What is the Indian guideline for Tuberculosis (TB) Post-Exposure Prophylaxis (PEP)?

Indian Guidelines for Tuberculosis Post-Exposure Prophylaxis

TB post-exposure prophylaxis in India should be initiated for all close contacts of infectious TB patients, with priority given to high-risk individuals such as children under 5 years, HIV-infected persons, and immunocompromised individuals, using isoniazid for 6-9 months as the standard regimen. 1

Candidates for TB Post-Exposure Prophylaxis

• Post-exposure prophylaxis should be offered to persons who have had recent contact with an infectious TB patient, regardless of age, tuberculin skin test (TST) results, or history of previous TB preventive treatment 1
• Priority should be given to contacts with positive TST results (≥5 mm induration), as they are considered recently infected with M. tuberculosis and at heightened risk for TB disease 2
• HIV-infected contacts should receive TB preventive treatment regardless of TST results, as they are at significantly higher risk of developing active TB 1, 2
• Children under 5 years of age who are close contacts of infectious TB cases should receive prophylaxis after active TB has been excluded 1, 2
• Tuberculin-negative children who have been close contacts of infectious persons within the past 3 months should receive preventive therapy until a repeat TST is done 12 weeks after contact with the infectious source 3

Recommended Prophylaxis Regimens

• The standard regimen for TB prophylaxis in India is isoniazid (INH) for 6-9 months at a dose of 10 mg/kg (up to 300 mg daily) in a single dose 3, 4
• For HIV-infected adults, a 9-month regimen of daily isoniazid is recommended 1, 2
• For HIV-infected children, a 12-month regimen of daily isoniazid is recommended 1
• In situations where adherence with daily preventive therapy cannot be assured, 20-30 mg/kg (not to exceed 900 mg) twice weekly under direct observation is recommended 3
• Concomitant administration of pyridoxine (B6) is recommended in malnourished individuals and those predisposed to neuropathy (e.g., alcoholics and diabetics) 3

Special Considerations for Drug-Resistant TB Exposure

• For contacts of drug-resistant TB patients, prophylaxis regimens should be tailored based on the resistance pattern of the index case 2, 4
• For contacts of isoniazid-resistant TB patients, 4 months of daily rifampin is recommended 2
• For contacts of multidrug-resistant TB (MDR-TB) patients, consultation with a TB expert is recommended as none of the potential regimens has been fully tested for efficacy 2
• Contacts who have received a diagnosis of infection attributed to MDR-TB should be monitored for 2 years after exposure 2

Monitoring and Follow-up

• Monthly clinical evaluation is recommended for adherence to treatment and monitoring for medication side effects 1
• Directly observed preventive therapy (DOT) is recommended for all intermittent dosing regimens when feasible 1
• For children, TST should be performed at or before age 9-12 months and repeated every 2-3 years if the child lives in a household with M. tuberculosis-infected persons 2

Considerations for Specific Populations

• For pregnant women, isoniazid is the prophylactic agent of choice after active TB has been excluded 2
• Due to theoretical concerns regarding teratogenicity during the first trimester, providers may choose to initiate prophylaxis after the first trimester 2
• For children receiving INH under the weight band system of the Revised National Tuberculosis Control Program (RNTCP), doses less than 10 mg/kg body weight may result in lower blood levels, suggesting caution with the INH doses being administered 5
• For HIV-coinfected children, higher doses of rifampin may be required as they display lower drug exposure and are associated with higher probability of unfavorable treatment outcomes 6

Common Pitfalls to Avoid

• Failure to rule out active TB before initiating preventive therapy, which could lead to inadequate treatment and development of drug resistance 4
• Inadequate treatment of isoniazid-resistant TB cases with the standard retreatment regimen, which may lead to poor treatment outcomes 7
• Neglecting to monitor for hepatic disorders and drug interactions, particularly with isoniazid 8
• Not completing the full course of preventive therapy, which is essential as relapse rates are higher if chemotherapy is stopped prematurely 3
• Administering BCG vaccine to HIV-infected persons, which is contraindicated due to potential for disseminated disease 2

By following these guidelines for TB post-exposure prophylaxis, healthcare providers in India can effectively prevent the development of active TB disease in exposed individuals, particularly those at highest risk.