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To compare the prevalence of tuberculosis infection and disease in household contacts of patients with bacteriologically confirmed tuberculosis disease and contacts of non-bacteriologically confirmed disease in western Kenya.We enrolled newly diagnosed index patients and their household contacts from March 2014 to June 2016. All contacts were evaluated with a symptom questionnaire, tuberculin skin test (TST) and HIV test. Clinical evaluation and sputum testing were performed for those with symptoms, positive TST result or HIV infection.We enrolled 1155 contacts of 330 index patients with bacteriologically confirmed tuberculosis and 192 contacts of 55 index patients with non-bacteriologically confirmed tuberculosis. 3.5% of contacts of patients with bacteriologically confirmed tuberculosis were diagnosed with tuberculosis, whereas no contacts of index patients with non-bacteriologically confirmed tuberculosis were. Of those diagnosed with tuberculosis disease, 58.5% reported symptoms, 34.1% reported no symptoms but had positive TST results, and 7.3% had neither symptoms nor positive TST but were HIV-positive. Among 872 contacts with a TST result, 50.9% of contacts of index patients with bacteriologically confirmed tuberculosis and 41.0% of contacts of index patients with non-bacteriologically confirmed tuberculosis had a positive result (prevalence ratio = 1.16, 95% confidence interval 0.92-1.48).In a high-burden setting, tuberculosis disease was more prevalent among contacts of patients with bacteriologically confirmed tuberculosis than contacts of patients with non-bacteriologically confirmed disease. TST was feasible to perform and helped to detect cases that would have been missed had only symptomatic contacts been evaluated.Comparer la prévalence de l'infection et de la maladie tuberculeuses chez les contacts familiaux des patients atteints de tuberculose confirmée bactériologiquement et les contacts de maladies non bactériologiquement confirmées dans l'ouest du Kenya. MÉTHODES: Nous avons recruté des patients indice nouvellement diagnostiqués et leurs contacts familiaux de mars 2014 à juin 2016. Tous les contacts ont été évalués à l'aide d'un questionnaire sur les symptômes, le test cutané à la tuberculine (TCT) et le test VIH. Une évaluation clinique et des tests d'expectoration ont été effectués pour les personnes présentant des symptômes, un résultat positif au TCT ou une infection par le VIH. RÉSULTATS: Nous avons recruté 1.155 contacts de 330 patients index avec une tuberculose confirmée bactériologiquement et 192 contacts de 55 patients indice avec une tuberculose non confirmée bactériologiquement. 3,5% des contacts des patients atteints de tuberculose confirmée bactériologiquement ont été diagnostiqués avec la tuberculose, alors qu'aucun contact des patients indice avec une tuberculose non bactériologiquement confirmée ne l'a été. Parmi les personnes diagnostiquées avec une tuberculose, 58,5% ont signalé des symptômes, 34,1% n'ont signalé aucun symptôme mais avaient des résultats positifs au TCT, et 7,3% n'avaient ni symptômes ni TCT positifs mais étaient VIH positifs. Parmi 872 contacts avec un résultat TCT, 50,9% des contacts des patients indice avec une tuberculose confirmée bactériologiquement et 41,0% des contacts des patients indice avec une tuberculose non bactériologiquement confirmée avaient un résultat positif (rapport de prévalence = 1,16, intervalle de confiance à 95%: 0,92-1,48 ).Dans un contexte de charge élevée, la maladie tuberculose était plus fréquente chez les contacts des patients atteints de tuberculose confirmée bactériologiquement que chez les contacts des patients atteints de la maladie non bactériologiquement confirmée. Le TCT était réalisable et a aidé à détecter les cas qui auraient été ratés si seuls les contacts symptomatiques avaient été évalués.

Objective HIV-associated mortality rates in Africa decreased by 10-20% annually in 2003-2011, after the introduction of antiretroviral therapy (ART). We sought to document HIV-associated mortality rates in the general population in Kenya after 2011 in an era of expanded access to ART. Design We obtained data on mortality rates and migration from a health and demographic surveillance system (HDSS) in Gem, western Kenya, and data for HDSS residents aged 15-64 years from home-based HIV counseling and testing (HBCT) rounds in 2011, 2012, 2013, and 2016. Methods Mortality trends were determined among a closed cohort of residents who participated in at least the 2011 round of HBCT. Results Of 32 467 eligible HDSS residents, 22 688 (70%) participated in the 2011 round and comprised the study cohort. All-cause mortality rates declined from 10.0 [95% confidence interval (CI) 8.4-11.7] per 1000 in 2011 to 7.4 (95% CI 5·7-9·0) in 2016, whereas the mortality rate was stable among HIV-uninfected residents, at 5.7 per 1000 person-years. Among HIV-infected residents, mortality rates declined from 30.5 per 1000 in 2011 to 15.9 per 1000 in 2016 (average decline 6% per year). The HIV-infected group receiving ART had higher mortality rates than the HIV-uninfected group [adjusted rate ratio (aRR) 2.8, 95% CI 2.2-3.4], as did the HIV-infected group who did not receive ART (aRR 5.3, 95% CI 4.5-6.2). Conclusions Mortality rates among HIV-infected individuals declined substantially during ART expansion between 2011 and 2016, though less than during early ART introduction. Mortality trends among HIV-infected populations are critical to understanding epidemic dynamics.

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.

Background Data on pneumococcal conjugate vaccine (PCV) indirect effects in low-income countries with high human immunodeficiency virus (HIV) burden are limited. We examined adult pneumococcal pneumonia incidence before and after PCV introduction in Kenya in 2011. Methods From 1 January 2008 to 31 December 2016, we conducted surveillance for acute respiratory infection (ARI) among ~12 000 adults (≥18 years) in western Kenya, where HIV prevalence is ~17%. ARI cases (cough or difficulty breathing or chest pain, plus temperature ≥38.0°C or oxygen saturation Results Pre-PCV (2008–2010) crude and adjusted ARI incidences were 3.14 and 5.30/100 person-years-observation (pyo), respectively. Among ARI cases, 39.0% (340/872) had both blood culture and UAT; 21.2% (72/340) had pneumococcus detected, yielding a baseline pneumococcal pneumonia incidence of 1.12/100 pyo (95% confidence interval [CI]: 1.0–1.3). In each post-PCV year (2012–2016), the incidence was significantly lower than baseline; with incidence rate ratios (IRRs) of 0.53 (95% CI: 0.31–0.61) in 2012 and 0.13 (95% CI: 0.09–0.17) in 2016. Similar declines were observed in HIV-infected (IRR: 0.13; 95% CI: 0.08–0.22) and HIV-uninfected (IRR: 0.10; 95% CI: 0.05–0.20) adults. Conclusions Adult pneumococcal pneumonia declined in western Kenya following PCV introduction, likely reflecting vaccine indirect effects. Evidence of herd protection is critical for guiding PCV policy decisions in resource-constrained areas.

Objectives To describe the epidemiology of childhood tuberculosis (TB) in Kenya, assess the magnitude of TB/human immunodeficiency virus (HIV) co-infection and identify risk factors for mortality during TB treatment. Study design We conducted a retrospective analysis of the Kenyan national TB program data for patients enrolled from 2013 through 2015. A total of 23 753 children aged less than 15 years were included in the analysis. Survival analysis was performed with censorship at 9 months and mortality was the main outcome. We used Cox proportional hazards regression for assessing risk factors for mortality. Results Childhood TB accounted for 9% (n = 24 216) of all patients with TB; 98% of the notified children (n = 23 753) were included in the analysis. TB/HIV co-infection was 28% (n = 6112). Most TB cases (71%; n = 16 969) were detected through self-referral. Treatment was successful in 90% (n = 19 088) and 4% (n = 1058) died. Independent risk factors for mortality included being HIV infected but not on antiretroviral therapy (adjusted hazard ratio [aHR], 4.84; 95% CI, 3.59-6.51), being HIV infected and on antiretroviral therapy (aHR, 3.69; 95% CI, 3.14-4.35), children aged less than 5 years (aHR, 1.25; 95% CI, 1.08-1.44), and being diagnosed with smear negative pulmonary disease (aHR, 1.68; 95% CI, 1.27-2.24). Conclusions Most childhood TB cases in Kenya were detected through passive case finding. TB/HIV co-infection is high among children on treatment for TB, and HIV is associated with an increased risk of death. There is a need to intensify active case finding among children. TB prevention interventions among HIV-infected children, early diagnosis of HIV, and early antiretroviral therapy initiation among children on TB treatment should be strengthened.

Background HIV is a major driver of the tuberculosis epidemic in sub-Saharan Africa. The population-level impact of antiretroviral therapy (ART) scale-up on tuberculosis rates in this region has not been well studied. We conducted a descriptive analysis to examine evidence of population-level effect of ART on tuberculosis by comparing trends in estimated tuberculosis notification rates, by HIV status, for countries in sub-Saharan Africa. Methods We estimated annual tuberculosis notification rates, stratified by HIV status during 2010–2015 using data from WHO, the Joint United Nations Programme on HIV/AIDS, and the United Nations Population Division. Countries were included in this analysis if they had ≥4 years of HIV prevalence estimates and ≥ 75% of tuberculosis patients with known HIV status. We compared tuberculosis notification rates among people living with HIV (PLHIV) and people without HIV via Wilcoxon rank sum test. Results Among 23 included countries, the median annual average change in tuberculosis notification rates among PLHIV during 2010–2015 was -5.7% (IQR -6.9 to -1.7%), compared to a median change of -2.3% (IQR -4.2 to -0.1%) among people without HIV (p-value = 0.0099). Among 11 countries with higher ART coverage, the median annual average change in TB notification rates among PLHIV was -6.8% (IQR -7.6 to -5.7%) compared to a median change of -2.1% (IQR -6.0 to 0.7%) for PLHIV in 12 countries with lower ART coverage (p = 0.0106). Conclusion Tuberculosis notification rates declined more among PLHIV than people without HIV, and have declined more in countries with higher ART coverage. These results are consistent with a population-level effect of ART on decreasing TB incidence among PLHIV. To further reduce TB incidence among PLHIV, additional scale-up of ART as well as greater use of isoniazid preventive therapy and active case-finding will be necessary.

Background: The World Health Organization (WHO) and the Global Burden of Disease (GBD) study at the Institute for Health Metrics and Evaluation (IHME) periodically provide global estimates of tuberculosis (TB) mortality. We compared the 2015 WHO and GBD TB mortality estimates and explored which factors might drive the differences. Methods: We extracted the number of estimated TB-attributable deaths, disaggregated by age, HIV status, sex and country from publicly available WHO and GBD datasets for the year 2015. We ‘standardized’ differences between sources by adjusting each country’s difference in absolute number of deaths by the average number of deaths estimated by both sources. Results: For 195 countries with estimates from both institutions, WHO estimated 1 768 482 deaths attributable to TB, whereas GBD estimated 1 322 916 deaths, a difference of 445 566 deaths or 29% of the average of the two estimates. The countries with the largest absolute differences in deaths were Nigeria (216 621), Bangladesh (49 863) and Tanzania (38 272). The standardized difference was not associated with HIV prevalence, prevalence of multidrug resistance or global region, but did show correlation with the case detection rate as estimated by WHO [r ¼ 0.37, 95% confidence interval (CI): 049; 0.24] or, inversely, with case detection rate based on GBD data (r ¼ 0.44, 95% CI: 0.31; 0.54). Countries with a recent national prevalence survey had higher standardized differences (higher estimates by WHO) than those without (P ¼ 0.006). After exclusion of countries with recent prevalence surveys, the overall correlation between both estimates was r ¼ 0.991. Conclusions: A few countries account for the large global discrepancy in TB mortality estimates. The differences are due to the methodological approaches used by WHO and GBD. The use and interpretation of prevalence survey data and case detection rates seem to play a role in the observed differences.

Summary Background In Kenya, coverage of antiretroviral therapy (ART) among people with HIV infection has increased from 7% in 2006, to 57% in 2016; and, in western Kenya, coverage of voluntary medical male circumcision (VMMC) increased from 45% in 2008, to 72% in 2014. We investigated trends in HIV prevalence and incidence in a high burden area in western Kenya in 2011–16. Methods In 2011, 2012, and 2016, population-based surveys were done via a health and demographic surveillance system and home-based counselling and testing in Gem, Siaya County, Kenya, including 28 688, 17 021, and 16 772 individuals aged 15–64 years. Data on demographic variables, self-reported HIV status, and risk factors were collected. Rapid HIV testing was offered to survey participants. Participants were tracked between surveys by use of health and demographic surveillance system identification numbers. HIV prevalence was calculated as a proportion, and HIV incidence was expressed as number of new infections per 1000 person-years of follow-up. Findings HIV prevalence was stable in participants aged 15–64 years: 15% (4300/28 532) in 2011, 12% (2051/16 875) in 2012, and 15% (2312/15 626) in 2016. Crude prevalences in participants aged 15–34 years were 11% (1893/17 197) in 2011, 10% (1015/10 118) in 2012, and 9% (848/9125) in 2016; adjusted for age and sex these prevalences were 11%, 9%, and 8%. 12 606 (41%) of the 30 520 non-HIV-infected individuals enrolled were seen again in at least one more survey round, and were included in the analysis of HIV incidence. HIV incidence was 11·1 (95% CI 9·1–13·1) per 1000 person-years from 2011 to 2012, and 5·7 (4·6–6·9) per 1000 person-years from 2012 to 2016. Interpretation With increasing coverage of ART and VMMC, HIV incidence declined substantially in Siaya County between 2011 and 2016. VMMC, but not ART, was suggested to have a direct protective effect, presumably because ART tended to be given to individuals with advanced HIV infection. HIV incidence is still high and not close to the elimination target of one per 1000 person-years. The effect of further scale-up of ART and VMMC needs to be monitored. Funding Data were collected under Cooperative Agreements with the US Centers for Disease Control and Prevention, with funding from the President's Emergency Fund for AIDS Relief.

OBJECTIVE: To evaluate the utility of a broad and nonspecific symptom screen for identifying people with undiagnosed HIV infection. DESIGN: Secondary analysis of operational data collected during implementation of a cluster-randomized trial for tuberculosis case detection. METHODS: As part of the trial, adults reporting cough, fever, night sweats, weight loss, or difficulty breathing for any duration in the past month were identified in health facilities and community-based mobile screening units in western Kenya. Adults reporting any symptom were offered HIV testing. We analysed the HIV testing data from this study, using modified Poisson regression, to identify predictors of new HIV diagnoses among adults with symptoms and initially unknown HIV status. RESULTS: We identified 3818 symptomatic adults, referred 1424 (37%) for testing, of whom 1065 (75%) accepted, and 107 (10%) were newly diagnosed with HIV. The prevalence of new HIV diagnoses was 21% [95% confidence interval (CI) 17–25%] among those tested in health facilities and 5% (95% CI 4–7%) among those tested in mobile units. More men were diagnosed with HIV than women, despite fewer men being screened. People who reported 4–5 symptoms were over twice as likely to be diagnosed with HIV compared to those reporting 1–3 symptoms (adjusted prevalence ratio in health facilities = 2.58, 95% CI 1.65–4.05; adjusted prevalence ratio in mobile units = 2.63, 95% CI 1.37–5.03). CONCLUSION: We observed a high yield of new HIV diagnoses among adults identified by active application of a broad symptom screen. Use of integrated tuberculosis and HIV screening could help close the detection gap for both conditions.

Although Kenya has a high burden of tuberculosis (TB), only 46% of cases were diagnosed in 2016.To identify strategies for increasing attendance at community-based mobile screening units.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 XpertA 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 (Mobile units were most effective and efficient when implemented as a single event with community health workers who are paid a daily wage.Bien que le Kenya soit lourdement affecté par la tuberculose (TB), seulement 46% des cas ont été diagnostiqués en 2016.Identifier les stratégies visant à augmenter la fréquentation des unités mobiles de dépistage en communauté.Nous avons analysé les données opérationnelles d'un essai randomisé en grappes, qui a inclus les unités mobiles de dépistage dans les communautés mises en œuvre entre février 2015 et avril 2016. Les travailleurs de santé communautaire (CHV) ont recruté des individus symptomatiques de la communauté, à qui ont été proposés un test de virus de l'immunodéficience humaine (VIH) et un recueil de crachats pour un test XpertAu total, 1424 adultes symptomatiques ont été dépistés dans 25 sites d'unités mobiles. La fréquentation médiane totale dans les sites a été de 54 (fourchette : 6–134; intervalle interquartile [IQR]: 24–84). Le rendement médian de diagnostic de TB et de nouveaux diagnostics de VIH a été de 2,4% (fourchette 0,0–16,7 ; IQR 0,0–5,3) et de 2,5% (fourchette 0,0–33,3 ; IQR 1,2–4,2), respectivement. La fréquentation dans les sites urbains a été variable ; la fréquentation dans les sites ruraux où les CHV ont reçu un salaire minimum journalier a été significativement plus élevée que dans les sites ruraux où les CHV ont reçu une compensation mensuelle modeste (Les unités mobiles ont été les plus efficaces et rentables quand elles ont été mises en œuvre sous forme d'un évènement unique avec les CHV qui sont payés chaque jour.A pesar de que Kenya tenga una carga de morbilidad por tuberculosis (TB) alta, en el 2016 solo se diagnosticaron 46% de los casos.Definir estrategias que aumenten la asistencia a las unidades móviles comunitarias de detección sistemática.Se analizaron los datos operativos de un ensayo clínico aleatorizado en conglomerados, que incluyó unidades móviles comunitarias de detección activa de la TB de febrero del 2015 a abril del 2016. Los agentes de salud comunitarios voluntarios (CHV) incorporaron a las personas sintomáticas de la comunidad, a quienes se ofreció la prueba diagnóstica del virus de la inmunodeficiencia humana (VIH) y el examen de muestras de esputo con la prueba XpertSe examinaron 1424 adultos sintomáticos en 25 puestos de unidades móviles. La mediana de la asistencia global en todos los puestos fue 54 (entre 6 y 134; amplitud intercuartil [IQR] 24–84). La mediana del rendimiento diagnóstico de TB fue 2,4% (entre 0,0 y 16,7; IQR 0,0–5,3) y la de diagnósticos nuevos de infección por el VIH fue 2,5% (entre 0,0 y 33,3; IQR 1,2–4,2). La asistencia a los puestos urbanos fue variable; en los puestos rurales, donde los CHV recibían un salario mínimo diario, la asistencia fue significativamente más alta que en los puestos donde los voluntarios recibían una remuneración nominal mensual (Las unidades móviles fueron más eficaces y eficientes cuando los CHV operaban en un evento único, con remuneración diaria.

Background Adolescents are a prime target group for tuberculosis (TB) vaccine trials that include prevention of infection (POI). The BCG vaccine is given at birth and does not prevent TB infection. TB infection, a critical endpoint for POI vaccine trials would need to be documented to estimate sample sizes in target populations. Methods Adolescents aged 12–18 years of age were enrolled in an area under continuous demographic surveillance. A tuberculin skin test (TST) survey was conducted as part of a study on TB prevalence and incidence. All adolescents got TSTs at enrolment and returned after 72 h for reading. A TST of ≥10 mm if HIV negative or ≥ 5 mm if HIV positive, was considered positive. Results Of 4808 adolescents returning for TST readings (96% of those enrolled), mean age was 14.4 (SD 1.9), 4518(94%) were enrolled in school and 21(0.4%) gave a previous history of tuberculosis. Among adolescents with TST reactivity, the mean TST induration was 13.2 mm (SD 5.4). The overall prevalence of latent TB infection was 1544/4808 (32.1, 95% CI 29.2–35.1) with a corresponding annual risk of TB infection (ARTI) of 2.6% (95% CI 2.2–3.1). Risk factors for a positive TST included being male (OR 1.3, 95% CI 1.2,1.5), history of having a household TB contact (OR 1.5, 95% CI 1.2,1.8), having a BCG scar (OR 1.5,95% CI 1.2,1.8), living in a rural area (OR 1.4, 95% CI 1.1,1.9), and being out of school (OR 1.8, 95% CI 1.4,2.3). Conclusion We conclude that the high TB transmission rates we found in this study, suggest that adolescents in this region may be an appropriate target group for TB vaccine trials including TB vaccine trials aiming to prevent infection. Electronic supplementary material The online version of this article (10.1186/s12879-019-4314-7) contains supplementary material, which is available to authorized users.

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.

Measuring tuberculosis transmission is exceedingly difficult, given the remarkable variability in the timing of clinical disease after Mycobacterium tuberculosis infection; incident disease can result from either a recent (ie, weeks to months) or a remote (ie, several years to decades) infection event. Although we cannot identify with certainty the timing and location of tuberculosis transmission for individuals, approaches for estimating the individual probability of recent transmission and for estimating the fraction of tuberculosis cases due to recent transmission in populations have been developed. Data used to estimate the probable burden of recent transmission include tuberculosis case notifications in young children and trends in tuberculin skin test and interferon γ–release assays. More recently, M. tuberculosis whole-genome sequencing has been used to estimate population levels of recent transmission, identify the distribution of specific strains within communities, and decipher chains of transmission among culture-positive tuberculosis cases. The factors that drive the transmission of tuberculosis in communities depend on the burden of prevalent tuberculosis; the ways in which individuals live, work, and interact (eg, congregate settings); and the capacity of healthcare and public health systems to identify and effectively treat individuals with infectious forms of tuberculosis. Here we provide an overview of these factors, describe tools for measurement of ongoing transmission, and highlight knowledge gaps that must be addressed.

Background Tuberculosis (TB) case finding is an important component of TB control because it can reduce transmission of Mycobacterium tuberculosis (MTB) through prompt detection and treatment of infectious patients. Methods Using population-based infectious disease surveillance (PBIDS) platforms with links to health facilities in Kenya we implemented intensified TB case finding in the community and at the health facilities, as an adjunct to routine passive case finding conducted by the national TB program. From 2011 to 2014, PBIDS participants ≥15 years were screened either at home or health facilities for possible TB symptoms which included cough, fever, night sweats or weight loss in the preceding 2 weeks. At home, participants with possible TB symptoms had expectorated sputum collected. At the clinic, HIV-infected participants with possible TB symptoms were invited to produce sputum. Those without HIV but with symptoms lasting 7 days including the visit day had chest radiographs performed, and had sputum collected if the radiographs were abnormal. Sputum samples were tested for the presence of MTB using the Xpert MTB/RIF assay. TB detection rates were calculated per 100,000 persons screened. Results Of 11,191 participants aged ≥15 years screened at home at both sites, 2695 (23.9%) reported possible TB symptoms, of whom 2258 (83.8%) produced sputum specimens. MTB was detected in 32 (1.4%) of the specimens resulting in a detection rate of 286/100,000 persons screened. At the health facilities, a total of 11,762 person were screened, 7500 (63.8%) had possible TB symptoms of whom 1282 (17.1%) produced sputum samples. MTB was detected in 69 (5.4%) of the samples, resulting in an overall detection rate of 587/100,000 persons screened. The TB detection rate was higher in persons with HIV compared to those without at both home (HIV-infected - 769/100,000, HIV-uninfected 141/100,000, rate ratio (RR) – 5.45, 95% CI 3.25–22.37), and health facilities (HIV-infected 3399/100,000, HIV-uninfected 294/100,000, RR 11.56, 95% CI 6.18–18.44). Conclusion Facility-based intensified TB case finding detected more TB cases per the number of specimens tested and the number of persons screened, including those with HIV, than home-based TB screening and should be further evaluated to determine its potential programmatic impact.

The lifetime risk of tuberculosis (TB) for infected contacts is often mentioned to be 5-10%, but these estimates are based on studies conducted decades ago, and thus may not reflect current epidemiologic conditions. To estimate the risk of TB among contacts with evidence of infection and to compare this with estimates often stated in the literature. A retrospective cohort study was performed using records on contacts of pulmonary TB patients at the Public Health Service Amsterdam, 2002-2011. The Public Health Service Amsterdam TB electronic registration system identified TB cases during follow-up until October 2012; these were defined as coprevalent if diagnosed less than or equal to 180 days and incident if diagnosed greater than 180 days after TB diagnosis of index patient. Cumulative TB risk was estimated with Kaplan-Meier curves. Of 9,332 contacts of pulmonary TB patients, 4,774 were screened for latent TB infection (LTBI) of whom 739 (16%) had evidence of infection. Among these the 5-year Kaplan-Meier TB cumulative risk was 9.5% (95% confidence interval, 7.5-11.9). This varied by age: 33.3% of 36 contacts aged less than 5 years, 19.1% of 84 contacts aged 5-14 years, and 6.7% of 619 contacts aged greater than or equal to 15 years (log rank, P < 0.001). Of 739 contacts with evidence of infection, 57 had coprevalent TB and 14 developed incident TB. Of patients without coprevalent TB but with LTBI diagnosis, 45% received preventive therapy. Five-year risk of incident TB was 2.4% (95% confidence interval, 1.2-4.7) among contacts with LTBI who did not start preventive therapy. Five-year risk of TB among contacts with evidence of infection was higher compared with older estimates, and differed considerably by age. Incidence of TB among contacts with LTBI was low, suggesting limited impact may be expected of expanding preventive therapy

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.

OBJECTIVES To assess the prevalence of tuberculous infection and the annual risk of tuberculous infection (ARTI) for 2007-2009 in Bangladesh, approximately 45 years after the first tuberculin survey in 1964-1966. METHODS A tuberculin survey was conducted along with the National Tuberculosis Disease Prevalence Survey in 2007-2009. This was a multistaged community-based, cross-sectional survey, including 17,718 children aged 5-14 years. The prevalence of tuberculous infection was estimated using the mixture method and a cut-off point of ≥ 8 mm. RESULTS The prevalence of infection was 10.0% (interquartile range [IQR] 8.6-12.2) in children aged 5-9 years and 17.9% (IQR 15.4-20.2) in those aged 10-14 years using the mixture analysis. Prevalence was 12.4% (95% confidence interval [CI] 11.7-13.1) in children aged 5-9 years and 22.6% (95%CI 21.6-23.4) in those aged 10-14 years using a cut-off point of ≥ 8 mm. The estimated ARTI was respectively 1.5% and 1.7% in 5-9 and 10-14 year olds using the mixture method and respectively 1.9% and 2.1% using the cut-off method. CONCLUSIONS The moderate reduction in the prevalence of infection and slow decline of the ARTI after two decades of DOTS implementation indicates considerable ongoing transmission.

Item does not contain fulltext 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-Guerin-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. 01 oktober 2013

Background Intensified case finding (ICF) and earlier antiretroviral therapy (ART) initiation are strategies to reduce burden of HIV-associated tuberculosis (TB). We describe incidence of and associated factors for TB among HIV-positive individuals with CD4 counts > 350 cells/μl in South Africa. Methods Prospective cohort study of individuals recruited for a TB vaccine trial. Eligible individuals without prevalent TB were followed up at 6 and 12 months after enrolment. Cox proportional hazards regression was used to determine factors associated with risk of incident TB. Results Six hundred thirty-four individuals were included in the analysis [80.9 % female, 57.9 % on ART, median CD4 count 562 cells/μl (IQR 466–694 cells/μl)]. TB incidence was 2.7 per 100 person-years (pyrs) (95 % CI 1.6–4.4 per 100 pyrs) and did not differ significantly between those on ART and those not on ART [HR 0.65 (95 % CI 0.24–1.81)]. Low body mass index (BMI

This study aimed to estimate the risk of progression to active tuberculosis (TB) within 2 yrs after entry in newly arriving immigrants who were screened with the QuantiFERON®-TB Gold In-Tube assay (QFT-GIT; Cellestis, Carnegie, Australia). In a case–base design, we determined the prevalence QFT-GIT-positive subjects among a representative sample of immigrants aged ≥18 yrs who arrived between April 2009 and March 2011 (the base cohort). Active TB patients (cases) within 2 yrs post-arrival in 2005, 2006 or 2007 were extracted from the Netherlands Tuberculosis Register. The risk of progression to active TB was estimated using Bayesian analyses to adjust for the sensitivity of QFT-GIT. Among the base cohort, 20% of 1,468 immigrants were QFT-GIT positive. Stratified by TB incidence in the person's country of origin as low (

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.

There is limited published information on mortality rates after successful completion of tuberculosis treatment. While tuberculosis treatment outcomes are routinely recorded, monitoring patients after completion of treatment is not recommended in WHO guidelines, except for one year post-treatment monitoring of drug-resistant TB patients to identify recurrent TB (1,2). In this issue Shuldiner et al. assessed post-treatment mortality through linkage of the national TB registry and civil registry in a cohort of 3250 successfully treated Israeli TB patients who had started treatment in the period 2000–2010 (3). These successfully treated patients had a 3.7 (95% CI 3.4–4.1) times higher risk of death than the general Israeli population. The standardized mortality ratio was highest in the age group 25–44 years and somewhat higher among men (4.2) than women (3.2). Shuldiner et al. suggest that increased mortality after successful tuberculosis treatment may be due to pulmonary impairment caused by tuberculosis and/or to shared risk factors, such as smoking, for tuberculosis and conditions such as lung cancer. Tuberculosis is more likely to occur in patients with underlying conditions such as cancer and diabetes, in patients with specific risk factors such as smoking and HIV infection, as well as in those with more general socio-economic determinants, owing to living and working conditions with a higher risk of exposure to Mycobacterium tuberculosis and less access to high-quality health care (4), all of which are also independently associated with increased mortality rates. Thus, it is possible that the increased mortality rates post-tuberculosis treatment would reflect the risks associated with these other risk factors and underlying conditions rather than lung damage after tuberculosis. Unfortunately, the wide range of causes of deaths identified by Shuldiner et al. suggests that an intervention to reduce post tuberculosis mortality may not be easy to find. Further studies to determine the causes of post TB treatment mortality, including the possible role of post-tuberculosis lung damage and therefore ideally involving autopsy studies, are important to inform intervention development.

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

Summary 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. Objectif: Evaluer le comportement de recours a la sante chez les adultes presentant une toux prolongee dans un echantillon national representatif de la population au Vietnam. Methodes: Enquete transversale menee de septembre 2006 a juillet 2007. Tous les habitants âges de ≥ 15 ans ont ete invites pour le depistage de la toux, l’historique du traitement de la tuberculose (TB) et l’examen radiographique du thorax (CXR). Les personnes suspectes de TB, definie comme tout participant a l’etude avec des anomalies CXR coherentes avec la TB, ou une toux productive de plus de deux semaines, ou un traitement en cours ou au cours des 2 annees precedentes pour la TB, ont soumis des echantillons d’expectoration pour l’examen des frottis et la culture et ont fourni les informations sur leurs comportements de recours a la sante dans une interview approfondie. Resultats: Parmi les 94.179 personnes participant a l’enquete, 4,6% avaient une toux productive prolongee. 44% de ceux-ci avaient sollicite des soins de sante et ont rapporte les pharmacies (35%), les postes de sante communaux (29%), les hopitaux publics (24%) et les medecins prives (10%) comme premiers points de contact. Seules 7% d’eux avaient subi un examen de frottis. Parmi les cas suspects de TB avec une toux productive prolongee, 2,9% ont ete diagnostiques avec la TB. 10,2% de ceux-ci avaient declare avoir eu un examen de frottis et 21,9%, un examen CXR lors de visite dans un etablissement de soins de sante. Le retard moyen des patients etait de 4,1 semaines (IC95%: 3,9 a 4,4) chez les suspects avec une toux et 4,0 semaines (IC95%: 3,1 a 4,9) chez les cas TB. Conclusions: Dans cette etude au Vietnam, pres de la moitie des personnes presentant une toux depuis plus de deux semaines avaient visite un fournisseur de soins de sante. Le centre de sante le plus couramment contacte en premier etait la pharmacie. Les frottis d’expectoration ont ete rarement examines, sauf dans l’hopital provincial de TB. Nos resultats soulignent la necessite d’ameliorer les pratiques de diagnostic par la reformation du personnel de sante sur la performance de l’examen des crachats des suspects TB. Objetivo: Evaluar el comportamiento de busqueda de salud de adultos con tos prolongada pertenecientes a una muestra nacional, representativa y basada en la poblacion en Vietnam. Metodos: Estudio croseccional realizado entre Septiembre del 2006 y Julio del 2007. Se invito a todos los habitantes con edades ≥15 anos a un cribado para tos, historia de tratamiento de TB y placa de Rayos X (PRX). Todos los sospechosos de padecer tuberculosis, definido como cualquier participante con anormalidades en la PRX consistentes con la tuberculosis, o tos productiva durante mas de 2 semanas, o recibiendo tratamiento para la tuberculosis en el momento del estudio o en los 2 anos anteriores, entregaron muestras de esputo para realizar un frotis y un cultivo y dieron informacion sobre su comportamiento de busqueda de salud durante una entrevista en profundidad. Resultados: De las 94,179 personas que participaron en el estudio, un 4.6% presentaban una tos productiva prolongada. Un 44% de aquellos que habian buscado cuidados sanitarios, lo habian hecho en farmacias (35%), puestos de salud comunitarios (29%), hospitales publicos (24%), y medicos privados (10%) como primer punto de contacto. Solo un 7% se habia realizado un frotis de esputo. De los sospechosos de TB con tos productiva prolongada, se diagnostico TB a un 2.9%. De estos, un 10.2% reporto haberse realizado un frotis y 21.9% reporto haberse realizado unos Rayos X durante la visita a un centro sanitario. El retraso promedio de los pacientes era de 4.1 semanas (95%IC: 3.9-4.4) entre los sospechosos de tos y 4.0 semanas (95%IC: 3.1-4.9) entre los casos de TB. Conclusiones: En este estudio Vietnamita, practicamente la mitad de las personas con una tos de mas de 2 semanas habia visitado algun proveedor sanitario. El establecimiento sanitario mas comunmente contactado fue la farmacia. Era raro que se examinaran los frotis de esputo, excepto en el hospital provincial para TB. Nuestros hallazgos resaltan la necesidad de mejorar las practicas diagnosticas, re-entrenando al personal sanitario en la realizacion del examen de esputo en sospechosos de TB.

BACKGROUND: Tuberculosis (TB) transmission is associated with patient-related risk factors. However, DNA fingerprint analysis has provided anecdotal evidence suggesting a role for bacteriological factors. METHODS: To examine the importance of the bacteriological component in TB transmission, we investigated the number of tuberculin skin test-positive (TST induration, >/= 10 mm) contacts and secondary cases observed in contact investigations around TB cases in relation to the size of the genotype cluster the patient belonged to at the time of diagnosis. We also compared the number of TST-positive contacts and secondary cases of patients with drug-resistant and drug-susceptible TB. RESULTS: Larger clusters were independently associated with an increased number of positive contacts. The mean number of positive contacts ranged from 3.8 for clusters of 2 cases, to 4.7 for clusters of 3-10 cases, to 6.0 for cases in clusters of >10 cases (mean increase in number of positive contacts for every extra case in the cluster, 0.21; 95% confidence interval, 0.09-0.26). The mean number of positive contacts was significantly lower among index cases with isoniazid-monoresistant TB (1.6) than among index cases with pan-susceptible TB (4.6; relative number, 0.45; 95% confidence interval, 0.22-0.92). CONCLUSION: These results suggest that spread of tuberculosis also depends on bacteriological factors.

Rationale: Limited information exists on the prevalence of tuberculosis and adequacy of case finding in African populations with high rates of HIV. Objectives: To estimate the prevalence of bacteriologically confirmed pulmonary tuberculosis (PTB) and the fraction attributable to HIV, and to evaluate case detection. Methods: Residents aged 15 years and older, from 40 randomly sampled clusters, provided two sputum samples for microscopy; those with chest radiograph abnormalities or symptoms suggestive of PTB provided one additional sputum sample for culture. Measurements and Main Results: PTB was defined by a culture positive for Mycobacterium tuberculosis or two positive smears. Persons with PTB were offered HIV testing and interviewed on care-seeking behavior. We estimated the population-attributable fraction of HIV on prevalent and notified PTB, the patient diagnostic rate, and case detection rate using provincial TB notification data. Among 20,566 participants, 123 had PTB. TB prevalence was 6.0/1,000 (95% confidence interval, 4.6-7.4) for all PTB and 2.5/1,000 (1.6-3.4) for smear-positive PTB. Of 101 prevalent TB cases tested, 52 (51%) were HIV infected, and 58 (64%) of 91 cases who were not on treatment and were interviewed had not sought care. Forty-eight percent of prevalent and 65% of notified PTB cases were attributable to HIV. For smear-positive and smear-negative PTB combined, the patient diagnostic rate was 1.4 cases detected per person-year among HIV-infected persons having PTB and 0.6 for those who were HIV uninfected, corresponding to case detection rates of 56 and 65%, respectively. Conclusions: Undiagnosed PTB is common in this community. TB case finding needs improvement, for instance through intensified case finding with mobile smear microscopy services, rigorous HIV testing, and improved diagnosis of smear-negative TB

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.

OBJECTIVE: To estimate the prevalence of tuberculosis in Viet Nam with data from a population-based survey, compare it with the prevalence estimated by the World Health Organization, and identify major demographic determinants of tuberculosis prevalence. METHODS: A cross-sectional survey with multistage cluster sampling, stratified by urban, rural and remote areas, was done in 2006-2007 in 70 communes. All inhabitants aged > or = 15 years were invited for cough and chest X-ray examination. Participants with findings suggestive of tuberculosis provided sputum specimens for smear examination and culture. Point prevalence estimates, 95% confidence intervals and design effects were calculated. Confidence intervals and P-values were adjusted for the cluster design. FINDINGS: Of 114,389 adult inhabitants, 94 179 (82.3%) were screened. Of 87,314 (92.7%) screened by both questionnaire and chest X-ray, 3522 (4.0%) had productive cough, 518 (0.6%) had a recent history of tuberculosis and 2972 (3.4%) had chest X-ray abnormalities suggestive of tuberculosis. Sputum tests were done for 7648 participants. Sputum test, bacterial culture or both confirmed 269 tuberculosis cases, 174 of which were smear-positive. The prevalence rate of smear-positive tuberculosis was 145 per 100,000 (95% confidence interval: 110-180) assuming no tuberculosis in persons aged < 15 years. Prevalence was 5.1 times as high in men as in women, increased with age, was higher in rural than in urban or remote areas and showed a north-to-south gradient. CONCLUSION: In Viet Nam, the tuberculosis prevalence rate based on positive sputum smear tests was 1.6 times as high as previously estimated. Age and sex patterns were consistent with notification data. Tuberculosis control should remain a high priority in Viet Nam

The authors determined the positive predictive value (PPV) for progression to tuberculosis (TB) of two interferon-gamma release assays (IGRAs), QuantiFERON-TB (R) Gold In-tube (QFT-GIT) and T-SPOT. TB (R), and the tuberculin skin test (TST) in immigrants contacts. Immigrant close contacts of sputum smear-positive TB patients were included when aged >= 16 yrs and their TST result was >= 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 >= 5 mm, 324 and 299 had valid results of QFT-GIT and T-SPOT. TB (R), 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 (R). The PPV for progression to TB during this period was 9/288=3.1% (95% CI 1.3-5.0%) for TST >= 10 mm, 7/184=3.8% (95% CI 1.7-5.9%) for TST >= 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 (R). Sensitivity was 100%, 88%, 63% and 75%, respectively. The predictive values of QFT-GIT, T-SPOT. TB (R) and TST for progression to TB disease among immigrant close contacts were comparable.

article i nfo Objective: Kenya is heralded as an example of declining HIV in Africa, while its tuberculosis (TB) numbers continue rising. We conducted a comparative investigation of TB-HIV co-dynamics in Africa to determine the likelihood of reported trends. Methods and results: Our mathematical modeling analysis exposes the notable incongruence of reported trends in Kenya because TB-HIV co-dynamics, tightly knit worldwide and most dramatically in sub-Saharan Africa, suggest that declining HIV trends should trigger reductions in TB trends. Moreover, a continental-scale analysis of TB-HIV trends places Kenya as an outlier in eastern and southern Africa, and shows TB outpacing HIV in western central Africa. We further investigate which TB processes across HIV stages have greater potential to reduce TB incidence via a sensitivity analysis. Conclusions: There are two parsimonious explanations: an unaccounted improvement in TB case detection has occurred, or HIV is not declining as reported. The TB-HIV mismatch could be compounded by surveillance biases due to spatial heterogeneity in disease dynamics. Results highlight the need to re- evaluate trends of both diseases in Kenya, and identify the most critical epidemiological factors at play. Substantial demographic changes have occurred in Kenya, including rapid urbanization accompanied by poor living conditions, which could disproportionately increase TB incidence. Other possible contributors include immune reconstitution due to the recent delivery of antiretrovirals, and an increased presence of the virulent Beijing/W TB genotype. Results support the importance of integrating information from closely interacting epidemics, because this approach provides critical insights unobtainable when components of generalized

Young adults may be introducing Beijing strains., Tuberculosis case notification rates (CNRs) for young adults in Vietnam are increasing. To determine whether this finding could reflect emergence of Mycobacterium tuberculosis Beijing genotype, we studied all new sputum smear–positive pulmonary tuberculosis patients registered for treatment in 3 rural districts in Vietnam during 2003–2006. Beijing strain infections were more frequent in younger patients (15–24 years of age, 53%) than in older patients (31%; p65 years of age, respectively (p

BACKGROUND: There is considerable variability in the outcome of Mycobacterium tuberculosis infection. We hypothesized that Mycobacterium africanum was less likely than M. tuberculosis to transmit and progress to tuberculosis disease. METHODS: In a cohort study of patients with tuberculosis and their household contacts in The Gambia, we categorized 1808 HIV-negative tuberculosis contacts according to exposure to M. tuberculosis or M. africanum. Positive skin test results indicated transmission, and development of tuberculosis during 2 years of follow-up indicated progression to disease. RESULTS: Transmission rates were similar, but rates of progression to disease were significantly lower in contacts exposed to M. africanum than in those exposed to M. tuberculosis (1.0% vs. 2.9%; hazard ratio [HR], 3.1 [95% confidence interval {CI}, 1.1-8.7]). Within M. tuberculosis sensu stricto, contacts exposed to a Beijing family strain were most likely to progress to disease (5.6%; HR relative to M. africanum, 6.7 [95% CI, 2.0-22]). CONCLUSIONS: M. africanum and M. tuberculosis transmit equally well to household contacts, but contacts exposed to M. africanum are less likely to progress to tuberculosis disease than those exposed to M. tuberculosis. The variable rate of progression by lineage suggests that tuberculosis variability matters in clinical settings and should be accounted for in studies evaluating tuberculosis vaccines and treatment regimens for latent tuberculosis infection

The aim of the present study was to determine the effectiveness of entry screening for tuberculosis and biannual follow-up screening among new immigrants in The Netherlands. To achieve this, the present authors analysed screening, prevalence and incidence data of 68,122 immigrants, who were followed for 29 months. Patients diagnosed within 5 months and 6-29 months after entry screening were considered to be detected at entry and during the follow-up period, respectively. Coverage of the second to fifth screening rounds was 59, 46, 36 and 34%, respectively. Yield of entry screening was 119 per 100,000 individuals, and prevalence at entry was 131 per 100,000. Average yield of follow-up screening was highest among immigrants with abnormalities on chest radiography (CXR) at entry (902 per 100,000 individuals). When excluding these, yield of follow-up screening was 9, 37 and 97 per 100,000 screenings for immigrants from countries with tuberculosis incidences of 200 per 100,000, respectively. The incidence during follow-up in individuals with a normal CXR was 11, 58 and 145 per 100,000 person-yrs follow-up in these groups. The proportion of cases detected through screening declined per screening round from 91 to 31%. Yield of entry screening was high. Overall coverage and yield of follow-up screening was low. Follow-up screening of immigrants with a normal chest radiograph from countries with an incidence of