Large-scale Population Surveys Research Articles

Prevalence of mass social media-induced illness presenting with Tourette-like behavior in Germany between 2019 and 2021

Starting in 2019, in Germany the first well documented outbreak of mass sociogenic illness induced by social media (mass social media-induced illness; MSMI) occurred presenting with functional Tourette-like behaviors (FTB). This study aimed to provide first data on the prevalence rate of MSMI-FTB in Germany between 2019 and 2021 in the general population. We conducted a large-scale representative population survey in cooperation with the USUMA market and social research institute. Between August and December 2021, n = 2.509 people (mean age: 49.5 years, range: 16–95 years, n = 1.276 females) were randomly selected, visited in their households, interviewed, and asked to answer for themselves, but also for close family members (n = 6.744). Thus, in total, we received answers for n = 9.253 people. Probable MSMI-FTB was found in n = 33 individuals (mean age at onset: 30.5 years, n = 8 females). Based on strict criteria, the diagnosis of MSMI-FTB was considered highly likely in 16/33 individuals (mean age at onset: 25.6 years, n = 2 females) corresponding to prevalence rates of 0.17% (CIlower = 0.10, CIupper = 0.28) and 0.36% (CIlower = 0.25, CIupper = 0.50), respectively. This is the first large-scale, population representative study investigating the prevalence of MSMI-FTB in the general population in Germany between 2019 and 2021. Based on the prevalence rates found, MSMI-FTB is highly relevant for health economy. Accordingly, we suggest educating healthcare professionals and the general public to avoid misdiagnosis and inefficient treatment.

From Global Domains to Physical Activity Environments: Development and Initial Validation of a Questionnaire-Based Physical Literacy Measure Designed for Large-Scale Population Surveys

ABSTRACT This study aimed to develop and test MyPL, a questionnaire that measures self-reported physical literacy (PL) among children and adolescents. First, the item pool was developed and adapted, and face validity was tested with cognitive interviewing. Then, factor structures were identified through multidimensional scaling and exploratory factor analyses in a sample of 951 children (ages 7–13). Then, the identified models were tested using confirmatory factor analyses CFA) within a sample of 2861 children (ages 7–12) and a sample of 1518 children (ages 13-15). Finally, measurement invariance and predictive validity were investigated. CFA showed that the identified physical activity (PA) environment-based models fitted better with the data than the domain-derived model. Reliability analyses showed that the internal consistency of the total PL scale was good and that, the reliability of the identified scales, except the cognitive scale, of the two models based on PA environments was satisfactory. Additionally, MyPL also showed measurement invariance across gender. This study suggests that the type of PA and the environment in which PA occur is important to consider when designing PL measurement tools. This study indicated that MyPL can be used to measure children and young people’s PL in large surveys.

Sense of Coherence and Incident Dementia in Older Japanese Adults: The Japan Gerontological Evaluation Study

ObjectivesThe sense of coherence refers to effectively using available resources to manage stress and promote overall health. Previous studies have linked it to various health outcomes; however, evidence regarding its association with the risk of incident dementia is limited. Hence, this study aimed to fill this research gap using data from a large-scale population survey. DesignProspective cohort study. Setting and ParticipantsThis study included 31,556 participants aged 65 years and older who were free from dementia and disabilities. The participants were enrolled in the 2010 baseline survey of the Japan Gerontological Evaluation Study, and were followed up until the end of 2019. MethodsThe sense of coherence was assessed using a 6-item short-version questionnaire. Incident dementia cases were ascertained through the public long-term care insurance database in Japan. ResultsDuring a median follow-up of 8.3 years, 4326 incident dementia cases were identified. After adjusting for conventional risk factors, the hazard ratios (95% CIs) for each quintile compared to the lowest quintile of the sense of coherence were 0.82 (0.75-0.90), 0.75 (0.68-0.83), 0.76 (0.68-0.84), and 0.78 (0.70-0.87), respectively. The multivariable hazard ratio (95% CI) per 1-SD increment was 0.91 (0.88-0.95). These inverse associations did not exhibit any gender differences (P for gender interaction = .11) and were further confirmed after excluding early incident cases. Similar associations were found for its components; the corresponding multivariable hazard ratios (95% CIs) per 1-SD increment were 0.94 (0.91-0.97) for comprehensibility, 0.92 (0.89-0.95) for manageability, and 0.93 (0.90-0.97) for meaningfulness. Conclusions and ImplicationsModerate and above sense of coherence was associated with the lower risk of dementia among the older population, suggesting a beneficial role of stress management in maintaining the cognitive health of older adults.

How to Detect and Influence Looking Up Answers to Political Knowledge Questions in Web Surveys

Abstract When answering political knowledge questions in web surveys, respondents can look up the correct answer on the Internet. This response behavior artificially inflates political knowledge scores that are supposed to measure fact-based information. In the present study, we address the existing knowledge gaps of previous research regarding looking up answers to political knowledge questions in web surveys. We conducted an experimental study based on the German Internet Panel, a large-scale population survey that uses a probability-based sample. Based on this experiment, we show that instructions help to reduce the number of lookups to knowledge questions in web surveys. We provide further evidence that looking up answers results in more correct answers to knowledge questions and, thus, in inflated political knowledge scores. Finally, our findings illustrate the challenges and benefits of using self-reported or paradata-based lookup measures as well as a combined measure that aims at utilizing both to detect lookups to political knowledge questions in web surveys.

A global survey of Salmonella plasmids and their associations with antimicrobial resistance.

Plasmids are the primary vector for horizontal transfer of antimicrobial resistance (AMR) within bacterial populations. We applied the MOB-suite, a toolset for reconstructing and typing plasmids, to 150 767 publicly available Salmonella whole-genome sequencing samples covering 1204 distinct serovars to produce a large-scale population survey of plasmids based on the MOB-suite plasmid nomenclature. Reconstruction yielded 183 017 plasmids representing 1044 primary MOB-clusters and 830 potentially novel MOB-clusters. Replicon and relaxase typing were able to type 83.4 and 58 % of plasmids, respectively, compared to 99.9 % for MOB-clusters. Within this work, we developed an approach to characterize the horizonal transfer of MOB-clusters and AMR genes across different serotypes, as well as the diversity of MOB-cluster associations with AMR genes. Aggregating conjugative mobility predictions provided by the MOB-suite and their corresponding serovar entropy demonstrated that non-mobilizable plasmids were associated with fewer serotypes compared to mobilizable or conjugative MOB-clusters. The host-range predictions for MOB-clusters also showed differences between the mobility classes, with mobilizable MOB-clusters accounting for 88.3 % of the multi-phyla (broad-host-range) predictions compared to 3 and 8.6 % for conjugative and non-mobilizable, respectively. A total of 296 (22 %) of identified MOB-clusters were associated with at least one resistance gene, indicating that the majority of Salmonella plasmids are not involved in AMR dissemination. Shannon entropy analysis of horizontal transfer of AMR genes across serovars and MOB-clusters demonstrated that horizonal transfer of genes is higher between serovars compared to transfer between different MOB-clusters. In addition to the population structure characterization based on primary MOB-clusters, we characterized a multi-plasmid outbreak responsible for the global dissemination of bla CMY-2 across different serotypes using higher resolution MOB-suite secondary cluster codes. The plasmid characterization approach developed here can be applied to different organisms to identify plasmids and genes which pose high risks for horizontal transfer.

Relationship between depression and lifestyle factors in Chinese adults using multi-level generalized estimation equation model.

Relationship between depression and lifestyle factors in Chinese adults using multi-level generalized estimation equation model.

Screening for loneliness in representative population samples: Validation of a single-item measure.

Loneliness is a highly relevant public mental health issue. This work presents the validation of a single-item measure of loneliness and its subjective experience: "I am frequently alone/have few contacts". It can be used in large-scale population surveys where an economical assessment is of key importance. Data was drawn from two representative German population surveys conducted in early and late 2020 (combined N = 4,984; 52.9% women; age: M = 48.39 years (SD = 17.88)). We determined the prevalence of loneliness in men and women across different age groups. In order to test concurrent validity, bivariate correlation analyses and Chi-square tests were performed. Convergent and discriminant validity were tested by investigating intercorrelations of the single-item measure of loneliness with another loneliness measure, other mental health outcomes, and associations with sociodemographic characteristics. Based on the single-item measure, 23.4% of participants reported some degree of loneliness, 3.4% among them severe loneliness. Comparisons with the LS-S showed similar prevalence rates of loneliness. A moderately positive relationship between the two loneliness measures was found by bivariate correlation analysis (ρ = .57, p < .001), but results indicated only weak convergent validity. Construct validity was supported by associations with depressive symptoms, anxiety symptoms, satisfaction with life, household size, and partnership. Loneliness is frequently reported in the general population. The single-item measure of loneliness is suitable as a brief screening measure in population-based assessments.

A Methodology for Integrating Population Health Surveys Using Spatial Statistics and Visualizations for Cross-Sectional Analysis.

Large-scale population surveys are beneficial in gathering information on the performance indicators of public well-being, including health and socio-economic standing. However, conducting national population surveys for low and middle-income countries (LMIC) with high population density comes at a high economic cost. To conduct surveys at low-cost and efficiently, multiple surveys with different, but focused, goals are implemented through various organizations in a decentralized manner. Some of the surveys tend to overlap in outcomes with spatial, temporal or both scopes. Mining data jointly from surveys with significant overlap gives new insights while preserving their autonomy. We propose a three-step workflow for integrating surveys using spatial analytic workflow supported by visualizations. We implement the workflow on a case study using two recent population health surveys in India to study malnutrition in children under-five. Our case study focuses on finding hotspots and coldspots for malnutrition, specifically undernutrition, by integrating the outcomes of both surveys. Malnutrition in children under-five is a pertinent global public health problem that is widely prevalent in India. Our work shows that such an integrated analysis is beneficial alongside independent analyses of such existing national surveys to find new insights into national health indicators.

Parton distributions need representative sampling

In global QCD fits of parton distribution functions (PDFs), a large part of the estimated uncertainty on the PDFs originates from the choices of parametric functional forms and fitting methodology. We argue that these types of uncertainties can be underestimated with common PDF ensembles in high-stake measurements at the Large Hadron Collider and Tevatron. A fruitful approach to quantify these uncertainties is to view them as arising from sampling of allowed PDF solutions in a multidimensional parametric space. This approach applies powerful insights gained in recent statistical studies of large-scale population surveys and quasi-Monte Carlo integration methods. In particular, PDF fits may be affected by the big data paradox, which stipulates that more experimental data do not automatically raise the accuracy of PDFs---close attention to the data quality and sampling of possible PDF solutions is as essential. To test if the sampling of the PDF uncertainty of an experimental observable is truly representative of all acceptable solutions, we introduce a technique (``a hopscotch scan'') based on a combination of parameter scans and stochastic sampling. With this technique, we examine the PDF uncertainty on key LHC cross sections at 13 TeV obtained with the public NNPDF4.0 fitting code, while accounting for the likelihood distribution. We show that the uncertainties on the charm distribution at a large momentum fraction $x$ and gluon PDF at small $x$ are enlarged. In PDF ensembles obtained in the analytic minimization (Hessian) formalism, the tolerance on the PDF uncertainty must be based on sufficiently complete sampling of PDF functional forms and choices of the experiments.

Prevalence and clinical correlates of misophonia symptoms in the general population of Germany.

Misophonia refers to a phenomenon in which affected individuals have a selective intolerance to sounds of mostly oral or nasal origin. This intolerance is typically associated with strong emotional reactions such as anger, irritation, and disgust. The aim of this study was to conduct the first large epidemiological survey to determine the prevalence of misophonia symptoms in the adult population in Germany. We conducted a large-scale representative population survey between December 2020 and March 2021. For this purpose, a sample of 2,519 people were visited in their households and assessed with the Misophonia Questionnaire (MQ) and the Amsterdam Misophonia Questionnaire (AMISOS-R) to document misophonic symptoms. The primary estimate of clinical misophonia symptoms prevalence was based on the MQ Severity Scale and a secondary estimate was based on the AMISOS-R. The survey further included self-ratings to measure perfectionism, not-just-right experience (NJRE), autonomous sensory meridian response (ASMR) and general health as well as demographic data. Five percent of the sample scored equal or above the MQ Severity Scale threshold for clinical misophonia symptoms (5.9% based on AMISOS-R). Individuals with clinical misophonia symptoms had a higher rate of perfectionism, a higher occurrence of NJRE, higher susceptibility to ASMR, and a worse general health status than those scoring below the cut-off-score. All those factors also independently predicted the severity of misophonia symptoms in a multiple regression model. Misophonia is a frequent condition and should further be examined as an independent diagnostic entity.

Survey of Trichogramma (Hymenoptera: Trichogrammatidae) Natural Populations in Quebec Cranberry Bogs and Identification Using rDNA ITS-2 Sequence Analysis.

The province of Quebec, Canada is the most important organic cranberry growing region worldwide. However, insect pest management methods are limited, and growers face significant yield loss each year, mostly caused by lepidopteran pests. Egg parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) are effective biocontrol agents of lepidopteran pests in many forests and agricultural systems. Herein, a two-year, large-scale population survey of Trichogramma spp. was performed using Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) as sentinel eggs in Quebec organic cranberry bogs. Collected specimens were identified by sequencing ribosomal DNA of the Internal Transcribed Spacer 2 (ITS-2) region and subjected to resemblance analysis with reference specimens for identification. Our results confirm that at least four Trichogramma species naturally occur in the studied agroecosystem. Those species are T. brassicae Bezdenko, T. minutum Riley, T. ostriniae (Pang et Chen), and T. pretiosum Riley. While some species have already been reported in cranberry bogs, this represents the first mention of T. brassicae and T. ostriniae as well as the first mention of T. minutum in Quebec cranberry bogs. All species collected are native from Eastern Canada except T. ostriniae. These species can be considered as biocontrol agent candidates for cranberry lepidopteran pests, but further efficacy trials are needed to identify the best species for each pest.

Two of a Kind? Similarities and Differences between Runners and Walkers in Sociodemographic Characteristics, Sports Related Characteristics and Wearable Usage.

As the two prime examples of sport light, running and walking have become very popular sports activities in the past decades. There are references in the literature of similarities between both sports, however these parallels have never been studied. In addition, the current digitalisation of society can have important influences on the further diversification of profiles. Data of a large-scale population survey among runners and walkers (n = 4913) in Flanders (Belgium) were used to study their sociodemographic, sports related and attitudinal characteristics, and wearable usage. The results showed that walkers are more often female, older, lower educated, and less often use wearables. To predict wearable usage, sports-related and attitudinal characteristics are important among runners but not among walkers. Motivational variables to use wearables are important to predict wearable usage among both runners and walkers. Additionally, whether or not the runner or walker registers the heart rate is the most important predictor. The present study highlights similarities and differences between runners and walkers. By adding attitudinal characteristics and including walkers this article provides new insights to the literature, which can be used by policymakers and professionals in the field of sport, exercise and health, and technology developers to shape their services accordingly.

Development and Validation of the Italian "Brief Five-Item Chronic Pain Questionnaire" for Epidemiological Studies.

BackgroundChronic pain (CP) prevalence estimates addressing a wide phenotype are still quite fragmented and may vary widely due to the lack of standardized tools of investigation. There is an urgent need to update general population CP estimates.MethodsFor this purpose, the Brief Five-item Chronic Pain Questionnaire was developed through experts’ consultations for design and content validity assessment; literature analysis of measures used to investigate CP for general population surveys; understandability evaluation through a survey on a convenience sample of affected and non-affected individuals; reliability assessment by means of two double-wave online surveys carried out by the Italian Twin Registry; criterion and construct validity assessment through the third wave of the 2019 European Health Interview Survey (Ehis).ResultsKey dimensions were defined to describe CP main aspects from a public health perspective. Literature analysis showed that validated questionnaires were rarely used to address important public health CP aspects. Understandability of the measure was good. Test-retest analyses showed adequate reliability of the measure: k values were at least “moderate” with highest values regarding CP “occurrence” and “intensity”. Correlations of CP with well-known comorbidities (cancer, depression), and specific traits (age, education) as well as of CP and its intensity with “physical pain occurrence and intensity” detected in the Ehis 2019, confirmed, respectively, a good construct and criterion validity. Construct validity was also evaluated through the correlation between “perceived treatment effectiveness” and “interference of pain in daily life activities” as recorded in the Ehis 2019.ConclusionThe designed questionnaire is a brief self-administered measure, particularly suitable to detect persistent states of pain and related intensity in large-scale general population surveys by means of a first filtering item followed by four further items. It is, in fact, designed to detect CP possible underlying causes/triggers, drugs/treatments taking and frequency, and self-perceived effectiveness among CP sufferers. Further validation of the measure in different social and cultural contexts is desirable.

Long-term and large-scale Quercus petraea population survey conducted in provenance tests installed in France

Key messageProvenance tests are invaluable resources in forest genetics and ecology. They were originally established for seed sourcing research, but they are now also used for monitoring and predicting population responses to environmental changes. They have also raised considerable interest for conservation purposes. We provide here a data resource for a multisite large-scale long-term provenance test on sessile oak (Quercus petraea (Matt.) Liebl.) setup in the late 1980s in France, supplemented with a few selected Q. robur provenances. The experimental layout comprises a range-wide collection of 124 provenances (109 Q. petraea and 15 Q. robur) planted at four experimental sites covering 90 ha in total. The dataset includes individual tree assessments of traits of functional, ecological and economic importance. Dataset access is at https://doi.org/10.15454/838U9L, and associated metadata are available at https://metadata-afs.nancy.inra.fr/geonetwork/srv/fre/catalog.search#/metadata/ede45af7-22bb-432b-8c30-af4c5248ff3e.

Using quantitative PCR to identify opportunities to strengthen soil-transmitted helminth control in Solomon Islands: A cross-sectional epidemiological survey

BackgroundThe Kato-Katz microscopy technique is the global standard for assessment of soil-transmitted helminth (STH) burden. However, major limitations include its poor sensitivity, requirement for rapid sample processing, and inability to differentiate hookworm species nor detect Strongyloides spp. infections. We assessed the prevalence and intensity of STH species in Solomon Islands by conducting a province-wide survey using quantitative PCR (qPCR) for diagnosis, which can provide much better characterisation of STH burden than microscopy.Methodology/Principal findingsWe conducted a cross-sectional survey in 18 villages in Western Province to detect infections with six STH species and quantify intensity with three. We used linear mixed model regression to identify potential water, sanitation, and hygiene (WASH) and environmental risk factors for infection. We collected stool specimens from 830 village residents. Overall STH prevalence was 63.3% (range 27.5 to 91.5% across villages), led by Necator americanus (54.5% [range 17.5–89.4%]), followed by Ancylostoma ceylanicum (15.5% [range 2.8–45.8%]), Trichuris trichiura (9.1% [range 0–79.2%]), and Strongyloides spp. (3.2% [range 0–29.2%]). Most infections were of light intensity for N. americanus (85.7%) and T. trichiura (90.7%). Owning a household latrine was associated with a lower risk of N. americanus infection (AOR 0.41, 95% CI 0.24–0.68) while greater precipitation was linked to more common T. trichiura infection (AOR 1.14, 95% CI 1.04–1.25).Conclusion/SignificanceIn this first large-scale population survey of STH in the Pacific using qPCR, we found evidence that ivermectin should be incorporated into STH control programmes because of the presence of T. trichiura and Strongyloides spp., both of which are poorly responsive to albendazole. Furthermore, One Health strategies are needed for improved A. ceylanicum and Strongyloides spp. control, WASH access and use should be improved to complement deworming programmes, and control efforts should ideally be expanded to entire communities.Trial registrationClinicalTrials.gov Australian and New Zealand Clinical Trials Registry ACTRN12618001086257.

A study of risk perception of radiofrequency electromagnetic field (RF-EMF) exposure from mobile phones and base stations in India

ABSTRACT Due to the ever-increasing use of mobile communications in India, health risks associated with exposure to radiofrequency electromagnetic field (RF-EMF) transmitted by mobile phones and base stations has become the focus of research. Internationally, there have been numerous studies on RF-EMF risk perception, but this issue is scarcely addressed in India. The present study evaluates the level of risk perception of Indians associated with RF-EMF exposure from mobile phones and base stations and assesses the underlying reasons for their concerns. We conducted a qualitative study on a small group of Indians (n = 25) from varied socioeconomic backgrounds, followed by a large-scale population (n = 500) survey to identify the primary issues of concern. The results show that many participants, irrespective of their social group, have a positive attitude towards mobile phones and are willing to accept the risks of using them, but are against the installation of base stations. Our study confirms that lack of knowledge about mobile communications technology, health concerns about mobile phones and base stations, community concern regarding base station deployment and media influence have a significant impact on risk perception among Indians. Carefully planned communication techniques are required to decrease risk perceptions and increase acceptance of mobile communications infrastructure.

Street Usage Characteristics, Subjective Perception and Urban Form of Aging Group: A Case Study of Shanghai, China

Against the background of the aging trend in China, construction and regeneration strategies for an aging-friendly built environment are becoming common, led by urban governments, and public street spaces are the focus of these strategies. Exploring such planning and design strategies can help to improve the social welfare of the aging population and meet their diverse needs. Thus, this paper, through analyzing the determinants of the elderly’s needs, examines the relationship between spatial perception and street form, using Shanghai, in China, as a case study. This study contributes to the current literature in two ways: first, it constitutes the first attempt to build a needs hierarchy for aging people in a Chinese developed city; second, our statistical analysis involves large-scale population surveys, which helps us to comprehensively and deeply understand the impact of detailed street forms on the elderly’s various spatial perceptions. Our results indicate that the renovation of street space in different areas of cities can be improved by the control of street form, to meet the diverse needs of the local aging group.

Method for biochemical monitoring of iodine. Determination of iodide-ion in urine with an ion-selective electrode

Determination of iodine in urine is an important methodology in the assessment of thyroid disorders. This indicator is often used in epidemiological studies of the state of iodine nutrition of the population, since the widespread prevalence of human iodine deficiency diseases is directly related to the lack of iodine intake with food and water. A method for the iodide ion determination in urine has been developed based on preliminary preservation of the sample in the presence of a buffer solution containing 4.28 %wt. H2O2 at pH 6.8 – 7.5 and measurements of the potential of the iodide selective electrode directly in the preserved sample solution without separation of the interfering components. After mixing the sample with a buffer solution in a ratio of 1:1, it is preserved after 18 – 24 h and stored for at least 30 days. The interfering effect of macro- and micro-components has been studied. It is shown that the amount of sodium chloride in the sample should be taken into account only in studying the severe iodine deficiency (≤20 μg/liter) and urea does not affect the potential of the electrode. To assess the total effect of the organic components of urine, we compared the results of parallel determinations of iodine in the samples, one of which was preserved, and organics was removed from the second one by alkaline ashing. It is shown that the discrepancies in the results were random and did not exceed 11.3 %. Iodine loss has not been determined, the bias between the concentration of the introduced and found additives was insignificant. Thus, in a buffer solution with hydrogen peroxide, not only the preservation of the urine sample for a long time takes place, but also the interfering influence of inorganic and organic components of the sample matrix on the membrane of the ion-selective electrode is eliminated. Metrological evaluation of the developed methodology was performed, which showed the precision and trueness of the procedure. The method was tested in an experiment on the correction and enrichment of iodine in the diet of schoolchildren. The low cost, convenient and easy to use equipment, the possibility of long-term storage of preserved samples makes the method mobile and suitable for biochemical monitoring of iodine consumption and deficiency during a large-scale population survey.

From Speculation to Substantiation: Empirically-Testing Societal Changes in Impact of Fit on Job Satisfaction from 1989, 1998, 2006, and 2016

Against the backdrop of large-scale changes in work over the past few decades, both business leaders and academics have speculated that employees’ job satisfaction is increasingly tied to the extent to which their jobs meet their desires for meaning and other reinforcers. However, empirical evidence has not yet been brought to bear on these arguments. In order to provide insights into potential socio-temporal changes in how employees derive job satisfaction from job characteristics, we analyzed repeated large-scale population surveys in the United States to examine the impact of fit between desiring and receiving job characteristics on job satisfaction across four time points (1989, 1998, 2006, and 2016). Moderated polynomial regression analyses indicated that employees in more recent years experience greater dissatisfaction by deficiencies in intrinsically-rewarding job characteristics. We interpret these findings against broader discussions of the changing employment narrative theorized to have occurred in the United States over the past several decades.

A Multiplex Noninvasive Salivary Antibody Assay for SARS-CoV-2 Infection and Its Application in a Population-Based Survey by Mail.

ABSTRACTNoninvasive salivary antibody immunoassays can enable low-cost epidemiological surveillance of infections. This study involved developing and validating a multiplex suspension immunoassay on the Luminex platform to measure immunoglobulin G (IgG) responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid and spike (S) proteins, and the spike protein’s S1 and S2 subunits and receptor binding domain. Multiple versions of these recombinant proteins acquired from commercial and noncommercial sources were evaluated. Assay development and validation utilized saliva and serum samples from coronavirus disease 2019 (COVID-19) cases procured from commercial sources and negative controls from a prepandemic survey. Saliva was also collected in a demonstration survey by mail involving adult individuals in the United States who were diagnosed with SARS-CoV-2 infection 15 to 80 days prior to sample collection. The survey had an 83% valid sample return rate (192 samples from 38 states). Most COVID-19 cases (93%) reported mildly symptomatic or asymptomatic infections. The final salivary assay based on the best-performing spike and nucleocapsid proteins had a sensitivity of 87.1% (95% bootstrap confidence interval, 82.1 to 91.7%) and specificity of 98.5% (95.0 to 100%) using 227 and 285 saliva samples, respectively. The same assay had 95.9% (92.8 to 98.9%) sensitivity and 100% (98.4 to 100%) specificity in serum (174 and 285 serum samples, respectively). Salivary and serum antibody responses to spike and nucleocapsid proteins were strongly correlated in 22 paired samples (r = 0.88 and r = 0.80, respectively). Antibody responses peaked at approximately 50 days postonset; greater illness severity was associated with stronger responses. This study demonstrated that a salivary antibody assay can be used in large-scale population surveys by mail to better characterize public health impacts of COVID-19.IMPORTANCE Given the enormous impacts of the COVID-19 pandemic, developing tools for population surveillance of infection is of paramount importance. This article describes the development of a multiplex immunoassay on a Luminex platform to measure salivary immunoglobulin G responses to the spike protein, its two subunits and receptor binding domain, and the nucleocapsid protein of SARS-CoV-2. The assay validation utilized serum and saliva samples from prepandemic controls and recent COVID-19 cases. A survey by mail targeting recent COVID-19 cases across the United States also demonstrated the utility of safe, at-home self-collection of saliva. By incorporating multiple SARS-CoV-2 proteins, this assay may differentiate responses to natural SARS-CoV-2 infections from responses to most vaccines. Application of this noninvasive immunoassay in COVID-19 surveillance can help provide estimates of cumulative incidence rates of symptomatic and asymptomatic infections in various communities and subpopulations, temporal patterns of antibody responses, and risk factors for infection.