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

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

Abstract

Background: 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). 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.

Methods: Demographic 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).

Results: The 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.

Conclusions: The 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.

Figures

Figure 1
Figure 1
Sampling process. <15 = Patient is under 15 years of age. ACF, active case finding; PCF, passive case finding; SS + ve, sputum-smear positive; SS -ve, sputum-smear negative.
Figure 2
Figure 2
Age distribution of cases by case-finding method.
Figure 3
Figure 3
Distribution of smear grade by case-finding method.

References

    1. Obermeyer Z, Abbott-Klafter J, Murray CJL. Has the DOTS strategy improved case finding or treatment success? An empirical assessment. PLoS One. 2008;3(3):e1721. doi: 10.1371/journal.pone.0001721.
    1. World Health Organization. Global Tuberculosis Control Report 2011. 2011.
    1. Onozaki I, Raviglione M. Stopping tuberculosis in the 21st century: goals and strategies. Respirology (Carlton, Vic.) 2010;15(1):32–43. doi: 10.1111/j.1440-1843.2009.01673.x.
    1. Golub JE. et al.Active case finding of tuberculosis: historical perspective and future prospects. Int J Tuberc Lung Dis. 2005;9(11):1183–1203.
    1. Borgdorff MW, Floyd K, Broekmans JF. Interventions to reduce tuberculosis mortality and transmission in low- and middle-income countries. Bull World Health Organ. 2002;80(3):217–227.
    1. Qureshi SA, Morkve O, Mustafa T. Patient and health system delays : Health-care seeking behaviour among pulmonary tuberculosis patients in Pakistan. J Pak Med Assoc. 2008;58(6):318–321.
    1. Murray CJ, Salomon JA. Expanding the WHO tuberculosis control strategy: rethinking the role of active case-finding. Int J Tuberc Lung Dis. 1998;2:9–15.
    1. National Center for Tuberculosis & Leprosy Control. National Health Strategic Plan for Tuberculosis Control in the Kingdom of Cambodia 2011-2015. Cambodia: Ministry of Health; 2011.
    1. Santha T. et al.Are community surveys to detect tuberculosis in high prevalence areas useful? Results of a comparative study from Tiruvallur District, South India. Int J Tuberc Lung Dis. 2003;7(3):258–265.
    1. Dye C. et al.Prospects for worldwide tuberculosis control under the WHO DOTS strategy. Directly observed short-course therapy. Lancet. 1998;352(9144):1886–1891.
    1. Murray CJ, Styblo K, Rouillon A. Tuberculosis in developing countries: burden, intervention and cost. Bull Int Union Tuberc Lung Dis. 1990;65(1):6–24.
    1. Rieder HL, Priorities for Tuberculosis Bacteriology Services in Low-Income Countries. 2nd ed. Paris: International Union Against Tuberculosis and Lung Disease; 2007.
    1. Hinderaker SG. et al.The FIDELIS initiative: innovative strategies for increased case finding. Int J Tuberc Lung Dis. 2011;15(1):71–76.
    1. Kranzer K. et al.Yield of HIV-associated tuberculosis during intensified case finding in resource-limited settings: a systematic review and meta-analysis. Lancet Infect Dis. 2010;10(2):93–102. doi: 10.1016/S1473-3099(09)70326-3.
    1. Kathryn C, Edward D. Tuberculosis in the elderly: Keep a high index of suspicion. The Journal of Respiratory Diseases. 2006;6:7.
    1. Rajagopalan S, Yoshikawa TT. Tuberculosis in the elderly. Z Gerontol Geriatr. 2000;33(5):374–380. doi: 10.1007/s003910070034.
    1. National Center for Tuberculosis & Leprosy Control. National Tuberculosis Prevalence Survey in Cambodia. Cambodia: Ministry of Health; 2002.
    1. Cassels A. et al.Tuberculosis case-finding in Eastern Nepal. Tubercle. 1982;63(3):175–185. doi: 10.1016/S0041-3879(82)80028-7.
    1. Liippo KK, Kulmala K, Tala EO. Focusing tuberculosis contact tracing by smear grading of index cases. Am Rev Respir Dis. 1993;148(1):235–236.
    1. Rajpal S, Dhingra VK, Aggarwal JK. Sputum grading as predictor of treatment outcome in pulmonary tuberculosis. Indian J Tuberc. 2002;49(3):139–142.
    1. Matsumoto K. et al.Investigation on "patient's delay" in TB detection. Kekkaku Tuberculosis. 2009;84(7):523–529.
    1. Lin X. et al.Dose-response relationship between treatment delay of smear-positive tuberculosis patients and intra-household transmission: a cross-sectional study. Trans R Soc Trop Med Hyg. 2008;102(8):797–804. doi: 10.1016/j.trstmh.2008.04.027.
    1. Güler M. et al.Factors influencing sputum smear and culture conversion time among patients with new case pulmonary tuberculosis. Int J Clin Pract. 2007;61(2):231–235.
    1. Elliott AM. et al.Negative sputum smear results in HIV-positive patients with pulmonary tuberculosis in Lusaka, Zambia. Int J Tuberc Lung Dis. 1993;74(3):191–194. doi: 10.1016/0962-8479(93)90010-U.
    1. Mfinanga GS. et al.The quality of sputum smear microscopy diagnosis of pulmonary tuberculosis in Dar es Salaam, Tanzania. Tanzan Health Res Bull. 2007;9(3):164–168.
    1. Rieder HL. et al.Quantitative differences in sputum smear microscopy results for acid-fast bacilli by age and sex in four countries. Int J Tuberc Lung Dis. 2009;13(11):1393–1398.
    1. Schifman RB, Meier F. Sputum Specimen Adequacy Data Analysis and Critique. 1991.
    1. Den Boon S. et al.Comparison of symptoms and treatment outcomes between actively and passively detected tuberculosis cases: the additional value of active case finding. Epidemiol Infect. 2008;136(10):1342–1349.

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