Misdiagnosis of leprosy in Brazil in the period 2003 - 2017: spatial pattern and associated factors.

Background: Leprosy causes a range of symptoms, and most diagnoses are established based on the clinical picture. Therefore, false negative and positive diagnoses are relatively common. We analyzed the spatial pattern of leprosy misdiagnosis and associated factors in Brazil.

Method: Exploratory analyses of Kernel density of the new case detection rate (NCDR) and proportion of misdiagnosis in Brazil, 2003-2017. Factors associated with misdiagnosis were identified by logistic regression at the 5% significance level.

Result: A total of 574,181 new leprosy cases were recorded in Brazil within the study period, of which 7,477 (1.3%) were misdiagnoses. No spatial correlation was observed between the proportion of misdiagnoses and the NCDR. The likelihood of misdiagnosis was elevated for females [OR: 1.58 (1.51-1.66)], children [OR: 1.49 (1.36-1.64)]; paucibacillary [OR: 1.08 (1.02-1.13)], indeterminate clinical forms [OR: 2.37 (2.15-2.62)], for cases diagnosed in the frame of mass screenings [OR: 3.36 (3.09- 3.73)] and contact examination [OR: 2.30 (2.13-2.49)] and for cases with affected nerves but no skin lesions [OR: 2.47 (2.19-2.77)] when compared with those presenting both skin lesion and affected nerves.

Conclusion: Misdiagnosis of leprosy is not correlated with the endemicity level in Brazil but rather with personal, diagnosis-related and disease characteristics.