Gaps in the tuberculosis preventive therapy care cascade in children in contact with TB

Background: Young children (<5 years) and children living with HIV in contact with an adult with tuberculosis (TB) should receive TB preventive therapy (TPT), but uptake is low. Aims: To determine gaps in the uptake of and adherence to TPT in child TB contacts under routine primary care clinic conditions. Methods: A cohort of child TB contacts (age <5 years or living with HIV <15 years) was followed at a primary care clinic in Johannesburg, South Africa. Results: Of 170 child contacts with 119 adult TB cases, only 45% (77/170) visited the clinic for TPT eligibility screening, two of whom had already initiated TPT at another clinic. Of the 75 other children, 18/75 (24%) commenced TB treatment and 56/75 (75%) started TPT. Health-care workers followed the guidelines, with 96% (64/67) of children screened for symptoms of TB and 97% (36/37) of those symptomatic assessed for TB, but microbiological testing was low (9/36, 25%) and none had microbiologically confirmed tuberculosis. Only half (24/46, 52%) of the children initiating TPT completed the 6-month course. Neither sociodemographic determinants (age, sex) nor clinical factors (HIV status, TB source, time to TPT initiation) was associated with non-adherence to TPT. Conclusion: Most child contacts of an adult TB case do not visit the clinic, and half of those initiating TPT did not adhere to the full 6-month course. These programme failures result in missed opportunities for early diagnosis of active TB and prevention of progression to disease in young and vulnerable children.