Visceral leishmaniasis in Rio de Janeiro, Brazil: eco-epidemiological aspects and control

Abstract

From 1977 (index case) to 2006, 87 cases of visceral leishmaniasis were confirmed in the municipality of Rio de Janeiro, Brazil, in periurban areas on the continental and coastal slopes of the Pedra Branca massif and the continental slopes of the Gericinó massif. The majority (65.5%) of the patients were more than five years old, predominantly males (61.5%), but without any difference between the sexes below the age of 14 years. The overall fatality rate was 10.4%. Two cases of visceral leishmaniasis/human immunodeficiency virus coinfection were detected. Leishmania chagasi was isolated from human and canine cases. The associations between the presence of phlebotomines and human and canine migrations, disorderly occupation involving degradation of environmental preservation areas and poor socioeconomic conditions may have created a favorable setting for the establishment and propagation of the disease. Close epidemiological surveillance associated with traditional control measures and others (active case researches, land clearing and health education), reduced the incidence of human cases from 2.8 per 100,000 inhabitants in 1981 to less than 0.01 per 100,000 since 1997. The canine infection rates decreased from 4.6% in 1984 to 1.6% in 2008. Lutzomyia longipalpis was not detected in some locations where human and canine cases occurred. In the years 2007 and 2008, no new human cases were reported, but there is a persistent and worrisome residual canine seroprevalence.

Canine visceral leishmaniasis: seroprevalence and risk factors in Cuiabá, Mato Grosso, Brazil

“…This rate of prevalence was higher than data reported in other studies accomplished in the same municipality FONTES, 2007;ALMEIDA et al, 2009), and the reason may be that there were human cases of the disease reported in the same neighborhood. According to Marzochi et al (2009) the canine disease tends to precede human cases, which are kept high in endemic areas. The presence of about 22% of leishmaniasis seropositive dogs is an important datum for the epidemiological surveillance of Cuiabá.…”

“…Environments degraded by disordered occupation have been described as another risk factor that facilitates the occurrence of CVL (MISSAWA;BORBA, 2009;MARZOCHI et al, 2009). The highest indexes of IFAT seropositive animals were observed in the neighborhoods located in rural environments and in the Jardim União neighborhood, which presented severe natural ecotope changes and where human cases of the disease were reported (personal communication).…”

“…The chronic disease is the most severe clinical form of leishmaniasis and a serious problem for Brazilian public health, mainly due to the high prevalence and increased number of cases in humans and dogs in urban and suburban areas of large cities (ARIAS et al, 1996;MORENO et al, 2005;MARZOCHI et al, 2009). CVL urbanization has been associated to migration processes linked to the deterioration of social and economic conditions of the population (ANTONIALLI et al, 2007;HARHAY et al, 2011).…”

How effective is dog culling in controlling zoonotic visceral leishmaniasis? a critical evaluation of the science, politics and ethics behind this public health policy

“…However, despite the continuity of the program, but with the help of pyrethroids instead of DDT, infection among dogs is reemerging 44 . Another successful experience in Brazil occurred in a small outbreak in Rio de Janeiro, between 1979 and 1985 45 , where they used organochlorines, followed by pyrethroids. However, there was no interruption of the transmission.…”

First autochthonous case of canine visceral leishmaniasis in Volta Redonda, Rio de Janeiro, Brazil

“…In 2011, another CVL case was described in Cachoeiras de Macacu, Rio de Janeiro (SILVA et al, 2011). Although the case was not autochthonous, it may have contributed to maintain the cycle in the region, since the presence of susceptible sand flies associated with human and canine migration, disorganized land occupation leading to the environmental degradation of protected areas, and low socioeconomic conditions may cause an epidemic (MARZOCHI et al, 2009). …”