You Know What I Know: Interviewer Knowledge Effects in Subjective Expectation Elicitation.

Directly eliciting individuals' subjective beliefs via surveys is increasingly popular in social science research, but doing so via face-to-face surveys has an important downside: the interviewer's knowledge of the topic may spill over onto the respondent's recorded beliefs. Using a randomized experiment that used interviewers to implement an information treatment, we show that reported beliefs are significantly shifted by interviewer knowledge. Trained interviewers primed respondents to use the exact numbers used in the training, nudging them away from higher answers; recorded responses decreased by about 0.3 standard deviations of the initial belief distribution. Furthermore, respondents with stronger prior beliefs were less affected by interviewer knowledge. We suggest corrections for this issue from the perspectives of interviewer recruitment, survey design, and experiment setup.

Health knowledge and non-pharmaceutical interventions during the Covid-19 pandemic in Africa.

Providing health information is a non-pharmaceutical intervention designed to reduce disease transmission and infection risk by encouraging behavior change. But does knowledge change behavior? We test whether coronavirus health knowledge promotes protective risk mitigation behaviors early in the Covid-19 pandemic in samples from four African countries (Ghana, Malawi, Sierra Leone, and Tanzania). Despite reputations for weak health sectors and low average levels of education, health knowledge of the symptoms and transmission mechanisms was high in all countries in the two months after the virus entered the country. Higher knowledge was associated with increased protective measures that would likely lower disease risk with one exception-knowledge was inversely correlated with social distancing. Respondents largely adhered to mask mandates and lockdowns, but continued coming into contact with others at small, informal gatherings, gatherings not affected by mandates. Knowledge alone did not reduce all risky activities, especially gatherings within other people's homes. Even early in the pandemic, income loss or stress were commonly reported. Our results suggest that early and consistent government provision of health information likely reduced the initial severity of the pandemic in Africa but was not a panacea.

Pediatric hospitalizations associated with 2009 pandemic influenza A (H1N1) in Argentina.

BACKGROUND: While the Northern Hemisphere experiences the effects of the 2009 pandemic influenza A (H1N1) virus, data from the recent influenza season in the Southern Hemisphere can provide important information on the burden of disease in children. METHODS: We conducted a retrospective case series involving children with acute infection of the lower respiratory tract or fever in whom 2009 H1N1 influenza was diagnosed on reverse-transcriptase polymerase-chain-reaction assay and who were admitted to one of six pediatric hospitals serving a catchment area of 1.2 million children. We compared rates of admission and death with those among age-matched children who had been infected with seasonal influenza strains in previous years. RESULTS: Between May and July 2009, a total of 251 children were hospitalized with 2009 H1N1 influenza. Rates of hospitalization were double those for seasonal influenza in 2008. Of the children who were hospitalized, 47 (19%) were admitted to an intensive care unit, 42 (17%) required mechanical ventilation, and 13 (5%) died. The overall rate of death was 1.1 per 100,000 children, as compared with 0.1 per 100,000 children for seasonal influenza in 2007. (No pediatric deaths associated with seasonal influenza were reported in 2008.) Most deaths were caused by refractory hypoxemia in infants under 1 year of age (death rate, 7.6 per 100,000). CONCLUSIONS: Pandemic 2009 H1N1 influenza was associated with pediatric death rates that were 10 times the rates for seasonal influenza in previous years.

T helper type 2 bias and type 17 suppression in primary dengue virus infection in infants and young children.

BACKGROUND: The immune response to dengue virus (DENV) primary infection in infants and young children is not well characterized. In Northern Argentina, >90% of the population was DENV-naïve before the 2009 outbreak, allowing evaluation of age-dependent primary responses to infection. METHODS: We conducted a comparative study of the immune response to DENV in 27 infected infants, young children and their mothers. Lymphocyte T helper (Th) 1, Th2, Th17 and inflammatory responses were assayed in blood during the 2009 DENV-1 epidemic. RESULTS: The immune response to DENV-1 was significantly biased to Th2 in infected infants and young children, compared to infants with other febrile illnesses (for IL-4 p < 0.001) and to their infected mothers (for IL-4 p < 0.01). In addition, IL-17 suppression was observed in the memory response to DENV-1 in infected infants (p < 0.01 vs placebo). CONCLUSION: Age-related differences in the primary response to DENV, characterized by an immature Th2 polarization and Th17 suppression in infants, should be studied further in order to expand our understanding of the mechanism of dengue pathogenesis.

Human rhinoviruses in severe respiratory disease in very low birth weight infants.

OBJECTIVES: To assess incidence, burden of illness, and risk factors for human rhinoviruses (HRVs) in a cohort of very low birth weight (VLBW) infants. METHODS: A 2-year prospective cohort study was conducted among VLBW premature infants in Buenos Aires, Argentina. Infants were enrolled in the NICU from June 1, 2003, to May 31, 2005, and managed monthly and with every acute respiratory illness (ARI) during the first year of life. Nasal wash samples were obtained during every respiratory episode and tested for HRV, respiratory syncytial virus (RSV), human parainfluenza viruses, influenza viruses, and human metapneumovirus using reverse transcriptase-polymerase chain reaction. RESULTS: Of 119 patients, 66 (55%) had HRV-associated ARIs. The incidence of HRV-associated ARI was 123 events per 100 child-years of follow-up. Of those infants experiencing an episode of bronchiolitis, 40% had HRV versus 7% with RSV. The incidence of HRV-associated bronchiolitis was 75 per 100 infant-years of follow-up. HRV was associated with 12 of 36 hospitalizations (33%), and RSV was associated with 9 of 36 hospitalizations (25%). The incidence of HRV-associated hospitalization was 12 per 100 infant-years of follow-up. The risk of HRV-associated hospitalization was higher for infants with bronchopulmonary dysplasia and those who were not breastfed. CONCLUSIONS: HRV is an important and frequent pathogen associated with severe respiratory infections in VLBW infants. Bronchopulmonary dysplasia and the absence of breastfeeding are risk factors for hospitalization. The results of our study reveal that HRV is the predominant pathogen of respiratory infections in premature infants.