Vaccine hesitancy in Argentina: Validation of WHO scale for parents.

BACKGROUND: The WHO SAGE Working Group on Vaccine Hesitancy developed the Vaccine Hesitancy Scale (VHS) to identify and compare hesitancy in different global settings. The objectives of the study were to describe and analyze vaccine hesitancy and to validate the VHS in a group of parents in Buenos Aires city, Argentina. METHODS: A cross-sectional survey was conducted in parents of 1-3 and 12-15 year-old children at three health centres in Buenos Aires City, between June 2018 and May 2019. Sociodemographic data were collected together with history of refusal and/or delay in children's vaccination (defined as hesitancy). The 10-item VHS using 5-point Likert-scale (higher scores indicating lower hesitancy) was administered and children's immunization record cards were verified. Link between hesitancy and socio-demographic variables, and hesitancy and vaccination status was analyzed for five specific vaccines. Cronbach's α was used to determine internal consistency reliability and factor analysis to confirm survey subdomains. Simple and multiple regression analysis was used to examine associations between VHS scores and hesitancy, and VHS scores and vaccination status. RESULTS: Six hundred parents were surveyed and 469 immunization cards verified; 11.5% (n = 69) parents were hesitant. High maternal educational level showed significant association with hesitancy (OR 2.66 95% CI: 1.20-5.9) in the adjusted model. Hesitancy was significantly associated with incomplete MMR vaccination in children (OR 4.43 95% CI: 1.08-8.20) and HPV vaccination in adolescents (OR 3.75 95% CI: 1.54-9.12). Cronbach's α was 0.66 and factor analysis identified three underlying constructs: "Benefits", "Harms" and "Confidence in healthcare system". High scores in VHS were associated with lack of hesitancy (OR 1.2 95% CI: 1.13-1.27) and complete vaccination status (OR 1.07 95% CI: 1.02-1.12). CONCLUSIONS: Hesitancy was associated with high maternal educational level, and incomplete MMR and HPV immunization status in children and adolescents. VHS was a reliable and valid tool in this population.

Urban Chagas disease in children and women in primary care centres in Buenos Aires, Argentina

The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruziinfection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate.

Urban Chagas disease in children and women in primary care centres in Buenos Aires, Argentina.

The primary objective of this study was to estimate the prevalence of this disease in women of childbearing age and children treated at health centres in underserviced areas of the city of Buenos Aires. Demographic and Chagas disease status data were collected. Samples for Chagas disease serology were obtained on filter paper and the reactive results were confirmed with conventional samples. A total of 1,786 subjects were screened and 73 positive screening results were obtained: 17 were from children and 56 were from women. The Trypanosoma cruzi infection risk was greater in those individuals who had relatives with Chagas disease, who remember seeing kissing bugs, who were of Bolivian nationality or were born in the Argentine province of Santiago del Estero. The overall prevalence of Chagas disease was 4.08%. Due to migration, Chagas disease is currently predominantly urban. The observed prevalence requires health programme activities that are aimed at urban children and their mothers. Most children were infected congenitally, which reinforces the need for Chagas disease screening of all pregnant women and their babies in Argentina. The active search for new cases is important because the appropriate treatment in children has a high cure rate.

TLR4 genotype and environmental LPS mediate RSV bronchiolitis through Th2 polarization.

While 30%-70% of RSV-infected infants develop bronchiolitis, 2% require hospitalization. It is not clear why disease severity differs among healthy, full-term infants; however, virus titers, inflammation, and Th2 bias are proposed explanations. While TLR4 is associated with these disease phenotypes, the role of this receptor in respiratory syncytial virus (RSV) pathogenesis is controversial. Here, we evaluated the interaction between TLR4 and environmental factors in RSV disease and defined the immune mediators associated with severe illness. Two independent populations of infants with RSV bronchiolitis revealed that the severity of RSV infection is determined by the TLR4 genotype of the individual and by environmental exposure to LPS. RSV-infected infants with severe disease exhibited a high GATA3/T-bet ratio, which manifested as a high IL-4/IFN-γ ratio in respiratory secretions. The IL-4/IFN-γ ratio present in infants with severe RSV is indicative of Th2 polarization. Murine models of RSV infection confirmed that LPS exposure, Tlr4 genotype, and Th2 polarization influence disease phenotypes. Together, the results of this study identify environmental and genetic factors that influence RSV pathogenesis and reveal that a high IL-4/IFN-γ ratio is associated with severe disease. Moreover, these molecules should be explored as potential targets for therapeutic intervention.