Ethnic disparities in the prevalence of diabetes and its association with sleep disorder among older adults in rural southwest China.

OBJECTIVES: This study aimed to examine ethnic disparities in the prevalence of diabetes and its association with sleep disorders among the older adults Han and ethnic minority (Bai, Ha Ni, and Dai) population in rural southwest China. METHODS: A cross-sectional survey of 5,642 was conducted among the rural southwest population aged ≥60 years, consisting of a structured interview and measurement of fasting blood glucose, height, weight, and waist circumference. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. RESULTS: The overall prevalence of diabetes and sleep disorder was 10.2% and 40.1%, respectively. Bai participants had the highest prevalence of diabetes (15.9%) and obesity (9.9%)(P < 0.01), while Ha Ni participants had the lowest prevalence of diabetes (5.1%) and obesity (3.4%)(P < 0.01). The highest prevalence of sleep disorder (48.4%) was recorded in Bai participants, while Dai participants had the lowest prevalence of sleep disorder (25.6%)(P < 0.01). In all four studied ethnicities, females had a higher prevalence of sleep disorder than males (P < 0.01), and the prevalence of sleep disorder increased with age (P < 0.01). The results of multivariate logistic regression analysis indicated older adults with sleep disorder had a risk of developing diabetes (P < 0.05). Moreover, the higher educational level, family history of diabetes, and obesity were the main risk factors for diabetes in participants (P < 0.01). CONCLUSION: There are stark ethnic disparities in the prevalence of diabetes and sleep disorders in southwest China. Future diabetes prevention and control strategies should be tailored to address ethnicity, and improving sleep quality may reduce the prevalence of diabetes.

Trends in prevalence of obesity and its association with hypertension across socioeconomic gradients in rural Yunnan Province, China.

BACKGROUND: This study aimed to uncover the changing prevalence of obesity and its association with hypertension across socioeconomic gradients in rural southwest China. METHODS: Data were collected from two cross-sectional health interviews and surveys from 2011 to 2021 among individuals aged ≥ 35 years in rural China. Each participant's height, weight, waist circumference, and blood pressure were measured. The overall prevalence of obesity, central obesity, and hypertension was directly standardized by age based on the total population of the two surveys. Multivariate logistic regression was used to analyze the association between obesity and prevalence of hypertension and an individual socioeconomic position (SEP) index was constructed using principal component analysis. RESULTS: From 2011 to 2021, the prevalence of obesity, central obesity, and hypertension increased substantially, from 5.9%, 50.2%, and 26.1-12.1%, 58.0%, and 40.4% (P < 0.01), respectively. These increasing rates existed in all subcategories, including sex, age, ethnicity, education, annual household income, access to medical services, and SEP (P < 0.05). In both 2011 and 2021, lower education level and poor access to medical services correlated with higher prevalence of central obesity, while higher SEP correlated with higher prevalence of obesity and central obesity (P < 0.01). Prevalence of obesity was higher in the Han ethnicity participants and individuals with poor access to medical services than in their counterparts (P < 0.01). Whereas the prevalence of central obesity was lower in Han participants than in ethnic minority participants in 2011 (P < 0.01), this trend reversed in 2021 (P < 0.01). A positive relationship between annual household income and prevalence of obesity and central obesity was only found in 2021 (P < 0.01). Obese and centrally obese participants were more likely to be hypertensive in both survey years (P < 0.01). CONCLUSIONS: Future interventions to prevent and manage obesity in rural China should give increased attention to high income, less educated, poor access to medical services, and high SEP individuals. The implementation of these obesity interventions would also help reduce the prevalence of hypertension.

The Scholarly and Pedagogical Benefits of the Legal Laboratory: Lessons from the Consortium for the Advanced Study of Brain Injury at Yale Law School.

In our article, we share the lessons we have learned after creating and running a successful legal laboratory over the past seven years at Yale Law School. Our legal laboratory, which focuses on the intersection of law and severe brain injury, represents a unique pedagogical model for legal academia, and is closely influenced by the biomedical laboratory.

Antigen concentration, viral load, and test performance for SARS-CoV-2 in multiple specimen types.

The relationship between N-antigen concentration and viral load within and across different specimens guides the clinical performance of rapid diagnostic tests (RDT) in different uses. A prospective study was conducted in Porto Velho, Brazil, to investigate RDT performance in different specimen types as a function of the correlation between antigen concentration and viral load. The study included 214 close contacts with recent exposures to confirmed cases, aged 12 years and older and with various levels of vaccination. Antigen concentration was measured in nasopharyngeal swab (NPS), anterior nares swab (ANS), and saliva specimens. Reverse transcriptase (RT)-PCR was conducted on the NPS and saliva specimens, and two RDTs were conducted on ANS and one RDT on saliva. Antigen concentration correlated well with viral load when measured in the same specimen type but not across specimen types. Antigen levels were higher in symptomatic cases compared to asymptomatic/oligosymptomatic cases and lower in saliva compared to NPS and ANS samples. Discordant results between the RDTs conducted on ANS and the RT-PCR on NPS were resolved by antigen concentration values. The analytical limit-of-detection of RDTs can be used to predict the performance of the tests in populations for which the antigen concentration is known. The antigen dynamics across different sample types observed in SARS-CoV-2 disease progression support use of RDTs with nasal samples. Given lower antigen concentrations in saliva, rapid testing using saliva is expected to require improved RDT analytical sensitivity to achieve clinical sensitivity similar to rapid testing of nasal samples.

Ethnic disparities in prevalence of chronic non-communicable diseases and its multimorbidity among older adults in rural southwest China.

BACKGROUND: As the population ages, chronic non-communicable diseases (NCDs) multimorbidity has emerged as a major public health issue globally. This study examines ethnic disparities in prevalence of NCDs and its multimorbidity among rural southwest Chinese older adults. METHODS: A cross-sectional survey was conducted in rural southwest population aged ≥ 60 years consisting of 5,642 consenting participants of Han and three ethnic minority groups (Dai, Ha Ni, and Bai). Information about participants' demographic characteristics and lifestyle behaviors was obtained using a standard questionnaire. Anthropometric measurements including height, weight, and waist circumference, fasting blood sugar and blood pressure measurement, as well as post-bronchodilator spirometry test were recorded for each participant. RESULTS: The age-standardized prevalence of five common chronic NCDs- hypertension, diabetes, coronary heart disease (CHD), stroke, chronic obstructive pulmonary disease (COPD) - and its multimorbidity was 72.8%, 15.9%, 4.0%, 10.0%, 9.8%, and 27.6%, respectively. Bai participants had both the highest overall and sex-specific prevalence rates of hypertension, diabetes, stroke, and COPD, whereas Han participants had the highest rates of CHD (P < 0.01). The results of multivariate logistic regression analysis indicated that female and older participants had a higher probability of chronic NCDs multimorbidity than their counterparts (P < 0.01). Bai ethnic minority participants were more likely to have NCDs multimorbidity while Ha Ni and Dai ethnic minority participants were less likely to have NCD multimorbidity relative to the Han participants (P < 0.05). Older adults with a higher level of education and family history of chronic NCDs, and who were also current smokers, current drinkers, obese, centrally obese, and physically inactive had a greater probability of developing chronic NCDs multimorbidity (P < 0.01). CONCLUSIONS: Ethnicity and individual demographic and lifestyle factors significantly impact prevalence of chronic NCDs multimorbidity. Future chronic NCDs prevention and control strategies must be tailored to address ethnicity, and culturally tailored lifestyle interventions may reduce the prevalence of chronic NCDs multimorbidity in rural southwest China.

A Reagent and Virus Benchmarking Panel for a Uniform Analytical Performance Assessment of N Antigen-Based Diagnostic Tests for COVID-19.

Rapid diagnostic tests (RDTs) that detect antigen indicative of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection can help in making quick health care decisions and regularly monitoring groups at risk of infection. With many RDT products entering the market, it is important to rapidly evaluate their relative performance. Comparison of clinical evaluation study results is challenged by protocol design variations and study populations. Laboratory assays were developed to quantify nucleocapsid (N) and spike (S) SARS-CoV-2 antigens. Quantification of the two antigens in nasal eluates confirmed higher abundance of N than S antigen. The median concentration of N antigen was 10 times greater than S per genome equivalent. The N antigen assay was used in combination with quantitative reverse transcription (RT)-PCR to qualify a panel composed of recombinant antigens, inactivated virus, and clinical specimen pools. This benchmarking panel was applied to evaluate the analytical performance of the SD Biosensor Standard Q COVID-19 antigen (Ag) test, Abbott Panbio COVID-19 Ag rapid test, Abbott BinaxNOW COVID-19 Ag test, and the LumiraDx SARS-CoV-2 Ag test. The four tests displayed different sensitivities toward the different panel members, but all performed best with the clinical specimen pool. The concentration for a 90% probability of detection across the four tests ranged from 21 to 102 pg/mL of N antigen in the extracted sample. Benchmarking panels provide a quick way to verify the baseline performance of a diagnostic and enable direct comparisons between diagnostic tests. IMPORTANCE This study reports the results for severe acute respiratory syndrome coronavirus-2 (SARS-COV-2) nucleocapsid (N) and spike (S) antigen quantification assays and their performance against clinical reverse transcription (RT)-PCR results, thus describing an open-access quantification method for two important SARS-CoV-2 protein analytes. Characterized N antigen panels were used to evaluate the limits of detection of four different rapid tests for SARS-CoV-2 against multiple sources of nucleocapsid antigen, demonstrating proof-of-concept materials and methodology to evaluate SARS-CoV-2 rapid antigen detection tests. Quantification of N antigen was used to characterize the relationship between viral count and antigen concentration among clinical samples and panel members of both clinical sample and viral culture origin. This contributes to a deeper understanding of protein antigen and molecular analytes and presents analytical methods complementary to clinical evaluation for characterizing the performance of both laboratory-based and point-of-care rapid diagnostics for SARS-CoV-2.

Trends in prevalence and clustering of modifiable cardiovascular disease risk factors across socioeconomic spectra in rural southwest China: a cross-sectional study.

OBJECTIVES: This study aimed to determine the changing prevalence of clustering of cardiovascular disease (CVD) risk factors across socioeconomic spectra in rural southwest China. DESIGN: Data were collected from two waves of cross-sectional health interviews and examinations among individuals aged ≥35 years in rural China. Anthropometric measurements, blood pressure and fasting blood sugar levels were recorded for each participant. SETTING: This study was conducted in rural Yunnan Province of China. PARTICIPANTS: 8187 individuals in 2011 and 7572 in 2021 consented to participate in this study. RESULTS: From 2011 to 2021, prevalence increased of hypertension (26.1% vs 41.6%), diabetes mellitus (5.9% vs 9.8%), obesity (5.9% vs 12.0%) and central obesity (50.0% vs 58.3%) (p<0.01), while prevalence decreased of current smoking (35.2% vs 29.6%), secondhand smoke exposure (42.6% vs 27.4%) and current drinking (26.6% vs 29.6%) (p<0.01). This decade also saw an increase in the prevalence of participants with clustering of ≥2 (61.8% vs 63.0%) and ≥3 CVD risk factors (28.4% vs 32.2%) (p<0.05). These increasing rates were also observed among subgroups categorised by sex, ethnicity, education level, income level and those ≥45 years of age (p<0.05). In both 2011 and 2021, male participants and participants with a lower education level had higher prevalence of clustering of ≥2 and ≥3 CVD risk factors than their counterparts (p<0.01). Ethnic minority participants and participants with higher annual income had higher prevalence of clustering of CVD risk factors in 2011 but presented opposite associations in 2021 (p<0.01). CONCLUSION: The prevalence of clustering of CVD risk factors increased substantially across all socioeconomic spectra in rural southwest China from 2011 to 2021. Future efforts to implement comprehensive lifestyle interventions to promote the prevention and control of CVD should in particular focus on men, those of Han ethnicity and those with low socioeconomic status.

Concordance between Ov16 Rapid Diagnostic Test(RDT) and Ov16 Enzyme-Linked Immunosorbent Assay (ELISA) for the Diagnosis of Onchocerciasis in Areas of Contrasting Endemicity in Cameroon.

The diagnosis of onchocerciasis in endemic areas has been demanding given the need to replace the invasive skin snip method with a more sensitive and specific rapid point-of-contact tool. Filarial antigen detection tests are better alternative methods in diagnosing Onchocercal infections, as they detect infections and could be used to monitor transmission in endemic areas following mass drug administration. With the shift in paradigme from control to elimination, a rapid point- of-contact tool is required to support elimination programs. This was a cross-sectional, community-based study conducted in 50 villages selected from six health districts using a systematic sampling technique. Individuals ≥17 years who had lived in the community for a duration of 5 years and above provided blood specimens for IgG4 antibodies testing against O. volvulus antigens. Data were analyzed using SPSS v.20 and expectation maximization to classify optical densities for positive and negative samples from ELISA results. The kappa statistics was used to measure the level of agreement between the two tests. In a total of 5001 participants which were recruited for the study, 4416 (88.3 %) participant samples passed the plate quality control criteria and were considered for the test comparison analysis. Out of the 4416 participants, 292 (6.6 %) tested positive with Ov16 RDT and 310 (7.0 %) with Ov16 ELISA. All those who tested positive with the rapid test agreed positive with ELISA. The overall percentage agreement was 99.2 %, the Kappa score of 0.936. The results obtained indicate an excellent agreement between ELISA and RDT as measured by kappa (0.936) which was statistically significant (P<0.001). Our experience with the Ov16 ELISA biplex rapid test was favorable. However, the Ov16 RDT test may be more appropriate to use in remote areas for the point diagnosis of onchocerciasis in view towards achieving elimination in Africa.

Rural-urban differentials of prevalence and lifestyle determinants of pre-diabetes and diabetes among the elderly in southwest China.

BACKGROUND: Diabetes has become a major public health problem in China. A better understanding of diabetes determinants and urban-rural differences is essential to crafting targeted diabetes prevention measures for the elderly living in both urban and rural areas. This study aimed to compare rural-urban differentials in prevalence and lifestyle determinants of pre-diabetes and diabetes among the elderly in southwest China. METHODS: A cross-sectional health interview and examination survey was conducted among individuals aged ≥ 60 years in both a rural and urban area of China. Anthropometric measurements, including height, weight, and waist circumference, as well as blood pressure and fasting blood glucose measurements were taken. Associated risk factors for pre-diabetes and diabetes were evaluated using multivariate logistic regression analysis. RESULTS: In total, 1,624 urban residents and 1,601 rural residents consented to participate in the study. The urban prevalence of pre-diabetes and diabetes (46.8% and 24.7%, respectively), was higher than the rural prevalence (23.4% and 11.0%, respectively, P<0.01). Urban elderly participants had markedly higher prevalence of obesity, central obesity, and physical inactivity than their rural counterparts (15.3%, 76.0%, and 9.2% vs. 4.6%, 45.6%, and 6.1%, P<0.01). In contrast, rural elderly adults had higher prevalence of smoking than urban ones (23.2% vs. 17.2%, P<0.01). Obese (OR 1.71, 95% CI 1.27-2.30 vs. OR 1.73, 95% CI 1.30-3.28) and centrally obese participants (OR 1.59, 95% CI 1.18-2.15 vs. OR 1.83, 95% CI 1.32-2.54) were more likely to suffer from diabetes in both urban and rural regions. Furthermore, urban current smokers had a higher probability of suffering from diabetes (OR 1.58, 95% CI 1.11-2.25), while hypertension was positively associated with the prevalence of diabetes in the rural area (OR 2.13, 95% CI 1.54-2.95). Obese participants in the rural area were more likely to suffer from pre-diabetes (OR 2.50, 95% CI 1.53-4.08), while physical inactivity was positively associated with prevalence of pre-diabetes in the urban area (OR 1.95, 95% CI 1.37-2.80). CONCLUSION: Pre-diabetes and diabetes are more prevalent among urban older adults than their rural counterparts in southwest China. The identified rural-urban differentials of lifestyle factors have significant impacts on prevalence of pre-diabetes and diabetes. Thus, tailored lifestyle interventions are needed to improve diabetes prevention and management among the elderly in southwest China.

Socioeconomic differentials of trends in the prevalence and economic burden of chronic obstructive pulmonary disease in rural southwest China.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a leading cause of mortality and morbidity, and imposes a substantial financial burden on society. However, few studies have examined the role of individual socioeconomic status (SES) in temporal trends of COPD prevalence and economic cost. This study aimed to uncover the changing prevalence and economic burden of COPD across socioeconomic gradients in rural southwest China. METHODS: Data were collected from two cross-sectional health interviews and examination surveys administered 10 years apart among individuals aged ≥ 35 years in rural China. A prevalence-based cost-of-illness method was used to estimate the cost of COPD. The individual socioeconomic position (SEP) index was constructed using principal component analysis. Post-bronchodilator spirometry tests were performed for each participant. RESULTS: From 2011 to 2021, the prevalence of COPD increased from 8.7% to 12.8% (P < 0.01), while the economic cost of COPD increased 1.9-fold. Unit hospital costs and outpatient costs increased 1.57-fold and 1.47-fold, while unit medication costs fell by 10.6%. Increasing prevalence was also observed when the data were stratified by sex, age, ethnicity, level of education, level of income, and SEP (P < 0.05). Men, ethnic minorities, and those with a lower educational level, lower income, or lower SEP had a higher prevalence of COPD than their counterparts both in 2011 and 2021 (P < 0.05). Unit outpatient costs and medication costs increased with patients' SEP in both survey years (P < 0.05). CONCLUSIONS: The prevalence and economic costs of COPD increased substantially across all socioeconomic gradients in rural southwest China in the decade from 2011 and 2021. Future COPD prevention and management interventions as well as efforts to improve access to affordable COPD medication and treatment should focus in particular on ethnic minority and low SEP populations.

Changes in Onchocerciasis Ov16 IgG4 Rapid Diagnostic Test Results Over One-Month Follow-up: Lessons for Reading Timeframe and Decision-Making.

The SD Bioline® IgG4 rapid diagnostic test (RDT) detects IgG4 antibodies induced by the Onchocerca volvulus-specific antigen Ov16. We evaluated the stability of the RDT results over 1 month, at different time points after completion of each assay, using eluted dried blood spots collected in central Cameroon. Agreement coefficients regarding positivity between 30 minutes and 24 hours, 1, 2, 3, and 4 weeks were, 96.4%, 93.4%, 93.3%, 93.2%, and 93.2%, respectively. Between 30 minutes and 24 hours, 3.6% of the 15,444 tests showed inconsistent results with 81.2% of these tests changing from negative to positive, increasing O. volvulus antibody prevalence from 23.9% to 26.2% (P < 0.0001). This change from negative to positive outcome was confirmed at the subsequent timepoints. Depending on the desired accuracy of prevalence estimates, reading time may have to be redefined more strictly.

Comparison of two malaria multiplex immunoassays that enable quantification of malaria antigens.

BACKGROUND: Immunoassay platforms that simultaneously detect malaria antigens including histidine-rich protein 2 (HRP2)/HRP3 and Plasmodium lactate dehydrogenase (pLDH), are useful epidemiological tools for rapid diagnostic test evaluation. This study presents the comparative evaluation of two multiplex platforms in identifying Plasmodium falciparum with presence or absence of HRP2/HRP3 expression as being indicative of hrp2/hrp3 deletions and other Plasmodium species. Moreover, correlation between the malaria antigen measurements performed at these platforms is assessed after calibrating with either assay standards or international standards and the cross-reactivity among Plasmodium species is examined. METHODS: A 77-member panel of specimens composed of the World Health Organization (WHO) international Plasmodium antigen standards, cultured parasites for P. falciparum and Plasmodium knowlesi, and clinical specimens with mono-infections for P. falciparum, Plasmodium vivax, and Plasmodium malariae was generated as both whole blood and dried blood spot (DBS) specimens. Assays for HRP2, P. falciparum-specific pLDH (PfLDH), P. vivax-specific pLDH (PvLDH), and all human Plasmodium species Pan malaria pLDH (PanLDH) on the Human Malaria Array Q-Plex and the xMAP platforms were evaluated with these panels. RESULTS: The xMAP showed a higher percent positive agreement for identification of hrp2-deleted P. falciparum and Plasmodium species in whole blood and DBS than the Q-Plex. For whole blood samples, there was a highly positive correlation between the two platforms for PfLDH (Pearson r = 0.9926) and PvLDH (r = 0. 9792), moderate positive correlation for HRP2 (r = 0.7432), and poor correlation for PanLDH (r = 0.6139). In Pearson correlation analysis between the two platforms on the DBS, the same assays were r = 0.9828, r = 0.7679, r = 0.6432, and r = 0.8957, respectively. The xMAP HRP2 assay appeared to cross-react with HRP3, while the Q-Plex did not. The Q-Plex PfLDH assay cross-reacted with P. malariae, while the xMAP did not. For both platforms, P. knowlesi was detected on the PvLDH assay. The WHO international standards allowed normalization across both platforms on their HRP2, PfLDH, and PvLDH assays in whole blood and DBS. CONCLUSIONS: Q-Plex and xMAP show good agreement for identification of P. falciparum mutants with hrp2/hrp3 deletions, and other Plasmodium species. Quantitative results from both platforms, normalized into international units for HRP2, PfLDH, and PvLDH, showed good agreement and should allow comparison and analysis of results generated by either platform.

Screening for Severe Acute Respiratory Syndrome Coronavirus 2 in Close Contacts of Individuals With Confirmed Infection: Performance and Operational Considerations.

BACKGROUND: Point-of-care and decentralized testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to inform public health responses. Performance evaluations in priority use cases such as contact tracing can highlight trade-offs in test selection and testing strategies. METHODS: A prospective diagnostic accuracy study was conducted among close contacts of coronavirus disease 2019 (COVID-19) cases in Brazil. Two anterior nares swabs (ANS), a nasopharyngeal swab (NPS), and saliva were collected at all visits. Vaccination history and symptoms were assessed. Household contacts were followed longitudinally. Three rapid antigen tests and 1 molecular method were evaluated for usability and performance against reference reverse-transcription polymerase chain reaction (RT-PCR) on nasopharyngeal swab specimens. RESULTS: Fifty index cases and 214 contacts (64 household) were enrolled. Sixty-five contacts were RT-PCR positive during ≥1 visit. Vaccination did not influence viral load. Gamma variants were most prevalent; Delta variants emerged increasingly during implementation. The overall sensitivity of evaluated tests ranged from 33% to 76%. Performance was higher among symptomatic cases and those with cycle threshold (Ct) values <34 and lower among oligosymptomatic or asymptomatic cases. Assuming a 24-hour time to results for RT-PCR, the cumulative sensitivity of an anterior nares swab rapid antigen test was >70% and almost 90% after 4 days. CONCLUSIONS: The near-immediate time to results for antigen tests significantly offsets lower analytical sensitivity in settings where RT-PCR results are delayed or unavailable.

Performance of anterior nares and tongue swabs for nucleic acid, Nucleocapsid, and Spike antigen testing for detecting SARS-CoV-2 against nasopharyngeal PCR and viral culture.

OBJECTIVES: This study assesses and compares the performance of different swab types and specimen collection sites for SARS-CoV-2 testing, to reference standard real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and viral culture. METHODS: Symptomatic adults with COVID-19 who visited routine COVID-19 testing sites used spun polyester and FLOQSwabs to self-collect specimens from the anterior nares and tongue. We evaluated the self-collected specimen from anterior nares and tongue swabs for the nucleocapsid (N) or spike (S) antigen of SARS-CoV-2 by RT-PCR and then compared these results with results from RT-PCR and viral cultures from nurse-collected nasopharyngeal swabs. RESULTS: Diagnostic sensitivity was highest for RT-PCR testing conducted using specimens from the anterior nares collected on FLOQSwabs (84%; 95% CI 68-94%) and spun polyester swabs (82%; 95% CI 66-92%), compared to RT-PCR tests conducted using specimens from nasopharyngeal swabs. Relative to viral culture from nasopharyngeal swabs, diagnostic sensitivities were higher for RT-PCR and antigen testing of anterior nares swabs (91-100%) than that of tongue swabs (18-81%). Antigen testing of anterior nares swabs had higher sensitivities against viral culture (91%) than against nasopharyngeal RT-PCR (38-70%). All investigational tests had high specificity compared with nasopharyngeal RT-PCR. Spun polyester swabs are equally effective as FLOQSwabs for anterior nasal RT-PCR testing. CONCLUSIONS: We found that anterior nares specimens were more sensitive than tongue swab specimens or antigen testing for detecting SARS-CoV-2 by RT-PCR. Thus, self-collected anterior nares specimens may represent an alternative method for diagnostic SARS-CoV-2 testing in some settings.

A Novel Point-of-Care Rapid Diagnostic Test for Screening Individuals for Antibody Deficiencies.

PURPOSE: No rapid diagnostic test exists to screen individuals for primary antibody deficiencies (PAD) at or near the point of care. In settings at risk for polio where live oral polio vaccine is utilized, undiagnosed PAD patients and cases with delayed diagnosis constitute a potential reservoir for neurovirulent polioviruses, undermining polio eradication. This research aimed to develop a rapid screening test suited for use in resource-limited settings to identify individuals with low immunoglobulin G (IgG) levels, enabling early diagnosis and appropriate treatment. METHODS: Three prototype tests distinguishing low and normal IgG levels were evaluated with a blinded panel of serum/plasma specimens from 32 healthy controls and 86 primary immunodeficiency-confirmed patients with agammaglobulinemia, common variable immunodeficiency, and hyper-IgM syndrome, including 57 not receiving IgG therapy. Prototype tests were compared to laboratory reference and clinical case definition. RESULTS: The leading prototype correctly identified 32 of 32 healthy controls. Among primary antibody deficiency patients not receiving IgG treatment, 17 of 19 agammaglobulinemia, 7 of 24 common variable immunodeficiency, and 5 of 14 hyper-IgM were correctly identified by the prototype, with 67% agreement with the reference assay. CONCLUSION: The Rapid IgG Screen (RIgGS) test can differentiate between low IgG levels associated with agammaglobulinemia and normal IgG antibody levels. Differentiating CVID and hyper IgM was challenging due to the wide range in IgG levels and influence of high IgM. This test can facilitate the identification of patients with primary antibody deficiencies and support polio surveillance initiatives.

Screening Antibodies Raised against the Spike Glycoprotein of SARS-CoV-2 to Support the Development of Rapid Antigen Assays.

Severe acute respiratory coronavirus-2 (SARS-CoV-2) is a novel viral pathogen and therefore a challenge to accurately diagnose infection. Asymptomatic cases are common and so it is difficult to accurately identify infected cases to support surveillance and case detection. Diagnostic test developers are working to meet the global demand for accurate and rapid diagnostic tests to support disease management. However, the focus of many of these has been on molecular diagnostic tests, and more recently serologic tests, for use in primarily high-income countries. Low- and middle-income countries typically have very limited access to molecular diagnostic testing due to fewer resources. Serologic testing is an inappropriate surrogate as the early stages of infection are not detected and misdiagnosis will promote continued transmission. Detection of infection via direct antigen testing may allow for earlier diagnosis provided such a method is sensitive. Leading SARS-CoV-2 biomarkers include spike protein, nucleocapsid protein, envelope protein, and membrane protein. This research focuses on antibodies to SARS-CoV-2 spike protein due to the number of monoclonal antibodies that have been developed for therapeutic research but also have potential diagnostic value. In this study, we assessed the performance of antibodies to the spike glycoprotein, acquired from both commercial and private groups in multiplexed liquid immunoassays, with concurrent testing via a half-strip lateral flow assays (LFA) to indicate antibodies with potential in LFA development. These processes allow for the selection of pairs of high-affinity antispike antibodies that are suitable for liquid immunoassays and LFA, some of which with sensitivity into the low picogram range with the liquid immunoassay formats with no cross-reactivity to other coronavirus S antigens. Discrepancies in optimal ranking were observed with the top pairs used in the liquid and LFA formats. These findings can support the development of SARS-CoV-2 LFAs and diagnostic tools.

Socioeconomic and lifestyle determinants of the prevalence of hypertension among elderly individuals in rural southwest China: a structural equation modelling approach.

BACKGROUND: This study examines the association between socioeconomic and lifestyle factors and the prevalence of hypertension among elderly individuals in rural Southwest China. METHODS: A cross-sectional survey of 4833 consenting adults aged ≥ 60 years in rural regions of Yunnan Province, China, was conducted in 2017. Data on individual socioeconomic status, sleep quality, physical activity level, and family history of hypertension were collected with a standardized questionnaire. Blood pressure, fasting blood glucose, height, weight, and waist circumference were also measured. An individual socioeconomic position (SEP) index was constructed using principal component analysis. Structural equation modelling (SEM) was applied to analyse the association between socioeconomic and lifestyle factors and the prevalence of hypertension. RESULTS: The overall prevalence of hypertension was 50.6% in the study population. Body fat distribution, including measures of obesity and central obesity, had the greatest total effect on hypertension (0.21), followed by family history of hypertension (0.14), biological sex (0.08), sleep quality (- 0.07), SEP (- 0.06), physical inactivity (0.06), and diabetes (0.06). Body fat distribution, SEP, and family history of hypertension had both direct and indirect effects on hypertension, whereas physical inactivity, diabetes, and sleep quality were directly associated with the prevalence of hypertension. Biological sex was indirectly associated with the prevalence of hypertension. CONCLUSIONS: SEP, body fat distribution, physical inactivity, diabetes, and sleep quality critically influence the prevalence of hypertension. Future interventions to prevent and control hypertension should give increased attention to individuals with low SEP and should focus on controlling diabetes and obesity, increasing physical activity levels, and improving quality of sleep among older adults aged ≥ 60 years in rural Southwest China.

Ultra-sensitive RDT performance and antigen dynamics in a high-transmission Plasmodium falciparum setting in Mali.

BACKGROUND: The recent expansion of tools designed to accurately quantify malaria parasite-produced antigens has enabled us to evaluate the performance of rapid diagnostic tests (RDTs) as a function of the antigens they detect-typically histidine rich protein 2 (HRP2) or lactate dehydrogenase (LDH). METHODS: For this analysis, whole blood specimens from a longitudinal study in Bancoumana, Mali were used to evaluate the performance of the ultra-sensitive HRP2-based Alere™ Malaria Ag P.f RDT (uRDT). The samples were collected as part of a transmission-blocking vaccine trial in a high transmission region for Plasmodium falciparum malaria. Furthermore, antigen dynamics after successful anti-malarial drug treatment were evaluated in these samples using the Q-Plex Human Malaria Array (4-Plex) to quantify antigen concentrations. RESULTS: The uRDT had a 50% probability of a positive result at 207 pg/mL HRP2 [95% credible interval (CrI) 160-268]. Individuals with symptomatic infection remained positive by uRDT for a median of 33 days [95% confidence interval (CI) 28-47] post anti-malarial drug treatment. Biphasic exponential decay models accurately captured the population level post-treatment dynamics of both HRP2 and Plasmodium LDH (pLDH), with the latter decaying more rapidly. Motivated by these differences in rates of decay, a novel algorithm that used HRP2:pLDH ratios to predict if an individual had active versus recently cleared P. falciparum infection was developed. The algorithm had 77.5% accuracy in correctly classifying antigen-positive individuals as those with and without active infection. CONCLUSIONS: These results characterize the performance of the ultra-sensitive RDT and demonstrate the potential for emerging antigen-quantifying technologies in the field of malaria diagnostics to be helpful tools in distinguishing between active versus recently cleared malaria infections.

Association of socioeconomic factors and prevalence of hypertension with sleep disorder among the elderly in rural southwest China.

OBJECTIVES: This study examines the distribution of sleep disorder prevalence across socioeconomic status (SES) and investigates the relationship between sleep disorders and hypertension among southwest China's rural older adult population. METHODS: A cross-sectional survey was conducted in rural Yunnan Province, China from 2017 to 2018, consisting of 4833 consenting participants aged ≥60 years. Each participant completed a structured interview and had their blood pressure measured. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Multivariate logistic regression was used to model variations in prevalence of sleep disorders and hypertension. RESULTS: In the study population, the prevalence rates of sleep disorders and hypertension were 46.5% and 50.3%, respectively. Women had higher prevalence of both chronic illnesses (53.4% vs. 38.7%, 53.1% vs. 47.6%, P < 0.01). After adjusting for age, sex, and residential status, older adults of minority ethnicity had a higher prevalence of sleep disorders than the Han ethnic majority (P < 0.01). Attainment of higher levels of education and lower annual household income were also associated with a greater risk of sleep disorders (P < 0.01). Further, logistic regression analysis indicated that older adults with sleep disorders had a greater risk of being hypertensive (P < 0.01). CONCLUSIONS: Sleep disorders are highly prevalent in rural southwest China. Future interventions to improve sleep quality would benefit from tailoring to address individual SES. Improving sleep quality profoundly reduces prevalence of hypertension.

Socioeconomic variations in chronic obstructive pulmonary disease prevalence, diagnosis, and treatment in rural Southwest China.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major and growing cause of morbidity and mortality throughout the world. However, there remains a limited understanding of the association between individual socioeconomic status (SES) and COPD diagnosis and treatment worldwide, including in China. This study investigates socioeconomic variations in prevalence, diagnosis, and treatment of COPD in rural China. METHODS: The present study employed a cross-sectional survey design. The study population was composed of Han majority as well as Na Xi and Bai ethnic minority individuals 35 years of age and older living in Yunnan Province from 2017 to 2019. In total, 7534 individuals consented to participate in the study and complete a structured interview as well as a post-bronchodilator spirometry test. Multivariate logistic regression was used to analyze the association between individual socioeconomic status variables and the prevalence, diagnosis, and treatment of COPD. RESULTS: The age-standardized prevalence of COPD in the present study was 14.3%. Prevalence differed by gender: prevalence for men was 17.1%, versus 11.4% for women (P = 0.0001). Overall, levels of diagnosis and treatment of COPD for participants with COPD were 24.2 and 23.1%, respectively. Multivariate logistic regression indicated that higher educational levels and good access to medical services was associated with an overall lower risk of COPD (P = 0.032 vs. P = 0.018) as well as a higher probability of COPD diagnosis among those with COPD (P = 0.0001 vs. P = 0.002). Participants with COPD with higher educational levels (P = 0.0001) and higher annual household incomes (P = 0.0001) as well as good access to medical services (P = 0.016) were more likely to receive COPD medications and treatment than their counterparts. While Na Xi and Bai participants had a higher probability of having COPD (P = 0.0001), they had a lower probability of having received a diagnosis or treatment for COPD than Han participants (P = 0.0001 vs. P = 0.0012). CONCLUSIONS: Future interventions to further control COPD and improve diagnosis and treatment should focus on ethnic minority communities, and those with low education levels, low annual household incomes, and poor access to medical services.