Are Perceived Prevalences of Infection also Biased and How? Lessons from Large Epidemics of Mosquito-Borne Diseases in Tropical Regions

The Role of Medical Mistrust in Vaccination Decisions in Rural, Indigenous Namibian Communities

OBJECTIVES

Substantial inequalities in access to healthcare are common in rural and marginalized populations in the Global South, and these inequalities can drive health disparities. Historical mistrust of healthcare institutions can further impact healthcare behaviors, including vaccination. Here, we apply the concept of medical mistrust, which has been widely applied to healthcare decisions in industrialized countries, across a rural-urban spectrum of communities in Namibia, and assess its utility in understanding vaccination decisions.

METHODS

Otjiherero-speaking indigenous communities of Kunene, Namibia, were surveyed to assess medical mistrust. Participants also answered questions about COVID-19 vaccination status, vaccine safety, and interest in a hypothetical malaria vaccine. Bayesian multilevel models were used to compare medical mistrust across communities and its influence on vaccination and vaccine perceptions.

RESULTS

The level of medical mistrust varied across contexts, with the highest level of mistrust in peri-urban communities. Medical mistrust predicted beliefs about vaccine safety and interest in the malaria vaccine, but not COVID-19 vaccine status, which was largely driven by access to the vaccine. For rural and peri-urban Himba, participants also expressed disinterest in the COVID-19 vaccine and worries about its safety.

CONCLUSION

Addressing global health disparities requires understanding how locally contextualized social and ecological experiences shape healthcare and vaccination decisions. Results of this study show fundamental differences in medical mistrust by community, which may be contributing to beliefs about vaccines. Understanding how medical mistrust varies across these contexts, and how it impacts perceptions about vaccination, can inform health communication and public policy in underserved communities.

Dengue as a Disease Threatening Global Health: A Narrative Review Focusing on Latin America and Brazil

Arboviruses constitute the largest known group of viruses. These viruses are the etiological agents of pathologies known as arboviruses, with dengue being one of the most prevalent. Dengue has resulted in important socioeconomic burdens placed on different countries around the world, including those in Latin America, especially Brazil. Thus, this work intends to carry out a narrative-based review of the literature, conducted using a study of the secondary data developed through a survey of scientific literature databases, and to present the situation of dengue, particularly its distribution in these localities. Our findings from the literature demonstrate the difficulties that managers face in controlling the spread of and planning a response against dengue, pointing to the high cost of the disease for public coffers, rendering the resources that are already limited even scarcer. This can be associated with the different factors that affect the spread of the disease, including ecological, environmental, and social factors. Thus, in order to combat the disease, it is expected that targeted and properly coordinated public policies need to be adopted not only in specific localities, but also globally.

Risky restrictions? Mobility restriction effects on risk awareness and anxiety

Although mobility restrictions during the COVID-19 pandemic were intended to change behaviours by influencing risk awareness, they might have prompted a rise in risk anxiety (‘worry for one's health’) both among individuals exposed to such restrictions and those living in border countries. This paper studies this question by examining survey data from 22 European countries in the first wave of the COVID-19 pandemic (March 20th and April 6th 2020). Drawing on an event study analysis we show that COVID-19 mobility restrictions raised individuals COVID-19 risk awareness both in the exposed and border countries for almost a week after the announcement. The spillover effect on border countries accounts for about 67% of the effect in the exposed country. However, mobility restrictions gave rise to an increase in  risk anxiety in low-risk countries (which is between 4 and 7 times higher than moderate and high-risk countries). These effects are heterogeneous across age, education and socioeconomic status.

Insight on Knowledge, Risk Perception and Practices to Prevent the Spread of COVID-19: A Cross-Sectional Study among Italian University Students

Addressing adherence to non-pharmaceutical interventions among young adults represents a public health priority since this age group did not directly experience a health risk from COVID-19. The study aims were to investigate the level of knowledge, risk perception and practices to prevent the spread of COVID-19 among undergraduate university students in Southern Italy. This cross-sectional study was conducted between the 1st and 31st of July 2020. An anonymous and structured questionnaire was sent via institutional email. Among the 1323 sampled students, more than two-thirds gave the correct answer to all the knowledge statements. Good knowledge about COVID-19 showed a positive association with those studying medical or life sciences majors. Almost two-fifths (38.5%) of the sample declared to have quite a bit/extreme fear of falling ill with COVID-19 and it was significantly more likely among females and those with good knowledge. Only 30.2% of the students did not touch their face mask while using it. Moreover, practicing respiratory etiquette was more likely among females, among respondents with higher levels of fear of falling ill with COVID-19 and among those who exhibited good knowledge about COVID-19. The study insights will be valuable for the ongoing mitigation of the current pandemic especially with regard to the correct use of face masks.

Unbiased assessment of disease surveillance utilities: A prospect theory application

Objectives

We contribute a new methodological approach to the ongoing efforts towards evaluating public health surveillance. Specifically, we apply a descriptive framework, grounded in prospect theory (PT), for the evaluation of decisions on disease surveillance deployment. We focus on two attributes of any surveillance system: timeliness, and false positive rate (FPR).

Methods

In a sample of 69 health professionals from a number of health related networks polled online, we elicited PT preferences, specifically respondents’ attitudes towards gains, losses and probabilities (i.e., if they overweight or underweight extreme probabilities) by means of a series of lotteries for either timeliness or FPR. Moreover, we estimated willingness to pay (WTP) for improvements in the two surveillance attributes. For contextualization, we apply our framework to rabies surveillance.

Results

Our data reveal considerable probability weighting, both for gains and losses. In other words, respondents underestimate their chances of getting a good outcome in uncertain situations, and they overestimate their chances of bad outcomes. Moreover, there is convex utility for losses and loss aversion, that is, losses loom larger than gains of the same absolute magnitude to the respondents. We find no differences between the estimated parameters for timeliness and FPR. The median WTP is $7,250 per day gained in detection time and $30 per 1/10,000 reduction in FPR.

Conclusion

Our results indicate that the biases described by PT are present among public health professionals, which highlights the need to incorporate a PT framework when eliciting their preferences for surveillance systems.

In this paper we contribute a new methodological approach to the ongoing efforts towards evaluating public health surveillance. Specifically, we apply a descriptive framework for the evaluation of decisions on disease surveillance deployment. We focus on two attributes of any surveillance system: timeliness and false positive rates. In a sample of 69 health professionals from a number of health related networks polled online, we elicited preferences, specifically respondents’ attitudes towards gains, losses and probabilities (i.e., if they overweight or underweight extreme probabilities) by means of a series of lotteries. For contextualization, we apply our framework to rabies surveillance. Our data reveal that respondents underestimate their chances of getting a good outcome in uncertain situations, and they overestimate their chances of bad outcomes. Moreover, losses loom larger than gains of the same absolute magnitude to the respondents. We find no differences between the estimated parameters for timeliness and false positive rates. Our results indicate that the biases described are present among public health professionals, and highlight the need to adjust for them when eliciting their preferences for surveillance systems.

Understanding health behaviour changes in response to outbreaks: Findings from a longitudinal study of a large epidemic of mosquito-borne disease

RATIONALE

Although greater attention has been recently given to the ecological determinants of health behaviours, we still do not know much about the behavioural changes induced by the spread of infectiousdiseases.

OBJECTIVE

In this study, we took advantage of a large epidemic of chikungunya, an emerging mosquito-borne disease, in French Guiana to examine the dynamic interaction between risk-related perceptions and behaviours that occurs in response to a disease outbreak. In particular, we tested empirically the assumption that both risk perceptions and health behaviours were elastic with respect to prevalence of chikungunya.

METHODS

A representative sample of French Guianan (N=434) was interviewed in January 2015 just after the peak of the epidemic, and again 2 months later. Participants were asked about their perceptions of the threat, as well as their engagement in a range of protective behaviours promoted by the regional health authorities to control the spread of the disease.

RESULTS

The surveys showed that (1) the frequency of some health behaviours - those related to visible control methods - significantly increased with the subjective and objective prevalence of the disease, (2) perceived risk of infection for oneself tended to decrease considerably over time, and (3) the risk reappraisal hypothesis failed to account for this paradoxical trend in the people's response to the risk of contracting the disease.

CONCLUSION

These findings suggest that people may fail to adjust their risk perceptions, and to a lesser extent their health protective behaviours, to the course of an epidemic. Notably, the prevalence elasticity of preventive action found in previous studies of behavioural response to infectious diseases differed substantially according to the type of intervention (personal versus environmental methods). This paradoxical trend may be attributed to risk habituation effects, which seem to vary significantly according to the social visibility of thepreventive actions.