lineages A.Br.001/002, and comparative genomic analyses of these strains with other isolates from other parts of the world showed that the strains from Ningxia were correlated with isolates from Europe, Indonesia, Georgia (USA), and Beijing (China). For the 20 isolates in Ningxia, the genetic relationship of the isolates isolated from the same year or region was relatively close. CONCLUSION: The A.Br.001/002 subgroup was the dominant endemic strain in Ningxia. The genetic relationship and phylogenesis between isolates from Ningxia and strains from Europe and Indonesia suggest that anthrax spread around the globe through ancient trade routes.
Asunto(s)
Carbunco , Bacillus anthracis , Genoma Bacteriano , Filogenia , Polimorfismo de Nucleótido Simple , Secuenciación Completa del Genoma , Bacillus anthracis/genética , Bacillus anthracis/aislamiento & purificación , Secuenciación Completa del Genoma/métodos , China/epidemiología , Carbunco/microbiología , Carbunco/epidemiología , Genoma Bacteriano/genética , Humanos , Tipificación de Secuencias Multilocus/métodosRESUMEN
BACKGROUND: Anthrax and brucellosis are endemic national priority zoonotic diseases in Ethiopia. This study assess the possible factors explaining the current limited information available on animal and human cases in pastoral communities. METHODS: Two questionnaire surveys gathered data from 509 pastoralists and 51 healthcare providers between February and April 2019 in five districts of Afar and the Somali region (SRS). RESULTS: Among the 51 healthcare providers, 25 (49%) and 38 (74.5%) had heard of brucellosis, and anthrax, respectively. Of those, only 3 (12%) and 14 (36.8%) knew the symptoms of brucellosis and Anthrax. None of the Health Extension Workers knew any disease symptoms. Healthcare providers recalled two human cases of brucellosis and 39 cases of Anthrax in the last 12 months, based on symptom-based diagnosis. Pastoralists had a moderate level of knowledge about diseases in their animals, with over half (52.4%; n = 267/509) understanding that animals can transmit diseases to people. Overall, 280 out of 508 (55.1%) and 333 out of 507 (65.7%) pastoralists had heard of brucellosis and Anthrax, respectively. Among the latter, 282 (51.3%) knew at least one preventive measure for Anthrax. However, disease knowledge among women was poor. Despite their knowledge, pastoralists engaged in risky unprotected animal handling, animal product consumption/usage as well as husbandry behaviors exposing them to pathogens and favoring the spread of diseases. They identified Anthrax as the most important zoonosis (47.6%) and as one of top three diseases suspected to cause mortality in their livestock. Pastoralists highlighted lack of vaccine coverage, availability and their timely administration. Both, pastoralists and healthcare providers stated the lack of disease awareness and the unavailability of drugs in the market as important challenges. Health facilities lacked protocols and standard operating procedures for managing zoonotic diseases, and did not have access to laboratory confirmation of pathogens. CONCLUSION: Our study revealed significant under-reporting of Anthrax and brucellosis, and weak prevention and response in humans, mostly associated with poor disease knowledge of healthcare providers. Ability to respond to animal outbreaks was limited by vaccine and drugs availability, timely vaccine administration and the mobility of pastoralists.
Asunto(s)
Carbunco , Brucelosis , Vacunas , Animales , Humanos , Femenino , Carbunco/epidemiología , Carbunco/prevención & control , Etiopía/epidemiología , Somalia/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Zoonosis/epidemiología , Zoonosis/prevención & control , Brucelosis/epidemiología , Brucelosis/prevención & controlRESUMEN
Anthrax, a widespread zoonosis in low and middle-income countries with low disease awareness and insufficient livestock vaccination coverage, has been known in Lao Cai Province in northern Vietnam for years before its apparent absence in 2009, which requires investigation as this infection is frequently reported from neighbouring provinces and countries. We aimed to describe the seasonal patterns of anthrax (1991-2008), compare livestock anthrax vaccine coverage to disease occurrence (1991- 2022), and delineate the high-risk areas to inform local disease surveillance in the province. We illustrated the seasonal pattern of anthrax and provided a comparison between livestock vaccine coverage and disease occurrence by purely spatial SaTScan (Poisson model, 25% population at risk) to detect spatial clusters of human and livestock anthrax using population derived from zonal statistics routines. The number of cases, crude cumulative incidence, and spatial clusters of human and livestock anthrax were mapped in QGIS. Results indicate peak anthrax incidence from May to October. Buffalo, domestic cattle, and horses accounted for 75% of total animal cases. Horse anthrax was more common in Lao Cai than in its neighbours and often occurred in years with human mortality. Vaccination covered less than 30% of the livestock population. We found an apparent pattern where anthrax was controlled from 1998-2003 with higher vaccine coverage (>20%) and identified spatial clusters of human and livestock anthrax in Muong Khuong, Bao Thang, and Bac Ha districts of Lao Cai. The local public health and veterinary agencies are recommended to revisit the high-risk areas and communicate with neighbouring provinces for a regional approach to anthrax surveillance and control.
Asunto(s)
Carbunco , Vacunas , Humanos , Bovinos , Animales , Caballos , Carbunco/epidemiología , Carbunco/veterinaria , Ganado , Laos , Vietnam/epidemiologíaRESUMEN
This study explores the application of GIS technologies in analyzing and visualizing spatial structures of especially dangerous infections (EPI) in Kazakhstan. International collaborations have facilitated projects studying the focal patterns of diseases, improving data analysis and visualization. Extensive electronic databases resulting from field research on EPI foci have elevated the study's depth. The dynamics of natural foci, influenced by intraspecific structures of infection carriers, are impacted by industrial and agricultural developments, urban expansions, and climate change. The study notes changes in the enzootic territory, affecting mammal migration and consequently altering natural focus boundaries. Industrial activities, rotational methods, and habitat changes contribute to the increased epidemic potential in enzootic areas. Despite anthropogenic and climatic influences, the prevalence of plague remains high in Kazakhstan, with a trend towards expanding enzootic territories. Unified electronic databases on plague, tularemia, anthrax, and other zoonoses, developed for GIS analysis, enable mapping and visualization of natural foci. Electronic maps aid in determining enzootic territory boundaries, assessing infectious disease activity, and planning preventive measures based on risk assessment. ESRI's ArcGIS Desktop 10.8 with Arc Toolbox modules facilitated data processing in the geoinformation environment. Data includes epidemiological examination results, species composition of carriers, and laboratory test outcomes, enhancing comprehensive analysis and decision-making for anti-epidemic measures. The study in Kazakhstan identifies and details six natural and twenty autonomous plague foci, categorizing them by main carriers and observing an expansion of natural hotspots. The enzootic territory is classified into four geographic zones, further divided into 105 landscape-epidemiological regions. Laboratory studies inform electronic maps for analyzing plague's dynamic situation. Anthrax prevalence, primarily in chernozem and chestnut soils, is assessed, revealing 1,778 unaffected settlements and spatially clustered points. An epidemiological index aids in zoning for anthrax trouble. Tularemia's landscape occurrence is classified into four types, with spatial analysis revealing clusters and potential epidemic danger in specific regions. Geographic information technologies highlight high-risk areas, justifying preventive measures for dangerous infections. The results obtained serve as a scientific justification for the priority of preventive measures within the boundaries of administrative territories characterized by a high degree of potential epidemic danger and objectively indicate the prospects for the introduction of GIS technologies into the practice of epidemiological surveillance of particularly dangerous infections.
Asunto(s)
Carbunco , Peste , Tularemia , Animales , Carbunco/epidemiología , Tularemia/epidemiología , Kazajstán/epidemiología , Sistemas de Información Geográfica , MamíferosRESUMEN
Even though anthrax is a disease of antiquity that has been studied for centuries, serious concerns have been raised about our understanding of its epidemiology. Since the 1960s, we have based the epidemiology of anthrax on the results of dose-dependent experiments, especially those involving cattle at that time. In this species the experiments demonstrated that the severity of infection was dependent upon the numbers of Bacillus anthracis spores ingested. The opinion was that ingesting only a few spores would be insufficient to cause an apparent infection; any infection that resulted would be latent (i.e., unrecognized). Based on the results of these experiments, it was accepted that the ingestion of large numbers of spores was the source of infection for hundreds of anthrax outbreaks. However, many investigations of both human and animal anthrax outbreaks have failed to identify sources of large numbers of spores, suggesting that these outbreaks are only rarely a consequence of ingestion or inhalation of large quantities of spores. This opinion piece builds upon the indirect evidence previously presented in an article focused on the existence of latent infections. Much of the evidence for the existence of latent infections was predicated upon a reduction of host resistance, which revealed how latent infections could be a source of more severe forms of the infection. That is, a latent infection can be the source of a severe infection, but the cause of the severe infection is the reduced host resistance. That first article concentrated on the arguments for latent infections, while this article concentrates on the arguments for host resistance. Host resistance is virtually impossible to measure objectively in the field. To provide a subjective measure of host resistance during anthrax outbreaks, we suggest the use of the opinions of livestock owners and or their veterinary practitioners and or field workers during investigations of anthrax outbreaks. When veterinary personal work in the field they are much like field biologists. In some ways field biologists better appreciate environmental factors, population ecology and other perspectives that are of use to epidemiologists. The more diverse the information the better the epidemiology is understood. To this effect we present our personal anecdotal and theoretical ideas from our experiences as well as a collection of bibliographic observations from others'. Our conclusions are that a combination of latent infections and reduced host resistance based on the host's relationship with its environment would better explain the epidemiology of severe infections in anthrax outbreaks for which large quantities of spores have not been located. This applies especially if the area has a history of the disease and/or if necropsies have shown the presence of latent infections in otherwise normal animals in the area and/or if environmental conditions are considered stressful and include intense insect activity.
Asunto(s)
Carbunco , Bacillus anthracis , Infección Latente , Animales , Humanos , Bovinos , Carbunco/epidemiología , Carbunco/veterinaria , Brotes de Enfermedades/veterinaria , Ecología , Infección Latente/epidemiologíaRESUMEN
BACKGROUND: In Zimbabwe, anthrax is endemic with outbreaks being reported almost annually in livestock, wildlife, and humans over the past 40 years. Accurate modelling of its spatial distribution is key in formulating effective control strategies. In this study, an Ensemble Species Distribution Model was used to model the current and future distribution of anthrax occurrence in Zimbabwe. METHODS: Bioclimatic variables derived from the Beijing Climate Centre Climate System Model were used to model the disease. Collinearity testing was conducted on the 19 bioclimatic variables and elevation to remove redundancy. Variables that had no collinearity were used for anthrax habitat suitability modelling. Two future climate change scenarios for different Representative Concentration Pathways (RCP), RCP4.5 and RCP8.5 were used. Model evaluation was done using true skill, Kappa statistics and receiver operating characteristics. RESULTS: The results showed that under current bioclimatic conditions, eastern and western districts of Zimbabwe were modelled as highly suitable, central districts moderately suitable and southern parts marginally suitable for anthrax occurrence. Future predictions demonstrated that the suitable (8%) and highly suitable (7%) areas for anthrax occurrence would increase under RCP4.5 scenario. In contrast, a respective decrease (11%) and marginal increase (0.6%) of suitable and highly suitable areas for anthrax occurrence were predicted under the RCP8.5 scenario. The percentage contribution of the predictors varied for the different scenarios; Bio6 and Bio18 for the current scenario, Bio2, Bio4 and Bio9 for the RCP4.5 and Bio3 and Bio15 for the RCP8.5 scenarios. CONCLUSIONS: The study revealed that areas currently suitable for anthrax should be targeted for surveillance and prevention. The predicted future anthrax distribution can be used to guide and prioritise surveillance and control activities and optimise allocation of limited resources. In the marginally to moderately suitable areas, effective disease surveillance systems and awareness need to be put in place for early detection of outbreaks. Targeted vaccinations and other control measures including collaborative 'One Health' strategies need to be implemented in the predicted highly suitable areas. In the southern part where a high decrease in suitability was predicted, continued monitoring would be necessary to detect incursions early.
Asunto(s)
Carbunco , Animales , Humanos , Carbunco/epidemiología , Carbunco/veterinaria , Cambio Climático , Zimbabwe/epidemiología , Ecosistema , Animales SalvajesRESUMEN
OBJECTIVES: Bacillus anthracis infection is a worldwide zoonosis that affects the most vulnerable population and has a high mortality rate without treatment, especially in non-cutaneous presentations. Cutaneous scarification is still common in some regions of the world for the treatment of certain diseases as part of traditional medicine. We describe a series of cutaneus anthrax from a rural setting in Angola where cutaneus scarification is common. CASE PRESENTATION: This is a retrospective observational study describing a series of cutaneous anthrax cases from Cubal (Angola), many of whom were treated with skin scarification before admission. A total of 26 cases were diagnosed from January 2010 to December 2018. None of the cases were confirmed and eight (30.8%) were probable cases according to the Centers for the Disease Control and Prevention anthrax case definition. The median age was 11 (4.7-30.5) years, 17 (65.4%) had lesions on the head, face, or neck and 15 (57.7%) were treated with cutaneous scarification. Nine (34.6%) patients died. Traditional cutaneous scarification was significantly associated with cutaneous superinfection, respiratory, systemic involvement, and death. CONCLUSION: Our case series points to increased complications and worse outcome of cutaneous anthrax disease if treated with skin scarification.
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Carbunco , Bacillus anthracis , Enfermedades Cutáneas Bacterianas , Niño , Humanos , Angola , Carbunco/diagnóstico , Carbunco/tratamiento farmacológico , Carbunco/epidemiología , Antibacterianos/uso terapéutico , Enfermedades Cutáneas Bacterianas/tratamiento farmacológico , Enfermedades Cutáneas Bacterianas/epidemiología , Enfermedades Cutáneas Bacterianas/diagnóstico , Estudios RetrospectivosRESUMEN
BACKGROUND: Anthrax, a zoonotic disease caused by the spore-forming bacterium Bacillus anthracis, remains a major global public health concern, especially in countries with limited resources. Sierra Leone, a West African country historically plagued by anthrax, has almost been out of report on this disease in recent decades. In this study, we described a large-scale anthrax outbreak affecting both animals and humans and attempted to characterize the pathogen using molecular techniques. METHODS: The causative agent of the animal outbreak in Port Loko District, Sierra Leone, between March and May 2022 was identified using the nanopore sequencing technique. A nationwide active surveillance was implemented from May 2022 to June 2023 to monitor the occurrence of anthrax-specific symptoms in humans. Suspected cases were subsequently verified using quantitative polymerase chain reaction. Full-genome sequencing was accomplished by combining long-read and short-read sequencing methods. Subsequent phylogenetic analysis was performed based on the full-chromosome single nucleotide polymorphisms. RESULTS: The outbreak in Port Loko District, Sierra Leone, led to the death of 233 animals between March 26th and May 16th, 2022. We ruled out the initial suspicion of Anaplasma species and successfully identified B. anthracis as the causative agent of the outbreak. As a result of the government's prompt response, out of the 49 suspected human cases identified during the one-year active surveillance, only 6 human cases tested positive, all within the first month after the official declaration of the outbreak. The phylogenetic analysis indicated that the BaSL2022 isolate responsible for the outbreak was positioned in the A.Br.153 clade within the TransEuroAsian group of B. anthracis. CONCLUSIONS: We successfully identified a large-scale anthrax outbreak in Sierra Leone. The causative isolate of B. anthracis, BaSL2022, phylogenetically bridged other lineages in A.Br.153 clade and neighboring genetic groups, A.Br.144 and A.Br.148, eventually confirming the spillover of anthrax from West Africa. Given the wide dissemination of B. anthracis spores, it is highly advisable to effectively monitor the potential reoccurrence of anthrax outbreaks and to launch campaigns to improve public awareness regarding anthrax in Sierra Leone.
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Carbunco , Bacillus anthracis , Animales , Humanos , Bacillus anthracis/genética , Carbunco/epidemiología , Carbunco/veterinaria , Carbunco/genética , Filogenia , Genoma Bacteriano , África Occidental/epidemiología , Brotes de EnfermedadesRESUMEN
BACKGROUND: Anthrax is a non-contagious zoonotic disease caused by the Gram-positive, spore-forming bacterium Bacillus anthracis. Infection is common in livestock and wild animals such as cattle, goats, sheep, camels, and antelopes. In humans, anthrax may occur after contact with contaminated carcasses or animal products like milk and meat. The best method to prevent anthrax in people is to ensure livestock are vaccinated, which significantly limits the risk of zoonotic spread to humans. However, the rate of vaccination of domesticated animals kept by nomadic pastoralists in West Africa is low. These groups regularly cross over national boundaries with their grazing herds. Nigeria is a country that historically has done comparatively well to contain this public health threat. However, in 2023 several outbreaks of human disease appear linked to the consumption of anthrax-contaminated animal products brought into Nigeria by pastoralists from neighboring countries. Clinical manifestations include skin sores or ulcers, nausea, vomiting, and fever. This article aims to raise awareness of recent outbreaks of anthrax in West Africa and to call for a renewed focus on measures to combat this neglected public health concern to the region. MAIN BODY: The imperative to pinpoint pivotal issues relating to the ongoing emergence of anthrax cases in Nigeria cannot be overstated. By delving into the prevalence of anthrax in both livestock and human populations residing along Nigeria's borders, unraveling the genetic diversity and potential sources of B. anthracis strains, and identifying the primary animal host(s) responsible for transmission, we stand to enhance our understanding of this critical issue. Furthermore, investigating the multifaceted factors contributing to anthrax transmission, assessing community knowledge and practices, mapping common migratory routes of pastoralists, and formulating targeted intervention strategies tailored to the challenges of border communities, are each crucial steps towards effective control and prevention. CONCLUSION: Closing these knowledge gaps on anthrax is not only essential for safeguarding both animal and human health but also for fostering sustainable and resilient communities. Addressing research questions on these interdisciplinary concerns will undoubtedly pave the way for informed decision-making, proactive measures, and a more secure future for Nigeria and its border regions.
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Carbunco , Bacillus anthracis , Bovinos , Humanos , Animales , Ovinos , Carbunco/epidemiología , Carbunco/prevención & control , Carbunco/veterinaria , Nigeria/epidemiología , Brotes de Enfermedades/veterinaria , Bacillus anthracis/genética , Zoonosis/epidemiología , Zoonosis/prevención & control , Ganado , CabrasRESUMEN
AIMS: Anthrax is reported with frequency but poorly understood in Southeast Asian countries including Vietnam. In Vietnam, anthrax surveillance is national. However, case detection, prevention, and control are implemented locally at the provincial level. Here, we describe the epidemiological characteristics, identify spatial clusters of human anthrax, and compare the variation in livestock anthrax vaccine coverage to disease incidence in humans and livestock using historical data in Son La province, Vietnam (2003-2020). METHODS AND RESULTS: Most human cases occurred between April and September. Most of the patients were male, aged 15-54 years old. The human cases were mainly reported by public district hospitals. There was a delay between disease onset and hospitalization of ~5 days. We identified spatial clusters of high-high incidence communes in the northern communes of the province using the local Moran's I statistic. The vaccine coverage sharply decreased across the study period. The province reported sporadic human anthrax outbreaks, while animal cases were only reported in 2005 and 2022. CONCLUSIONS: These results suggest underreporting for human and livestock anthrax in the province. Intersectoral information sharing is needed to aid livestock vaccination planning, which currently relies on reported livestock cases. The spatial clusters identify areas for targeted surveillance and livestock vaccination, while the seasonal case data suggest prioritizing vaccination campaigns for February or early March ahead of the April peak. A regional approach for studying the role of livestock trading between Son La and neighbouring provinces in anthrax occurrence is recommended.
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Carbunco , Humanos , Carbunco/epidemiología , Carbunco/veterinaria , Carbunco/prevención & control , Vietnam/epidemiología , Animales , Adolescente , Masculino , Persona de Mediana Edad , Adulto , Adulto Joven , Femenino , Ganado/microbiología , Vacunas contra el Carbunco/administración & dosificación , Incidencia , Estaciones del Año , Brotes de Enfermedades , NiñoRESUMEN
In July 2023, the Minnesota Department of Health (MDH) was notified of possible occupational exposures to anthrax during an outbreak in animals. In consultation with the Centers for Disease Control and Prevention, MDH epidemiologists created a questionnaire that assessed exposure risks and helped determine individual illness monitoring and antibiotic post-exposure prophylaxis needs. This investigation and the resources developed for it could be useful in future scenarios where there are occupational exposures to naturally occurring anthrax.
Asunto(s)
Carbunco , Brotes de Enfermedades , Ganado , Exposición Profesional , Humanos , Carbunco/epidemiología , Carbunco/veterinaria , Carbunco/transmisión , Minnesota/epidemiología , Exposición Profesional/efectos adversos , Animales , Ganado/microbiología , Masculino , Encuestas y Cuestionarios , Adulto , Femenino , Bovinos , Bacillus anthracis/aislamiento & purificación , Persona de Mediana Edad , Profilaxis PosexposiciónRESUMEN
Anthrax is a serious infection caused by Bacillus anthracis. The anthracis spores are highly resistant and can persist in the environment for several decades. Therefore, anthrax is considered a global health threat affecting wildlife, livestock, and the general public. The resistance mechanism is influenced not only by the environment or the ecological niche but also by virulence factors. In the last 10 years the Southern and Southeastern Europe have been confronted with this threat. Recently, there have been 8 human anthrax cases reported in Croatia (2022), and 4 cases in Romania (2023). Moreover, this incident and the COVID situation could be a starting point to encourage researchers to raise the alarm. On the other hand, climate change is causing glaciers to melt and land to thaw, and many wetlands and swampy areas are being drained. It should not be forgotten that epidemiological and epizootic threats significantly affect the country's economic development. The Covid-19 epidemic best illustrates these threats.