Visceral leishmaniasis (VL) is a disease caused by a protozoon belonging to the genus Leishmania, and it is transmitted through the bite of sand flies. Endemic regions have widened, and canine visceral leishmaniasis (CVL) occurs mainly in the Mediterranean region and South America. There is no consensus on the risk factors associated with CVL, as results differ between the studied regions and countries. This chapter describes the main aspects of epidemiology, immunology, clinical signs, diagnosis treatment, and control of canine visceral leishmaniasis with emphasis on Brazil.

Introduction: Visceral leishmaniasis has a broad worldwide distribution and constitutes a public health problem in the Northeast of Brazil. Located in this region is the state of Alagoas, where the disease is endemic in humans and where there has been a significant increase in the number of positive dogs. The objective of this study was to describe the temporal and spatial distribution of the cases of human VL in the state of Alagoas with the aim of identifying transmission risk areas in the period from 2007 to 2018. Methods: The data available in the National Disease Notification System (SINAN-NET) were used. The Bayesian incidence rate and the Moran's global index were calculated using the Terra View 4.2.2 program, and the maps were created using QGIS2.18.0. Results: From the 102 municipalities, 68.6% (n= 70) had at least one notified case of VL in the years of study. A total of 489 cases were registered, with an average of 40.7 cases per year and an incidence rate of 1.25/100,000 inhabitants. The highest number of confirmed cases (105) occurred in 2018. Male individuals and children between 1-4 years old were the most affected, and 64% of the cases were in rural areas. Spatial dependence was detected in all the intervals except for the first triennium, and clusters were formed in the west of the state. Conclusions: Alagoas presented an accentuated geographical expansion of VL, and it is necessary to prioritize areas and increase surveillance actions and epidemiological control.

Toxoplasmosis is a parasitic disease, which is prevalent across the world and has a strong environmental component in its transmission chain. The present study determined the seroprevalence and factors related to Toxoplasma gondii infection among free-range chickens from an Atlantic Forest area in Northeastern Brazil. A total of 550 free-range chickens were tested for T. gondii antibodies usingthe indirect fluorescent antibody test (IFAT, cut-off point 1:16), and 269 (48.9%; 95% CI = 44.7-53.1%) were positive. Among the 61 properties 57 (93.4%) had at least one seropositive animal. The robust Poisson regression model showed that the variables/categories associated with the seroprevalence of T. gondii were: region of origin of the animals/urban area (prevalence ratio [PR] = 2.346; P<0.001), management system/use of cages (PR = 1.591; P = 0.019), presence of rodents/yes (PR = 1.295; P = 0.035), and the type of food/use of food scraps (PR = 1.603; P = 0.009). The high prevalence found suggest that this scenario demands careful management, mainly regarding the use of scraps of undercooked or raw food, adequate environmental hygiene and frequent rodentcontrol.

Visceral leishmaniasis (VL) is a zoonosis with a worldwide distribution that has a major impact on public health. The aim of this study was to verify the prevalence of canine infection by Leishmania infantum, the factors associated with the infection and its spatial distribution in the municipality of Mãe D’Água, in the Sertão region of Paraíba State, Northeast Brazil. Blood samples were collected from 150 dogs for diagnosis by the DPP®, ELISA-S7®, ELISA-EIE® and qPCR assays. The prevalence was calculated considering the positivity in at least two tests. SaTScan® was used for spatial analysis. The prevalence of canine infection with Leishmania was 18.6% (28/150), with the rural area being identified as a risk factor (Odds Ratio (OR) = 2.93). The permanence of the dog loose during the night (OR = 0.33) and deworming (OR = 0.30) were identified as protective factors. A risk cluster was formed in the northern region of the urban area. Mãe D’Água showed a pattern of active transmission in the rural area, but VL control measures also need to be carried out in the urban area to prevent human cases and the spread of the disease in the risk zone.