Persisting leprosy transmission despite increased control measures in an endemic cluster in Brazil: the unfinished...

To provide an evidence base for improvement of leprosy control in Brazil's high transmission areas.

We obtained data from municipalities in a major disease cluster from databases for notifiable diseases of four states (Maranhão, Parâ, Tocantins, Piauí), including notifications from 2001 to 2009. Indicators for monitoring and evaluation of leprosy according to the World Health Organization were evaluated with emphasis on the rates of new cases presenting grade-2 disabilities and among children < 15 years of age, indicating late diagnosis and active transmission, respectively.

A total of 82,463 leprosy cases were detected in the area (mean annual case detection rate: 95.9/100,000; RR = 4.56 as compared to the rest of Brazil; 95% CI: 4.45-4.66, P < 0.0001). There was a steady decrease of detection rates in the study period, from 100.8 to 75.6/100,000 inhabitants. In children <15 years of age, 9,009 cases of leprosy were detected (28.40/100,000), significantly more than in the rest of Brazil (RR = 5.80; 95% CI: 5.39-6.25, P < 0.0001). New cases with grade-2 disabilities/100,000 population maintained a stable trend at a high level (4.43 cluster vs. 1.28 rest of country; RR = 3.46; 95% CI: 3.11-3.84, P < 0.0001), whereas the proportion of new cases with grade-2 was slightly lower than the country's average (5.51% vs. 6.75%; RR = 0.84; 95% CI: 0.81-0.86, P < 0.0001).

Despite recently improved leprosy control measures, there is still major active transmission and late diagnosis in the cluster. Further specific actions are needed to improve early case detection and prompt treatment with the aim to reduce disease burden in the population, considering social inequities.