02835nas a2200265 4500000000100000008004100001260005300042653001900095653001400114653002400128653002600152653001200178100001700190700001400207700001500221700001200236700001500248700001200263700001400275245012700289856007300416300001100489520204400500022002502544 2026 d c07/2026bSpringer Science and Business Media LLC10aHansen disease10aPrisoners10aActive case finding10aserological screening10aleprosy1 ade Lucena TS1 aGalani LC1 aBarbosa LD1 aDias GF1 aSantana JM1 aLima FR1 aFrade MAC00aHidden burden of leprosy in incarcerated populations in northeast Brazil: active case detection and serological assessment uhttps://link.springer.com/content/pdf/10.1007/s10096-026-05578-2.pdf a1 - 113 a

Background

Leprosy remains a public health challenge in Brazil’s Northeast, where prison overcrowding may facilitate transmission. Limited data exist on leprosy screening strategies in incarcerated populations.

Methods

This observational, cross-sectional study was conducted at Baldomero Cavalcante Male Penitentiary in Maceió, Alagoas, Brazil. A total of 915 inmates were approached using the Leprosy Suspicion Questionnaire (LSQ) as an active case-finding tool. Neurodermatological examinations were performed on 260 participants, and serological testing for anti-PGL-I (IgM) and anti-Mce1A antibodies (IgA, IgM, IgG) was conducted on 244 plasma samples using indirect ELISA.

Results

Of 842/915 returned questionnaires (92%), 240/842 (28.5%) were positive in the LSQ. Clinical examination revealed 8 new leprosy cases among 260/842 evaluated inmates with positive and negative LSQ, yielding an overall new case detection rate (NCDR) of 3.08%, which increased to 6.52% among symptomatic individuals. All diagnosed patients were classified as having multibacillary disease, with 100% presenting some grade of physical disability at diagnosis, and 75% LSQ were positive ( p  = 0.0249), while only 34.1% in the non-leprosy group. Anti-Mce1A IgM showed 37.7% seropositivity rate, and 19.9% for anti-PGL-I among clinically unaffected individuals. IgA (100%), IgM (37.5%), and IgG (25%) anti-Mce1A antibodies were positive in the leprosy group.

Conclusions

The LSQ may be effective as a screening tool. The study confirms significant underdiagnosis of leprosy in prison populations and highlights that anti-Mce1A serology showed higher positivity among diagnosed cases than anti-PGL-I, particularly for the detection of early-stage and neural forms of the disease. These findings support enhanced active surveillance strategies in high-risk populations to achieve leprosy elimination goals.

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