Early detection of tuberculosis through community-based active case finding in Cambodia

Mao Tan Eang,Pieter Van-Maaren,Rajendra Prasad Yadav,Catharina Lambregts-Van Weezenbeek,Peou Satha,Nobuyuki Nishikiori,Fukushi Morishita

doi:10.1186/1471-2458-12-469

Mao Tan Eang, Pieter Van-Maaren + Show 5 more

Open Access

https://doi.org/10.1186/1471-2458-12-469

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Abstract

BackgroundSince 2005, Cambodia’s national tuberculosis programme has been conducting active case finding (ACF) with mobile radiography units, targeting household contacts of TB patients in poor and vulnerable communities in addition to routine passive case finding (PCF). This paper examines the differences in the demographic characteristics, smear grades, and treatment outcomes of pulmonary TB cases detected through both active and passive case finding to determine if ACF could contribute to early case finding, considering associated project costs for ACF.MethodsDemographic characteristics, smear grades, and treatment outcomes were compared between actively (n = 405) and passively (n = 602) detected patients by reviewing the existing programme records (including TB registers) of 2009 and 2010. Additional analyses were performed for PCF cases detected after the ACF sessions (n = 91).ResultsThe overall cost per case detected through ACF was US$ 108. The ACF approach detected patients from older populations (median age of 55 years) compared to PCF (median age of 48 years; p < 0.001). The percentage of smear-negative TB cases detected through ACF was significantly higher (71.4%) than that of PCF (40.5%). Among smear-positive patients, lower smear grades were observed in the ACF group compared to the PCF group (p = 0.002). A fairly low initial defaulter rate (21 patients, 5.2%) was observed in the ACF group. Once treatment was initiated, high treatment success rates were achieved with 96.4% in ACF and with 95.2% in PCF. After the ACF session, the smear grade of TB patients detected through routine PCF continued to be low, suggesting increased awareness and early case detection.ConclusionsThe community-based ACF in Cambodia was found to be a cost-effective activity that is likely to have additional benefits such as contribution to early case finding and detection of patients from a vulnerable age group, possibly with an extended benefit for reducing secondary cases in the community. Further investigations are required to clarify the primary benefits of ACF in early and increased case detection and to assess its secondary impact on reducing on-going transmission.

Highlights

Since 2005, Cambodia’s national tuberculosis programme has been conducting active case finding (ACF) with mobile radiography units, targeting household contacts of TB patients in poor and vulnerable communities in addition to routine passive case finding (PCF)
We reviewed the records of all pulmonary TB cases detected by both active and passive case finding in the designated health centres
Number needed to screen Between 2005 and 2010, 33 631 TB suspects who presented to the ACF sessions were registered for screening across Cambodia and all were screened by chest radiography

Summary

Introduction

Since 2005, Cambodia’s national tuberculosis programme has been conducting active case finding (ACF) with mobile radiography units, targeting household contacts of TB patients in poor and vulnerable communities in addition to routine passive case finding (PCF). Successful expansion of the internationally recommended directly observed treatment, short-course (DOTS) strategy since the mid-1990s has achieved remarkable progress in TB control in many parts of the world. The DOTS strategy promotes passive case finding (PCF), whereby patients with signs and symptoms of TB present themselves at health facilities for diagnosis and treatment [4]. While this conventional approach has been recognized as cost-effective [5], people who have limited access to TB services often fail to receive timely diagnosis and life-saving treatment. Active case finding (ACF), on the other hand, systematically looks for cases of TB, rather than waiting for people to develop symptoms and seek treatment. ACF has been implemented for decades primarily in resource rich settings, there is growing interest in using this approach for early case detection in developing countries [4,7]

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