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

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.

Screening difficult-to-reach populations for tuberculosis using a mobile medical unit, Punjab India

“…[1][2][3][4][5][6][7][8][9] India is a low-to middle-income country, with approximately 30% of the population earning below the international poverty line (US$1.25 per day). 10 Despite a well-developed public health system, many populations in India remain either underserved or without access to the health services available from the public health facilities.…”

Cost-Effectiveness of a Tuberculosis Active Case Finding Program Targeting Household and Neighborhood Contacts in Cambodia

“…This ratio was adjusted by the sensitivity of the GeneXpert MTB/RIF assay in detecting each of these types (76% for smear-negative cases and 98% for smear-positive cases11,12). A previous study of ACF activities in Cambodia found slightly higher mortality rates in PCF cases than in ACF cases 2. We used these data to extrapolate the respective mortality rates for treated smear-positive and smear-negative TB, which resulted in beta distributions with a mean of 2.2% and 0.7% respectively, and with considerable overlap in the two distributions.…”

Intensified tuberculosis case finding amongst vulnerable communities in southern India

“…4 In the results of the FIDELIS (Fund for Innovative DOTS Expansion through Local Initiatives to Stop TB) project in China, which massively mobilised school students for case finding, the case detection in intervention counties increased by a factor of 3.5 relative to the pre-intervention period. 5 There were some limitations to our study. While our approach demonstrated a potential for improved case detection in the short term, we do not know if these trends are sustainable; we will need to re-examine the results once all the mapped households in the intervention area are covered.…”

“…Community-based ICF interventions implemented elsewhere in India and other countries have shown similar results; this reflects the replicability and scalability of such interventions. [3][4][5] An intervention in Orissa, India, increased case detection by 11%. 3 A similar ICF activity conducted in Ethiopia doubled the pulmonary TB case notification rate, from 64 to 127/100 000 population/year.…”