Secular trends of new leprosy cases diagnosed in Brazil during 1987-2006.

OBJECTIVE: To analyze trends in occurrence of new leprosy cases in Brazil in the light of changes in public health policy during the period 1987-2006. MATERIAL AND METHODS: Study of secular trends in New case detection rate (NCDR), viz. for leprosy in Brazil between 1987 and 2006. A linear trend was used to analyze separately the detection rate during the two decades 1987-1996 and 1997-2006. The cut-off point was the year with the peak detection rate in 1997. To analyze the potential increase in accessibility to diagnosis and treatment, a comparison was made between the proportion of cases diagnosed within the health services and municipalities over a 20-year period, split into four 5-year intervals. RESULTS: The variation of the NCDR between 1987 and 2006 more than doubled between 1987 and 1997, decreased from 1997 to 2000, increased up to 2003 and then dropped considerably between 2004 and 2006. The number of facilities providing health services for the 5-year periods showed a marked increase-more than doubling between the second and third and between the third and fourth periods. The number and therapeutic services are indications that Brazil is perhaps making considerable progress towards eliminating leprosy as a public health problem.

Transmission of Hansen's disease and unscreened household contacts.

INTRODUCTION: Leprosy household contact investigation has been recommended as an epidemiological surveillance strategy for more than 50 years. OBJECTIVE: The purpose of this study was to estimate the yield that could be achieved in case detection if four contacts could be examined for every case found. METHODS: For the estimation of the number of cases not detected (lost) and yield per contact investigation in Mato Grosso, the incidence rates and yield calculations from a cohort study conducted in Rio de Janeiro by Matos et al (1999) were applied to data from the state of Mato Grosso. Also, to identify high-risk groups for leprosy, a cross-sectional study was conducted in which leprosy cases found as a result of a contact investigation were compared with index cases detected by other means. RESULTS: The lost cases among household contacts were at least 4 per every 10 new cases detected. This is the result of insufficient contact investigations--it being 0.8 instead of 4 contact investigations per each case as recommended by the Brazilian Ministry of Health. Up to 60% of the incidence of leprosy could be explained by the high number of lost cases among household contacts not examined. Women and children are more likely to be contacts. CONCLUSION: The lost cases due to insufficient contact investigation represent lost opportunities in early detection and treatment, thus losing the opportunity to reduce leprosy transmission.