Visceral leishmaniasis in Brazil: trends and challenges

Abstract

The urbanization of visceral leishmaniasis in Brazil has been related to environmental changes, migration, interaction and spread of sylvatic reservoirs and infected dogs to areas with no transmission, and adaptation of the vector Lutzomyia longipalpis to the peridomiciliary environment. From 1980 to 2005, Brazil recorded 59,129 cases of visceral leishmaniasis, 82.5% of which in the Northeast region. Visceral leishmaniasis gradually spread to other regions of the country: in 1998 these other regions reported 15% of all cases, but by 2005 this proportion had increased to 44%. From 1998 to 2005, indigenous cases were reported in 1,904 different municipalities of the country (34.2%). Reservoir and vector control pose major challenges for disease control, since there is a need for better knowledge of vector behavior in urban areas, and control activities involve high operational costs. In recent years the Brazilian Ministry of Health has supported research on the laboratory diagnosis of infection and disease in humans and dogs, treatment of patients, evaluation of the effectiveness of control strategies, and development of new technologies that could contribute to the surveillance and control of visceral leishmaniasis in the country.

Profile and geographic distribution of reported cases of visceral leishmaniasis in Campo Grande, State of Mato Grosso do Sul, Brazil, from 2002 to 2009

“…The symptoms exhibited by patients in the present investigation have also been reported in other studies conducted in Brazil 21,[28][29][30] .…”

“…Death rates higher than those observed in the present study have been found in Natal, RN (9%) 34 and in the City of São Paulo (9.3%) 30 . Early diagnosis and treatment are required if morbidity and mortality from VL are to be reduced, as early-treated patients are clinically cured in 98% of cases, 34 while the fatality rate is near 95% in untreated cases 35 .…”

Transmission, reservoir hosts and control of zoonotic visceral leishmaniasis

“…Control of ZVL transmission is thus focused on vector control and, in some areas, culling of infected dogs ; there is currently no vaccine, and treatment of infected dogs is not usually curative (Baneth and Shaw, 2002). However, the rising incidence of ZVL in Brazil and elsewhere suggests that existing control measures have not been effective (Maia-Elkhoury et al 2008 ;Antoniou et al 2009). A number of reasons have been suggested to explain this, including operational and logistical difficulties, but also the potential role of non-sandfly transmission routes and additional reservoir hosts.…”

Diversity of sand flies in domiciliary environment of Santarém, state of Pará, Brazil: species composition and abundance patterns in rural and urban areas

“…Currently, risk estimates of leishmaniasis transmission are still very poor due to the lack of parameters based on vector presence, its abundance, and infestation level in a given habitat (Maia-Elkhoury et al 2008). However, the evaluation of species abundance patterns should allow inferences about some ecological aspects as local population size, rarity, and dominance of species, endemicity, and habitat specialization (Magurran 2004).…”