The many gaps observed in the cascade of care of tuberculosis (TB) child contacts occur mostly in the screening, preventive therapy (PT) initiation and PT completion steps and the main drivers of these gaps are considered to be the health system infrastructure, limited worker resources and parents' reluctance to bring their children to the facility for screening. There would be great advantages of using a symptom-based screening at community level where only the symptomatic contacts are referred to hospital for further evaluation and asymptomatic contacts are started on PT in the community. Household or community-based screening is likely to improve the uptake and acceptability of child contact screening and management as well as adherence to PT and to reduce cost and workload at facility level.

This study proposes to compare the cascade of care between two models for TB screening and management of household TB child contacts in two high TB burden and limited resource countries, Cameroon and Uganda. In the facility-based model, children will be screened at facility (Cameroon) or household level (Uganda) and preventive therapy initiation, refills of PT therapy and follow-up will be done at facility level. In the intervention group (community-based model), child contacts will be screened in the household by a community health worker (CHW). Those with symptoms suggestive of TB will be referred to the facility for TB investigations. Asymptomatic child contacts from high risk groups (under-5 years or HIV infected 5-14) will be initiated on PT (3 months isoniazid-rifampicin) in the household. Refills of PT therapy will also be done in the communities by the CHW. In both models, symptomatic children requiring further investigations for TB diagnosis will be referred to a health facility.

The primary study objective is to compare the proportion of household child TB contacts eligible for PT (under-5 years and HIV-infected children 5-14 years without active TB) who initiate and complete PT using facility-based and decentralized community-based models of care for contact screening and management.

Secondary objectives are:

1. To compare the facility and community-based models in terms of:

   • The full cascade of care for the initiation and completion of PT in child TB contacts < 5 years or HIV+ children 5-14 years .
   • Cascade of care for the detection and treatment of TB in child contacts (all ages):
   • PT tolerability and adherence among eligible child contacts initiated on PT.
   • Treatment uptake and outcomes for child contacts diagnosed with TB .
   • Child contact outcomes at 6 months after enrollment for all child contacts.
   • Acceptability by the parents/guardians, health personnel and community of the different models of care.
   • Cost and cost-effectiveness of the different models.
   • Fidelity of the implementation of the model activities as compared to the protocol.

2. To assess the number of adult contact cases diagnosed with TB through the community-based screening.

3. To compare between the pre- (baseline assessment) and post-intervention (by model of care) data related to:

   • Children diagnosed with TB and registered at facility level and their treatment outcome.
   • Adults diagnosed with TB and registered at facility level and their treatment outcome.
   • PT initiation and outcomes.

This study will be implemented under the frame of the Catalyzing Pediatric TB Innovation (CaP TB) Project, funded by Unitaid and implemented by the Elizabeth Glaser Pediatric AIDS Foundation (EGPAF). The goal of CaP TB is to improve the pediatric TB morbidity and mortality by catalyzing the wide uptake of the new first-line fixed dose combination drugs for children and optimizing the use of these drugs through improved case detection and innovative models of care. In both models of care, contacts with TB suggestive symptoms will be investigated for TB at the cluster facility that is supported by EGPAF within the CaP TB project. In Cameroon the CaP TB project will be implemented in the Central and Littoral regions and in Uganda in the South-West region.

Inclusion Criteria:

• Inclusion of the index cases

  • Age > 15 years
  • Newly bacteriologically confirmed TB case (less than a month since diagnosis)
  • Reports child contact(s)
  • Written informed consent signed by the index case and by parents/guardians for minors or incapacitated people

• Inclusion of contacts

  • Household contact
  • Age
  • Facility-based model in Cameroon: < 5 years or HIV infected 5-14 years and all self-referred adults or children*.
  • Facility-based model in Uganda and community-based model on both countries: all ages
  • Written informed consent signed by adult contacts and by parents/guardians for minors or incapacitated people
  • Written assent for children > 7 years in Cameroon and ≥8 years in Uganda

Under the facility-based model in Cameroon, although there is no systematic request to screen adults or HIV-negative child contacts 5-14 years old, first inclusions showed that some of them came by themselves for TB screening. This justifies their inclusion in the study in order to ensure the completeness of data for all contacts screened under the facility-based model.

Exclusion Criteria:

- Exclusion of index cases

• Index cases who do not have child household contacts living in the catchment area of one of the study clusters
• Index cases diagnosed with rifampicin resistance, multidrug-resistant (MDR) or extensively drug-resistant (XDR) TB *Index cases from a household screened within the CONTACT study and that does not declare child contacts from another household.*
• Index cases that are prisoners

TB confirmed adult contacts cases living in the same household as an index case already enrolled in the study will not be included as new index cases unless they declare additional contacts from another household

- Exclusion of the contacts

• If the contact is already on PT or on TB treatment