Correlates of isoniazid preventive therapy failure in child household contacts with infectious tuberculosis in high burden settings in Nairobi, Kenya – a cohort study

Abstract

BackgroundSub-Saharan Africa continues to document high pediatric tuberculosis (TB) burden, especially among the urban poor. One recommended preventive strategy involves tracking and isoniazid preventive therapy (IPT) for children under 5 years in close contact with infectious TB. However, sub-optimal effectiveness has been documented in diverse settings. We conducted a study to elucidate correlates to IPT strategy failure in children below 5 years in high burden settings.MethodsA prospective longitudinal cohort study was done in informal settlings in Nairobi, where children under 5 years in household contact with recently diagnosed smear positive TB adults were enrolled. Consent was sought. Structured questionnaires administered sought information on index case treatment, socio-demographics and TB knowledge. Contacts underwent baseline clinical screening exclude TB and/or pre-existing chronic conditions. Contacts were then put on daily isoniazid for 6 months and monitored for new TB disease, compliance and side effects. Follow-up continued for another 6 months.ResultsAt baseline, 428 contacts were screened, and 14(3.2%) had evidence of TB disease, hence excluded. Of 414 contacts put on IPT, 368 (88.8%) completed the 1 year follow-up. Operational challenges were reported by 258(70%) households, while 82(22%) reported side effects. Good compliance was documented in 89% (CI:80.2–96.2). By endpoint, 6(1.6%) contacts developed evidence of new TB disease and required definitive anti-tuberculosis therapy. The main factor associated with IPT failure was under-nutrition of contacts (p = 0.023).ConclusionUnder-nutrition was associated with IPT failure for child contacts below 5 years in high burden, resource limited settings. IPT effectiveness could be optimized through nutrition support of contacts.Electronic supplementary materialThe online version of this article (10.1186/s12879-017-2719-8) contains supplementary material, which is available to authorized users.

Practical and psychosocial challenges faced by caregivers influence the acceptability of multidrug-resistant tuberculosis preventive therapy for young children

“…Despite the broad nature of the definition presented above, measures of acceptability have predominantly revolved around the palatability of drug formulations and the ease of treatment administration [ 35 ]. Our findings corroborate recent research among caregivers in Africa which suggests that the use and uptake of TPT, as well as other long-term medical conditions in children, is complicated by the psychosocial circumstances into which children’s treatment is introduced [ 50 , 51 ]. Other research has also illustrated how the everyday practices of caring for children is further complicated when caregivers themselves were sick [ 25 , 52 ].…”

Barriers to the Implementation of Isoniazid Preventive Therapy Among Children Under Five Years Old in Close Contact With Sputum Smear-Positive Tb Patients

“…The gender factor that did not have a significant association as a barrier is in line with studies in India (95% CI 0.8-1.5), New Zealand (p=0.09), and Nigeria (p=0.750) regarding adherence to child medication [18][19][20]. These results, however, contrast with findings from a research that was conducted in Kenya where boys were influential as a factor in the failure of IPT (p=0.02) [21].…”

Barriers to the implementation of isoniazid preventive therapy for tuberculosis in children in endemic settings: A review

“…Improved education around IPT from health‐care workers, particularly concerning the benefit and duration of therapy is required. Additional common obstacles to IPT included the fear of the side effects of medication, and the preference of parents in certain areas to opt for alternative, traditional treatments rather than modern medicine …”

“…I have no confidence to explain IPT to the patient’ . An additional concern was the belief by many health‐care workers that IPT induces the development of antibiotic‐resistant TB, a claim for which there is currently limited evidence for . Increased emphasis on staff education and training in relation to IPT would be useful for maximising patient outcomes.…”

“…Education is an important issue but it is not the only impediment faced by health‐care workers trying to deliver IPT to children in TB‐endemic settings. Some health‐care centres lacked the equipment to rule out active TB, which they saw as necessary to initiating IPT, while others encountered supply chain difficulties in procuring sufficient isoniazid to provide patients . The labour‐intensive preparation of paediatric doses was reported as placing additional strain on already stretched staffing arrangements in some areas although child‐friendly dispersible formulations are now becoming available in most countries through the Global Development Fund .…”