The Yield of Community-Based “Retrospective” Tuberculosis Contact Investigation in a High Burden Setting in Ethiopia

Abstract

ObjectiveTo determine the yield and determinants of retrospective TB contact investigation in selected zones in Ethiopia.Materials and MethodsThis was a community-based cross-sectional study conducted during June-October 2014.Trained lay providers performed symptom screening for close contacts of index cases with all types of TB registered for anti-TB treatment within the last three years. We used logistic regression to determine factors associated with TB diagnosis among the contacts.ResultsOf 272,441 close contacts of 47, 021 index cases screened, 13,886 and 2, 091 had presumptive and active TB respectively. The yield of active TB was thus 768/100, 000, contributing 25.4% of the 7,954 TB cases reported from the study zones over the study period. The yield was highest among workplace contacts (12,650/100, 000). Active TB was twice more likely among contacts whose index cases had been registered for TB treatment within the last 12 months compared with those who had been registered 24 or more months earlier (adjusted odds ratio, AOR: 1.77 95% CI 1.42–2.21). Sex or clinical type of TB in index cases was not associated with the yield. Smear negative (SS-) index cases (AOR: 1.74 955 CI 1.13–2.68), having index cases who registered for treatment within <12 months (AOR: 2.41 95% CI 1.51–3.84) and being household contact (AOR: 0.072 95% CI 0.01–0.52) were associated with the occurrence of active TB in children.ConclusionsThe yield of retrospective contact investigation was about six times the case notification in the study zones, contributing a fourth of all TB cases notified over the same period. The yield was highest among workplace contacts and in those with recent past history of contact. Retrospective contact screening can serve as additional strategy to identify high risk groups not addressed through currently recommended screening approaches.

Drop-out from the tuberculosis contact investigation cascade in a routine public health setting in urban Uganda: A prospective, multi-center study

“…[12][13][14][15][16][17] To improve delivery of contact investigation and other active case-finding strategies, there is a need for attention to each step in the process to avoid excessive cumulative losses. We applied a cascade analysis to identify the greatest gaps in delivery of household contact investigation and follow-up evaluation in a programmatic setting.…”

Effectiveness of Contact Tracing of Index Tuberculosis Cases in Nigeria

“…The retrospective cross sectional approach was applied by [4] while [72] used quantitative retrospective cross sectional study. Interventional methodology with quantitative arm was used by, [49] while longitudinal prospective approach was adopted by [75].…”

“…The strategy is an effective secondary prevention method for managing sub-clinical manifestation and transmission of TB [3]. The close proximity of Household or workplace contacts to an index TB case is a major predisposing factor to TB transmission and infection [4]. A contact of index TB case is defined, as a person living with an infectious TB case over a period of three months before diagnosis [4].…”

“…The close proximity of Household or workplace contacts to an index TB case is a major predisposing factor to TB transmission and infection [4]. A contact of index TB case is defined, as a person living with an infectious TB case over a period of three months before diagnosis [4]. Searching for these contacts as part of active case finding strategy by the National Tuberculosis control program provides a useful opportunity for detecting undiagnosed TB cases [1].…”

Uptake of home-initiated tuberculosis evaluation during household contact investigation in Kampala, Uganda: A mixed-methods study

“…[1][2][3][4][5] One important tool for active case-finding is household contact investigation. 6 However, case-finding through contact investigation depends on contacts' ability and willingness not only to complete screening for TB symptoms and risk factors, but also to complete TB evaluation if referred.…”