Clinical context
In the Leprosy Control Program, the goal of contact management is to find undiagnosed leprosy and tuberculosis early while protecting eligible contacts from developing leprosy.
Single-dose rifampicin post-exposure prophylaxis (
SDR-PEP) is a preventive intervention, not a treatment for active disease. Before giving SDR-PEP, the nurse must confirm that the contact does not already have leprosy or TB, because rifampicin alone is inadequate and inappropriate for active infection.
Step-by-step decision
The DOH guideline sets three main conditions for SDR-PEP eligibility: the contact must be at least
2 years old, must have no signs or symptoms suggesting active leprosy, and must have no signs or symptoms suggesting active TB. Pregnancy and liver disease are additional contraindications, but the scenario states that none of the household members has these conditions.
The
35-year-old wife has no lesions and no TB symptoms. She is older than 2 years, has no evidence of active leprosy, and has no evidence of TB. She therefore meets all criteria for SDR-PEP today.
The
62-year-old mother has coughed for
3 weeks. A cough lasting 2 weeks or more is a presumptive TB symptom. She must be evaluated for TB first, and SDR-PEP should not be given until active TB is excluded.
The
11-year-old daughter has a pale, numb patch. A hypopigmented or anesthetic skin patch is a classic sign of leprosy. She is a suspected leprosy case and needs diagnostic evaluation, not prophylaxis.
The
20-month-old son has no lesions or symptoms, but he is below the minimum age of
2 years. SDR-PEP is not indicated for him at this time.
Why exclusion of active disease matters
SDR-PEP is intended for contacts who are currently free of leprosy and TB. If rifampicin is given to someone with active leprosy, it may partially suppress the infection without curing it, delaying diagnosis and allowing nerve damage to progress. If given to someone with active TB, rifampicin monotherapy can promote drug resistance. Therefore, screening before prophylaxis is a safety step, not just a formality.
Age limit and contact risk
The
2-year age cutoff reflects both safety and developmental considerations. Very young children have different drug metabolism and require careful weight-based dosing. In addition, the risk of leprosy is highest among household contacts and blood relatives, especially of multibacillary patients, but prophylaxis is only offered once the child reaches the eligible age.
Comparison of household members
| Household member | Key finding | Interpretation | SDR-PEP today |
|---|
| 35-year-old wife | No lesions, no TB symptoms | Active leprosy and TB excluded; age eligible | Yes |
| 62-year-old mother | Cough for 3 weeks | Presumptive TB; needs TB evaluation first | No |
| 11-year-old daughter | Pale, numb patch | Suspected leprosy; needs leprosy evaluation first | No |
| 20-month-old son | No lesions or symptoms | Below age limit of 2 years | No |
Program-level perspective
The WHO recommends SDR-PEP for contacts of leprosy patients as part of active case finding and prevention. Field programmes in high-endemic settings have shown that screening contacts and providing SDR-PEP can reduce new case detection rates. However, the effectiveness depends on correctly excluding active disease and respecting age and clinical eligibility criteria. The nurse at the RHU is performing exactly this screening function when examining household members.
Key point! SDR-PEP is prevention, not treatment. Any contact with a suspicious skin lesion or TB symptom must be referred for diagnosis before prophylaxis is considered.
Watch out! A cough of
3 weeks is enough to classify the mother as a presumptive TB case, even if she has no other symptoms.
Watch out! The pale, numb patch in the daughter is a leprosy sign, not a reason to give prophylaxis. She needs a full skin and neurological assessment.