Problematic Internet Use Was Associated With Psychological Problems Among University Students During COVID-19 Outbreak in China

(In)Congruence in Perceived Mother-child Cohesion and Informants' Depressive Symptoms: A Dyadic Response Surface Analysis

Mother-child cohesion, reflecting the emotional connection between mothers and children, is a protective factor for individuals' mental health. The Modified Operations Triad Model suggests that children and mothers hold either congruent or incongruent views of their perceived cohesion, which reflects family functioning and is an indication of future mental health outcomes for family members. Despite increasing research on the impact of (in)congruence in perceived family functioning on children's mental health, few studies concurrently address the mental health of both mothers and children, overlooking their interdependence. This longitudinal study with multi-informant reports explored the long-term and developmental effects of (in)congruence in perceived mother-child cohesion on informants' depressive symptoms. A total of 577 families participated at the first time point, comprising 577 children (52.34% girls, Mage = 10.11 years) and 577 mothers (Mage = 37.32 years). The Dyadic Response Surface Analysis revealed that mother-child congruence at high levels of cohesion (versus low levels) predicted fewer depressive symptoms in mothers and children after three and nine months, as well as decreased depressive symptoms over nine months. Children who reported higher levels of cohesion than their mothers experienced fewer depressive symptoms after three months. Mothers with higher levels of cohesion than their children reported fewer depressive symptoms after three months. The current findings emphasize the importance of identifying and resolving discrepancies in perceived mother-child cohesion between mothers and children to promote a healthy family environment.

Technostress and academic motivation: direct and indirect effects on university students' psychological health

Introduction

Research has well demonstrated that the pandemic entailed several implications among university students worldwide in terms of increased use of Information and Communication Technologies (ICTs), technostress, disruptions in academic goals and motivation processes, and growing psychological suffering. Responding to the new research need to go in-depth into the processes linking technostress and motivation dimensions to inform current research/interventions, the present study aimed to explore the direct effects of perceived Technostress dimensions (Techno-Overload, Work-Home Conflict, Pace of Change, Techno-Ease, Techno-Reliability, and Techno-Sociality) and Academic Motivation dimensions (Amotivation, Intrinsic, and Extrinsic Motivation dimensions) on students' perceived levels of Anxiety/Depression and test the potential indirect effect (mediating role) of Academic Motivation dimensions in the associations between Technostress and psychological health conditions.

Methods

Overall, 1,541 students from five European countries (Czech Republic, Greece, Italy, Serbia, United Kingdom) completed a survey comprising a Background Information Form, the Technostress Scale, the Academic Motivation Scale-College, and the Hospital Anxiety and Depression Scale. Hayes' PROCESS tool was used to test direct and indirect (mediating) effects.

Results

Data revealed that Techno-Overload, Work-Home Conflict, Amotivation, and Extrinsic Motivation-Introjected had a direct negative effect, whereas Techno-Ease, Techno-Reliability, Techno-Sociality, all Intrinsic Motivation dimensions, and Extrinsic Motivation-Identified had a direct protective role for students' psychological health. The significant indirect role of motivation dimensions in the associations between Technostress dimensions and Anxiety/Depression was fully supported.

Discussion

Findings allow gaining further insight into the pathways of relationships between technostress, motivation, and psychological health, to be used in the current phase, featured by the complete restoration of face-to-face contacts, to inform the development of tailored research and interventions, which address lights and shadows of the technology use, and which take into account the necessity to enhance its potentials yet without impairing students' motivation and psychological health.

Knowledge, attitudes, and practices regarding COVID-19 and mental health status among college students in China: a cross-sectional study

Background

During the prevalence of coronavirus disease 2019 (COVID-19), little was known about the knowledge, attitudes, practices (KAP) about COVID-19 and psychological status of college students in minority areas. This study aimed to evaluate the KAP of college students in minority areas of China toward COVID-19 and to provide a scientific basis for health education and policy formulation.

Methods

From October 28th to November 6th, 2021, a cross-sectional study was conducted with 5,272 college students to examine KAP and its effects on mental health.

Results

Regarding COVID-19 knowledge, the overall awareness rate was 24.11% (1,271). Regarding health attitudes, most students had positive attitudes about COVID-19 prevention and control (94.95%), and females had higher positive attitudes than males (OR: 1.920; CI: 1.494-2.469). Regarding preventive behaviors, more than half of the students took preventive measures (53.48%), and freshmen had the highest health behavior scores. In terms of psychological status, there were fewer females with depression and stress than males.

Conclusion

College students in minority areas have positive health attitudes; however, their knowledge of COVID-19 prevention and control is low. Moreover, their precautionary behaviors are insufficient, and they have many negative emotions.

Anxiety, depression, insomnia, and PTSD among college students after optimizing the COVID-19 response in China

BACKGROUND

The number of COVID-19 infections has increased sharply and quickly after optimizing the COVID-19 response in China. In the context of this population-size infection, college students' psychological response is yet to be understood.

METHODS

A cross-sectional study was designed to investigate anxiety, depression, insomnia, and post-traumatic stress disorder (PTSD) symptoms among college students from December 31, 2022, to January 7, 2023. The questionnaire included the Generalized Anxiety Disorder 7 (GAD-7), Patient Health Questionnaire 9 (PHQ-9), Insomnia Severity Index (ISI), Impact of Event Scale (IES-R), and self-designed questionnaire.

RESULTS

Of the 22,624 respondents, the self-reported prevalence of anxiety, depression, insomnia, PTSD, and any of the four psychological symptoms appeared as 12.7 %, 25.8 %, 11.6 %, 7.9 %, and 29.7 %, respectively. The self-reported COVID-19 infection rate was 80.2 %. Changes in the place for learning, longer time online, not recovering after infection, a higher proportion of family member infection, insufficient drug reserve, worry about sequela after infection, future studies, or employment contributed to a higher risk of anxiety/depression/insomnia symptoms or PTSD symptoms. Multinomial logistic regression showed that those who spent more extended time on the Internet, recovered after infection, and had insufficient drug reserves were less likely to have PTSD than anxiety/depression/insomnia symptoms.

LIMITATIONS

The study was a non-probability sampling survey.

CONCLUSIONS

Anxiety, depression, insomnia, and PTSD were common psychological symptoms among college students when infection went through a large-scale population. This study highlights the importance of continuing to care for the psychological symptoms of college students, especially timely responses to their concerns related to the epidemic situation and COVID-19 infection.

The prevalence of post-traumatic stress disorder in college students by continents and national income during the COVID-19 pandemic: a meta-analysis

Introduction

The present study aimed to provide a more accurate representation of post-traumatic stress disorder (PTSD) in college students during COVID-19 by performing meta-analyses by continents, national income, and study majors, and comparing the results with estimated pooled prevalence.

Methods

Based on the guideline of PRISMA, literature was searched in PubMed, Web of Science, and Embase. The prevalence of PTSD was estimated through a random model based on the different continents and levels of national income, as well as study majors, and compared with the pooled prevalence of PTSD among college students.

Results

Totally 381 articles were retrieved from electronic databases and 38 articles were included in the present meta-analysis. The results showed that the pooled prevalence of college students' PTSD was 25% (95% CI: 21-28%). Prevalence estimates of PTSD among college students were statistically significant (p < 0.00001) when stratified with geographical regions, income levels, and study majors. In comparison with the pooled prevalence of PTSD (25%), subgroups of Africa and Europe, lower-middle-income countries, and medical college students possessed higher prevalence estimates.

Discussion

The findings of the study showed that the prevalence of PTSD in college students worldwide during COVID-19 was relatively high and varied in different continents and countries with different income levels. Therefore, healthcare providers should pay attention to the psychologically healthy condition of college students during COVID-19.

Children's excessive digital media use, mental health problems and the protective role of parenting during COVID-19

COVID-19's outbreak in March 2020 and the social distancing measures that followed it changed the lives of children worldwide. Studies assessing the pandemic's implications for children have reported an alarming increase in the use of digital media (DM) and warned of its adverse impacts on children's functioning and development. The current study aimed to assess the relationship between excessive and problematic DM use and emotional, behavioral, and academic functioning among Israeli adolescents during COVID-19 and to identify adolescents at elevated risk of developing problematic DM use. Three hundred forty-seven Israeli parent-child dyads (M age = 11.81, SD = 1.41) separately completed measures assessing children's DM use (time and addiction), functioning (academic, social, emotional, and behavioral), behavioral dysregulation, and the parents' parenting practices. The results showed that DM addiction, but not DM use, was related to children's emotional, behavioral, and academic difficulties. Moreover, the results indicated that negative parenting and behavioral dysregulation increased the risk of DM addiction, which in turn increased emotional, behavioral, and academic difficulties. The results underscored parents' role in preventing problematic DM use and highlighted the need to treat DM use and problematic DM use as distinct constructs.

The prevalence and risk factors of mental problems in medical students during COVID-19 pandemic: A systematic review and meta-analysis

BACKGROUND

This meta-analysis and systematic review aimed to evaluate the global prevalence and risk factors of mental problems (i.e., depression, anxiety, stress, sleep disorder, posttraumatic stress disorder (PTSD), burnout, psychological distress, and suicidal ideation) among medical students during the COVID-19 pandemic.

METHOD

We searched PubMed, Embase, Web of Science, psycARTICLES, PsycINFO, CNKI, and Wan Fang for studies on the prevalence of mental problems among medical students from January 1, 2020, to April 1, 2022. The pooled prevalence was calculated by random-effect models. We performed a narrative review to identify the risk factors.

RESULTS

The meta-analysis included 201 studies (N = 198,000). The prevalence of depression (41 %, 95 % CI, 37-45 %,), anxiety (38 %,95 % CI, 34 %-42 %), stress (34 %, 95 % CI, 27 %-42 %), sleep disorder (52 %, 95 % CI, 44 %-60 %), psychological distress (58 %, 95 % CI, 51 %-65 %), PTSD (34 %, 95 % CI, 22 %-46 %), suicidal ideation (15 %, 95 % CI, 11 %-18 %) and burnout (38 %, 95 % CI, 25 %-50 %) was high. The major risk factors were being female, being junior or preclinical students, exposure to COVID-19, academic stress, psychiatric or physical disorders history, economic trouble, fear of education impairment, online learning trouble, fear of infection, loneliness, low physical activity, low social support, problematic internet or smartphone use, and young age.

LIMITATIONS

Most studies were cross-sectional. Few studies provided a reasonable response rate, suggesting potential selection bias.

CONCLUSIONS

The study demonstrated a high prevalence and risk factors for mental problems during COVID-19, calling for mental health services. Our findings are valuable for college and health authorities to identify high-risk students and provide targeted intervention.

Problematic internet use and depressive symptoms among the school-going adolescents in Bangladesh during the COVID-19 pandemic: A cross-sectional study findings

Background and Aims

Problematic internet use (PIU) by children and adolescents is a concern for many parents. Several factors, including students' education level, the method of instruction, the dependence on the internet, and their intended use of the internet, could all be contributing factors to PIU and depression. Disturbed mental health may be attributed to the cancellation of physical education classes because of the COVID-19 outbreak. This study aimed to assess the association of COVID-19 pandemic with PIU and depressive symptoms in adolescent students.

Methods

We performed this cross-sectional study among 491 school-going adolescents of 10 to 16 years. Self-administered questionnaires were applied to collect sociodemographic information and the internet usage pattern of the participants. We measured the prevalence of PIU and depressive symptoms using the PIU questionnaire (PIUQ-SF-6) and patient health questionnaire-9 (PHQ-9).

Results

The estimations of the risk group for PIU and depressive symptoms among school-going adolescents were 80.04% and 77.80%, respectively. The latent profiling of PIU scores for obsession, neglect, and control sub-groups were 5.82, 6.12, and 6.35, respectively. Moreover, we observed mild, moderate, and severe depressive symptoms in 48.68%, 27.70%, and 1.43% of cases. Age, education level, medium of education, financial impression, internet connection, the device used, the purpose for internet use, and the living status of respondents were significantly associated with the PIU. Reported mental health issues was associated with education level, medium of education, financial impression, and internet connection.

Conclusion

The present study revealed an association of PIU and depressive symptoms with sociodemographic factors and internet usage patterns. Therefore, these results might have practical implications in clinical psychology, psychiatry, and psychotherapy. The healthcare professional can develop a context-specific comprehensive clinical intervention plan for children and adolescents.

Problematic use of the Internet in low- and middle-income countries before and during the COVID-19 pandemic: a scoping review

People from low- and middle-income countries (LMICs) represent large portions of the world population, often occupy less favorable living conditions, and typically suffer greater health risks, yet frequently receive little research and global health attention. The present study reviews emerging evidence on problematic use of the Internet (PUI) in LMICs prior/during the COVID-19 pandemic. Analyzed studies mainly focused on general properties of PUI in university students, problematic gaming in youth, or problematic use of social media in adults, registering higher prevalence estimates, as compared with earlier reports. Research mainly focused on initially affected regions and COVID-exposed populations. Overall, unfavorable circumstances, including poor social support, family relationships, and lifestyle tendencies/habits, may present potential risk for PUI in LMICs, likely exacerbated during the pandemic.

Estimation of Behavioral Addiction Prevalence During COVID-19 Pandemic: A Systematic Review and Meta-analysis

Purpose of Review

The COVID-19 pandemic changed people’s lifestyles and such changed lifestyles included the potential of increasing addictive behaviors. The present systematic review and meta-analysis aimed to estimate the prevalence of different behavioral addictions (i.e., internet addiction, smartphone addiction, gaming addiction, social media addiction, food addiction, exercise addiction, gambling addiction, and shopping addiction) both overall and separately.

Recent Findings

Four databases (PubMed, Scopus, ISI Web of Knowledge, and ProQuest) were searched. Peer-reviewed papers published in English between December 2019 and July 2022 were reviewed and analyzed. Search terms were selected using PECO-S criteria: population (no limitation in participants’ characteristics), exposure (COVID-19 pandemic), comparison (healthy populations), outcome (frequency or prevalence of behavioral addiction), and study design (observational study). A total of 94 studies with 237,657 participants from 40 different countries (mean age 25.02 years; 57.41% females). The overall prevalence of behavioral addiction irrespective of addiction type (after correcting for publication bias) was 11.1% (95% CI: 5.4 to 16.8%). The prevalence rates for each separate behavioral addiction (after correcting for publication bias) were 10.6% for internet addiction, 30.7% for smartphone addiction, 5.3% for gaming addiction, 15.1% for social media addiction, 21% for food addiction, 9.4% for sex addiction, 7% for exercise addiction, 7.2% for gambling addiction, and 7.2% for shopping addiction. In the lockdown periods, prevalence of food addiction, gaming addiction, and social media addiction was higher compared to non-lockdown periods. Smartphone and social media addiction was associated with methodological quality of studies (i.e., the higher the risk of boas, the higher the prevalence rate). Other associated factors of social media addiction were the percentage of female participants, mean age of participants, percentage of individuals using the internet in country, and developing status of country. The percentage of individuals in the population using the internet was associated with all the prevalence of behavioral addiction overall and the prevalence of sex addiction and gambling addiction. Gaming addiction prevalence was associated with data collection method (online vs. other methods) that is gaming addiction prevalence was much lower using online methods to collect the data.

Summary

Behavioral addictions appeared to be potential health issues during the COVID-19 pandemic. Healthcare providers and government authorities should foster some campaigns that assist people in coping with stress during COVID-19 pandemics to prevent them from developing behavioral addictions during COVID-19 and subsequent pandemics.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40429-022-00435-6.

Internet Addiction in Socio-Demographic, Academic, and Psychological Profile of College Students During the COVID-19 Pandemic in the Czech Republic and Slovakia

Internet addiction is a serious problem among young adults that requires increased attention, especially at a time of distance learning during the coronavirus disease 2019 (COVID-19) pandemic. The aim of the study was to assess the relationships between internet addiction and selected socio-demographic, study-related, and psychological characteristics of college students. Internet addiction was measured using the Internet Addiction Test both overall and in its individual subscales (Salience, Excessive Use, Neglect Work, Anticipation, Lack of Control, and Neglect Social Life). The selected characteristics represented (1) socio-demographic profile (gender, age, residence, family), (2) academic profile (housing during the semester, form of study), and (3) psychological profile (depressive symptoms—the Patient Health Questionnaire, stress—the Perceived Stress Scale, anxiety symptoms—the Generalized Anxiety Disorder). Data collection took place during the first wave of the COVID-19 pandemic in 2020 at Czech and Slovak colleges, with 1,422 students from the Czech Republic and 1,677 students from Slovakia participating in the research. The analytical processes were carried out through descriptive analysis, non-parametric difference analysis, and multiple negative binomial regression. Mild internet addiction was found in 387 (27.2%) Czech and 452 (27.0%) Slovak students. Moderate internet addiction was identified in 49 (3.4%) students from the Czech Republic and in 100 (6.0%) students from Slovakia. Two (0.1%) Czech and three (0.2%) Slovak students reported severe internet addiction. Increased likelihood of internet addiction overall, as well as in most individual subscales, was found particularly among male students and students who lived away from home during the semester. Depressive symptoms and stress could also be considered significant predictors in both countries. These results are important for the development of effective strategies and prevention programs, as Internet addiction may be a serious problem in the future, given the current times. When assessing internet addiction among college students, it would also be appropriate to evaluate the individual internet addiction subscales and their specifics.

Internet Addiction, Symptoms of Anxiety, Depressive Symptoms, Stress Among Higher Education Students During the COVID-19 Pandemic

Poor mental health is a growing concern among young people during the coronavirus disease 2019 (COVID-19) pandemic. The aim of this study was to assess the associations of Internet addiction with depressive symptoms, anxiety symptoms, and stress in higher education students during the COVID-19 pandemic, as well as to examine these mental health problems in the context of study-related characteristics. The research sample consisted of 3,099 participants from the Czech Republic (CZ: 1,422) and Slovak Republic (SK: 1,677). The Internet Addiction Test (IAT), the Generalized Anxiety Disorder (GAD-7) scale, the Patient Health Questionnaire for depressive symptoms (PHQ-9), and the Perceived Stress Scale (PSS) were used to measure mental health problems. The analyses also included demographic data (gender and age) and study-related characteristics (form of study, degree of study, field of study, distance between college and home, and housing during the semester). Based on the results of frequency and descriptive analyses, the prevalence of mental health problems was high. The most serious levels of Internet addiction (IAT cut-off point ≥ 50), to which attention should be paid, were found in 3.5% of Czech and 6.2% of Slovak students. Using the standard cut-off point of GAD-7 ≥ 10, 14.1% of Czech and 11.6% of Slovak students were identified with anxiety symptoms. Regarding the PHQ-9 with the cut-off point ≥ 10, 23.4% of Czech and 19.1% of Slovak students had depressive symptoms, which should be addressed. Using the PSS cut-off point ≥ 27, 12.9% of Czech students and 9.1% of Slovak students perceived high stress. The quantile regression analysis showed that Internet addiction was positively associated with anxiety symptoms, depressive symptoms, and stress in all of the analyzed cases (p-value < 0.001). In terms of study-related characteristics, the binomial logistic regression analysis revealed that risk factors for mental health problems in Czech and Slovak students were mainly full-time form of study and living away from home during the semester. Internet addiction, anxiety symptoms, depressive symptoms, and stress are issues that require increased attention, and professionals and policy-makers should implement interventions to effectively prevent and help students with psychological problems.

Prevalence of smartphone addiction and its effects on subhealth and insomnia: a cross-sectional study among medical students

OBJECTIVE

This study aimed to assess Chinese medical students' smartphone addiction and its effects on subhealth and insomnia.

METHODS

A cross-sectional survey was conducted from October 14, 2020 to November 14, 2020 by administering an online questionnaire to Wannan Medical College students.

RESULTS

Of 2741 students who completed the survey, 1,447 (52.8%) had smartphone addiction. Medical specialty (p = 0.004), alcohol consumption (p = 0.001), smartphone use in bed (p = 0.000), depression (p = 0.000) and anxiety (p = 0.000) were strongly associated with smartphone addiction. The impacts of smartphone addiction on subhealth (p = 0.000) and insomnia (p = 0.000) were significant.

CONCLUSION

This survey shows that the smartphone addiction detection rate among medical students was 52.8%. Students who did not like their medical specialty, consumed alcohol, used their smartphones in bed, and suffered from depression and anxiety had a higher smartphone addiction detection rate. The subhealth and insomnia of medical students are adversely associated with smartphone addiction.

COVID-19-Related Social Isolation Predispose to Problematic Internet and Online Video Gaming Use in Italy

COVID-19 pandemic and its related containment measures have been associated with increased levels of stress, anxiety and depression in the general population. While the use of digital media has been greatly promoted by national governments and international authorities to maintain social contacts and healthy lifestyle behaviors, its increased access may also bear the risk of inappropriate or excessive use of internet-related resources. The present study, part of the COVID Mental hEalth Trial (COMET) study, aims at investigating the possible relationship between social isolation, the use of digital resources and the development of their problematic use. A cross sectional survey was carried out to explore the prevalence of internet addiction, excessive use of social media, problematic video gaming and binge watching, during Italian phase II (May-June 2020) and III (June-September 2020) of the pandemic in 1385 individuals (62.5% female, mean age 32.5 ± 12.9) mainly living in Central Italy (52.4%). Data were stratified according to phase II/III and three groups of Italian regions (northern, central and southern). Compared to the larger COMET study, most participants exhibited significant higher levels of severe-to-extremely-severe depressive symptoms (46.3% vs. 12.4%; p < 0.01) and extremely severe anxiety symptoms (77.8% vs. 7.5%; p < 0.01). We also observed a rise in problematic internet use and excessive gaming over time. Mediation analyses revealed that COVID-19-related general psychopathology, stress, anxiety, depression and social isolation play a significant role in the emergence of problematic internet use, social media addiction and problematic video gaming. Professional gamers and younger subjects emerged as sub-populations particularly at risk of developing digital addictions. If confirmed in larger and more homogenous samples, our findings may help in shedding light on possible preventive and treatment strategies for digital addictions.

Do Academic Stress, Burnout and Problematic Internet Use Affect Perceived Learning? Evidence from India during the COVID-19 Pandemic

Distress in online classrooms and problematic internet use are two issues that have caused student burnout and affect perceived learning during the COVID-19 pandemic. Given the high pressure placed on students throughout COVID-19, it is critical to understand the influence of problematic internet use (PIU), psychological stress, academic burnout, and resilience on perceived learning (PL). A cross-sectional analytical study was chosen to collect data from 350 learners pursuing undergraduate and postgraduate business/management degrees in Karnataka, India. The data were analyzed using SPSS (Statistical Package for Social Science) and Smart PLS 3. The present study reports a non-significant negative total effect of stress on PL, while there was a significant positive direct effect but a significant indirect negative effect of multiple mediators, namely PIU, burnout, and resilience. In the relationship between stress and PL, burnout has full competitive mediation, and the suppressive effect of burnout and resilience wipes out the beneficial benefit of stress on PL, resulting in reduced PL. As a societal problem, a change in educational policy and prevention strategies for students and organizations (reducing the number of courses, number of exams, and handling parental expectations) would be effective. Emotional intelligence to improve resilience, which assists students in sailing through a current challenging situation and using IT for reducing negative and unexpected emotional outbursts should be encouraged.

Self-reported mental health symptoms, quality of life and coping strategies in French health sciences students during the early stage of the COVID-19 pandemic: An online survey

Introduction

Health sciences students usually report high rates of mental health problems. The COVID-19 pandemic context may have serious psychological impacts in this at-risk population. We aimed to assess the self-reported mental health status, health-related quality of life and coping strategies of health sciences students during the early stage of the pandemic.

Method

An online 128-item questionnaire sent to 17,673 health sciences students from the Claude Bernard University Lyon 1 in April 2020 assessed: a) sociodemographic characteristics, b) conditions of lockdown, c) depressive (Beck Depression Inventory- Short Form, BDI-SF), anxiety (State-Trait Anxiety Inventory-A, STAI-A) and traumatic symptoms (Impact of Event Scale -Revised, IES-R), d) health-related quality of life (SF12) and e) coping strategies (Brief Coping Orientation to Problems Experienced, Brief COPE).

Results

The participation rate was 9.9% (n = 1,765). A total of 19.5% of participants reported an IES-R > 33, 11.6% depressive symptoms, 58.1% anxiety symptoms, and 4.4% suicidal ideation. Their mental health-related quality of life was significantly poorer than for physical health. Female gender, COVID-like symptoms, social isolation due to the lockdown, pandemic-related financial restraint and exams-related stress were significantly associated with poorer self-reported mental health conditions. Volunteering in the healthcare system was significantly associated with lower mental health scores. Coping strategies were mostly oriented toward avoidance and positive appraisal.

Conclusion

French health sciences students exhibited high levels of self-reported mental health problems and a poor mental health-related quality of life during the early stage of the COVID-19 pandemic. Specific risk factors related to the pandemic partly explain the observed prevalence.