Social Contact Behavior Research Articles

Modelling wellbeing during public health interventions for respiratory epidemics

Throughout the COVID-19 pandemic, the use of non-pharmaceutical interventions (NPIs), including lockdown measures, by governments around the world has been informed by mathematical modelling. Broadly, these models look to gauge how well NPIs control disease transmission. Here we present a model that not only forecasts the effectiveness of NPIs in restricting contacts but also assesses their influence on the mental wellbeing of affected populations. Our model is informed by data from the United Kingdom Time Use Survey, 2014-2015. This survey recorded the time participants spent in different social settings as well as self-reported enjoyment in these settings, allowing us to augment a quantitative model of social contact behaviour with associated wellbeing estimates. We use this model to assess the effectiveness of NPIs aimed at reducing social contacts in different settings and estimate their impact on population-level wellbeing. Our findings indicate that workplace closures represent the most effective intervention for slowing disease spread, while NPIs targeting other contact locations have comparatively limited impacts on transmission. Our model suggests that workplace closures not only effectively reduce infections but also have a relatively modest effect on population wellbeing levels.

Social contacts in Switzerland during the COVID-19 pandemic: Insights from the CoMix study

To mitigate the spread of SARS-CoV-2, the Swiss government enacted restrictions on social contacts from 2020 to 2022. In addition, individuals changed their social contact behavior to limit the risk of COVID-19. In this study, we aimed to investigate the changes in social contact patterns of the Swiss population. As part of the CoMix study, we conducted a survey consisting of 24 survey waves from January 2021 to May 2022. We collected data on social contacts and constructed contact matrices for the age groups 0–4, 5–14, 15–29, 30–64, and 65 years and older. We estimated the change in contact numbers during the COVID-19 pandemic to a synthetic pre-pandemic contact matrix. We also investigated the association of the largest eigenvalue of the social contact and transmission matrices with the stringency of pandemic measures, the effective reproduction number (Re), and vaccination uptake. During the pandemic period, 7084 responders reported an average number of 4.5 contacts (95% confidence interval, CI: 4.5–4.6) per day overall, which varied by age and survey wave. Children aged 5–14 years had the highest number of contacts with 8.5 (95% CI: 8.1–8.9) contacts on average per day and participants that were 65 years and older reported the fewest (3.4, 95% CI: 3.2–3.5) per day. Compared with the pre-pandemic baseline, we found that the 15–29 and 30–64 year olds had the largest reduction in contacts. We did not find statistically significant associations between the largest eigenvalue of the social contact and transmission matrices and the stringency of measures, Re, or vaccination uptake. The number of social contacts in Switzerland fell during the COVID-19 pandemic and remained below pre-pandemic levels after contact restrictions were lifted. The collected social contact data will be critical in informing modeling studies on the transmission of respiratory infections in Switzerland and to guide pandemic preparedness efforts.

Chronic disease patients have fewer social contacts: A pilot survey with implications for transmission dynamics

Non-communicable diseases (NCD) are the most important cause of death in the world. The socio-economic costs associated with NCDs makes it imperative to prevent and control them in the 21st century. The severe toll that the COVID-19 pandemic has taken worldwide is an unfortunate illustration of our limited insight into the infectious risk for the global population. Co-incidence between NCD and infection offers an underexplored opportunity to design preventive policies. In a pilot survey, we observed that the NCD population displays a substantial reduction in their social contacting behavior as compared to the general population. This indicates that existing mathematical models based on contact surveys in the general population are not applicable to the NCD population and that the risk of acquiring an infection following a contact is probably underestimated. Our demonstration of reduced social mixing in several chronic conditions, raises the question to what extent the social mixing is influenced by the burden of disease. We advocate the design of disease-specific contact surveys to address how the burden of disease associates with social contact behavior and the risk of infection. The SARS-CoV-2 pandemic offers an unprecedented opportunity to gain insight into the importance of infection in the NCD population and to find ways to improve healthcare procedures.

Suppression of Cofilin function in the somatosensory cortex alters social contact behavior in the BTBR mouse inbred line.

Sensory differences are a core feature of autism spectrum disorders (ASD) and are predictive of other ASD core symptoms such as social difficulties. However, the neurobiological substrate underlying the functional relationship between sensory and social functioning is poorly understood. Here, we examined whether misregulation of structural plasticity in the somatosensory cortex modulates aberrant social functioning in BTBR mice, a mouse model for autism spectrum disorder-like phenotypes. By locally expressing a dominant-negative form of Cofilin (CofilinS3D; a key regulator of synaptic structure) in the somatosensory cortex, we tested whether somatosensory suppression of Cofilin activity alters social functioning in BTBR mice. Somatosensory Cofilin suppression altered social contact and nest-hide behavior of BTBR mice in a social colony, assessed for seven consecutive days. Subsequent behavioral testing revealed that altered social functioning is related to altered tactile sensory perception; CofilinS3D-treated BTBR mice showed a time-dependent difference in the sensory bedding preference task. These findings show that Cofilin suppression in the somatosensory cortex alters social functioning in BTBR mice and that this is associated with tactile sensory processing, a critical indicator of somatosensory functioning.

DDT and titanium dioxide nanoparticle coexposure induced neurobehavioral deficits in zebrafish

Both dichlorodiphenyltrichloroethane (DDT) and titanium dioxide nanoparticle (TiO2 NP) have worldwide-scale commercial applications, resulting in their co-pollution in the ecosystems and posing combined health risks. However, there is a lack of toxicity studies for the interactions of DDT and TiO2 NP in the environmental relevant concentrations. In this study, we characterized the coexposures using a zebrafish waterborne exposure approach and evaluated the neurotoxicity response of the treated embryos or adults. Our results showed that DDT/TiO2 NP coexposure enhanced the DDT accumulation in vivo and increased the larval locomotor. The chronic DDT/TiO2 NP coexposure did not affect the overall survival rate, sex ratio and growth. However, DDT/TiO2 NP coexposure severely affected the adult locomotor activity, social contact, shoaling and aggressive behaviors compared to single treatment groups or controls. These adult behavioral deficits were accompanied by changes in neurotransmitter acetylcholine (ACH) level in the brain and muscle tissues, as well as neural development genes expression activation of growth-associated protein 43 (gap43) and synaptic vesicle glycoprotein 2 (sv2) in the brain. The significantly increased ACH level and the activated neural genes expression in the DDT/TiO2 NP co-exposed fish may account for the observed hyperactivity and social deficits.

Effectiveness of contact tracing for COVID-19 in Belgium

Contact tracing and investigation can prevent infectious disease transmission when carried out promptly. Data obtained from contact tracing also provides unique information on transmission dynamics that can be useful for policy making. The proportion of secondary infections arising from index cases that were previously identified as a close contact, hence “known index cases”, has been indicated by ECDC as a key performance indicator for contact tracing. Few empirical studies have been published on the effectiveness of contact tracing and investigation during the COVID-19 pandemic.
 Using data from the Belgian COVID-19 contact tracing (Sept 2020 – Dec 2021), we investigated the impact of contact tracing on onward transmission. Known index cases were compared to those not previously identified as close contact. More specifically, we compared their traced contacts and secondary cases as well as the serial interval, representing the time from illness onset in the primary case to illness onset in the secondary case. In addition, we investigated contact and transmission characteristics by age.
 Known index cases, previously informed about their exposure, were linked to fewer high-risk contacts and secondary infections. In addition, they presented a lower secondary attack rate compared to those not previously identified by contact investigation, suggesting behavioural changes. Also, a shorter serial interval was observed for known index cases. In addition to breaking transmission chains, contact tracing provides important information on transmission characteristics. When exploring age-specific data, we observed increased transmission rates from children to adults during the circulation of Delta and Omicron variants without an increase in contact rates between these age groups.
 The lower secondary attack rates for known index cases suggest that contact tracing in Belgium has been effective in reducing onward transmission. Their lower number of traced contacts and shorter serial interval are indicative that individuals aware of their exposure to SARS-CoV-2 were more reserved in their social contact behaviour. This reflects the mandatory quarantine for high-risk contacts. Our study also shows that in times of high burden on the healthcare system, key performance indicators of contact tracing should be interpreted with caution in light of changing intervention strategies. Many external factors influence the effectiveness of contact tracing like testing policy and compliance, the cooperation of index cases, and the imposed and adopted quarantine and isolation policies.

Distinct roles of amylin and oxytocin signaling in intrafamilial social behaviors at the medial preoptic area of common marmosets

Calcitonin receptor (Calcr) and its brain ligand amylin in the medial preoptic area (MPOA) are found to be critically involved in infant care and social contact behaviors in mice. In primates, however, the evidence is limited to an excitotoxic lesion study of the Calcr-expressing MPOA subregion (cMPOA) in a family-living primate species, the common marmoset. The present study utilized pharmacological manipulations of the cMPOA and shows that reversible inactivation of the cMPOA abolishes infant-care behaviors in sibling marmosets without affecting other social or non-social behaviors. Amylin-expressing neurons in the marmoset MPOA are distributed in the vicinity of oxytocin neurons in the anterior paraventricular nucleus of the hypothalamus. While amylin infusion facilitates infant carrying selectively, an oxytocin’s inverse agonist, atosiban, reduces physical contact with non-infant family members without grossly affecting infant care. These data suggest that the amylin and oxytocin signaling mediate intrafamilial social interactions in a complementary manner in marmosets.

The influence of COVID-19 risk perception and vaccination status on the number of social contacts across Europe: insights from the CoMix study

BackgroundThe SARS-CoV-2 transmission dynamics have been greatly modulated by human contact behaviour. To curb the spread of the virus, global efforts focused on implementing both Non-Pharmaceutical Interventions (NPIs) and pharmaceutical interventions such as vaccination. This study was conducted to explore the influence of COVID-19 vaccination status and risk perceptions related to SARS-CoV-2 on the number of social contacts of individuals in 16 European countries.MethodsWe used data from longitudinal surveys conducted in the 16 European countries to measure social contact behaviour in the course of the pandemic. The data consisted of representative panels of participants in terms of gender, age and region of residence in each country. The surveys were conducted in several rounds between December 2020 and September 2021 and comprised of 29,292 participants providing a total of 111,103 completed surveys. We employed a multilevel generalized linear mixed effects model to explore the influence of risk perceptions and COVID-19 vaccination status on the number of social contacts of individuals.ResultsThe results indicated that perceived severity played a significant role in social contact behaviour during the pandemic after controlling for other variables (p-value < 0.001). More specifically, participants who had low or neutral levels of perceived severity reported 1.25 (95% Confidence intervals (CI) 1.13 - 1.37) and 1.10 (95% CI 1.00 - 1.21) times more contacts compared to those who perceived COVID-19 to be a serious illness, respectively. Additionally, vaccination status was also a significant predictor of contacts (p-value < 0.001), with vaccinated individuals reporting 1.31 (95% CI 1.23 - 1.39) times higher number of contacts than the non-vaccinated. Furthermore, individual-level factors played a more substantial role in influencing contact behaviour than country-level factors.ConclusionOur multi-country study yields significant insights on the importance of risk perceptions and vaccination in behavioral changes during a pandemic emergency. The apparent increase in social contact behaviour following vaccination would require urgent intervention in the event of emergence of an immune escaping variant.

Initial response to the COVID-19 pandemic on real-life well-being, social contact and roaming behavior in patients with schizophrenia, major depression and healthy controls: A longitudinal ecological momentary assessment study

The COVID-19 pandemic strongly impacted people's daily lives. However, it remains unknown how the pandemic situation affects daily-life experiences of individuals with preexisting severe mental illnesses (SMI). In this real-life longitudinal study, the acute onset of the COVID-19 pandemic in Germany did not cause the already low everyday well-being of patients with schizophrenia (SZ) or major depression (MDD) to decrease further. On the contrary, healthy participants’ well-being, anxiety, social isolation, and mobility worsened, especially in healthy individuals at risk for mental disorder, but remained above the levels seen in patients. Despite being stressful for healthy individuals at risk for mental disorder, the COVID-19 pandemic had little additional influence on daily-life well-being in psychiatric patients with SMI. This highlights the need for preventive action and targeted support of this vulnerable population.

Adolescence Predatory Risk Alters Social Behaviors and Cognitive Ability and Central Oxytocin and Vasopressin Expression in Adult Brandt’s Voles

Introduction: Stress during adolescence causes long-term behavioral changes in adulthood. We previously found that adolescent exposure to predatory risk augments adolescent social contact and adult parental behavior in Brandt’s voles (Lasiopodomys brandtii). Methods: Here, we determined whether this experience alters sexual behavior, pair-bond formation, and recognition ability as well as basal HPA axis activity, central oxytocin (OT), and arginine-vasopressin (AVP) expression in adulthood. Results: In the social interaction test, repeated cat odor (CO) exposure enhanced the frequency of lordosis by female voles toward an unfamiliar opposite-sex conspecific. CO voles preferred to engage with their partners after 48-h cohabitation whereas the control groups did not, which may reflect stable pair bonds in the CO treatment group. Furthermore, adolescent exposure to CO inhibited novel object recognition and place recognition ability, while it influenced social recognition only among adult males. No effect of adolescent CO exposure was observed for basal HPA axis activity, showing a habituation effect. Finally, we found that CO exposure increased OT and decreased AVP expression in the hypothalamus, including the paraventricular nucleus and anterior hypothalamus. The levels of OT in the medial amygdala were lower, and AVP in the lateral septum was higher in CO voles compared with the control. Conclusion: These findings demonstrate that adolescent exposure to predator risk promotes adult reproductive behavior of Brandt’s voles. Deficits in recognition ability may necessitate alterations in reproductive strategies to enhance inclusive fitness. OT and AVP systems may play a modulatory role in the alteration of social behaviors elicited by adolescent predatory risk.

Pregnancy during COVID-19: social contact patterns and vaccine coverage of pregnant women from CoMix in 19 European countries

BackgroundEvidence and advice for pregnant women evolved during the COVID-19 pandemic. We studied social contact behaviour and vaccine uptake in pregnant women between March 2020 and September 2021 in 19 European countries.MethodsIn each country, repeated online survey data were collected from a panel of nationally-representative participants. We calculated the adjusted mean number of contacts reported with an individual-level generalized additive mixed model, modelled using the negative binomial distribution and a log link function. Mean proportion of people in isolation or quarantine, and vaccination coverage by pregnancy status and gender were calculated using a clustered bootstrap.FindingsWe recorded 4,129 observations from 1,041 pregnant women, and 115,359 observations from 29,860 non-pregnant individuals aged 18–49. Pregnant women made slightly fewer contacts (3.6, 95%CI = 3.5–3.7) than non-pregnant women (4.0, 95%CI = 3.9–4.0), driven by fewer work contacts but marginally more contacts in non-essential social settings. Approximately 15–20% pregnant and 5% of non-pregnant individuals reported to be in isolation and quarantine for large parts of the study period.COVID-19 vaccine coverage was higher in pregnant women than in non-pregnant women between January and April 2021. Since May 2021, vaccination in non-pregnant women began to increase and surpassed that in pregnant women.InterpretationLimited social contact to avoid pathogen exposure during the COVID-19 pandemic has been a challenge to many, especially women going through pregnancy. More recognition of maternal social support desire is needed in the ongoing pandemic. As COVID-19 vaccination continues to remain an important pillar of outbreak response, strategies to promote correct information can provide reassurance and facilitate informed pregnancy vaccine decisions in this vulnerable group.

The association of cultural orientation with adherence to social distancing behaviors during the early COVID-19 pandemic in the United States: A cross-sectional survey.

Non-pharmaceutical interventions are one of the major tools to prevent the spread of SARS-CoV-2. Information about these behaviors is disseminated by messaging campaigns. However, people differ in their responses to persuasive messages. Here, we examine whether cultural orientation is associated with adherence to recommended COVID-19 prevention guidelines. Participants (n = 443, 201 from the United States via Amazon Mechanical Turk and 242 from Central New York via a convenience, snowball sample) completed an online survey during April and May 2020. Cultural orientation was measured via the Horizontal and Vertical Individualism and Collectivism Scale. Adherence to limiting social contact was self-reported. Multi-level Poisson regression assessed the association between cultural orientation and social contact behaviors. Those high in horizontal individualist characteristics had a positive association with increased social contact behaviors (RR: 2.20, 95%CI: 1.97-2.47, p<0.001). Those high in vertical collectivist characteristics had a negative association with those behaviors (RR: 0.59, 95%CI: 0.52-0.67, p<0.000). We found an association with cultural orientation and adherence to social contact behaviors during the beginning of the COVID-19 pandemic. In the United States, effective public health messages to promote adherence to preventative behaviors should be tailored to horizontal individualists, those least likely to engage in recommended behaviors.

Impact of the COVID-19 Pandemic on Incidence of Asthma Exacerbations and Hospitalizations in US Subspecialist-Treated Patients with Severe Asthma: Results from the CHRONICLE Study.

PurposePatients with severe asthma (SA) are at an increased risk of asthma-related hospitalizations and exacerbations. Despite concerns that COVID-19 circulation would increase exacerbations of SA, anecdotal reports suggest that social distancing and exposure avoidance may have led to reduced exacerbations.Patients and methodsCHRONICLE is an ongoing noninterventional observational study of 3100 subspecialist-treated patients with SA. Eligible adults (≥ 18 years of age) have (1) current use of monoclonal antibody (ie, biologic) therapy for SA, (2) use of maintenance systemic corticosteroids (mSCS) or other systemic immunosuppressants for ≥ 50% of the prior 12 months for SA, or (3) persistently uncontrolled asthma while treated with high-dosage inhaled corticosteroids with additional controllers. For enrolled patients, electronic medical records were reviewed to record all exacerbations and asthma-related hospitalizations. Descriptive analyses were conducted of the monthly incidence of exacerbations, exacerbation-related visits to the emergency department (ED), and asthma hospitalizations from July 2018 through July 2021.ResultsExacerbations, exacerbation-related ED visits, and hospitalizations decreased since April 2020. Exacerbations in 2020 were 20% to 52% lower in April through August relative to the same months in 2019. Exacerbations remained lower than the prior year through May 2021. Similar results were observed by United States (US) census region, with an earlier decrease in exacerbation rates in the western US versus other regions. Across all months, exacerbation rates were lower among biologic recipients.ConclusionIn a clinical cohort of subspecialist-treated patients with SA, there was a meaningful reduction in exacerbations, exacerbation-related ED visits, and asthma hospitalizations following COVID-19–related stay-at-home orders and social distancing recommendations. Reasons for these reductions are likely multifactorial, including reduced viral infections due to less social contact and altered patient behavior.

The influence of risk perceptions on close contact frequency during the SARS-CoV-2 pandemic

Human behaviour is known to be crucial in the propagation of infectious diseases through respiratory or close-contact routes like the current SARS-CoV-2 virus. Intervention measures implemented to curb the spread of the virus mainly aim at limiting the number of close contacts, until vaccine roll-out is complete. Our main objective was to assess the relationships between SARS-CoV-2 perceptions and social contact behaviour in Belgium. Understanding these relationships is crucial to maximize interventions’ effectiveness, e.g. by tailoring public health communication campaigns. In this study, we surveyed a representative sample of adults in Belgium in two longitudinal surveys (survey 1 in April 2020 to August 2020, and survey 2 in November 2020 to April 2021). Generalized linear mixed effects models were used to analyse the two surveys. Participants with low and neutral perceptions on perceived severity made a significantly higher number of social contacts as compared to participants with high levels of perceived severity after controlling for other variables. Our results highlight the key role of perceived severity on social contact behaviour during a pandemic. Nevertheless, additional research is required to investigate the impact of public health communication on severity of COVID-19 in terms of changes in social contact behaviour.

COVID-19 Vaccinations: Perceptions and Behaviours in People with Primary Ciliary Dyskinesia.

Primary ciliary dyskinesia (PCD) is a rare genetic disease that causes recurrent respiratory infections. People with PCD may be at higher risk of severe coronavirus disease 2019 (COVID-19), and therefore vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important. We studied vaccination willingness, speed of vaccination uptake, side effects, and changes in social contact behaviour after vaccination in people with PCD. We used data from COVID-PCD, an international participatory cohort study. A COVID-19 vaccination questionnaire was emailed to participants in May 2021 and 423 participants from 31 countries replied (median age: 30 years, range 1–85 years; 261 (62%) female). Vaccination uptake and willingness were high, with 273 of 287 adults (96%) being vaccinated or willing to be in June 2021; only 4% were hesitant. The most common reason for hesitancy was fear of side effects, reported by 88%. Mild side effects were common, but no participant reported severe side effects. Half of the participants changed their social behaviour after vaccination by seeing friends and family more often. The high vaccination willingness in the study population might reflect the extraordinary effort taken by PCD support groups to inform people about COVID-19 vaccination. Clear and specific information and involvement of representatives is important for high vaccine uptake.

The population attributable fraction of cases due to gatherings and groups with relevance to COVID-19 mitigation strategies.

Many countries have banned groups and gatherings as part of their response to the pandemic caused by the coronavirus, SARS-CoV-2. Although there are outbreak reports involving mass gatherings, the contribution to overall transmission is unknown. We used data from a survey of social contact behaviour that specifically asked about contact with groups to estimate the population attributable fraction (PAF) due to groups as the relative change in the basic reproduction number when groups are prevented. Groups of 50+ individuals accounted for 0.5% of reported contact events, and we estimate that the PAF due to groups of 50+ people is 5.4% (95% confidence interval 1.4%, 11.5%). The PAF due to groups of 20+ people is 18.9% (12.7%, 25.7%) and the PAF due to groups of 10+ is 25.2% (19.4%, 31.4%). Under normal circumstances with pre-COVID-19 contact patterns, large groups of individuals have a relatively small epidemiological impact; small- and medium-sized groups between 10 and 50 people have a larger impact on an epidemic.This article is part of the theme issue ‘Modelling that shaped the early COVID-19 pandemic response in the UK’.

Social contact behaviors are associated with infection status for Trichuris sp. in wild vervet monkeys (Chlorocebus pygerythrus).

Social grooming in the animal kingdom is common and serves several functions, from removing ectoparasites to maintaining social bonds between conspecifics. We examined whether time spent grooming with others in a highly social mammal species was associated with infection status for gastrointestinal parasites. Of six parasites detected, one (Trichuris sp.) was associated with social grooming behaviors, but more specifically with direct physical contact with others. Individuals infected with Trichuris sp. spent significantly less time grooming conspecifics than those not infected, and time in direct contact with others was the major predictor of infection status. One model correctly predicted infection status for Trichuris sp. with a reliability of 95.17% overall when the variables used were time spent in direct contact and time spent grooming others. This decrease in time spent grooming and interacting with others is likely a sickness behavior displayed by individuals with less energy or motivation for non-essential behaviors. This study emphasizes the possible links between host behavior and parasitic infections and highlights the need for an understanding of a study population's parasitic infections when attempting to interpret animal behavior.

Geriatric Syndromes and Incident Chronic Health Conditions Among 9094 Older Community-Dwellers: Findings from the Lifelines Cohort Study.

To determine the association between geriatric syndromes and any specific incident chronic health conditions among older community-dwellers. Population-based cohort study over a median follow-up period of 43months. Participants from the Lifelines Cohort Study aged 60years and older without presence of the studied chronic health conditions at baseline (n=9094). Baseline assessment took place between November 2006 and December 2013 and included information on socioeconomic (age, sex, level of education and income), social contact, and health-related factors [eg, self-rated health, body mass index, chronic health conditions, and health behavior (alcohol consumption and smoking)]. Participants also reported the presence of geriatric syndromes (ie, included falls, incontinence, vision impairment, hearing impairment, depressive symptoms, and frailty at baseline). Three follow-up questionnaires were used to examine the incidence of any and specific chronic health conditions (ie, pulmonary and cardiovascular diseases, diabetes, cancer, and neurological diseases). Cox regression was used to analyze the longitudinal associations between geriatric syndromes and incident chronic health conditions. Older community-dwelling individuals with at least one geriatric syndrome (44.7%, n=4038) had an increased risk of developing any new chronic health condition [hazard ratio (HR) 1.35; 95% confidence interval (CI) 1.21-1.51]. The association was attenuated but remained significant after adjustment for socioeconomic factors, social contact, health status, and health behavior (HR 1.27; 95% CI 1.12-1.43). Analyses for specific chronic health conditions showed that compared with older community-dwellers without geriatric syndromes, those with geriatric syndromes had an increased risk to develop a cardiovascular health condition (HR 1.42; 95% CI 1.13-1.79) or diabetes (HR 1.53; 95% CI 1.11-2.11). They had no increased risk to develop pulmonary conditions, cancer, or neurological conditions. The presence of geriatric syndromes is associated with incident chronic health conditions, specifically cardiovascular conditions and diabetes. Increased awareness is needed among older people with geriatric syndromes and their physicians. Comprehensive assessments of geriatric syndromes may help to prevent or at least delay the development of chronic health conditions.

Predator odor exposure increases social contact in adolescents and parental behavior in adulthood in Brandt’s voles

Research suggests that predation risk during adolescence can program adult stress response and emotional behavior; however, little is known about the short-term and lasting residual effects of this experience on social behavior. We explored this concept in social Brandt’s voles (Lasiopodomys brandtii). Adolescent male and female voles were exposed to distilled water, rabbit urine (as a non-predator stimulus), and cat urine for 60 min daily from postnatal day (PND) 28–49. Social play tests were conducted immediately following exposure on PND 28, 35, 42, and 49. In the social play test, repeated cat odor (CO) exposure enhanced the contact behavior of voles with their cagemate. Adolescent exposure to CO did not affect behavioral responses toward unrelated pups in the alloparental behavior test or same-sex individuals in the social interaction test. However, exposure to CO significantly enhanced the licking/grooming behavior of voles towards their own pups in the home cage parental behavior test. Repeated CO exposure significantly inhibited weight gain in male voles during adolescence. This effect was transmitted to the next generation, with lower weight gain in offspring before weaning. Following repeated CO exposure, males tended to have more female offspring whereas females produced more offspring, suggesting an adaptive strategy to increase inclusive fitness under predatory risk. These findings demonstrate that adolescent exposure to predatory risk augments adolescent social contact and adult parental behavior and suggest a role for improved inclusive fitness in mediating long-term outcomes.

Optimizing antiviral treatment for seasonal influenza in the USA: a mathematical modeling analysis

BackgroundSeasonal influenza remains a major cause of morbidity and mortality in the USA. Despite the US Centers for Disease Control and Prevention recommendation promoting the early antiviral treatment of high-risk patients, treatment coverage remains low.MethodsTo evaluate the population-level impact of increasing antiviral treatment timeliness and coverage among high-risk patients in the USA, we developed an influenza transmission model that incorporates data on infectious viral load, social contact, and healthcare-seeking behavior. We modeled the reduction in transmissibility in treated individuals based on their reduced daily viral load. The reduction in hospitalizations following treatment was based on estimates from clinical trials. We calibrated the model to weekly influenza data from Texas, California, Connecticut, and Virginia between 2014 and 2019. We considered in the baseline scenario that 2.7–4.8% are treated within 48 h of symptom onset while an additional 7.3–12.8% are treated after 48 h of symptom onset. We evaluated the impact of improving the timeliness and uptake of antiviral treatment on influenza cases and hospitalizations.ResultsModel projections suggest that treating high-risk individuals as early as 48 h after symptom onset while maintaining the current treatment coverage level would avert 2.9–4.5% of all symptomatic cases and 5.5–7.1% of all hospitalizations. Geographic variability in the effectiveness of earlier treatment arises primarily from variabilities in vaccination coverage and population demographics. Regardless of these variabilities, we found that when 20% of the high-risk individuals were treated within 48 h, the reduction in hospitalizations doubled. We found that treatment of the elderly population (> 65 years old) had the highest impact on reducing hospitalizations, whereas treating high-risk individuals aged 5–19 years old had the highest impact on reducing transmission. Furthermore, the population-level benefit per treated individual is enhanced under conditions of high vaccination coverage and a low attack rate during an influenza season.ConclusionsIncreased timeliness and coverage of antiviral treatment among high-risk patients have the potential to substantially reduce the burden of seasonal influenza in the USA, regardless of influenza vaccination coverage and the severity of the influenza season.