Knowledge of Dentists and Dental Undergraduates Related to COVID-19

Abstract Objective: To assess the knowledge of Brazilian dentists and final-year dental undergraduates concerning COVID-19. Material and Methods: We conducted a self-administered online questionnaire about the symptoms, incubation period, and transmission routes of COVID-19. In total, there were three questions addressing these topics and 15 correct answers, so each participant could score from 0 to 15 points. Besides that, data such as sex, age, education level, years of work experience and place of work were collected. All data were submitted to statistical analysis with a 5% significance level. Results: 476 participants were recruited. Regarding the respondents' perception of the most common symptoms of COVID-19, 99.4% responded fever, 95.2% cough, and 99.2% dyspnea. About the incubation period, 56.3% answered from 1 to 14 days. About the transmission routes, 98.3% recognized transmission through droplets, 80.3% through direct contact with infected persons, and 70.4% through indirect routes. The median knowledge score was 10 (4 - 14). Regarding the socio-demographic variables, participants aged 30 years or more had a higher score than those aged up to 29 years old (p=0.004). For education level, specialist dentists presented a higher score than undergraduates (p=0.006), general dentists (p=0.048) and Ph.D. (p=0.016). Participants with 15 years or more of work experience had a higher score than undergraduates (p=0.003). Concerning the workplace, participants working in the public sector had a higher score than those working in the private sector or universities (p=0.015). Conclusion: Participants recognized the main symptoms, incubation period, and transmission routes of the COVID-19 virus; however, the knowledge level of specialist dentists, older dentists, more experienced dentists, and dentists working in the public sector was higher than the other participants (AU).

Epidemics of chikungunya, Zika, and COVID-19 reveal bias in case-based mapping (preprint)

ABSTRACT Accurate tracing of epidemic spread over space enables effective control measures. We examined three metrics of infection and disease in a pediatric cohort (N ≈ 3,000) over two chikungunya and one Zika epidemic, and in a household cohort (N=1,793) over one COVID-19 epidemic in Managua, Nicaragua. We compared spatial incidence rates (cases/total population), infection risks (infections/total population), and disease risks (cases/infected population). We used generalized additive and mixed-effects models, Kulldorf’s spatial scan statistic, and intracluster correlation coefficients. Across different analyses and all epidemics, incidence rates considerably underestimated infection and disease risks, producing large and spatially non-uniform biases distinct from biases due to incomplete case ascertainment. Infection and disease risks exhibited distinct spatial patterns, and incidence clusters inconsistently identified areas of either risk. While incidence rates are commonly used to infer infection and disease risk in a population, we find that this can induce substantial biases and adversely impact policies to control epidemics. Article summary line Inferring measures of spatial risk from case-only data can substantially bias estimates, thereby weakening and potentially misdirecting measures needed to control an epidemic.