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SETTING: Although Kenya has a high burden of tuberculosis (TB), only 46% of cases were diagnosed in 2016. OBJECTIVE: To identify strategies for increasing attendance at community-based mobile screening units. DESIGN: We analysed operational data from a cluster-randomised trial, which included community-based mobile screening implemented during February 2015-April 2016. Community health volunteers (CHVs) recruited individuals with symptoms from the community, who were offered testing for human immunodeficiency virus (HIV) and sputum collection for Xpert® MTB/RIF testing. We compared attendance across different mobile unit sites using Wilcoxon rank-sum test. RESULTS: A total of 1424 adults with symptoms were screened at 25 mobile unit sites. The median total attendance among sites was 54 (range 6-134, interquartile range [IQR] 24-84). The median yields of TB diagnoses and new HIV diagnoses were respectively 2.4% (range 0.0-16.7, IQR 0.0-5.3) and 2.5% (range 0.0-33.3, IQR 1.2-4.2). Attendance at urban sites was variable; attendance at rural sites where CHVs were paid a daily minimum wage was significantly higher than at rural sites where CHVs were paid a nominal monthly stipend (P < 0.001). CONCLUSION: Mobile units were most effective and efficient when implemented as a single event with community health workers who are paid a daily wage.

RESUMEN

SETTING: Efficient tuberculosis (TB) active case-finding strategies are important in settings with high TB burdens and limited resources, such as those in western Kenya.OBJECTIVE: To guide efforts to optimize screening efficiency, we identified the predictors of TB among people screened in health facilities and communities.DESIGN: During February 2015-June 2016, adults aged ≥15 years reporting any TB symptom were identified in health facilities and community mobile screening units, and evaluated for TB. We assessed the predictors of TB using a modified Poisson regression with generalized estimating equations to account for clustering according to screening site.RESULTS: TB was diagnosed in 484 (20.3%) of 2394 symptomatic adults in health facilities and 39 (3.4%) of 1424 in communities. In health facilities, >10% of symptomatic adults in all demographic groups had TB, and no predictors were associated with a ≥2-fold increased risk. In communities, the independent predictors of TB were male sex (adjusted prevalence ratio [aPR] = 4.26, 95%CI 2.43-7.45), HIV infection (aPR 2.37, 95%CI 1.18-4.77), and household TB contact in the last 2 years (aPR 2.84, 95%CI 1.62-4.96).CONCLUSION: Our findings support the notion of general TB screening in health facilities and evaluation of the adult household contacts of TB patients.

Asunto(s)

Accesibilidad a los Servicios de Salud , Tamizaje Masivo/normas , Tuberculosis Pulmonar/prevención & control , Adolescente , Adulto , Servicios de Salud Comunitaria/normas , Comorbilidad , Femenino , Infecciones por VIH , Instituciones de Salud/normas , Humanos , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Análisis de Regresión , Factores Sexuales , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/microbiología , Adulto Joven

RESUMEN

BACKGROUND: In response to rising TB notification rates in England, universal strain typing was introduced in 2010. We evaluated the acceptability, effectiveness and cost-effectiveness of the TB strain typing service (TB-STS). METHODS: We conducted a mixed-methods evaluation using routine laboratory, clinic and public health data. We estimated the effect of the TB-STS on detection of false positive Mycobacterium tuberculosis diagnoses (2010-2012); contact tracing yield (number of infections or active disease per pulmonary TB case); and diagnostic delay. We developed a deterministic age-structured compartmental model to explore the effectiveness of the TB-STS, which informed a cost-effectiveness analysis. RESULTS: Semi-structured interviews explored user experience. Strain typing identified 17 additional false positive diagnoses. The TB-STS had no significant effect on contact tracing yield or diagnostic delay. Mathematical modelling suggested increasing the proportion of infections detected would have little value in reducing TB incidence in the white UK-born population. However, in the non-white UK-born and non-UK-born populations, over 20 years, if detection of latent infection increases from 3% to 13% per year, then TB incidence would decrease by 11%; reducing diagnostic delay by one week could lead to 25% reduction in incidence. The current TB-STS was not predicted to be cost-effective over 20 years (£95 628/quality-adjusted life-years). Interviews found people had mixed experiences, but identified broader benefits, of the TB-STS. CONCLUSIONS: To reduce costs, improve efficiency and increase effectiveness, we recommend changes to the TB-STS, including discontinuing routine cluster investigations and focusing on reducing diagnostic delay across the TB programme. This evaluation of a complex intervention informs the future of strain typing in the era of rapidly advancing technologies.

Asunto(s)

Técnicas de Tipificación Bacteriana/economía , Mycobacterium tuberculosis/genética , Evaluación de Programas y Proyectos de Salud , Salud Pública , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/microbiología , Análisis Costo-Beneficio , Inglaterra/epidemiología , Servicios de Salud/economía , Servicios de Salud/normas , Humanos , Incidencia , Mycobacterium tuberculosis/aislamiento & purificación , Vigilancia de la Población/métodos , Estudios Prospectivos , Tuberculosis Pulmonar/economía , Tuberculosis Pulmonar/epidemiología

RESUMEN

Tuberculosis (TB) has re-emerged over the past two decades: in industrialized countries in association with immigration, and in Africa owing to the human immunodeficiency virus epidemic. Drug-resistant TB is a major threat worldwide. The variable and uncertain impact of TB control necessitates not only better tools (diagnostics, drugs, and vaccines), but also better insights into the natural history and epidemiology of TB. Molecular epidemiological studies over the last two decades have contributed to such insights by answering long-standing questions, such as the proportion of cases attributable to recent transmission, risk factors for recent transmission, the occurrence of multiple Mycobacterium tuberculosis infection, and the proportion of recurrent TB cases attributable to re-infection. M. tuberculosis lineages have been identified and shown to be associated with geographical origin. The Beijing genotype is strongly associated with multidrug resistance, and may have escaped from bacille Calmette-Guérin-induced immunity. DNA fingerprinting has quantified the importance of institutional transmission and laboratory cross-contamination, and has helped to focus contact investigations. Questions to be answered in the near future with whole genome sequencing include identification of chains of transmission within clusters of patients, more precise quantification of mixed infection, and transmission probabilities and rates of progression from infection to disease of various M. tuberculosis lineages, as well as possible variations in vaccine efficacy by lineage. Perhaps most importantly, dynamics in the population structure of M. tuberculosis in response to control measures in high-prevalence areas should be better understood.

Asunto(s)

Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/genética , Tuberculosis/epidemiología , Tuberculosis/genética , Humanos , Epidemiología Molecular , Filogeografía , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Resistente a Múltiples Medicamentos/genética

RESUMEN

OBJECTIVES: To estimate the prevalence of infection with Mycobacterium tuberculosis and the annual risk of tuberculous infection (ARTI) and to compare this with the prevalence of tuberculosis (TB) over study clusters and households. METHODS: A nationwide, stratified cluster sample survey was carried out in 2006-2007 in Viet Nam to assess the prevalence of infection with M. tuberculosis. A representative sample of children aged 6-14 years underwent a tuberculin skin test (TST) using the Mantoux method. RESULTS: Of 23,160 children registered, 21,487 (92.8%) were tested and read and available for analysis. Using a cut-off point of 10 mm, the estimated prevalence of TST positivity was 16.7%, and the ARTI was 1.7% (95%CI 1.5-1.8). Higher infection rates were found in urban than in rural and remote areas, and infection rates increased with age. There was significant association between the prevalence of TB disease and infection at the cluster level (regression coefficient 0.54, 95%CI 0.06-1.01, P = 0.027, correlation coefficient R(2) 0.120). Children with a (recent) case of TB in the household were 1.6 times more likely to be TST-positive than children in households with no recent cases (P < 0.05). CONCLUSION: The estimated nationwide ARTI was 1.7%. TST positivity was associated with the presence of a TB case in the household.

Asunto(s)

Salud de la Familia/estadística & datos numéricos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis/epidemiología , Adolescente , Ageísmo , Niño , Análisis por Conglomerados , Femenino , Humanos , Masculino , Prevalencia , Análisis de Regresión , Población Rural/estadística & datos numéricos , Prueba de Tuberculina , Tuberculosis/diagnóstico , Población Urbana/estadística & datos numéricos , Vietnam/epidemiología

RESUMEN

SETTING: Primary health care facilities in five provinces of South Africa. OBJECTIVE: To investigate the association between the proportion of sputum results with a prolonged smear turnaround time and the proportion of smear-positive tuberculosis (TB) cases initially lost to follow-up. DESIGN: The unit of investigation was a primary health care facility and the outcome was the initial loss to follow-up rate per facility, which was calculated by comparing the sputum register with the TB treatment register. A prolonged turnaround time was defined as more than 48 h from when the sputum sample was documented in the sputum register to receipt of the result at the facility. RESULTS: The mean initial loss to follow-up rate was 25% (95%CI 22-28). Smear turnaround time overall was inversely associated with initial loss to follow-up (P = 0.008), when comparing Category 2 (33-66% turnaround time within 48 h) with Category 1 (0-32%) (OR 0.73, 95%CI 0.48-1.13, P = 0.163) and when comparing Category 3 (67-100%) with Category 1 (OR 0.62, 95%CI 0.39-0.99, P = 0.045). The population preventable fraction of initial loss to follow-up (when turnaround time was <48 h in ≥67% of smear results) was 21%. CONCLUSION: Initial loss to follow-up should be reported as part of the TB programme to ensure that patients are initiated on treatment to prevent transmission within communities.

Asunto(s)

Antituberculosos/uso terapéutico , Atención Primaria de Salud , Tiempo de Tratamiento , Tuberculosis Pulmonar/tratamiento farmacológico , Técnicas Bacteriológicas , Humanos , Análisis Multivariante , Mycobacterium tuberculosis/aislamiento & purificación , Oportunidad Relativa , Valor Predictivo de las Pruebas , Sistema de Registros , Factores de Riesgo , Sudáfrica , Esputo/microbiología , Factores de Tiempo , Resultado del Tratamiento , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/transmisión

RESUMEN

SETTING: This study was conducted in Cape Town in two primary health care facilities in a sub-district with a high prevalence of bacteriologically confirmed pulmonary tuberculosis (TB). OBJECTIVE: To determine the proportion of adults with respiratory symptoms who attend health care facilities but are not examined for nor diagnosed with TB in facilities where routine TB diagnosis depends on passive case finding. DESIGN: A total of 423 adults with respiratory symptoms exiting primary health care services were consecutively enrolled during April-July 2011. RESULTS: Twenty-one (5%) participants were diagnosed with culture-positive TB. None had sought care at the facility for their respiratory symptoms, none were asked about respiratory symptoms during their visit and none were asked to produce a sputum sample. Nine cases had attended the facility for reasons regarding their own health, while 12 cases were accompanying someone else attending the facility, or for another reason. CONCLUSION: Patients with infectious TB attend primary health care facilities, but are not recognised and diagnosed as cases. Health care staff should search actively within facilities for cases who attend the health care services to ensure that cases are not missed. Intensified case finding should start within the facility, and should not be limited to patients who report respiratory symptoms or who are human immunodeficiency virus positive.

Asunto(s)

Técnicas Bacteriológicas , Errores Diagnósticos , Atención Primaria de Salud , Tuberculosis Pulmonar/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/aislamiento & purificación , Valor Predictivo de las Pruebas , Prevalencia , Factores de Riesgo , Sudáfrica/epidemiología , Esputo/microbiología , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/transmisión , Adulto Joven

RESUMEN

OBJECTIVES: To evaluate excess mortality and risk factors for death during anti-tuberculosis treatment in Western Kenya. METHODS: We abstracted surveillance data and compared mortality rates during anti-tuberculosis treatment with all-cause mortality from a health and demographic surveillance population to obtain standardised mortality ratios (SMRs). Risk factors for excess mortality were obtained using a relative survival model, and for death during treatment using a proportional hazards regression model. RESULTS: The crude mortality rate during anti-tuberculosis treatment was 18.0 (95%CI 16.8-19.2) per 100 person-years. The age and sex SMR was 8.8 (95%CI 8.2-9.4). Excess mortality was greater in human immunodeficiency virus (HIV) positive TB patients (excess hazard ratio [eHR] 2.1, 95%CI 1.5-3.1), and lower in patients who were female or started treatment in a later year. Mortality was high in patients with unknown HIV status (HR 2.9, 95%CI 2.2-3.8) or, if HIV-positive, not on antiretroviral treatment (ART; HR 3.3, 95%CI 2.5-4.5) or not known to be on ART (HR 2.8, 95%CI 2.1-3.7). The attributable fraction of incomplete uptake of HIV testing and ART on mortality was 31% (95%CI 15-45) compared to HIV-positive patients on ART. CONCLUSION: Increasing the uptake of HIV testing and ART would further reduce mortality during anti-tuberculosis treatment by an estimated 31%.

Asunto(s)

Antituberculosos/uso terapéutico , Tuberculosis/tratamiento farmacológico , Tuberculosis/mortalidad , Adolescente , Adulto , Factores de Edad , Anciano , Antirretrovirales/uso terapéutico , Causas de Muerte , Coinfección/diagnóstico , Coinfección/tratamiento farmacológico , Coinfección/mortalidad , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/mortalidad , Humanos , Kenia/epidemiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Prevalencia , Modelos de Riesgos Proporcionales , Factores de Riesgo , Factores Sexuales , Factores de Tiempo , Resultado del Tratamiento , Tuberculosis/diagnóstico , Adulto Joven

RESUMEN

BACKGROUND: Tuberculosis (TB) prevalence surveys generally rely on a combination of screening methods to identify suspects eligible for sputum culture. OBJECTIVE: To assess the yield of screening methods applied in a recent prevalence survey in Viet Nam and estimate the proportion of TB cases missed due to incomplete participation. METHODS: TB suspects were identified based on self-reported TB history or productive cough by interview and chest X-ray (CXR). We calculated the case yield of these two screening methods by dividing the number of cases detected per method by the total number of cases detected. As not all participants underwent the full screening procedure, we recalculated the maximum yield of the screening methods using multiple imputation methods. RESULTS: The yield from screening by interview and CXR were respectively 38% and 91%. Adjusting for missing data by multiple imputation, we estimated that we missed 9.9% (95%CI 6.8-14.2) of expected TB cases. CONCLUSION: In prevalence surveys, screening by pre-structured interview is insufficient, and should be supplemented with CXR to achieve sufficient identification of TB cases. The effect of incomplete participation in the full screening procedure may be substantial and should be adjusted for in the analysis.

Asunto(s)

Entrevistas como Asunto , Tamizaje Masivo/métodos , Radiografía Torácica , Tuberculosis Pulmonar/epidemiología , Estudios Transversales , Femenino , Encuestas Epidemiológicas , Humanos , Masculino , Mycobacterium tuberculosis/aislamiento & purificación , Valor Predictivo de las Pruebas , Prevalencia , Sensibilidad y Especificidad , Esputo/microbiología , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/diagnóstico por imagen , Tuberculosis Pulmonar/microbiología , Vietnam/epidemiología

RESUMEN

SETTING: An increasing proportion of tuberculosis (TB) patients in low-incidence countries are immigrants. It is unclear whether contact investigations among immigrant patients are adequate. OBJECTIVE: To determine whether ethnicity of pulmonary TB patients was associated with coverage and yield of contact investigations in the Netherlands. DESIGN: Contact investigation results were extracted from records of patients reported in the nationwide surveillance register in 2006 and 2007. Prevalence odds ratios (PORs) with 95% confidence intervals (CIs) were calculated to determine the association between patient ethnicity and coverage of contact investigations and the yield of individuals with Mycobacterium tuberculosis infection or TB. RESULTS: Of the 1040 pulmonary TB patients reported, 642 (62%) were eligible for analysis. Compared to close contacts of Dutch patients, close contacts of immigrant patients were significantly less likely to be examined for TB (89% vs. 93%, POR 0.6, 95%CI 0.5-0.7) and infection (50% vs. 75%, POR 0.3, 95%CI 0.3-0.4), whereas the yield was significantly higher for disease (1.5% vs. 0.4%, POR 3.4, 95%CI 1.8-6.4) and infection (13% vs. 10%, POR 1.2, 95%CI 1.0-1.5). CONCLUSION: The effectiveness of contact investigations in the Netherlands can be optimised by expanding the investigation of contacts of immigrant patients.

Asunto(s)

Trazado de Contacto/estadística & datos numéricos , Emigrantes e Inmigrantes/estadística & datos numéricos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Pulmonar/epidemiología , Adulto , Anciano , Etnicidad/estadística & datos numéricos , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Vigilancia de la Población , Prevalencia , Sistema de Registros , Tuberculosis Pulmonar/diagnóstico , Adulto Joven

RESUMEN

OBJECTIVE: To assess health-seeking behaviour among adults with prolonged cough in a population-based, nationally representative sample in Vietnam. METHODS: Cross-sectional survey conducted from September 2006 to July 2007. All inhabitants aged ≥15 years were invited for screening for cough, history of tuberculosis (TB) treatment and chest X-ray (CXR) examination. TB suspects, defined as any survey participant with CXR abnormalities consistent with TB, or productive cough for more than 2 weeks or TB treatment either currently or in the preceding 2 years submitted sputum specimens for smear examination and culture and provided information on health-seeking behaviour in an in-depth interview. RESULTS: Of 94 179 persons participating in the survey, 4.6% had prolonged productive cough. Forty-four percentage of those had sought health care and reported pharmacies (35%), commune health posts (29%), public hospitals (24%) and private physicians (10%) as first point of contact. Only 7% had undergone sputum smear examination. Of TB suspects with prolonged productive cough, 2.9% were diagnosed with TB; 10.2% of these reported smear and 21.9% reported X-ray examination when visiting a health care facility. The average patient delay was 4.1 weeks (95% CI: 3.9-4.4) among cough suspects and 4.0 weeks (95% CI: 3.1-4.9) among TB cases. CONCLUSIONS: In this Vietnamese survey, nearly half of persons with cough for more than 2 weeks had visited a health care provider. The commonest first health facility contacted was the pharmacy. Sputum smears were rarely examined, except in the provincial TB hospital. Our findings highlight the need to improve diagnostic practices by retraining health staff on the performance of sputum examination for TB suspects.

Asunto(s)

Tos/microbiología , Conductas Relacionadas con la Salud , Aceptación de la Atención de Salud/estadística & datos numéricos , Tuberculosis Pulmonar/complicaciones , Tuberculosis Pulmonar/diagnóstico , Adulto , Anciano , Enfermedad Crónica , Estudios Transversales , Diagnóstico Diferencial , Femenino , Humanos , Conducta en la Búsqueda de Información , Masculino , Persona de Mediana Edad , Población Rural/estadística & datos numéricos , Distribución por Sexo , Encuestas y Cuestionarios , Factores de Tiempo , Población Urbana/estadística & datos numéricos , Vietnam/epidemiología

RESUMEN

OBJECTIVE: To study the association between TB and household expenditure in a nationwide TB prevalence survey in Viet Nam using nine household characteristics. METHOD: To assess the prevalence of TB in Viet Nam, a nationwide stratified cluster sample survey was conducted from 2006 to 2007. Nine household characteristics used in the second Viet Nam Living Standards Survey (VLSS) were scored per household. In the VLSS dataset, we regressed these nine characteristics against household expenditure per capita, and used the coefficients to predict household expenditure level (in quintiles) in our survey and assess its relation with TB prevalence. RESULTS: The prevalence of bacteriologically confirmed TB was 307 per 100,000 population in persons aged ≥ 15 years (95%CI 249-366). After adjustment for confounders, prevalence was found to be associated with household expenditure level: the rate was 2.5 times higher for those in the lowest household expenditure quintile (95%CI 1.6-3.9) than those in the highest quintile. CONCLUSION: With a set of nine household characteristics, we were able to predict household expenditure level fairly accurately. There was a significant association between TB prevalence rates and estimated household expenditure level, showing that TB is related to poverty in Viet Nam.

Asunto(s)

Composición Familiar , Pobreza , Factores Socioeconómicos , Tuberculosis/epidemiología , Adolescente , Adulto , Censos , Análisis por Conglomerados , Estudios Transversales , Femenino , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Prevalencia , Curva ROC , Reproducibilidad de los Resultados , Medición de Riesgo , Factores de Riesgo , Tuberculosis/diagnóstico , Vietnam/epidemiología , Adulto Joven

RESUMEN

SETTING: Two thirds of tuberculosis (TB) patients in the Netherlands are foreign-born. OBJECTIVE: To determine if travelling to the country of origin is a risk factor for TB among two different immigrant groups that have lived in the Netherlands for at least 2 years. DESIGN: In this unmatched case-control study, the frequency and duration of travel to the country of origin in the preceding 12 months were compared between adult Moroccan and Turkish TB patients and community controls. RESULTS: Moroccan patients had travelled more often (26/32 = 81%) in the preceding year than Moroccan controls (472/816 = 58%). The travel-associated odds ratio (OR) for TB among Moroccans was 3.2 (95%CI 1.3-7.7), and increased to 17.2 (95%CI 3.7-79) when the cumulative duration of travel exceeded 3 months. The corresponding population fraction of Moroccan TB cases attributable to recent travel was 56% (95%CI 19-71). Among Turkish immigrants TB was not associated with travel (OR 0.9, 95%CI 0.3-2.4). CONCLUSION: Travel to the country of origin was a risk factor for TB among Moroccans, but not among Turkish people living in the Netherlands. The difference in travel-associated OR between these two immigrant groups is probably related to differences in TB incidence in these countries.

Asunto(s)

Emigrantes e Inmigrantes , Viaje , Tuberculosis/epidemiología , Adolescente , Adulto , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Femenino , Humanos , Incidencia , Modelos Logísticos , Masculino , Persona de Mediana Edad , Marruecos/etnología , Países Bajos/epidemiología , Oportunidad Relativa , Medición de Riesgo , Factores de Riesgo , Encuestas y Cuestionarios , Factores de Tiempo , Tuberculosis/diagnóstico , Turquía/etnología , Adulto Joven

RESUMEN

BACKGROUND: Chest radiographs (CXRs) are used in tuberculosis (TB) prevalence surveys to identify participants for bacteriological examination. Expert readers are rare in most African countries. In our survey, clinical officers scored CXRs of 19 216 participants once. We assessed to what extent missed CXR abnormalities affected our TB prevalence estimate. METHODS: Two experts, a radiologist and pulmonologist, independently reviewed 1031 randomly selected CXRs, mixed with lms of confirmed TB cases. CXRs with disagreement on 'any abnormality' or 'abnormality consistent with TB' were jointly reviewed during a consensus panel. We compared the nal expert and clinical of cer classifications with bacteriologically confirmed TB as the gold standard. RESULTS: After the panel, 199 (19%) randomly selected CXRs were considered abnormal by both expert reviewers and another 82 (8%) by one reviewer. Agreement was good among the experts (κ 0.78, 95%CI 0.73-0.82) and moderate between the clinical officers and experts (κ range 0.50-0.62). The sensitivity of 'any abnormality' was 95% for the clinical officers and 83% and 81% for the respective experts. The specificities were respectively 73%, 74% and 80%. TB prevalence was underestimated by 1.5-5.0%. CONCLUSIONS: Acceptable CXR screening can be achieved with clinical officers. Reviewing a sample of CXRs by two experts allows an assessment of prevalence underestimation.

Asunto(s)

Competencia Clínica , Personal de Salud , Radiografías Pulmonares Masivas , Tuberculosis Pulmonar/diagnóstico por imagen , Tuberculosis Pulmonar/epidemiología , Competencia Clínica/normas , Personal de Salud/normas , Humanos , Kenia/epidemiología , Radiografías Pulmonares Masivas/normas , Variaciones Dependientes del Observador , Vigilancia de la Población , Valor Predictivo de las Pruebas , Prevalencia , Reproducibilidad de los Resultados , Sensibilidad y Especificidad

RESUMEN

OBJECTIVE: To assess the availability of second-line drugs (SLDs) and the use of drug susceptibility testing (DST) results for the treatment of tuberculosis (TB) in China. DESIGN: Cross-sectional survey in 4675 health care facilities, 1960 of which have a dedicated TB clinic, in 12 provinces in China. RESULTS: More than 70% of TB clinics at the provincial and prefecture levels had at least one SLD available compared to 41.8% of facilities at the county/district level. The proportion of facilities at provincial, prefecture and county levels with any fluoroquinolone was respectively 74.1%, 64.9% and 34.5%. Sputum culture was performed at 6.0% of TB clinics at the county level, 37.5% at the prefecture and 59.3% at the provincial levels, while DST was performed only at the prefecture (28.6%) and provincial (44.4%) levels. Only 18% of the facilities that used SLDs for the treatment of multidrug-resistant TB (MDR-TB) based treatment regimens on DST results. CONCLUSION: SLDs are widely available in China for the treatment of both TB and other infectious diseases. To prevent the development of Mycobacterium tuberculosis resistance to SLDs, the availability of SLDs should be limited and they should be used with caution in the treatment of MDR-TB.

Asunto(s)

Antituberculosos/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis/tratamiento farmacológico , Antituberculosos/provisión & distribución , China , Estudios Transversales , Fluoroquinolonas/farmacología , Encuestas de Atención de la Salud , Humanos , Pruebas de Sensibilidad Microbiana , Esputo/microbiología , Tuberculosis/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/microbiología

RESUMEN

This study aimed to determine to what extent tuberculosis trends in the Netherlands depend on secular trend, immigration and recent transmission. Data on patients in the Netherlands Tuberculosis Register in the period 1993-2007 were matched with restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis isolates. Index patients were defined as patients with pulmonary tuberculosis whose isolates had RFLP patterns not observed in another patient in the previous 2 yrs. Among 8,330 patients with pulmonary tuberculosis the isolates of 56% of native and 50% of foreign-born patients were clustered. Of these, 5,185 were included in detailed analysis: 1,376 native index patients, 2,822 foreign-born index patients and 987 secondary cases within 2 yrs of diagnosis of the index case. The incidence of native and foreign-born index patients declined by 6% and 2% per year, respectively. The number of secondary cases per index case was 0.24. The decline of native cases contributed most to the overall decline of tuberculosis rates and was largely explained by a declining prevalence of latent infection. Tuberculosis among immigrants was associated with immigration figures. Progress towards elimination of tuberculosis would benefit from intensifying diagnosis and treatment of latent infection among immigrants and global tuberculosis control.

Asunto(s)

Mycobacterium tuberculosis/genética , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/terapia , Adolescente , Adulto , Anciano , Análisis por Conglomerados , Control de Enfermedades Transmisibles , Progresión de la Enfermedad , Emigrantes e Inmigrantes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular/métodos , Polimorfismo de Longitud del Fragmento de Restricción , Tuberculosis Pulmonar/genética , Tuberculosis Pulmonar/prevención & control , Tuberculosis Pulmonar/transmisión

RESUMEN

The authors determined the positive predictive value (PPV) for progression to tuberculosis (TB) of two interferon-gamma release assays (IGRAs), QuantiFERON-TB Gold In-tube (QFT-GIT) and T-SPOT.TB, and the tuberculin skin test (TST) in immigrants contacts. Immigrant close contacts of sputum smear-positive TB patients were included when aged > or =16 yrs and their TST result was > or =5 mm 0 or 3 months after diagnosis of the index patient. Contacts were followed for the next 2 yrs for development of TB disease. Of 339 immigrant contacts with TST > or =5 mm, 324 and 299 had valid results of QFT-GIT and T-SPOT.TB, respectively. Nine contacts developed active TB. One patient had not been tested with TST, while another patient had not been tested with QFT-GIT and T-SPOT.TB. The PPV for progression to TB during this period was 9/288 = 3.1% (95% CI 1.3-5.0%) for TST > or =10 mm, 7/184 = 3.8% (95% CI 1.7-5.9%) for TST > or =15 mm, 5/178 = 2.8% (95% CI 1.0-4.6%) for QFT-GIT and 6/181 = 3.3% (95% CI 1.3-5.3%) for T-SPOT.TB. Sensitivity was 100%, 88%, 63% and 75%, respectively. The predictive values of QFT-GIT, T-SPOT.TB and TST for progression to TB disease among immigrant close contacts were comparable.

Asunto(s)

Trazado de Contacto/métodos , Trazado de Contacto/estadística & datos numéricos , Emigrantes e Inmigrantes/estadística & datos numéricos , Interferón gamma/metabolismo , Prueba de Tuberculina , Tuberculosis Pulmonar , Adolescente , Adulto , Ensayo de Inmunoadsorción Enzimática , Estudios de Seguimiento , Humanos , Incidencia , Países Bajos/epidemiología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Juego de Reactivos para Diagnóstico , Factores de Riesgo , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/epidemiología , Tuberculosis Pulmonar/transmisión , Adulto Joven

RESUMEN

OBJECTIVE: To assess the association between remote exposure to tuberculosis (TB) and results of the tuberculin skin test (TST), and two interferon-gamma release assays (IGRAs)-QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB-in immigrant contacts of sputum smear-positive TB patients. METHODS: Immigrants aged >or=16 years in close contact with smear-positive TB patients were included. QFT-GIT and T-SPOT.TB were performed if the TST induration size was >or=5 mm. Associations between test results and origin from an endemic country were assessed. RESULTS: Of 433 close contacts, 322 (74%) had TST >or=5 mm, of whom, 282 (88%) had valid test results for all assays. Positive QFT-GIT results were obtained for 152/282 (54%) and positive T-SPOT.TB for 168/282 (60%). After adjustment for age, sex and recent contact, positive IGRA results and TST results >/=10 mm were found to be more frequent among immigrants who originated from Africa, in particular sub-Saharan Africa. CONCLUSION: When IGRAs are used to determine latent TB infection in foreign-born individuals, positive findings not only relate to recent TB infection, but also reflect prior TB exposure in the country of origin. This late reactivity will limit their usefulness in contact investigations among immigrants originating from endemic areas.

Asunto(s)

Trazado de Contacto , Interferón gamma/sangre , Tamizaje Masivo/métodos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Pulmonar/transmisión , Adolescente , Adulto , Distribución de Chi-Cuadrado , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esputo/microbiología , Migrantes , Prueba de Tuberculina , Tuberculosis Pulmonar/sangre , Tuberculosis Pulmonar/diagnóstico

RESUMEN

BACKGROUND: Associations between multidrug resistance and the Mycobacterium tuberculosis Beijing genotype have been described mainly in populations with poor tuberculosis (TB) control such as prisons and inner cities, and may reflect shared risk factors rather than a biological association. OBJECTIVE: To study the association between genotype and drug resistance among TB patients in a population with adequate TB control. SETTING: Three rural districts in Vietnam. The study was performed at the Pham Ngoc Thach Tuberculosis and Lung Disease Hospital, Ho Chi Minh City, and the Tien Giang Provincial Tuberculosis and Lung Disease Hospital, My Tho, Vietnam. METHODS: Pretreatment sputum specimens were collected for culture, drug susceptibility testing and spoligotyping of all sputum smear-positive pulmonary TB patients consecutively diagnosed over a 3-year period. RESULTS: Beijing genotype infections were observed in 614 of 1744 (35%) patients. Beijing strains were more common among female (adjusted odds ratio [aOR] 1.4, P = 0.005), young (aOR 2.8, P < 0.001) and previously treated patients (aOR 2.4, P < 0.001). The Beijing genotype was associated with any resistance (aOR 3.7, P < 0.001) and multidrug resistance (aOR 6.8, P < 0.001) among new patients, and with any resistance (aOR 2.7, P = 0.005) but not with multidrug resistance (aOR 1.4, P = 0.545) among previously treated patients. CONCLUSION: In Vietnam, Beijing genotype is associated with young age and in new patients with multidrug resistance despite adequate TB control, suggesting a biological association. This potentially undermines the effectiveness of TB control in countries where Beijing genotype infections are common.

Asunto(s)

Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/genética , Adulto , Factores de Edad , Anciano , Vacuna BCG/administración & dosificación , Distribución de Chi-Cuadrado , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Prevalencia , Factores de Riesgo , Población Rural , Esputo/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Vietnam/epidemiología

RESUMEN

The Tuberculosis Surveillance and Research Unit (TSRU) held its last annual meeting in Helsinki, Finland, from 1 to 4 April 2008. Several topics of current interest for tuberculosis (TB) research and new research projects were presented and discussed in depth by 60 delegates from Europe, Africa and Asia. This paper summarises some of the highlights of the meeting which may be of interest to epidemiologists and managers active in the field of TB.

Asunto(s)

Vigilancia de la Población/métodos , Tuberculosis/epidemiología , Adulto , Niño , Preescolar , Comorbilidad , Congresos como Asunto , Salud Global , Infecciones por VIH/epidemiología , Humanos , Incidencia , Prevalencia , Retratamiento , Factores de Riesgo , Tuberculosis/tratamiento farmacológico , Tuberculosis/prevención & control , Tuberculosis Resistente a Múltiples Medicamentos