A cross-sectional childhood M. tuberculosis infection survey of age-specific rates (defined by positivity to the test QuantiFERON-TB Gold Plus) will be conducted in Senegal to collect information on the local TB endemic to inform site selection, sample size, and recruitment strategies for a future efficacy trial of vaccine candidate MTBVAC in young children.

MTBVAC is a new TB vaccine candidate based on an attenuated clinical isolate of M. tuberculosis. The clinical development consortium of this EDCTP program is preparing for future years an MTBVAC efficacy trial by setting up a network of three African sites in South Africa, Senegal and Madagascar. Each site has established an operational clinical research infrastructure. As a first step, Senegal site needs to collect crucial epidemiological data on TB in children, to allow a rapid transition to a phase 3 trial in infants.

The primary objective is to estimate the prevalence of TB infection by the QuantiFERON-TB Gold Plus technique in 500 children splined in 1-year, 2-year, 5-year, and 12-year-old age groups living in the study area (Saint Louis, Senegal).

Secondary objectives are:

• To study the socio-demographic characteristics, the vaccination history of each subject and the possible tuberculous contacts he has.
• To map selected populations (from GPS residence data) according to the status (infected or uninfected) of each subject.
• To ensure the orientation of children found positive by the QuantiFERON-TB Gold Plus test for care and follow-up related to the TB diagnosis and treatment at one of the Health Centers (THC) located in the study areas.
• To estimate the number of tuberculosis cases detected in children aged up to 12 years and resident in the study area from THC registries and data from the National Tuberculosis Control Plan (PNB).

Inclusion Criteria:

• Children resident in the study area (St Louis City)

• Obtaining written consent from one of the parents / guardians.

• Children meeting one the following age criterion:

  • 1-year old child (12 months -1/+4 months);
  • 2-year-old child (24 months -1/+4 months);
  • 5-year old child (60 months +/-6 months);
  • 12-year old child (12 years old +/-6 months);

Exclusion Criteria:

• Child resident outside the study area.
• Participation refusal by one of the parents / guardians.
• Objection of the child belonging to the 12-year old group.
• Child with a known chronic pathology (severe asthma, epilepsy, type 1 diabetes, severe immunosuppression ...)
• Child considered by the Principal Investigator as medically unfit to participate in the study.

A convenience sample taking into account the constraints related to the QuantiFERON-TB Gold Plus technique was chosen. One hundred and twenty-five (125) children per age group (1 year, 2 years, 5 years and 12 years) will be included. In total, 500 children will be recruited.

A plan to make individual participant data (IPD) collected in this study, including data dictionaries, available to other researchers will be defined in the next semester by partners of the project.