Vaccination coverage is decreasing worldwide, favoring the potential reemergence of vaccine-preventable diseases. In this study, we performed a longitudinal characterization of vaccination coverage in Brazil and compared the profiles between the distinct regions in the country to test whether there has been a substantial change over the last 5 years. De-identified publicly available data were retrieved from the repository of the Brazilian Ministry of Health, comprising detailed information on vaccination coverage in all age groups between 1994 and 2019. The vaccination coverage for the whole country and for each Brazilian region, by year, was examined, and a time-series pattern analysis was performed. A significant decrease in overall vaccination coverage across the country regions was observed between 2017 and 2019, especially in childhood immunization. A reduction in BCG, hepatitis B, influenza, and rotavirus vaccine coverage was observed. Conversely, vaccines against measles, mumps, rubella, varicella, and meningococcus showed an increase in coverage. Region-specific changes in vaccination patterns within the study period were observed. A substantial reduction in vaccination coverage was detected in Brazil, a country already highly susceptible to the emergence of epidemic infectious diseases. Continuing evaluation of the immunization program actions may help to improve vaccination coverage and prevent new epidemics.

Significance: Sand fly females suck blood from vertebrate animals, including humans, and thereby transmit Leishmania parasites and arboviruses. In addition, both sand fly sexes consume plant-derived sugar meals. Therefore, the structure of plant communities can influence the transmission dynamics of sand fly-borne diseases. Our findings demonstrate that, in proportion to their abundance, Cannabis sativa plants were consumed by sand flies much more frequently than expected (i.e., C. sativa is probably highly attractive to sand flies). We discuss the conceivable influence of C. sativa on the transmission of Leishmania and its potential utility for sand fly control.

Visceral leishmaniasis (VL) is a zoonosis caused by the protozoan Leishmania infantum and in Brazil is transmitted mainly by the bite of Lutzomuyia longipalpis sand flies. Data about the presence, distribution, natural infection rate, seasonal and monthly dynamics of the vector population are important for optimizing the measures to control VL in endemic areas. This study aimed to identify sand fly fauna in an endemic area for VL to detect the prevalence of L. infantum infection in the Lu. longipalpis population and to elucidate the influence of bioclimatic factors on the monthly fluctuations of this vector. HP light traps were monthly set in the intradomicile and peridomicile of residences located in the central and beachfront areas of Camaçari, a VL endemic area. The sand fly collection was conducted in two periods: i) period 1—between December 2011 and November 2012 and ii) period 2—August 2014 and July 2015. Sand fly species were identified and detection of L. infantum infection by qPCR was performed in pools of female Lu. longipalpis. For the first time, the parasite load of positive pools was correlated with the number of Lu. longipalpis captured per month in both periods. Correlation analyses between the monthly fluctuation of the sand fly population and bioclimatic indices of the municipality in both collection periods were also performed. In both evaluated periods, more than 98% of the collected sand flies were Lu. longipalpis, confirming the predominance of this species in the region. It was captured mostly in the beachfront area in all months evaluated (99%). For the period 1, Leishmania DNA was detected in 81% of tested pools representing a minimal infection rate of 9.6%. In the period 2, 40% of the pools were positive with a minimal infection rate of 10.2%. Infected sand flies were only detected in the beachfront area in both periods. The parasite load was low and did not vary in the evaluated months despite the number of collected sand flies. No correlation was observed for climatic factors in both areas of Camaçari. These findings emphasize the high risk of Leishmania transmission in Camaçari regardless of the season and that other factors, aside from bioclimatic elements, are influencing the sand fly population monthly fluctuation. Visceral leishmaniasis (VL) is a parasitic disease transmited by a sand fly vector. VL is an important public health issue in Brazil occurring in all its regions with increasing incidences in big urban centers. In the State of Bahia, VL has spread to new hotspots in the last decade reaching the coastal area to the north of Bahia State capital, Salvador. This region underwent several environmental changes due to a rapid urbanization and construction of touristic and vacation complexes. Our investigation represents the first entomological study conducted in Camaçari. We evaluated the prevalence of the parasite infection in the sand fly population in two periods, between December 2011 and November 2012 and between August 2014 and July 2015. Our findings indicate that VL transmission occurs during the whole year and support the idea that the vector is not sensible to bioclimatic variations in Camaçari. Additionally, the maintenance of the parasite infection in the vector regardless of the season, indicates that the disease is well stablished in Camaçari, especially in the coastal area. These results emphasizes the urgency for a rigorous entomological and epidemiological survey aiming to guide control strategies to decrease VL cases.

Background: Reports have shown correlations between the immune response to vector saliva and Leishmaniasis outcome. We followed dogs in an endemic area for two years characterizing resistance or susceptibility to canine visceral leishmaniasis (CVL) according to Leishmania infantum diagnosis and clinical development criteria. Then, we aimed to identify a biosignature based on parasite load, serum biological mediators’ interactions, and vector exposure intensity associated with CVL resistance and susceptibility. Methodology/Principal findings: A prospective two-year study was conducted in an area endemic for CVL. Dogs were evaluated at 6-month intervals to determine infection, clinical manifestations, immune profile, and sandfly exposure. CVL resistance or susceptibility was determined upon the conclusion of the study. After two years, 78% of the dogs were infected with L. infantum (53% susceptible and 47% resistant to CVL). Susceptible dogs presented higher splenic parasite load as well as persistence of the parasite during the follow-up, compared to resistant ones. Susceptible dogs also displayed a higher number of correlations among the investigated biological mediators, before and after infection diagnosis. At baseline, anti-saliva antibodies, indicative of exposure to the vector, were detected in 62% of the dogs, reaching 100% in one year. Higher sandfly exposure increased the risk of susceptibility to CVL by 1.6 times (CI: 1.11–2.41). We identified a discriminatory biosignature between the resistant and susceptible dogs assessing splenic parasite load, interaction of biological mediators, PGE₂ serum levels and intensity of exposure to sandfly. All these parameters were elevated in susceptible dogs compared to resistant animals. Conclusions/Significance: The biosignature identified in our study reinforces the idea that CVL is a complex multifactorial disease that is affected by a set of factors which are correlated and, for a better understanding of CVL, should not be evaluated in an isolated way.