Epidemiological profile of American tegumentary leishmaniasis in the municipality of Manhuaçu, state of Minas Gerais, Brazil

A serious public health problem, American Tegumentary Leishmaniasis (ATL) is a widely distributed anthropozoonosis caused by protozoa Leishmania spp. This study aimed to evaluate the profile of human cases of cutaneous leishmaniasis Americana in Manhuaçu, MG from 2010 through 2015. A descriptive, retrospective and ecological study of the confirmed cases of ATL was carried out based on age, sex, place of dwelling, type of entry (new diagnosis or recurrence), and clinical form of the disease as recorded in the Brazilian system of notifiable disease – Sistema de Informação de Agravos de Notificação (SINAN). The first quarter of the years higher witnessed the highest numbers of notifications. All 58 notifications corresponded to new diagnoses, most of which in the cutaneous form (95%), in males (76%), in inhabitants of the rural area (86%), and in people aged 20-59 years old (60%). Thus, the epidemiological profile of ATL in Manhuaçu indicates that males aged between 20 and 59 years old and living in rural areas are more likely to get infected. The epidemiological profile of ATL is an important step to promote adequate health surveillance and prevent the disease in the region.


Introduction
American Tegumentary Leishmaniasis (ATL) is a widely distributed zoonotic disease affecting people from several regions, such as the Americas, the Mediterranea, Central and West Asia, including the Middle East, which accounts for one-third of the cases reported (ALVAR et al., 2012). A serious public health problem, ATL is caused by protozoa Leishmania spp. and is characterised by severe skin and mucosal injury CUNHA, 2007;BRASIL, 2009;GOSCH et al., 2017).  (NAME et al., 2005). Additionally, there is a less frequent form of ATL is related to the absence of lesions, but with alteration of the lymphatic system in some individuals (MARZOCHI;MARZOCHI, 1994).
CL is characterized by a painless ulcerative or nodular lesion in commonly exposed areas of the skin. In Brazil, CL can be caused by different Leishmania spp., L. brasiliensis, L. amazonensis and L.
guyanensis (BRASIL, 2013), and its manifestations range of single or multiple cutaneous tegumentary lesions, internal mucosal lesions and glandular leishmaniasis (MARZOCHI; MARZOCHI, 1994). ML, which is mostly caused by L. brasiliensis, is often characterised by a destructive mucosal inflammation (BRASIL, 2013). When both CL and ML unfold concomitantly, their association is called MCL, which is characterised by multiple lesions through the body.
ATL, as one of the major zoonotic diseases in the Americas, has been reported from the South of the United States of America to the North of Argentina (SILVA et al., 2012). Due to the increased number of ATL cases worldwide, the WHO has considered it a major parasitic-infectious disease (NAME et al., 2005). However, ATL is a notifiable disease in only 32 out of the 88 countries where it is prevalent (NEVES, 2011).
In Brazil, leishmaniasis is a notifiable disease within the first 180 days upon diagnosis. All cases are recorded in the SINAN (Sistema de Informação de Agravos de Notificação), a federal agency for epidemiological surveillance that has been gradually implemented since 1993 (BRASIL, 2007). Leishmaniasis has been the second most reported vector-borne Additionally, the place of dwelling is associated with ATL, due to uncontrolled land occupation, deforestation, presence of the vector and the human presence near secondary forests or forest residues (BRASIL, 2013).
Notwithstanding, the ATL epidemiological profile in Brazil has been changing due to the recent climate and environmental changes (DE AGUIAR et al., 2014).
In the State of Minas Gerais (MG), leishmaniasis has been reported since 1940, with prevalence in rural and peri-urban areas (NASCIMENTO et al., 2013). However, there have been constant outbreaks in urban areas and in rainforest regions throughout the state (VALE and FURTADO, 2005). FERREIRA, 2014). The following variables were used to profile the disease in this study: age, sex, place of dwelling, type of entry during hospital admission (new diagnosis or recurrence), and clinical manifestations.
Additionally, the disease incidence per age group was calculated with a view to gaining a better understanding of its distribution in the period.

Results
A total of 58 cases of ATL were reported in Manhuaçu from 2010 through 2015, i.e., 9.67 cases per year on average ( Table 1). The highest numbers of diagnoses took place in the first quarter of the years.    In an analysis of notifications per age group, the highest incidence was found for those aged 40-59 (34%), followed by those aged 20-39 years old (26%) (Figure 1) Lima, Mol, Mol, Oliveira, Teixeira Epidemiological profile of American tegumentary… The incidence of ATL per 10.000 inhabitants was calculated for the period (Table 3) based on data provided by IBGE (2010). A higher incidence of ATL was found in individuals aged 40 to 59 years old (11.27 cases per 10.000 hab.), followed by those older than 60 years.

Discussion
A higher incidence of ATL was found in the first quarter of the years under scrutiny. This period coincides with the rainy season in the region, when the high temperature and humidity levels favour the reproduction of phlebotomine sandflies (NIKONAHAD et al., 2017;OVALLOS, 2011). Lemos and Lima (2005) reported that some sandflies species are specifically found during this time.
The data also showed that most infections occurred in the rural areas, where people are usually close to secondary vegetation and remaining forests, which also favours the disease transmission (BRASIL, 2013, MELO et al., 2017. Leishmaniasis is endemic in Brazil, and the close proximity of populations in the rural areas to the wildlife, especially mammals, makes it a broader reservoir for the parasite (PASSOS et al., 1993). Nevertheless, transmission can also be linked to domesticated animals or to people from urban areas who work in the field (TEMPONI et al., 2018).
The parasite-host relationship is a complex and multifactorial issue (BRASIL, 2017), and the diversity of reservoirs for Leishmania sp.
includes wild, domesticated and synanthropic animals, as well as canids, felids, marsupials, xenarthrans, chiropters, rodents, and equids. Further studies are necessary to fully understand the role of reservoirs in the transmission in Manhuaçu.
According to Basano and Camargo (2004), the ATL infection profile in the peri-urban areas is linked to places of 'old colonization', such as Manhuaçu. The low number of notifications in this particular area may indicate some inconsistency in the data provided by SINAN. It is possible that people from peri-urban areas were classified as being originally from rural areas. In contrast, Soares et al. (2014) reported that active transmission of leishmaniasis is linked to deforestation in the outskirts of urban areas. Therefore, the low occurrence in peri-urban areas may be justified by the classification of the place of dwelling wrong.
This study confirms the higher incidence of ATL in people aged 20 to 59 years, this result is similar to those found by Melo et al. (2017).