Yellow Fever (YF) is a severe disease caused by Yellow Fever Virus (YFV), endemic in some parts of Africa and America. In Brazil, YFV is maintained by a sylvatic transmission cycle involving non-human primates (NHP) and forest canopy-dwelling mosquitoes, mainly Haemagogus-spp and Sabethes-spp. Beginning in 2016, Brazil faced one of the largest Yellow Fever (YF) outbreaks in recent decades, mainly in the southeastern region. In São Paulo city, YFV was detected in October 2017 in Aloutta monkeys in an Atlantic Forest area. From 542 NHP, a total of 162 NHP were YFV positive by RT-qPCR and/or immunohistochemistry, being 22 Callithrix-spp. most from urban areas. Entomological collections executed did not detect the presence of strictly sylvatic mosquitoes. Three mosquito pools were positive for YFV, 2 Haemagogus leucocelaenus, and 1 Aedes scapularis. In summary, YFV in the São Paulo urban area was detected mainly in resident marmosets, and synanthropic mosquitoes were likely involved in viral transmission.

three sylvatic yellow fever outbreaks occurred in the state between 2000 and 2010, two of them in a transition area and the other in an area considered to be unaffected; vaccination and maintaining immunization coverage are necessary for preventing the disease.

We investigated the sylvatic yellow fever (SYF) diffusion process in São Paulo (SP) between 2016 and 2019. We developed an ecological study of SYF through autochthonous human cases and epizootics of non-human primates (NHPs) that were spatiotemporally evaluated. We used kriging to obtain maps with isochrones representative of the evolution of the outbreak and characterized its diffusion pattern. We confirmed 648 human cases of SYF in SP, with 230 deaths and 843 NHP epizootics. Two outbreak waves were identified: one from West to East (2016 and 2017), and another from the Campinas region to the municipalities bordering Rio de Janeiro, Minas Gerais, and Paraná and those of the SP coast (2017–2019). The SYF outbreak diffusion process was by contagion. The disease did not exhibit jumps between municipalities, indicating that the mosquitoes and NHPs were responsible for transmitting the virus. There were not enough vaccines to meet the population at risk; hence, health authorities used information about the epizootic occurrence in NHPs in forest fragments to identify priority populations for vaccination.

1. Landscape connectivity is important for a wide range of ecological processes, including to disease spread, once it describes the degree to which landscapes facilitate or impede vector and hosts dispersion. Understanding connectivity is extremely important to identify where pathogens can move, and at what speed, allowing the organization of vaccination campaigns or other preventive measures.2. To better understand the effects of landscape connectivity on yellow fever virus (YFV) dispersion in Brazil, we used a network approach and modelled the movement of non-human primates' cases, the so-called epizootic events, over time. The networks consider each epizootic event as a node and the dispersion between nodes as links. Those links were established considering, respectively, the date of each epizootic event, the distance among the nodes and the permeability of the landscape between each pair of nodes.3. Our results demonstrated that on average YFV dispersed 1.42 km/day, with the largest movement being 6.9 km/day. Dispersions were longer in summer (1.2 km/day) than in winter (0.22 km/day). Most dispersal movements occurred up to 1 km/day (71%) and within a week after the arrival of the virus in the source node (73%), except in winter, where dispersions occurred within a period of up to 20 days. The best model indicates that YFV disperses mainly through roads adjacent to forest areas, and along forest edges (within a range of 100 m) in interface with agricultural areas, water and forestry areas. Core areas of urban, agricultural and forest regions were important barriers for virus movement.

Objective: to characterize cases of congenital syndrome associated with Zika virus infection (CZS) and other infectious etiologies, resident in the state of São Paulo, Brazil, from October 30, 2015, to June 30, 2017. Methods: this was a descriptive study of suspected cases of CZS and other infectious etiologies notified on the Public Health Events Registry. Results: 960 cases were investigated up to epidemiological week 26/2017, and 146 were confirmed for congenital infection; of these, 59 (40.4%) were confirmed for congenital infection without etiological identification and 87 (59.6%) with laboratory confirmation, of which 55 were congenital syndrome associated with Zika virus and 32 were congenital syndrome associated with other infectious agents. Conclusion: this study enabled the detection of 23.9% CZS cases among suspected cases of infectious etiology.