As the study showing the protozoan disease visceral leishmaniasis (VL) has recently expanded to places where it had not previously been reported and has expanded its geographic distribution within countries where it was already endemic. The study describing three dispersion routes that have moved Leishmania infantum into and through central-Southern Brazil, helping shed light on the overall mechanisms of VL dispersal. Leishmania (Leishmania) infantum is the zoonotic agent of visceral leishmaniasis (VL), a disease with a global distribution.
But human Visceral Leishmaniasis (hVL) is a widely distributing neglected disease causing by the protozoans Leishmania (Leishmania) infantum in Asia, Africa, Europe and Americas, and L. (L.) donovani in Asia and Africa. Currently, 1.69 billion people are estimating to be living in VL transmission areas worldwide and 90% of VL cases occurred in six countries; including Brazil. Between 1920 and 1980, VL was restricting to rural areas in Northeast Brazil; however the disease then spread to urban areas in other regions of the country.
The protozoan disease
The dispersal of the protozoan is poorly understanding, and in 2012; the parasite was reporting in the western region (Foz do Iguaçu) of Paraná state, far from the epidemic regions. These parasites use the domestic dog as a reservoir, in which it causingcanine Visceral Leishmaniasis (cVL), and Phlebotominae sand fly species of Phlebotomus and Lutzomyia longipalpis as vectors in the Old and New World, respectively; although other phlebotominae species have been hypothesized as secondary vectors in the latter region.
The transmission scenario of VL has been undergoing changes worldwide; with the biologic cycle invading urbanized areas and dispersing the parasites into other previously free areas. The epidemiological cycle in Brazil has dispersing from the Northeast to other regions of the country. The epidemiological cycle in Brazil has dispersing from the Northeast to other regions of the country.
Development of plans
But the researchers describe three dispersion routes that have likely carried VL into central-Southern Brazil dispersion from Bolivia via the Bolivia-Brazil gas pipeline from 1998 to 2005, dispersion from Paraguay after 2012, and emergence of a new cluster in western Santa Catarina State in 2013 and its dispersion to southern Paraná State. The routes help highlight risk factors for the dispersion of L. infantum; including the lack of joint policies with countries bordering Brazil.
However, understanding how VL has dispersed is vital to the development of control measures; for this disease and to avoid future dispersion events; but the study results highlight the need for the development of plans; that efficiently avoid the dispersion of VL in the central-southern Brazil that includes monitoring of this diseases; and joint policies with countries bordering this Brazilian region. But hypotheses regarding possible entring of Leishmania infantum; into the area of the triple border are presenting and discussing. Understanding how VL has dispersing is vital; to the development of control measures for this disease and to avoid future dispersion events.