Social immunology
This paper calls for increased attention to the ways in which immune function – including its behavioral aspects – are responsive to social contexts at multiple levels. Psychoneuroimmunology has demonstrated that the quantity and quality of social connections can affect immune responses, while newer research is finding that sickness temporarily affects these same social networks and that some aspects of culture can potentially “get under the skin” to affect inflammatory responses. Social immunology, the research framework proposed here, unifies these findings and also considers the effects of structural factors – that is, a society's economic, political, and environmental landscape – on exposure to pathogens and subsequent immune responses. As the COVID-19 pandemic has highlighted, a holistic understanding of the effects of social contexts on the patterning of morbidity and mortality is critically important. Social immunology provides such a framework and can highlight important risk factors related to impaired immune function.
Sickness Behavior and Cultural Models of Sickness
Sickness behavior, a coordinated set of
behavioral changes in response to infection, lies at the intersection of immunology, endocrinology, and evolutionary biology. Sickness behavior is elicited by proinflammatory cytokines, is thought to be an adaptive means of redirecting energy away from disadvantageous behaviors and toward mounting an effective immune response, and may be modulated by hormones, including
testosterone and oxytocin. Research on sickness behavior in humans has lagged behind non-human animal research due to methodological complexities. Here we review what is known about sickness behavior in humans, the effects of various hormones on sickness behavior, the possible role of cytokine gene variation in
influencing sickness behavior responses, and the ways in which culture and gender norms could similarly influence these behavioral changes. We also propose methodologies for advancing further studies of sickness behavior in humans.
Spread of contagious pathogens critically depends on the number and types of contacts between infectious and susceptible hosts. Changes in social behavior by susceptible, exposed, or sick individuals thus have far-reaching downstream consequences for infectious disease spread. Although “social distancing” is now an all too familiar strategy for managing COVID-19, nonhuman animals also exhibit pathogen-induced changes in social interactions. Here, we synthesize the effects of infectious pathogens on social interactions in animals (including humans), review what is known about underlying mechanisms, and consider implications for evolution and epidemiology.
Presenteeism among healthcare providers, staff, and students in Jalisco, Mexico: a descriptive study
Objective
We measured presenteeism (continuing to attend work or other activities while sick) in a sample ofhealthcare workers in Jalisco, Mexico to better understand the phenomenon, which can place patients at riskof infection.
Methods
An online survey link was distributed to all healthcare professionals, staff, and students registered with the Jalisco Ministry of Health starting in March 2020. Completed surveys (n = 196) collected between March and July 2020 were analyzed using bivariate and descriptive statistics including Kruskal-Wallis rank sum tests and Fisher’s tests.
Results
Most participants (67.5%) reported working while sick. Primary reasons included concerns about patients and continuity of care. Approximately 97% of respondents believed that working while sick could put patients at risk but still attended work with multiple symptoms.
Conclusion
These presenteeism rates and motivations are comparable to data from the US and other countries. We suggest that state and federal medical organizations address presenteeism to prevent nosocomial outbreaks.
Sickness behavior is an evolutionarily conserved phenomenon found across a diverse range of animals involving a change in motivational priorities to theoretically maximize energetic investment in immune function and recovery. Typical components of sickness behavior include reduced sociability and activity, changes in diet, and depressed affect. Importantly, however, sickness behavior appears to be subject to other demands of life history in animal models, including reproduction and offspring survival. Thus, “feeling sick” is often context dependent with possible effects on morbidity and mortality. While humans may not always face the same life history trade-offs, sociocultural norms and values may similarly shape sickness behavior by establishing internalized parameters for “socially appropriate sickness.” We explore the role of these factors in shaping sickness behavior by surveying a national U.S. sample (n = 1,259). Self-reported and recalled sickness behavior was measured using the SicknessQ instrument, which has previously been validated against experimentally induced sickness behavior. After post-stratification weighting and correction for Type I error, generalized linear models showed that sickness behavior is significantly affected by various factors across sex and racial/ethnic groupings. Income below the national mean (b = 1.85, adj. p = 0.025), stoic endurance of pain and discomfort (b = 1.61, adj. p < 0.001), and depressive symptomology (b = 0.53, adj. p < 0.001) were each associated with greater sickness behavior scores. Familism (b = 1.59, adj. p = 0.008) was positively associated with sickness behavior in men, but not women. Endurance of pain and discomfort was associated with greater sickness behavior in Whites only (b = 1.94, adj. p = 0.002), while familism approached significance in African Americans only (b = 1.86, adj. p = 0.057). These findings may reflect different social contexts of sickness across demographic groups, which may in turn have important implications for pathogen transmission and recovery times, potentially contributing to health disparities.
Culture and Health
Objectives: Vaccines are highly successful in preventing disease, but misinformation has fueled vaccine hesitancy globally, thereby reducing immunization rates and weakening herd immunity. Vaccine knowledge and hesitancy among hunter-gatherers is a crucial area of research and intervention, as their mobile lifestyle exacerbates other challenges, such as marginalization and medical mistrust.
Methods: In our exploratory study, we surveyed 91 Hadzabe adults across six camps (mean age = 39, 46% female) about their knowledge of vaccines and their safety and efficacy. Differences between sexes and camps were tested using Fisher's exact tests.
Results: Half of participants reported not knowing what a vaccine is, while one-third described vaccines as protecting health or preventing disease. About 32% were unsure about vaccine safety, while most Hadzabe adults strongly agreed vaccines are effective (65.3%). A majority (72%) agreed vaccines are important for children, yet only one-third strongly agreed on their importance for adults. More females than males expressed uncertainty about the importance of adult vaccines (p = 0.03). Participants in our sample perceived vaccines as less effective and more safe than the general Tanzanian population, based on 2018 Wellcome data.
Discussion: In our sample, results indicate that while Hadzabe participants generally agree that vaccines are important, particularly for children, important gaps in vaccine knowledge remain. There is a clear need to communicate vaccine information to the Hadzabe community in a culturally appropriate manner. Such efforts are critical in safeguarding the health of Indigenous populations experiencing greater market integration, thereby supporting access to vaccines against diseases.
Other Resources
As part of a field school in 2023, undergraduate students worked with Wixárika nurses and artists to create anatomy posters with both Wixárika and Spanish terms and pronunciations. Our goal with this project was to address language barriers in healthcare settings. It's our hope that these posters can be placed in doctors' offices to help bridge the linguistic and cultural gap between providers and patients. They are available for download by clicking above.