Time filter

Source Type

Genève, Switzerland

Khan A.J.,Interactive Research and Development | Khan A.J.,Indus Hospital Research Center | Khowaja S.,Indus Hospital Research Center | Khan F.S.,Indus Hospital Research Center | And 12 more authors.
The Lancet Infectious Diseases | Year: 2012

Background: In many countries with a high burden of tuberculosis, most patients receive treatment in the private sector. We evaluated a multifaceted case-detection strategy in Karachi, Pakistan, targeting the private sector. Methods: A year-long communications campaign advised people with 2 weeks or more of productive cough to seek care at one of 54 private family medical clinics or a private hospital that was also a national tuberculosis programme (NTP) reporting centre. Community laypeople participated as screeners, using an interactive algorithm on mobile phones to assess patients and visitors in family-clinic waiting areas and the hospital's outpatient department. Screeners received cash incentives for case detection. Patients with suspected tuberculosis also came directly to the hospital's tuberculosis clinic (self-referrals) or were referred there (referrals). The primary outcome was the change (from 2010 to 2011) in tuberculosis notifications to the NTP in the intervention area compared with that in an adjacent control area. Findings: Screeners assessed 388 196 individuals at family clinics and 81 700 at Indus Hospital's outpatient department from January-December, 2011. A total of 2416 tuberculosis cases were detected and notified via the NTP reporting centre at Indus Hospital: 603 through family clinics, 273 through the outpatient department, 1020 from self-referrals, and 520 from referrals. In the intervention area overall, tuberculosis case notification to the NTP increased two times (from 1569 to 3140 cases) from 2010 to 2011-a 2·21 times increase (95% CI 1·93-2·53) relative to the change in number of case notifications in the control area. From 2010 to 2011, pulmonary tuberculosis notifications at Indus Hospital increased by 3·77 times for adults and 7·32 times for children. Interpretation: Novel approaches to tuberculosis case-finding involving the private sector and using laypeople, mobile phone software and incentives, and communication campaigns can substantially increase case notification in dense urban settings. Funding: TB REACH, Stop TB Partnership. © 2012 Elsevier Ltd. Source

Lienhardt C.,Stop TB Partnership
International Journal of Tuberculosis and Lung Disease | Year: 2010

Studies have shown that when using microbiologically confirmed active TB as a gold standard, the pooled sensitivity is 76% (72-80) across Quanti FERON studies, 78% (73-82) for QFT-G, 70% (63-78) for QFT-GIT, and 90% (86-93) for T-SPOT. This compares to 77% (71-82) for the TST. The pooled specificity for IGRA studies is 98% across the QFT assays and 93% (86-100) for T-SPOT. This compares to 97% for the TST in non-BCG-vaccinated populations and 59% in BCG-vaccinated populations (highly heterogeneous). There is consistently high specificity of IGRAs and they appear to be unaffected by BCG vaccination. What is the added value of IGRAs compared to the TST? The expectations are for better accuracy than with the TST for reliable detection of LTBI, to permit better targeted preventive therapy (contacts of TB cases, HIV-infected individuals, children). The problem though is the lack of a gold standard and the need to use active TB as a proxy for LTBI. A positive IGRA result does not necessarily indicate the presence of active TB and a negative IGRA result would not conclusively rule out active disease in an individual suspected of having TB. IGRAs can be useful as an aid in the diagnostic workup of smear-negative pulmonary or extra-pulmonary TB. Discordance between the TST and IGRAs are frequently reported, but largely unexplained. The significance of conversions and reversions in repeated IGRA testing is not clear. There are insufficient data so far to draw conclusions on the ability of IGRAs to reliably identify individuals with LTBI at greater risk of progression to active TB. Given the multitude of published studies and guidelines on IGRAs and their role in TB control, the WHO anticipates issuing policy guidance in 2010, following due WHO process. For the time being further research is needed, including: 1) better assessment of test accuracy and validity in various epidemiological settings (low vs. medium vs. high-burden countries) and various specific groups (children, immunocompromised individuals, health care workers, etc.); and 2) large-scale prospective studies to address the key issues of test prognostic values in high-risk settings and populations, the definition of appropriate thresholds, and variability of IGRA response in serial testing. All this is needed for the best informed decisions. © 2010 The Union. Source

Dowdy D.W.,Johns Hopkins University | Lotia I.,Interactive Research and Development | Creswell J.,Stop TB Partnership | Sahu S.,Stop TB Partnership | Khan A.J.,Interactive Research and Development
PLoS ONE | Year: 2013

Background:The potential population-level impact of private-sector initiatives for tuberculosis (TB) case finding in Southeast Asia remains uncertain. In 2011, the Indus Hospital TB Control Program in Karachi, Pakistan, undertook an aggressive case-finding campaign that doubled notification rates, providing an opportunity to investigate potential population-level effects.Methods:We constructed an age-structured compartmental model of TB in the intervention area. We fit the model using field and literature data, assuming that TB incidence equaled the estimated nationwide incidence in Pakistan (primary analysis), or 1.5 times greater (high-incidence scenario). We modeled the intervention as an increase in the rate of formal-sector TB diagnosis and evaluated the potential impact of sustaining this rate for five years.Results:In the primary analysis, the five-year intervention averted 24% (95% uncertainty range, UR: 18-30%) of five-year cumulative TB cases and 52% (95% UR: 45-57%) of cumulative TB deaths. Corresponding reductions in the high-incidence scenario were 12% (95% UR: 8-17%) and 27% (95% UR: 21-34%), although the absolute number of lives saved was higher. At the end of five years, TB notification rates in the primary analysis were below their 2010 baseline, incidence had dropped by 45%, and annual mortality had fallen by 72%. About half of the cumulative impact on incidence and mortality could be achieved with a one-year intervention.Conclusions:Sustained, multifaceted, and innovative approaches to TB case-finding in Asian megacities can have substantial community-wide epidemiological impact. © 2013 Dowdy et al. Source

Blok L.,Koninklijk Instituut Voor de Tropen KIT Health | Sahu S.,Stop TB Partnership | Creswell J.,Stop TB Partnership | Alba S.,Koninklijk Instituut Voor Of Tropen Kit Biomedical Research | And 2 more authors.
PLoS ONE | Year: 2015

Background: Screening of household contacts of tuberculosis (TB) patients is a recommended strategy to improve early case detection. While it has been widely implemented in low prevalence countries, the most optimal protocols for contact investigation in high prevalence, low resource settings is yet to be determined. This study evaluated contact investigation interventions in eleven lower and middle income countries and reviewed the association between context or program-related factors and the yield of cases among contacts. Methods: We reviewed data from nineteen first wave TB REACH funded projects piloting innovations to improve case detection. These nineteen had fulfilled the eligibility criteria: contact investigation implementation and complete data reporting. We performed a cross-sectional analysis of the percentage yield and case notifications for each project. Implementation strategies were delineated and the association between independent variables and yield was analyzed by fitting a random effects logistic regression. Findings: Overall, the nineteen interventions screened 139,052 household contacts, showing great heterogeneity in the percentage yield of microscopy confirmed cases (SS+), ranging from 0.1% to 6.2%). Compared to the most restrictive testing criteria (at least two weeks of cough) the aOR's for lesser (any TB related symptom) and least (all contacts) restrictive testing criteria were 1.71 (95%CI 0.94-3.13) and 6.90 (95% CI 3.42-13.93) respectively. The aOR for inclusion of SS- and extra-pulmonary TB was 0.31 (95% CI 0.15-0.62) compared to restricting index cases to SS+ TB. Contact investigation contributed between <1% and 14% to all SS+ cases diagnosed in the intervention areas. Conclusions: This study confirms that high numbers of active TB cases can be identified through contact investigation in a variety of contexts. However, design and program implementation factors appear to influence the yield of contact investigation and its concomitant contribution to TB case detection. © 2015 Blok et al. Source

John S.,Adamawa State Tuberculosis and Leprosy Control Programme | Gidado M.,KNCV TB CARE 1 | Dahiru T.,Netherlands Leprosy Relief | Fanning A.,University of Alberta | And 2 more authors.
International Journal of Tuberculosis and Lung Disease | Year: 2015

Background: Nomadic populations are often isolated and have difficulty accessing health care, leading to increased morbidity and mortality. Although Nigeria has one of the highest tuberculosis (TB) burdens in Africa, case detection rates remain relatively low. Methods: Active case finding for TB among nomadic populations was implemented over a 2-year period in Adamawa State. A total of 378 community screening days were organised with local leaders; community volunteers provided treatment support. Xpert® MTB/RIF was available for nomads with negative smear results. Results: Through active case finding, 96 376 nomads were verbally screened, yielding 1310 bacteriologically positive patients. The number of patients submitting sputum for smear microscopy statewide increased by 112% compared with the 2 years before the intervention. New smear-positive notifications increased by 49.5%, while notifications of all forms of TB increased by 24.5% compared with expected notifications based on historical trends. Nomads accounted for respectively 31.4% and 26.0% of all smear-positive and all forms TB notifications. Pre-treatment loss to follow-up and treatment outcomes were similar among nomads and non-nomads. Discussion: Nomads in Nigeria have high TB rates, and active case-finding approaches may be useful in identifying and successfully treating them. Large-scale interventions in vulnerable populations can improve TB case detection. © 2015 The Union. Source

Discover hidden collaborations