Spatial clustering and local risk of leprosy in São Paulo, Brazil

Abstract

BackgroundAlthough the detection rate is decreasing, the proportion of new cases with WHO grade 2 disability (G2D) is increasing, creating concern among policy makers and the Brazilian government. This study aimed to identify spatial clustering of leprosy and classify high-risk areas in a major leprosy cluster using the SatScan method.MethodsData were obtained including all leprosy cases diagnosed between January 2006 and December 2013. In addition to the clinical variable, information was also gathered regarding the G2D of the patient at diagnosis and after treatment. The Scan Spatial statistic test, developed by Kulldorff e Nagarwalla, was used to identify spatial clustering and to measure the local risk (Relative Risk—RR) of leprosy. Maps considering these risks and their confidence intervals were constructed.ResultsA total of 434 cases were identified, including 188 (43.31%) borderline leprosy and 101 (23.28%) lepromatous leprosy cases. There was a predominance of males, with ages ranging from 15 to 59 years, and 51 patients (11.75%) presented G2D. Two significant spatial clusters and three significant spatial-temporal clusters were also observed. The main spatial cluster (p = 0.000) contained 90 census tracts, a population of approximately 58,438 inhabitants, detection rate of 22.6 cases per 100,000 people and RR of approximately 3.41 (95%CI = 2.721–4.267). Regarding the spatial-temporal clusters, two clusters were observed, with RR ranging between 24.35 (95%CI = 11.133–52.984) and 15.24 (95%CI = 10.114–22.919).ConclusionThese findings could contribute to improvements in policies and programming, aiming for the eradication of leprosy in Brazil. The Spatial Scan statistic test was found to be an interesting resource for health managers and healthcare professionals to map the vulnerability of areas in terms of leprosy transmission risk and areas of underreporting.

Leprosy in the North and Northeast regions of Brazil: an integrated spatiotemporal approach

“…The study reinforces the idea that leprosy persists in municipalities with poor social indicators, increasing the risk for occurrence of the disease and leading to greater disease severity as well as to disability and death due to complications associated with the disease . Most of the affected individuals are between 15 and 59 years of age (economically active population), similar to the observation made in a study conducted in the municipalities of Foz do Iguaçu and São Paulo, in which there was a predominance of multibacillary (MB) cases . A study conducted in the city of Juazeiro do Norte found risk factors in the population over 45 years of age and MB cases .…”

“…The greater incidence of NCs among males in the general population and the greater incidence of G2D in the male population in this study reinforce the idea that sex is a determinant of risk to leprosy. Similar results were obtained in studies of cases diagnosed from 2001 to 2014 in Brazil and in the state of Bahia and may indicate late diagnosis in males who visit the health services only after the onset of physical disability . The lack of trends in G2D reflects the low access of primary health care (PHC) by men, the feminization of health services, problems associated with incompatible schedules and excessive demands and other factors .…”

Panniculitis by leprosy: Case report of a diagnostic challenge

“…It presents with lesions with marked erythema, infiltration, light skin, orange peel type, and overlapping areas of papules, nodules and tumors. The borderline form is characterized by immunological instability and, within the possible spectrum of cutaneous lesions, we can observe from macules, erythematous, in light skin, to hypochromic, in dark skin, which sometimes assumes coppery tonality, being also common the presence of papules, nodules, tumors and plaques [1,7].…”

“…Leprosy, or Hansen's disease, is a chronic infectious-contagious disorder that affects skin and peripheral nervous system [1]. It is characterized as a high infectiousness and low pathogenicity illness, which advances slowly but can potentially generate severe disabilities and stigma.…”

“…Both nasal and skin secretions from these people can shed the bacterium into the environment. Leprosy presents an extensive variety of clinical, histological and immunological appearances, which are determined by the natural resistance of the host to invasion of M. leprae [1,2].…”