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Active Case Finding for Tuberculosis in Nepal

Gurung, Suman Chandra (2023) Active Case Finding for Tuberculosis in Nepal, Thesis (Doctoral), Liverpool School of Tropical Medicine.

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Background: Tuberculosis is one of the leading causes of death in globally and especially in LMICs. Despite being a preventable, curable disease, a person dies of TB every 20 seconds and every 2 minutes child dies because of tuberculosis. The Covid-19 pandemic had a devastating impact on access to TB diagnosis and treatment and the burden of TB disease. 10.6 million people fell ill with TB in 2021. Of these, approximately 6.4 million people with TB were ‘missing’: i.e. not diagnosed and notified through national TB programmes.
The first national TB Prevalence survey for Nepal revealed that the burden of TB in Nepal is 1.6 times higher than WHO previously estimated. This showed that there are about 40,000 TB cases ‘missing’ every year in Nepal. This case detection gap reflects the substantial barriers to access TB diagnosis and care, particularly in rural Nepal. It is vital that Nepal closes the case detection gap to achieve the commitments to the END TB strategy and accelerate progress towards TB elimination. Active Case Finding is an essential component, of a comprehensive strategy to find, diagnosis and treat missing cases, but stronger evidence is required for national TB programmes to build evidence informed and cost-effective ACF strategies integrated with, and complementary to, existing passive case finding services.

Aims: The thesis aimed to strengthen evidence to inform policy on effective ACF strategies appropriate to be implemented by the Nepali National TB programme embedded within the Nepali health system.
Two major themes were explored (1) yields and additionality achieved using different ACF models (2) the potential impact of ACF on prevalence and intensity of catastrophic costs for TB patients in Nepal.

Methods: The studies reported in this thesis were conducted within two major Birat Nepal Medical Trust (BNMT) community based TB active case finding implementation projects: the TB REACH wave 5 and IMPACT TB projects. The TB REACH project was implemented in 8 districts in the mid west and far west region. The IMPACT TB project was implemented in 4 districts of the central region of Nepal. Within both projects, the yield and additionality of active case finding using either the advanced molecular diagnostic GeneXpert test or smear microscopy for TB diagnosis was compared. Three case finding strategies were employed: social contact tracing, TB camps in hard-to-reach areas and screening at hospital OPD visits (TB REACH only). A network of community health workers identified individuals for screening, through interviewing index TB patients or consultation with health service providers. After verbal screening, symptomatic individuals were tested using either smear microscopy or GeneXpert tests. Case notification and additionality (crude and adjusted) was compared with control districts using TB REACH recommended methodology for analysis.
The second theme of the thesis explored patient incurred costs for TB and the potential role of ACF in reducing prevalence and intensity of catastrophic costs. Patient Cost data were collected using an adapted, translated and validated version of the WHO TB patient costing tool. For the TB REACH project, a cross sectional (single interview timepoint) survey wasconducted during the intensive phase of treatment. During the IMPACT TB study, the costing tool was adapted to a longitudinal design and additional interviews conducted during the continuation phase and at treatment completion. Socio-economic impacts were also evaluated throughout the treatment to understand changes in socioeconomic impacts and household recovery during treatment.

Results: The yield study from TB REACH project (chapter 3) showed that the project identified 1,092 TB cases. The highest yield was obtained from OPD screening at hospitals (n=566/1092; 52%). The proportion of positive test using GeneXpert (n=859/15637; 5.5%) was significantly higher than from smear microscopy testing (n=120/6309; 2%). The project achieved 29% additionality in case notifications in the GeneXpert intervention districts.
Similarly, the IMPACT TB yield study (chapter 4) showed that the project identified 1,133 TB positive cases during community-based TB ACF implementation. The positive rate of tested individuals during active case finding using GeneXpert and microscopy was (n=764/17114; 4.5%) and (n=437/13285; 3.3%), respectively. Social contact tracing for TB using GeneXpert testing yielded an additional 22% to district level TB notifications in Nepal.
The TB REACH cross sectional patient costing study (chapter 5) revealed that the prevalence of direct catastrophic costs was lower for ACF patients when compared with PCF patients (13% vs 33%, p = 0.029). Furthermore, patients over 60 were particularly vulnerable to catastrophic costs when diagnosed passively rather than actively.
The IMPACT TB longitudinal costing study (chapter 6) revealed that the socio-economic impact was severe for both groups (ACF and PCF) throughout the whole treatment, with 32% of households incurring catastrophic costs. ACF was associated with significantly lower patient costs during the pre-treatment period (mean total pretreatment costs of 56 USD and 87 USD for ACF and PCF groups, respectively. P<0.001). Three quarters of patients experienced extreme poverty in the intensive phase of treatment. ACF reached more vulnerable patient groups, with those diagnosed more likely to have no formal education, work in the informal sector or be from the lowest socioeconomic groups. Incurment of costs over the catastrophic costs threshold was also associated with ‘no education’ status, reflecting the severest financial impact of TB on the most vulnerable population groups.

Conclusions: Community based ACF is an important strategy to both close the case detection gap, improve equity of access to TB services and reduce patient incurred direct and catastrophic costs. Substantial additionality in TB case notifications was demonstrated through OPD screening and social-contact tracing strategies. GeneXpert based ACF was a more effective strategy with higher yields than smear microscopy based ACF. Although TB camps had a relatively low yield, this strategy reaches remote populations and is an important component of comprehensive TB case finding strategy in the context of Nepal. Early detection and treatment of TB can subsequently prevent suffering, death and further transmission of TB and substantially contribute to achieve the WHO End TB strategy targets by 2035. The community based ACF approach mitigated costs and reached the most vulnerable patients. Socio-economic consequences are severe and sustained on TB affected households in Nepal and therefore social protection policies have to be implemented to achieve the zero catastrophic costs milestone of the End TB strategy.
This thesis provided significant evidence to inform both national and global TB ACF policy, and translation of policy to effective action.
ACF should be scaled up nationwide, integrated within the existing health services applying comprehensive access to GeneXpert testing. It is vital that Nepal closes the case detection gap for TB to accelerate progress towards the END TB strategy goals. ACF scale-up has significant potential to contribute to the reduction of TB and to the elimination of catastrophic costs for TB patients in Nepal.

Item Type: Thesis (Doctoral)
Subjects: WF Respiratory System > Tuberculosis > WF 200 Tuberculosis (General)
WF Respiratory System > Tuberculosis > WF 205 Epidemiology
Faculty: Department: Clinical Sciences & International Health > Clinical Sciences Department
Depositing User: Lynn Roberts-Maloney
Date Deposited: 30 Aug 2023 09:34
Last Modified: 30 Nov 2023 04:12


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