Prison Leprosy Screening Detects Hidden Cases

LEPROSY screening identified undiagnosed multibacillary disease and disability among incarcerated men in northeastern Brazil.

Leprosy Screening Reveals Missed Cases

Researchers conducted an observational cross sectional study at a high security male penitentiary in Maceió, Alagoas, where 915 people were incarcerated in a facility designed for 773. The team distributed the 14 item Leprosy Suspicion Questionnaire as an active case finding tool, receiving 842 completed questionnaires. Of these, 240, or 28.5%, indicated signs or symptoms consistent with possible leprosy.

Neurodermatological examinations were completed in 260 participants with both positive and negative questionnaire results. Eight new cases were diagnosed, producing an overall new case detection rate of 3.08%. Among the 92 examined participants with positive questionnaire results, six had leprosy, raising the detection rate to 6.52%.

The questionnaire was positive in 75% of diagnosed cases, compared with 34.1% of participants without leprosy. Numbness in the hands and feet and nerve pain were the most frequently reported symptoms among diagnosed participants.

Neurological Disease Present at Diagnosis

All eight cases were classified as multibacillary leprosy and showed peripheral nerve involvement. Six participants had borderline forms and two had pure neural leprosy. Approximately 62.5% experienced dysesthesia without classical skin lesions, highlighting the potential for neurological manifestations to complicate recognition.

Every diagnosed participant had physical disability at detection. Seven had Grade 1 disability and one had Grade 2 disability, indicating that disease had progressed before diagnosis. All newly diagnosed individuals were referred for standard multidrug therapy.

Serology Highlights Potential Screening Marker

Serological testing was performed on plasma from 244 clinically evaluated participants. Among the eight diagnosed cases, anti-Mce1A IgA antibodies were detected in 100%, while IgM and IgG antibodies were positive in 37.5% and 25%, respectively. Anti-PGL-I serology was negative in all diagnosed cases.

Among participants without a clinical diagnosis, anti-Mce1A IgM seropositivity reached 37.7%, compared with 19.9% for anti-PGL-I. The researchers noted that these results may reflect exposure or subclinical infection, but the small number of diagnosed cases prevented reliable assessment of diagnostic accuracy.

The findings support structured leprosy screening and follow-up in incarcerated populations. However, only 260 of 842 questionnaire respondents received clinical examinations because the study was suspended following a potential riot, meaning the detected cases may represent only part of the true burden.

Reference
de Lucena TS et al. Hidden burden of leprosy in incarcerated populations in northeast Brazil: active case detection and serological assessment. Eur J Clin Microbiol Infect Dis. 2026; doi:10.1007/s10096-026-05578-2.

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