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1.
Parasit Vectors ; 16(1): 444, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38037186

RESUMO

BACKGROUND: In Togo, malaria remains a major public health problem, and the management of suspected cases requires confirmation with appropriate biological methods. Malaria diagnosis has been improved by the introduction of rapid diagnostic tests (RDTs), recommended by the World Health Organization (WHO) for areas where microscopy is not available. To be used, these RDTs must meet performance criteria defined by the WHO. This study was conducted to evaluate the diagnostic performance of two RDTs: Advantage P.f. Malaria Card® detecting HRP2 antigen and Advantage Malaria Pan + Pf Card® detecting both HRP2 and pLDH antigens. METHODS: This was a cross-sectional analytical study conducted from December 2019 to February 2020 on malaria-suspected cases received in three sentinel sites in Togo and from whom capillary blood was collected to perform the two RDTs according to the manufacturer's instructions. Sensitivity and specificity were estimated by comparing to thick/thin blood smear, the gold standard, and to PCR, which is a more sensitive. RESULTS: A total of 390 participants (54.9% female) with a median age of 18 (± 0.8) years were included in the study. The sensitivity of both Advantage P.f. Malaria Card® and Advantage Malaria Pan + Pf Card® compared to thick/thin blood smear was 91.8% and 91.3%, respectively, and for both the specificity was 94.7%. Compared to PCR, the sensitivity was 84.2% and 83.8%, respectively, and the specificity 96.5%. CONCLUSIONS: The performances of the Advantage P.f. Malaria Card® and Advantage Malaria PAN + Pf Card® compared to microscopy, considered the gold standard, were acceptable under the field conditions found in Togo. They can therefore be used for the biological diagnosis of malaria.


Assuntos
Malária Falciparum , Malária , Humanos , Feminino , Adolescente , Masculino , Malária Falciparum/diagnóstico , Plasmodium falciparum , Testes Diagnósticos de Rotina/métodos , Testes de Diagnóstico Rápido , Estudos Transversais , Togo/epidemiologia , Malária/diagnóstico , Antígenos de Protozoários/análise , Sensibilidade e Especificidade
2.
BMC Infect Dis ; 21(1): 1186, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34823479

RESUMO

BACKGROUND: Nucleic acid-based amplification tests (NAAT), above all (q)PCR, have been applied for the detection of Mycobacterium leprae in leprosy cases and household contacts with subclinical infection. However, their application in the field poses a range of technical challenges. Loop-mediated isothermal amplification (LAMP), as a promising point-of-care NAAT does not require sophisticated laboratory equipment, is easy to perform, and is applicable for decentralized diagnosis at the primary health care level. Among a range of gene targets, the M. leprae specific repetitive element RLEP is regarded as highly sensitive and specific for diagnostic applications.  METHODS: Our group developed and validated a dry-reagent-based (DRB) RLEP LAMP, provided product specifications for customization of a ready-to-use kit (intended for commercial production) and compared it against the in-house prototype. The assays were optimized for application on a Genie® III portable fluorometer. For technical validation, 40 "must not detect RLEP" samples derived from RLEP qPCR negative exposed and non-exposed individuals, as well as from patients with other conditions and a set of closely related mycobacterial cultures, were tested together with 25 "must detect RLEP" samples derived from qPCR confirmed leprosy patients. For clinical validation, 150 RLEP qPCR tested samples were analyzed, consisting of the following categories: high-positive samples of multibacillary (MB) leprosy patients (> 10.000 bacilli/extract), medium-positive samples of MB leprosy patients (1.001-10.000 bacilli/extract), low-positive samples of MB leprosy patients (1-1.000 bacilli/extract), endemic controls and healthy non-exposed controls; each n = 30.  RESULTS: Technical validation: both LAMP formats had a limit of detection of 1.000 RLEP copies, i.e. 43-27 bacilli, a sensitivity of 92% (in-house protocol)/100% (ready-to-use protocol) and a specificity of 100%. Reagents were stable for at least 1 year at 22 °C. Clinical validation: Both formats showed a negativity rate of 100% and a positivity rate of 100% for high-positive samples and 93-100% for medium positive samples, together with a positive predictive value of 100% and semi-quantitative results. The positivity rate for low-positive samples was 77% (in-house protocol)/43% (ready-to-use protocol) and differed significantly between both formats.  CONCLUSIONS: The ready-to-use RLEP DRB LAMP assay constitutes an ASSURED test ready for field-based evaluation trials aiming for routine diagnosis of leprosy at the primary health care level.


Assuntos
Laboratórios , Hanseníase , DNA Bacteriano , Humanos , Hanseníase/diagnóstico , Técnicas de Diagnóstico Molecular , Mycobacterium leprae/genética , Técnicas de Amplificação de Ácido Nucleico , Testes Imediatos , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
3.
PLoS Negl Trop Dis ; 15(3): e0009157, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33657104

RESUMO

Buruli ulcer (BU) is a disabling and stigmatising neglected tropical disease (NTD). Its distribution and burden are unknown because of underdiagnosis and underreporting. It is caused by Mycobacterium ulcerans, an environmental pathogen whose environmental niche and transmission routes are not fully understood. The main control strategy is active surveillance to promote early treatment and thus limit morbidity, but these activities are mostly restricted to well-known endemic areas. A better understanding of environmental suitability for the bacterium and disease could inform targeted surveillance, and advance understanding of the ecology and burden of BU. We used previously compiled point-level datasets of BU and M. ulcerans occurrence, evidence for BU occurrence within national and sub-national areas, and a suite of relevant environmental covariates in a distribution modelling framework. We fitted relationships between BU and M. ulcerans occurrence and environmental predictors by applying regression and machine learning based algorithms, combined in an ensemble model to characterise the optimal ecological niche for the disease and bacterium across Africa at a resolution of 5km x 5km. Proximity to waterbodies was the strongest predictor of suitability for BU, followed potential evapotranspiration. The strongest predictors of suitability for M. ulcerans were deforestation and potential evapotranspiration. We identified patchy foci of suitability throughout West and Central Africa, including areas with no previous evidence of the disease. Predicted suitability for M. ulcerans was wider but overlapping with that of BU. The estimated population living in areas predicted suitable for the bacterium and disease was 46.1 million. These maps could be used to inform burden estimations and case searches which would generate a more complete understanding of the spatial distribution of BU in Africa, and may guide control programmes to identify cases beyond the well-known endemic areas.


Assuntos
Úlcera de Buruli/epidemiologia , Mycobacterium ulcerans , África/epidemiologia , Clima , Ecossistema , Humanos , Modelos Teóricos
4.
Influenza Other Respir Viruses ; 15(4): 495-505, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33150650

RESUMO

BACKGROUND: Influenza surveillance helps time prevention and control interventions especially where complex seasonal patterns exist. We assessed influenza surveillance sustainability in Africa where influenza activity varies and external funds for surveillance have decreased. METHODS: We surveyed African Network for Influenza Surveillance and Epidemiology (ANISE) countries about 2011-2017 surveillance system characteristics. Data were summarized with descriptive statistics and analyzed with univariate and multivariable analyses to quantify sustained or expanded influenza surveillance capacity in Africa. RESULTS: Eighteen (75%) of 24 ANISE members participated in the survey; their cumulative population of 710 751 471 represent 56% of Africa's total population. All 18 countries scored a mean 95% on WHO laboratory quality assurance panels. The number of samples collected from severe acute respiratory infection case-patients remained consistent between 2011 and 2017 (13 823 vs 13 674 respectively) but decreased by 12% for influenza-like illness case-patients (16 210 vs 14 477). Nine (50%) gained capacity to lineage-type influenza B. The number of countries reporting each week to WHO FluNet increased from 15 (83%) in 2011 to 17 (94%) in 2017. CONCLUSIONS: Despite declines in external surveillance funding, ANISE countries gained additional laboratory testing capacity and continued influenza testing and reporting to WHO. These gains represent important achievements toward sustainable surveillance and epidemic/pandemic preparedness.


Assuntos
Influenza Humana , Infecções Respiratórias , África/epidemiologia , Humanos , Influenza Humana/epidemiologia , Influenza Humana/prevenção & controle , Pandemias , Infecções Respiratórias/epidemiologia , Inquéritos e Questionários
5.
PLoS One ; 15(11): e0242124, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33166369

RESUMO

BACKGROUND: In December 2019, the COVID-19 outbreak began in China and quickly spread throughout the world and was reclassified as a pandemic in March 2020. The first case of COVID-19 was declared in Togo on March 5. Two months later, few data were available to describe the circulation of the new coronavirus in the country. OBJECTIVE: This survey aimed to estimate the prevalence of SARS-CoV-2 in high-risk populations in Lomé. MATERIALS AND METHODS: From April 23, 2020, to May 8, 2020, we recruited a sample of participants from five sectors: health care, air transport, police, road transport and informal. We collected oropharyngeal swabs for direct detection through real-time reverse transcription polymerase chain reaction (rRT-PCR) and blood for antibody detection by serological tests. The overall prevalence (current and past) of infection was defined by positivity for both tests. RESULTS: A total of 955 participants with a median age of 36 (IQR 32-43) were included, and 71.6% (n = 684) were men. Approximately 22.1% (n = 212) were from the air transport sector, 20.5% (n = 196) were from the police sector, and 38.7% (n = 370) were from the health sector. Seven participants (0.7%, 95% CI: 0.3-1.6%) had a positive rRT-PCR test result at the time of recruitment, and nine (0.9%, 95% CI: 0.4-1.8%) were seropositive for IgM or IgG against SARS-CoV-2. We found an overall prevalence of 1.6% (n = 15), 95% CI: 0.9-2.6%. CONCLUSION: The prevalence of SARS-CoV-2 infection among high-risk populations in Lomé was relatively low and could be explained by the various measures taken by the Togolese government. Therefore, we recommend targeted screening.


Assuntos
Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , Adulto , Anticorpos Antivirais/sangue , Betacoronavirus/genética , Betacoronavirus/isolamento & purificação , COVID-19 , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Estudos Transversais , Feminino , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Prevalência , RNA Viral/genética , RNA Viral/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Risco , SARS-CoV-2 , Togo/epidemiologia
6.
J Infect Dis ; 220(220 Suppl 4): S216-S224, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31671438

RESUMO

BACKGROUND: During 2014, 4 regions in Togo within the African meningitis belt implemented vaccination campaigns with meningococcal serogroup A conjugate vaccine (MACV). From January to July 2016, Togo experienced its first major Neisseria meningitidis serogroup W (NmW) outbreak. We describe the epidemiology, response, and management of the outbreak. METHODS: Suspected, probable, and confirmed cases were identified using World Health Organization case definitions. Through case-based surveillance, epidemiologic and laboratory data were collected for each case. Cerebrospinal fluid specimens were analyzed by polymerase chain reaction, culture, or latex agglutination. Vaccination campaigns were conducted in affected districts. RESULTS: From January 11 to July 5, 2016, 1995 suspected meningitis cases were reported, with 128 deaths. Among them, 479 (24.0%) were confirmed by laboratory testing, and 94 (4.7%) and 1422 (71.3%) remained as probable and suspected cases, respectively. Seven epidemic districts had cumulative attack rates greater than 100 per 100 000 population. Of the confirmed cases, 91.5% were NmW; 39 of 40 available NmW isolates were sequence type-11/clonal complex-11. CONCLUSIONS: This outbreak demonstrates that, although high coverage with MACV has reduced serogroup A outbreaks, large meningococcal meningitis outbreaks due to other serogroups may continue to occur; effective multivalent meningococcal conjugate vaccines could improve meningococcal disease prevention within meningitis belt populations.


Assuntos
Meningite Meningocócica/epidemiologia , Meningite Meningocócica/microbiologia , Neisseria meningitidis/classificação , Surtos de Doenças , Geografia , História do Século XXI , Humanos , Incidência , Vacinação em Massa , Meningite Meningocócica/história , Meningite Meningocócica/prevenção & controle , Vacinas Meningocócicas/administração & dosagem , Vacinas Meningocócicas/imunologia , Vigilância da População , Sorogrupo , Togo/epidemiologia
7.
BMC Infect Dis ; 19(1): 753, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462296

RESUMO

BACKGROUND: Leprosy continues to be a health problem in endemic areas. More than 200,000 new cases of leprosy per year suggest that transmission of the disease is still ongoing, presumably as airborne infection through nasal droplets. Late diagnosis supports continued transmission and increases the individual risk for functional disabilities. Laboratory tools are considered beneficial to facilitate early detection and clinical assessment of cases. The aim of this study was to validate molecular tools allowing detection, quantification and assessment of viability of M. leprae from nasal swab samples which are easy to obtain without the need of any invasive procedures. METHODS: Validation of two real-time PCRs detecting M. leprae DNA (RLEP qPCR) and RNA (16S rRNA RT qPCR) was conducted on "must not detect"/"must detect" samples and 160 pre-treatment nasal swab samples from 20 clinically diagnosed multibacillary (MB) leprosy patients from Togo. RESULTS: Both assays were 100% M. leprae specific and showed analytical sensitivities of three templates each. Out of 20 clinically diagnosed MB leprosy patients, 15 (75.0%) had a positive RLEP qPCR result from nasal swab samples. The 16S rRNA RT qPCR detected viable bacilli in nasal swab samples of ten out of these 15 RLEP positive patients (66.7%). CONCLUSION: The combined RLEP/16S rRNA (RT) qPCR assay provides a sensitive and specific tool to determine the bacterial load and viability of M. leprae from nasal swab samples and is applicable for early diagnosis, monitoring treatment response and investigating the role of nasal carriage of M. leprae in human-to-human transmission through aerosol infection.


Assuntos
Hanseníase/microbiologia , Mycobacterium leprae/genética , Cavidade Nasal/microbiologia , RNA Ribossômico 16S , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , DNA Bacteriano/genética , Humanos , Hanseníase/diagnóstico , Hanseníase Multibacilar/diagnóstico , Hanseníase Multibacilar/microbiologia , Pessoa de Meia-Idade , Mycobacterium leprae/isolamento & purificação , Mycobacterium leprae/patogenicidade , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Togo , Adulto Jovem
8.
Lancet Glob Health ; 7(7): e912-e922, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31200890

RESUMO

BACKGROUND: Buruli ulcer can cause disfigurement and long-term loss of function. It is underdiagnosed and under-reported, and its current distribution is unclear. We aimed to synthesise and evaluate data on Buruli ulcer prevalence and distribution. METHODS: We did a systematic review of Buruli ulcer prevalence and used an evidence consensus framework to describe and evaluate evidence for Buruli ulcer distribution worldwide. We searched PubMed and Web of Science databases from inception to Aug 6, 2018, for records of Buruli ulcer and Mycobacterium ulcerans detection, with no limits on study type, publication date, participant population, or location. English, French, and Spanish language publications were included. We included population-based surveys presenting Buruli ulcer prevalence estimates, or data that allowed prevalence to be estimated, in the systematic review. We extracted geographical data on the occurrence of Buruli ulcer cases and M ulcerans detection from studies of any type for the evidence consensus framework; articles that did not report original data were excluded. For the main analysis, we extracted prevalence estimates from included surveys and calculated 95% CIs using Byar's method. We included occurrence records, reports to WHO and the Global Infectious Diseases and Epidemiology Network, and surveillance data from Buruli ulcer control programmes in the evidence consensus framework to grade the strength of evidence for Buruli ulcer endemicity. This study is registered with PROSPERO, number CRD42018116260. FINDINGS: 2763 titles met the search criteria. We extracted prevalence estimates from ten studies and occurrence data from 208 studies and five unpublished surveillance datasets. Prevalence estimates within study areas ranged from 3·2 (95% CI 3·1-3·3) cases per 10 000 population in Côte d'Ivoire to 26·9 (23·5-30·7) cases per 10 000 population in Benin. There was evidence of Buruli ulcer in 32 countries and consensus on presence in 12. INTERPRETATION: The global distribution of Buruli ulcer is uncertain and potentially wider than currently recognised. Our findings represent the strongest available evidence on Buruli ulcer distribution so far and have many potential applications, from directing surveillance activities to informing burden estimates. FUNDING: AIM Initiative.


Assuntos
Úlcera de Buruli/epidemiologia , Mapeamento Geográfico , Saúde Global , Humanos , Mycobacterium ulcerans/isolamento & purificação , Prevalência
9.
PLoS Negl Trop Dis ; 12(5): e0006455, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29782522

RESUMO

BACKGROUND: Buruli Ulcer (BU) is a neglected tropical skin infection caused by Mycobacterium ulcerans. Residence near aquatic areas has been identified as an important source of transmission of M. ulcerans with increased risk of contracting Buruli ulcer. However, the reservoir and the mode of transmission are not yet well known. The aim of this study was to identify the presence of M. ulcerans in the environment and its relationship with Buruli ulcer occurrence in Zio and Yoto districts of the maritime region in south Togo. METHODS: A total of 219 environmental samples including soil (n = 119), water (n = 65), biofilms/plants (n = 29) and animals' feces (n = 6) were collected in 17 villages of Zio and Yoto districts of the maritime region in Togo. DNA of M. ulcerans including IS2404 and IS2606 insertions sequences and mycolactone ketoreductase-B gene (KR-B) was detected using real time PCR amplification (qPCR) technique. In parallel, clinical samples of patients were tested to establish a comparison of the genetic profile of M. ulcerans between the two types of samples. A calibration curve was generated for IS2404 from a synthetic gene of M. ulcerans Transposase pMUM001, the plasmid of virulence. RESULTS: In the absence of inhibition of the qPCR, 6/219 (2.7%) samples were tested positive for M. ulcerans DNA containing three sequences (IS2404/IS2606/KR-B). Positive samples of M. ulcerans were consisting of biofilms/plants (3/29; 10.3%), water (1/65; 1.7%) and soil (2/119; 1.5%). Comparative analysis between DNA detected in environmental and clinical samples from BU patients showed the same genetic profile of M. ulcerans in the same environment. All these samples were collected in the environment of Haho and Zio rivers in the maritime region. CONCLUSION: This study confirms the presence of M. ulcerans in the environment of the Zio and Yoto districts of the maritime region of Togo. This may explain partially, the high rates of Buruli ulcer patients in this region. Also, water, plants and soil along the rivers could be possible reservoirs of the bacterium. Therefore, Haho and Zio rivers could be potential sources of infection with M. ulcerans in humans in these districts.


Assuntos
Úlcera de Buruli/microbiologia , Microbiologia Ambiental , Mycobacterium ulcerans/genética , Mycobacterium ulcerans/isolamento & purificação , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Úlcera de Buruli/epidemiologia , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Fezes/microbiologia , Humanos , Gado , Mycobacterium ulcerans/classificação , Mycobacterium ulcerans/fisiologia , Plasmídeos/genética , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , População Rural , Microbiologia do Solo , Togo/epidemiologia
10.
Parasit Vectors ; 11(1): 244, 2018 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-29661231

RESUMO

BACKGROUND: Togo is a country previously endemic for lymphatic filariasis (LF). In 2010, following nine years of mass drug administration (MDA) for LF, the country established a post-treatment surveillance (PTS) system. We present here the results of these PTS activities, carried out from 2010 to 2015, as well as the findings of follow-up investigations in 2016 to confirm the absence of infection in previously infected individuals. METHODS: The routine surveillance established in 2010 consisted of a network of 47 laboratories, which searched for Wuchereria bancrofti microfilaria on nocturnal blood smears collected for malaria diagnosis and an additional network of 20 peripheral health facilities, which collected dried blood spots and tested them for Og4C3 antigen. Two transmission assessment surveys (TAS) were also undertaken, as recommended by WHO, in 2012 and 2015. Any positive case identified through any surveillance activity was immediately retested by nocturnal smear and confirmed cases were immediately investigated by screening family members and neighboring household members. In 2016, 32 of the 40 positive cases detected during TAS or laboratory and health facility network activities were traced and whether confirmed positive by nocturnal smear or not were tested again simultaneously by filariasis test strip (FTS), Og4C3 and a nocturnal blood smear to rule out any active infection. RESULTS: From 2010 to 2015, the laboratory network identified one microfilaria-positive individual (0.0% of 26,584 persons tested) and the peripheral health facility network detected 19 Og4C3-positive individuals (0.28% of 6788 persons tested). All 19 Og4C3 cases were negative for microfilaremia by nocturnal blood smear. In the 2012 and 2015 TAS, thirteen and six ICT/FTS positive cases, respectively, were identified, which were significantly below the critical cut-off (18-20 cases) across all evaluation units. Three of the six ICT/FTS-positive cases from the 2015 TAS were positive by nocturnal smear; immediate investigation identified one additional microfilaria-positive individual. Epidemiological investigation revealed that four of the five cases of microfilaremia were imported from another country in the region. In 2016, 32 of the 40 positive cases detected by at least one test during all surveillance activities were traced: four (12.5%) individuals were still positive by FTS but all 32 individuals were negative for microfilaremia and Og4C3 antigen. CONCLUSION: The results of post-treatment surveillance in Togo have demonstrated that W. bancrofti filariasis is no longer of public health concern in Togo, more than six years after stopping MDA. Every possible effort should be made to maintain surveillance in order to promptly detect any resurgence and preserve this achievement.


Assuntos
Filariose Linfática/epidemiologia , Filariose Linfática/prevenção & controle , Monitoramento Epidemiológico , Filaricidas/administração & dosagem , Pesquisa sobre Serviços de Saúde , Administração Massiva de Medicamentos , Animais , Sangue/parasitologia , Filariose Linfática/tratamento farmacológico , Microscopia , Parasitologia , Togo/epidemiologia , Wuchereria bancrofti/isolamento & purificação
11.
BMC Infect Dis ; 18(1): 48, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29351741

RESUMO

BACKGROUND: Buruli ulcer (BU) is a neglected mycobacterial skin infection caused by Mycobacterium ulcerans. This disease mostly affects poor rural populations, especially in areas with low hygiene standards and sanitation coverage. The objective of this study was to identify these risk factors in the districts of Zio and Yoto of the Maritime Region in Togo. METHODS: We conducted a case-control study in Zio and Yoto, two districts proved BU endemic from November 2014 to May 2015. BU cases were diagnosed according to the WHO clinical case definition at the Centre Hospitalier Régional de Tsévié (CHR Tsévié) and confirmed by Ziehl-Neelsen (ZN) microscopy and IS2404 polymerase chain reaction (PCR). For each case, up to two controls matched by sex and place of residence were recruited. Socio-demographic, environmental or behavioral data were collected and conditional logistic regression analysis was used to identify and compare risk factors between BU cases and controls. RESULTS: A total of 83 cases and 128 controls were enrolled. The median age was 15 years (range 3-65 years). Multivariate conditional logistic regression analysis after adjustment for potential confounders identified age (< 10 years (OR =11.48, 95% CI = 3.72-35.43) and 10-14 years (OR = 3.63, 95% CI = 1.22-10.83)), receiving insect bites near a river (OR = 7.8, 95% CI = 1.48-41.21) and bathing with water from open borehole (OR = 5.77, (1.11-29.27)) as independent predictors of acquiring BU infection. CONCLUSIONS: This study identified age, bathing with water from open borehole and receiving insect bites near a river as potential risk of acquiring BU infection in Zio and Yoto districts of the Maritime Region in south Togo.


Assuntos
Úlcera de Buruli/epidemiologia , Úlcera de Buruli/microbiologia , Rios/microbiologia , Adolescente , Adulto , Idoso , Animais , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Mordeduras e Picadas de Insetos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mycobacterium ulcerans/genética , Mycobacterium ulcerans/patogenicidade , Reação em Cadeia da Polimerase , Fatores de Risco , População Rural , Togo/epidemiologia , Adulto Jovem
12.
BMC Infect Dis ; 17(1): 745, 2017 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-29202715

RESUMO

BACKGROUND: Over the last decade, capacity for influenza surveillance and research in West Africa has strengthened. Data from these surveillance systems showed influenza A(H1N1)pdm09 circulated in West Africa later than in other regions of the continent. METHODS: We contacted 11 West African countries to collect information about their influenza surveillance systems (number of sites, type of surveillance, sampling strategy, populations sampled, case definitions used, number of specimens collected and number of specimens positive for influenza viruses) for the time period January 2010 through December 2012. RESULTS: Of the 11 countries contacted, 8 responded: Burkina Faso, Cote d'Ivoire, Mali, Mauritania, Niger, Nigeria, Sierra Leone and Togo. Countries used standard World Health Organization (WHO) case definitions for influenza-like illness (ILI) and severe acute respiratory illness (SARI) or slight variations thereof. There were 70 surveillance sites: 26 SARI and 44 ILI. Seven countries conducted SARI surveillance and collected 3114 specimens of which 209 (7%) were positive for influenza viruses. Among influenza-positive SARI patients, 132 (63%) were influenza A [68 influenza A(H1N1)pdm09, 64 influenza A(H3N2)] and 77 (37%) were influenza B. All eight countries conducted ILI surveillance and collected 20,375 specimens, of which 2278 (11%) were positive for influenza viruses. Among influenza-positive ILI patients, 1431 (63%) were influenza A [820 influenza A(H1N1)pdm09, 611 influenza A(H3N2)] and 847 (37%) were influenza B. A majority of SARI and ILI case-patients who tested positive for influenza (72% SARI and 59% ILI) were children aged 0-4 years, as were a majority of those enrolled in surveillance. The seasonality of influenza and the predominant influenza type or subtype varied by country and year. CONCLUSIONS: Influenza A(H1N1)pdm09 continued to circulate in West Africa along with influenza A(H3N2) and influenza B during 2010-2012. Although ILI surveillance systems produced a robust number of samples during the study period, more could be done to strengthen surveillance among hospitalized SARI case-patients. Surveillance systems captured young children but lacked data on adults and the elderly. More data on risk groups for severe influenza in West Africa are needed to help shape influenza prevention and clinical management policies and guidelines.


Assuntos
Influenza Humana/epidemiologia , Adolescente , Adulto , África Ocidental/epidemiologia , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H3N2/patogenicidade , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Estações do Ano , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/virologia , Adulto Jovem
13.
PLoS Negl Trop Dis ; 9(11): e0004219, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26566026

RESUMO

BACKGROUND: As the major burden of Buruli ulcer disease (BUD) occurs in remote rural areas, development of point-of-care (POC) tests is considered a research priority to bring diagnostic services closer to the patients. Loop-mediated isothermal amplification (LAMP), a simple, robust and cost-effective technology, has been selected as a promising POC test candidate. Three BUD-specific LAMP assays are available to date, but various technical challenges still hamper decentralized application. To overcome the requirement of cold-chains for transport and storage of reagents, the aim of this study was to establish a dry-reagent-based LAMP assay (DRB-LAMP) employing lyophilized reagents. METHODOLOGY/PRINCIPAL FINDINGS: Following the design of an IS2404 based conventional LAMP (cLAMP) assay suitable to apply lyophilized reagents, a lyophylization protocol for the DRB-LAMP format was developed. Clinical performance of cLAMP was validated through testing of 140 clinical samples from 91 suspected BUD cases by routine assays, i.e. IS2404 dry-reagent-based (DRB) PCR, conventional IS2404 PCR (cPCR), IS2404 qPCR, compared to cLAMP. Whereas qPCR rendered an additional 10% of confirmed cases and samples respectively, case confirmation and positivity rates of DRB-PCR or cPCR (64.84% and 56.43%; 100% concordant results in both assays) and cLAMP (62.64% and 52.86%) were comparable and there was no significant difference between the sensitivity of the assays (DRB PCR and cPCR, 86.76%; cLAMP, 83.82%). Likewise, sensitivity of cLAMP (95.83%) and DRB-LAMP (91.67%) were comparable as determined on a set of 24 samples tested positive in all routine assays. CONCLUSIONS/SIGNIFICANCE: Both LAMP formats constitute equivalent alternatives to conventional PCR techniques. Provided the envisaged availability of field friendly DNA extraction formats, both assays are suitable for decentralized laboratory confirmation of BUD, whereby DRB-LAMP scores with the additional advantage of not requiring cold-chains. As validation of the assays was conducted in a third-level laboratory environment, field based evaluation trials are necessary to determine the clinical performance at peripheral health care level.


Assuntos
Úlcera de Buruli/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Adolescente , Adulto , Criança , Pré-Escolar , Estudos Transversais , Feminino , Liofilização , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
14.
PLoS Negl Trop Dis ; 9(1): e3457, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25569674

RESUMO

BACKGROUND: The only available vaccine that could be potentially beneficial against mycobacterial diseases contains live attenuated bovine tuberculosis bacillus (Mycobacterium bovis) also called Bacillus Calmette-Guérin (BCG). Even though the BCG vaccine is still widely used, results on its effectiveness in preventing mycobacterial diseases are partially contradictory, especially regarding Buruli Ulcer Disease (BUD). The aim of this case-control study is to evaluate the possible protective effect of BCG vaccination on BUD. METHODOLOGY: The present study was performed in three different countries and sites where BUD is endemic: in the Democratic Republic of the Congo, Ghana, and Togo from 2010 through 2013. The large study population was comprised of 401 cases with laboratory confirmed BUD and 826 controls, mostly family members or neighbors. PRINCIPAL FINDINGS: After stratification by the three countries, two sexes and four age groups, no significant correlation was found between the presence of BCG scar and BUD status of individuals. Multivariate analysis has shown that the independent variables country (p = 0.31), sex (p = 0.24), age (p = 0.96), and presence of a BCG scar (p = 0.07) did not significantly influence the development of BUD category I or category II/III. Furthermore, the status of BCG vaccination was also not significantly related to duration of BUD or time to healing of lesions. CONCLUSIONS: In our study, we did not observe significant evidence of a protective effect of routine BCG vaccination on the risk of developing either BUD or severe forms of BUD. Since accurate data on BCG strains used in these three countries were not available, no final conclusion can be drawn on the effectiveness of BCG strain in protecting against BUD. As has been suggested for tuberculosis and leprosy, well-designed prospective studies on different existing BCG vaccine strains are needed also for BUD.


Assuntos
Vacina BCG/imunologia , Úlcera de Buruli/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , República Democrática do Congo/epidemiologia , Feminino , Gana/epidemiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Togo/epidemiologia , Adulto Jovem
15.
BMC Public Health ; 14: 981, 2014 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-25239536

RESUMO

BACKGROUND: The emergence of avian influenza A/H5N1 in 2003 as well as the pandemic influenza A (H1N1) pdm09 highlighted the need to establish influenza sentinel surveillance in Togo. The Ministry of Health decided to introduce Influenza to the list of diseases with epidemic potential. By April 2010, Togo was actively involved in influenza surveillance. This study aims to describe the implementation of ILI surveillance and results obtained from April 2010 to December 2012. METHODS: Two sites were selected based on their accessibility and affordability to patients, their adequate specimen storage capacity and transportation system. Patients with ILI presenting at sentinel sites were enrolled by trained medical staff based on the World Health Organization (WHO) case definitions. Oropharyngeal and nasopharyngeal samples were collected and they were tested at the National Influenza Reference Laboratory using a U.S. Centers for Disease Control and Prevention (CDC) validated real time RT-PCR protocol. Laboratory results and epidemiological data were reported weekly and shared with all sentinel sites, Ministry of Health, Division of Epidemiology, WHO and CDC/NAMRU-3. RESULTS: From April 2010 to December 2012, a total of 955 samples were collected with 52% of the study population aged between 0 and 4 years. Of the 955 samples, 236 (24.7%) tested positive for influenza viruses; with 136 (14.2%) positive for influenza A and 100 (10.5%) positive for influenza B. The highest influenza positive percentage (30%) was observed in 5-14 years old and patients aged 0-4 and >60 years had the lowest percentage (20%). Clinical symptoms such as cough and rhinorrhea were associated more with ILI patients who were positive for influenza type A than influenza type B. Influenza viruses circulated throughout the year with the positivity rate peaking around the months of January, May and again in October; corresponding respectively to the dry-dusty harmattan season and the long and then the short raining season. The pandemic A (H1N1) pdm09 was the predominantly circulating strain in 2010 while influenza B was the predominantly circulating strain in 2011. The seasonal A/H3N2 was observed throughout 2012 year. CONCLUSIONS: This study provides information on influenza epidemiology in the capital city of Togo.


Assuntos
Influenza Humana/epidemiologia , Vigilância de Evento Sentinela , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Cidades , Feminino , Humanos , Lactente , Recém-Nascido , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Orthomyxoviridae/genética , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano , Togo/epidemiologia , Estados Unidos
17.
PLoS Negl Trop Dis ; 7(1): e2011, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23359828

RESUMO

BACKGROUND: In a previous study PCR analysis of clinical samples from suspected cases of Buruli ulcer disease (BUD) from Togo and external quality assurance (EQA) for local microscopy were conducted at an external reference laboratory in Germany. The relatively poor performance of local microscopy as well as effort and time associated with shipment of PCR samples necessitated the implementation of stringent EQA measures and availability of local laboratory capacity. This study describes the approach to implementation of a national BUD reference laboratory in Togo. METHODOLOGY: Large scale outreach activities accompanied by regular training programs for health care professionals were conducted in the regions "Maritime" and "Central," standard operating procedures defined all processes in participating laboratories (regional, national and external reference laboratories) as well as the interaction between laboratories and partners in the field. Microscopy was conducted at regional level and slides were subjected to EQA at national and external reference laboratories. For PCR analysis, sample pairs were collected and subjected to a dry-reagent-based IS2404-PCR (DRB-PCR) at national level and standard IS2404 PCR followed by IS2404 qPCR analysis of negative samples at the external reference laboratory. PRINCIPAL FINDINGS: The inter-laboratory concordance rates for microscopy ranged from 89% to 94%; overall, microscopy confirmed 50% of all suspected BUD cases. The inter-laboratory concordance rate for PCR was 96% with an overall PCR case confirmation rate of 78%. Compared to a previous study, the rate of BUD patients with non-ulcerative lesions increased from 37% to 50%, the mean duration of disease before clinical diagnosis decreased significantly from 182.6 to 82.1 days among patients with ulcerative lesions, and the percentage of category III lesions decreased from 30.3% to 19.2%. CONCLUSIONS: High inter-laboratory concordance rates as well as case confirmation rates of 50% (microscopy), 71% (PCR at national level), and 78% (including qPCR confirmation at external reference laboratory) suggest high standards of BUD diagnostics. The increase of non-ulcerative lesions, as well as the decrease in diagnostic delay and category III lesions, prove the effect of comprehensive EQA and training measures involving also procedures outside the laboratory.


Assuntos
Úlcera de Buruli/diagnóstico , Técnicas de Laboratório Clínico/métodos , Técnicas de Laboratório Clínico/normas , Adolescente , Adulto , Idoso , Úlcera de Buruli/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Microscopia/métodos , Microscopia/normas , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/normas , Garantia da Qualidade dos Cuidados de Saúde , Padrões de Referência , Togo/epidemiologia , Adulto Jovem
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