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Window Period Prophylaxis for Children Exposed to Tuberculosis, Houston, Texas, USA, 2007-2017
Insights
Window period prophylaxis is safe for young children exposed to tuberculosis (TB). Tuberculin skin test (TST) conversions were uncommon and linked to parental exposure, not TB severity.
Area of Science:
- Pediatrics
- Infectious Diseases
- Public Health
Background:
- Tuberculosis (TB) prevention in children under 5 years exposed to infectious adults is critical.
- Assessing the safety and efficacy of initiating treatment during the 'window period' before TB infection is detectable is essential.
Observation:
- A retrospective study analyzed 752 children under 5 exposed to adult TB cases between 2007-2017.
- Children received isoniazid prophylaxis during the window period, with most cases utilizing directly observed therapy.
- Initial examinations, chest X-rays, and TB infection tests were negative for all included children.
Findings:
- No instances of hepatotoxicity or developing active tuberculosis disease were observed in the children receiving prophylaxis.
- Tuberculin skin test (TST) conversion, indicating TB infection, occurred in 4.9% of children.
- Parental relationship to the index patient significantly increased the odds of TST conversion (OR 3.2).
- TST conversion was not correlated with sputum smear results, culture positivity, or cohabitation status.
Implications:
- The safety profile of window period prophylaxis supports its use in young children exposed to TB.
- Low thresholds for initiating prophylaxis are recommended due to medication safety and challenges in precise risk stratification.
- Further research may refine strategies for identifying high-risk children for earlier intervention.
Abstract:
In this retrospective study, we assessed the safety of window period prophylaxis and proportion of tuberculin skin test (TST) conversions in children <5 years of age who were exposed to an adult with tuberculosis disease during 2007-2017. Children included in this study had unremarkable examination and chest radiograph findings and negative test results for TB infection. In total, 752 children (41% cohabitating with the index patient) received prophylaxis during the window period, usually directly observed therapy with isoniazid. Hepatotoxicity and tuberculosis disease did not develop in any child. TST conversion occurred in 37 (4.9%) children and was associated with the index patient being the child's parent (odds ratio 3.2, 95% CI 1.2-8.2). TST conversion was not associated with sputum smear results, culture positivity, or cohabitation. Thresholds for initiation of window prophylaxis in exposed young children should be low given the safety of medication and difficulties with risk stratification.
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