Evolution, Medicine, and Public Health最新文献

Background and objectives: Birth is a critical event in women's lives. Since humans have evolved to give birth in the context of social support, not having it in modern settings might lead to more complications during birth. Our aim was to model how emotional factors and medical interventions related to birth outcomes in hospital settings in Poland, where c-section rates have doubled in the last decade.

Methodology: We analysed data from 2363 low-risk primiparous women who went into labor with the intention of giving birth vaginally. We used a model comparison approach to examine the relationship between emotional and medical variables and birth outcome (vaginal or c-section), including sociodemographic control variables in all models.

Results: A model with emotional factors better explained the data than a control model (Δ_AIC = 470.8); women with continuous personal support during labor had lower odds of a c-section compared to those attended by hospital staff only (OR = 0.12, 95% CI = 0.09 - 0.16). A model that included medical interventions also better explained the data than a control model (Δ_AIC = 133.6); women given epidurals, in particular, had increased odds of a c-section over those who were not (OR = 3.55, 95% CI = 2.95 - 4.27). The best model included variables for both the level of personal support and the use of epidural (Δ_AIC = 598.0).

Conclusions and implications: Continuous personal support during childbirth may be an evolutionarily informed strategy for reducing complications, including one of the most common obstetrical complications in modern hospital settings, the c-section.

Exposure to social environmental adversity is associated with health and survival across many social species, including humans. However, little is known about how these health and mortality effects vary across the lifespan and may be differentially impacted by various components of the environment. Here, we leveraged a relatively new and powerful model for human aging, the companion dog, to investigate which components of the social environment are associated with dog health and how these associations vary across the lifespan. We drew on comprehensive survey data collected on 21,410 dogs from the Dog Aging Project and identified five factors that together explained 33.7% of the variation in a dog's social environment. Factors capturing financial and household adversity were associated with poorer health and lower physical mobility in companion dogs, while factors that captured social support, such as living with other dogs, were associated with better health when controlling for dog age and weight. Notably, the effects of each environmental component were not equal: the effect of social support was 5× stronger than financial factors. The strength of these associations depended on the age of the dog, including a stronger relationship between the owner's age and the dog's health in younger as compared to older dogs. Taken together, these findings suggest the importance of income, stability and owner's age on owner-reported health outcomes in companion dogs and point to potential behavioral and/or environmental modifiers that can be used to promote healthy aging across species.

Racial health disparities are a pervasive feature of modern experience and structural racism is increasingly recognized as a public health crisis. Yet evolutionary medicine has not adequately addressed the racialization of health and disease, particularly the systematic embedding of social biases in biological processes leading to disparate health outcomes delineated by socially defined race. In contrast to the sheer dominance of medical publications which still assume genetic 'race' and omit mention of its social construction, we present an alternative biological framework of racialized health. We explore the unifying evolutionary-ecological principle of niche construction as it offers critical insights on internal and external biological and behavioral feedback processes environments at every level of the organization. We Integrate insights of niche construction theory in the context of human evolutionary and social history and phenotype-genotype modification, exposing the extent to which racism is an evolutionary mismatch underlying inequitable disparities in disease. We then apply ecological models of niche exclusion and exploitation to institutional and interpersonal racial constructions of population and individual health and demonstrate how discriminatory processes of health and harm apply to evolutionarily relevant disease classes and life-history processes in which socially defined race is poorly understood and evaluated. Ultimately, we call for evolutionary and biomedical scholars to recognize the salience of racism as a pathogenic process biasing health outcomes studied across disciplines and to redress the neglect of focus on research and application related to this crucial issue.

Background and objectives: Childbirth fear, which has been argued to have an adaptive basis, exists on a spectrum. Pathologically high levels of childbirth fear is a clinical condition called tokophobia. As a chronic stressor in pregnancy, tokophobia could impact birth outcomes. Many factors associated with tokophobia, including inadequate labor support, were exacerbated by the COVID-19 pandemic.

Methodology: We used longitudinally collected data from a convenience sample of 1775 pregnant persons in the USA to evaluate the association between general and COVID-19 pandemic-related factors and tokophobia using the fear of birth scale. We also assessed associations between tokophobia, low birth weight and preterm birth when adjusting for cesarean section and other covariates among a subset of participants (N = 993).

Results: Tokophobia was highly prevalent (62%). Mothers who self-identified as Black (odds ratio (OR) = 1.90), had lower income (OR = 1.39), had less education (OR = 1.37), had a high-risk pregnancy (OR = 1.65) or had prenatal depression (OR = 4.95) had significantly higher odds of tokophobia. Concerns about how COVID-19 could negatively affect maternal and infant health and birth experience were also associated with tokophobia (ORs from 1.51 to 1.79). Tokophobia was significantly associated with increased odds of giving birth preterm (OR = 1.93).

Conclusions and implications: Tokophobia increases the odds of preterm birth and is more prevalent among individuals who are Black, have a lower income, and have less education. Tokophobia may, therefore, be an underappreciated contributor to inequities in US birth outcomes. The COVID-19 pandemic likely compounded these effects.

There is growing concern with social disparities in health, whether relating to gender, ethnicity, caste, socio-economic position or other axes of inequality. Despite addressing inequality, evolutionary biologists have had surprisingly little to say on why human societies are prone to demonstrating exploitation. This article builds on a recent book, 'The Metabolic Ghetto', describing an overarching evolutionary framework for studying all forms of social inequality involving exploitation. The dynamic 'producer-scrounger' game, developed to model social foraging, assumes that some members of a social group produce food, and that others scrounge from them. An evolutionary stable strategy emerges when neither producers nor scroungers can increase their Darwinian fitness by changing strategy. This approach puts food systems central to all forms of human inequality, and provides a valuable lens through which to consider different forms of gender inequality, socio-economic inequality and racial/caste discrimination. Individuals that routinely adopt producer or scrounger tactics may develop divergent phenotypes. This approach can be linked with life history theory to understand how social dynamics drive health disparities. The framework differs from previous evolutionary perspectives on inequality, by focussing on the exploitation of foraging effort rather than inequality in ecological resources themselves. Health inequalities emerge where scroungers acquire different forms of power over producers, driving increasing exploitation. In racialized societies, symbolic categorization is used to systematically assign some individuals to low-rank producer roles, embedding exploitation in society. Efforts to reduce health inequalities must address the whole of society, altering producer-scrounger dynamics rather than simply targeting resources at exploited groups.

Trypanosomatids are a diverse family of protozoan parasites, some of which cause devastating human and livestock diseases. There are two distinct infection life cycles in trypanosomatids; some species complete their entire life cycle in a single host (monoxenous) while others infect two hosts (dixenous). Dixenous trypanosomatids are mostly vectored by insects, and the human trypanosomatid diseases are caused mainly by vectored parasites. While infection prevalence has been described for subsets of hosts and trypanosomatids, little is known about whether monoxenous and dixenous trypanosomatids differ in infection prevalence. Here, we use meta-analyses to synthesise all published evidence of trypanosomatid infection prevalence for the last two decades, encompassing 931 unique host-trypansomatid systems. In examining 584 studies that describe infection prevalence, we find, strikingly, that monoxenous species are two-fold more prevalent than dixenous species across all hosts. We also find that dixenous trypanosomatids have significantly lower infection prevalence in insects than their non-insect hosts. To our knowledge, these results reveal for the first time, a fundamental difference in infection prevalence according to host specificity where vectored species might have lower infection prevalence as a result of a potential 'jack of all trades, master of none' style trade-off between the vector and subsequent hosts.

Background and objectives: Selection in utero predicts that population stressors raise the standard for how quickly fetuses must grow to avoid spontaneous abortion. Tests of this prediction must use indirect indicators of fetal loss in birth cohorts because vital statistics systems typically register fetal deaths at the 20th week of gestation or later, well after most have occurred. We argue that tests of selection in utero would make greater progress if researchers adopted an indicator of selection against slow-growing fetuses that followed from theory, allowed sex-specific tests and used readily available data. We propose such an indicator and assess its validity as a dependent variable by comparing its values among monthly birth cohorts before, and during, the first 10 months of the COVID-19 pandemic in Sweden.

Methodology: We apply Box-Jenkins methods to 50 pre-pandemic birth cohorts (i.e., December 2016 through January 2020) and use the resulting transfer functions to predict counterfactual values in our suggested indicator for selection for ten subsequent birth cohorts beginning in February 2020. We then plot all 60 residual values as well as their 95% detection interval. If birth cohorts in gestation at the onset of the pandemic lost more slow-growing fetuses than expected from history, more than one of the last 10 (i.e. pandemic-exposed) residuals would fall below the detection interval.

Results: Four of the last 10 residuals of our indicator for males and for females fell below the 95% detection interval.

Conclusions and implications: Consistent with selection in utero, Swedish birth cohorts in gestation at the outset of the COVID-19 pandemic included fewer than expected infants who grew slowly in utero.

Background and objectives: Body odor conveys information about health status to conspecifics and influences approach-avoidance behaviors in animals. Experiments that induce sickness in otherwise healthy individuals suggest that humans too can detect sensory cues to infection in others. Here, we investigated whether individuals could detect through smell a naturally occurring acute respiratory infection in others and whether sickness severity, measured via body temperature and sickness symptoms, was associated with the accuracy of detection.

Methodology: Body odor samples were collected from 20 donors, once while healthy and once while sick with an acute respiratory infection. Using a double-blind, two-alternative forced-choice method, 80 raters were instructed to identify the sick body odor from paired sick and healthy samples (i.e. 20 pairs).

Results: Sickness detection was significantly above chance, although the magnitude of the effect was low (56.7%). Raters' sex and disgust sensitivity were not associated with the accuracy of sickness detection. However, we find some indication that greater change in donor body temperature, but not sickness symptoms, between sick and healthy conditions improved sickness detection accuracy.

Conclusion and implications: Our findings suggest that humans can detect individuals with an acute respiratory infection through smell, albeit only slightly better than chance. Humans, similar to other animals, are likely able to use sickness odor cues to guide adaptive behaviors that decrease the risk of contagion, such as social avoidance. Further studies should determine how well humans can detect specific infections through body odor, such as Covid-19, and how multisensory cues to infection are used simultaneously.