Divergent profile of emerging cutaneous leishmaniasis in subtropical Brazil: new endemic areas in the southern frontier

Abstract

Background: Although known to be highly endemic in the Amazon regions of Brazil, the presence of cutaneous leishmaniasis (CL) in the subtropical southern part of the country has largely been ignored. This study was conducted to demonstrate CL is emerging in the Brazilian state of Santa Catarina, as well as to characterize the epidemiological profile and Leishmania species involved.

Methodology/principal findings: For this cross-sectional study, data from all CL cases from Santa Catarina, Brazil, reported to the Brazilian National Notifiable Diseases Information System from 2001 to 2009 were investigated. Amplification of the kDNA minicircle conserved region followed by restriction fragment length polymorphism (PCR-RFLP) was conducted to screen for Leishmania species present in patient biopsy. Overall, 542 CL cases were reported, with majority resulting from autochthonous transmission (n = 401, 73.99%) and occurring in urban zones (n = 422, 77.86%). Age, gender, zone of residence, origin of case, clinical form and case outcome were found to differ significantly by region. Imported cases were over seven times more likely to relapse (95% CI 2.56-21.09). Mapping of cases revealed new endemic areas in northeastern Santa Catarina with two species present. With the exception of three L. (Leishmania) amazonensis cases (1.20%), majority of PCR positive samples were found to be L. (Viannia) braziliensis (n = 248, 98.80%).

Conclusions/significance: CL is now endemic in the state of Santa Catarina, Brazil, with case profiles varying significantly by region. L. (V.) braziliensis has been identified as the predominant species in the region.

Figure 1. Comparison of maps demonstrating cutaneous leishmaniasis case origin by municipality between the time periods of 2001–2004 and 2005–2009.

Figure 2. Map of cutaneous leishmaniasis cases by zone of residence (urban/peri-urban/rural), Santa Catarina, Brazil (n = 452, 2001–2009).

Figure 3. Seasonal distribution of cutaneous leishmaniasis in Santa Catarina, Brazil, by region; NE = Northeastern region, SW = Southern and western regions (n = 452, 2001–2009).

Figure 4. Molecular characterization of Leishmania species present in biopsy sample.

(A) PCR amplification products of the Leishmania kDNA minicircle conserved region from cutaneous leishmaniasis cases in Santa Catarina, Brazil, stained with ethidium bromide; Restriction fragment length polymorphism (RFLP) of the amplified the kDNA minicircle conserved region digested with restriction enzymes HaeIII (B) and AvaI (C), and analyzed by electrophoresis in 10% polyacrylamide gels with silver staining; Lane 1–2 = L. (V.) braziliensis cases from the northeastern region; Lane 3–4 = L. (V.) braziliensis cases from the southern and western regions, Lane 5–6 = L. (L.) amazonensis cases, Lane 7 = reference strain L. (V.) braziliensis (MHOM/BR/75/M-2904), Lane 8 = reference strain L. (L.) amazonensis (IFLA/BR/67/PH8), NC = negative control, MW = molecular weight.