Are backyard characteristics relevant factors for the occurrence of human visceral leishmaniasis in Central-Western Brazil?

BACKGROUND: This retrospective case-control study aimed to investigate the factors associated with the occurrence of human visceral leishmaniasis (VL) in the municipality of Rondonópolis, which is a highly endemic area for VL in Central-Western Brazil. METHODS: All VL cases reported in Rondonópolis from 2011 to 2016 were included. For each case, two neighborhood- and age-matched controls with the absence of past and present history of VL and negative rk39-based immunochromatographic test, were recruited. Data were retrospectively collected through interviews that assessed socioeconomic aspects, housing features, backyard characteristics, presence of animals and daily habits. A multivariate conditional logistic regression analysis was used to identify factors associated with human VL. RESULTS: During the study period, 81 VL cases were reported in Rondonópolis, of which 37 (45.7%) were included in this study. Seventy controls were also included. The variables associated with VL occurrence were the outdoor location of a bathroom and/or kitchen separated from the rest of the house (OR 7.8; 95% CI 2.1 to 29.5), the presence of a vegetable garden (OR 5.3; 95% CI 1.3 to 21.2) and the presence of decaying fruits (OR 10.7; 95% CI 2.0 to 52.1) in the backyard. CONCLUSIONS: Our findings suggest an association between backyard characteristics and VL. This may be useful in guiding preventive and control measures against zoonotic VL worldwide.

Where, when, and how the diagnosis of human visceral leishmaniasis is defined: answers from the Brazilian control program.

BACKGROUND: Timely diagnosis is recommended by the Brazilian Visceral Leishmaniasis (VL) Surveillance and Control Program to reduce case fatality. Attempts at assessing this topic in Brazil are scarce. OBJECTIVE: This study aimed to describe where, when, and how the diagnosis of VL has been performed in a Brazilian endemic setting. METHODS: Data of all autochthonous cases confirmed between 2011 and 2016 (N = 81) were recorded. The care-seeking itinerary until the confirmation of VL diagnosis was assessed among 57 patients. FINDINGS: The majority of VL cases (79.1%) were reported by referral hospitals. The patients mainly sought primary health care centres at the onset of symptoms. However, they had to visit seven health services on average to achieve a confirmed diagnosis. The time from the onset of symptoms to the diagnosis of VL (TD) ranged from 1-212 (median, 25) days. The TD was longer among adult patients. There was a direct correlation between the patient's age and TD (r = 0.22; p = 0.047) and a higher occurrence of deaths due to the disease among older patients (p = 0.002). Almost all the patients (98.9%) underwent laboratory investigation, and the VL diagnosis was mainly confirmed based on clinical-laboratory criteria (92.6%). Positive results for the indirect fluorescence antibody test (22.7%) and parasitological examination plus rk39-based immunochromatographic tests (21.3%) were commonly employed. MAIN CONCLUSIONS: VL diagnosis was predominantly conducted in hospitals with a long TD and wide application of serology. These findings may support measures focused on early diagnosis, including a greater involvement of the primary health care system.

Visceral leishmaniasis in a Brazilian endemic area: an overview of occurrence, HIV coinfection and lethality.

The Brazilian municipality of Rondonópolis, Mato Grosso State, represents an important visceral leishmaniasis (VL) endemic area. This study described epidemiological and clinical aspects of the occurrence, VL/HIV coinfection and lethality related to VL in Rondonópolis. Data from autochthonous cases reported between 2011 and 2016 were obtained from official information systems. During this period, 81 autochthonous cases were reported, with decreasing incidence through 2016. Contrastingly, the lethality rate was 8.6% overall, but varied widely, reaching a peak (20%) in 2016. Almost 10% of patients had VL/HIVcoinfection. The occurrence of VL prevailed among men (56.8%), brown-skinned (49.4%), urban residents (92.6%), aged 0-4 years (33.3%). Housewives or retired (29.6%) were the most affected occupational groups. Lower age was the main difference among the total VL cases and those who were coinfected or died. Clinically, fever, weakness and splenomegaly were more frequent among all VL cases and VL/HIV coinfected individuals. Bacterial infections (p=0.001) and bleeding (p<0.001) were associated with death due to VL. Pentavalent antimonial and liposomal amphotericin B were the first choices for treatment among all VL cases (71.6%) and those who died (71.4%), respectively. VL/HIV patients were equally treated with both drugs. These findings may support control measures and demonstrate the need for further investigations.