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.

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.

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.

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.

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.

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.

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.

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.

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.

Integrating Multiple Biomarkers to Increase Sensitivity for the Detection of Onchocerca volvulus Infection.

BACKGROUND: Serological assessments for human onchocerciasis are based on IgG4 reactivity against the OV-16 antigen, with sensitivities of 60-80%. We have previously identified 7 novel proteins that could improve serodiagnosis. METHODS: IgG4 responses to these 7 proteins were assessed by luciferase immunoprecipitation (LIPS) and enzyme-linked immunosorbent (ELISA) immunoassays. RESULTS: OVOC10469 and OVOC3261 were identified as the most promising candidates by IgG4-based immunoassays with sensitivities of 53% for rOVOC10469 and 78% for rOVOC3261 while specificity for each was >99%. These 2 antigens in combination with OV-16 increased the sensitivity for patent infections to 94%. The kinetics of appearance of these IgG4 responses based on experimentally infected non-human primates indicated that they were microfilarial- driven. Further, the IgG4 responses to both OVOC10469 and OVOC3261 (as well as to OV-16) drop significantly (p<0.05) following successful treatment for onchocerciasis. A prototype lateral flow rapid diagnostic test to detect IgG4 to both Ov-16 and OVOC3261 was developed and tested demonstrating an overall 94% sensitivity. CONCLUSION: The combined use of rOVOC3261 with OV-16 improved serologic assessment of O. volvulus infection, a current unmet need toward the goal of elimination of transmission of O. volvulus.

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 and lifestyle factors with chronic non-communicable diseases and multimorbidity among the elderly in rural southwest China.

BACKGROUND: This study estimates the prevalence of five chronic non-communicable disease (NCDs) (hypertension, diabetes, CHD, COPD and stroke) and its multimorbidity, and examines the relationship between SES and lifestyle factors and multimorbidity among older adults in rural southwest China. METHODS: A cross-sectional survey of 4833 consenting adults aged ≥60 years was conducted in 2017. Data on the demographics, smoking, drinking, height, weight, blood pressure and fasting blood glucose were collected. RESULTS: Among the participants, the overall prevalence of hypertension, diabetes, stroke, COPD and CHD was 50.6, 10.2, 6.4, 5.4 and 5.5%, respectively, and of multimorbidity was 16.1%. Females had a higher prevalence of hypertension, diabetes and multimorbidity of chronic NCDs, but a lower prevalence of COPD than males (P < 0.05). Older adults with good household assets and access to medical services were less likely to experience multimorbidity, whereas obese and centrally obese participants, current smokers, current drinkers and those with a family history of chronic NCDs had a greater probability of multimorbidity. CONCLUSIONS: The findings suggest that effective strategies for prevention and control of chronic NCDs and its multimorbidity are urgently needed, especially for low-income, elderly, ethnic minority adults with poor access to medical services.

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.

Predictive Value of Ov16 Antibody Prevalence in Different Subpopulations for Elimination of African Onchocerciasis.

The World Health Organization currently recommends assessing elimination of onchocerciasis by testing whether Ov16 antibody prevalence in children aged 0-9 years is below 0.1%. However, the certainty of evidence for this recommendation is considered to be low. We used the established ONCHOSIM model to investigate the predictive value of different Ov16-antibody prevalence thresholds in various age groups for elimination of onchocerciasis in a variety of endemic settings and for various mass drug administration scenarios. According to our simulations, the predictive value of Ov16 antibody prevalence for elimination depends highly on the precontrol epidemiologic situation, history of mass drug administration, the age group that is sampled, and the chosen Ov16-antibody prevalence threshold. The Ov16 antibody prevalence in children aged 5-14 years performs best in predicting elimination. Appropriate threshold values for this age group start at 2.0% for very highly endemic areas; for lower-endemic areas, even higher threshold values are safe to use. Guidelines can be improved by sampling school-aged children, which also is operationally more feasible than targeting children under age 10 years. The use of higher threshold values allows sampling of substantially fewer children. Further improvement can be achieved by taking a differentiated sampling approach based on precontrol endemicity.

Ethnic disparities in prevalence and clustering of cardiovascular disease risk factors in rural Southwest China.

BACKGROUND: This study examines how prevalence and clustering of cardiovascular disease (CVD) risk factors differ by ethnicity and socioeconomic status (SES) among rural southwest Chinese adults. METHODS: A cross-sectional survey of 7027 adults aged ≥35 years of Han and four ethnic minority group descent (Na Xi, Li Shu, Dai, and Jing Po) was used to derive prevalence of tobacco smoking and exposure to secondhand smoke (SHS) as well as alcohol consumption and physical activity data. Anthropometric measurements were also taken, including height, weight, and waist and hip circumference, as well as blood pressure (BP) and fasting blood glucose (FBG) measurements. RESULTS: Current smoking and drinking status were the top two CVD risk factors in the study population. Dai ethnic minority participants had the highest prevalence of hypertension, obesity, and central obesity, whereas Jing Po ethnic minority participants had the highest prevalence of current smoking status, SHS exposure, and current drinking status (P < 0.01). Han participants had the highest prevalence of diabetes and physical inactivity (P < 0.01). 11.1% of all participants did not have any of the studied CVD risk factors, while 68.6% of Han, 60.2% of Na Xi, 50.7% of Li Shu, 82.2% of Dai, and 73.0% of Jing Po participants had clustering of two or more CVD risk factors. Prevalence of CVD risk factor clusters increased with age (P < 0.01). Males and individuals with lower education levels and lower annual household income were more likely to have CVD risk factors than their counterparts (P < 0.01). CONCLUSION: Clustering of CVD risk factors is common in rural southwest China. Ethnicity and individual SES significantly impact prevalence of CVD risk factors and their clustering.

Socioeconomic disparities in prevalence and behaviors of smoking in rural Southwest China.

BACKGROUND: This study examines how prevalence and behaviors of smoking differ by socioeconomic status among rural southwest Chinese adults. METHODS: A cross-sectional survey was conducted including 7743 adults aged ≥35 years in rural regions of Yunnan Province, China from 2016 to 2018. Information on individual socioeconomic status (SES), ethnicity, and self-reported smoking behaviors was collected utilizing a standardized questionnaire. The individual socioeconomic position (SEP) index was constructed using principal component analysis. Multivariate logistic regression models were used to analyze the association between individual SES variables and the prevalence and behaviors of smoking. RESULTS: In the study population, the overall prevalence rate of current smokers was 33.5%. Males had a markedly higher prevalence of current smokers than females (62.6% vs. 4.8%, P < 0.01). Of these smokers, 74.5% began smoking during adolescence, 88.8% had never attempted to quit smoking, and 81.1% reported smoking in public places. Ethnic minority participants and those with low levels of education and/or low SEP were more likely to use tobacco as well as more likely to start smoking, and regularly smoke, during adolescence (P < 0.01). Participants with poor access to medical services had a higher prevalence of current smoking than their counterparts (P < 0.01). Among current smokers, Han ethnicity, good access to medical services, and high SEP were positively associated with the probability of having attempted to quit smoking at least once, while a high level of education and high SEP were negatively associated with the probability of smoking in public places. CONCLUSIONS: Disparities in prevalence and behaviors of smoking exist across a diversity of indicators of individual SES in rural southwest China. Future tobacco cessation interventions should focus on men, ethnic minorities, and those with low education levels, poor access to medical services, and low SEP.

Trends in diabetes and pre-diabetes prevalence and diabetes awareness, treatment and control across socioeconomic gradients in rural southwest China.

Background: This study aimed to determine trends in pre-diabetes and diabetes prevalence and diabetes awareness, treatment and control across socioeconomic gradients in rural southwest China. Methods: Data were collected from two cross-sectional health interviews and examination surveys among individuals aged ≥35 years in rural China. Fasting blood sugar levels were measured for each participant. Results: From 2009 to 2016, the overall prevalence of pre-diabetes and diabetes increased from 8.4 and 7.7% to 19.0 and 9.5%, respectively, while awareness, treatment and control of diabetes increased from 32.7, 20.0 and 6.1% to 49.3, 32.1 and 13.5%, respectively (P < 0.01). Participants with higher annual incomes had higher diabetes prevalence and treatment levels than their counterparts and showed a remarkably high increase in rate of pre-diabetes (P < 0.01). Whereas prevalence of pre-diabetes and diabetes increased across all ethnic groups during the study period, increased rates of diabetes awareness, treatment and control were only observed among Han Chinese (P < 0.01). Diabetic patients with higher levels of education had higher awareness, control and treatment of diabetes than their counterparts (P < 0.05). Conclusions: The prevalence of pre-diabetes and diabetes and the level of diabetes awareness, treatment and control increased substantially across all socioeconomic gradients in rural southwest China.

Tobacco exposure and alcohol drinking prevalence and associations with hypertension in rural southwest China: A cross-sectional study.

INTRODUCTION: This study examined the prevalence of tobacco exposure and drinking and ascertained the relationships between tobacco exposure, alcohol drinking, concurrent smoking and drinking, and hypertension in rural southwestern China. METHODS: Data were collected from a cross-sectional health interview and examination survey, which included 7572 adults aged ≥35 years, in rural China. Participant demographic characteristics, smoking habits, exposure to secondhand smoke (SHS), and alcohol drinking habits were obtained using a standard questionnaire. Blood pressure (BP), height, weight, and waist circumference were measured for each participant. RESULTS: The overall prevalence of smoking, SHS exposure, drinking, concurrent smoking and drinking, concurrent exposure to SHS and drinking, and hypertension was 37.7%, 27.4%, 16.2%, 12.6%, 1.6%, and 41.3%, respectively. Males had a significantly higher prevalence of smoking (74.1% vs 2.2%, p<0.01), drinking (31.1% vs 1.7%, p<0.01), and concurrent smoking and drinking than females (25.3% vs 0.3%, p<0.01). However, females had a higher prevalence of SHS exposure than males (30.2% vs 20.6%, p<0.01). Ethnic minorities had a higher prevalence of SHS exposure, drinking, and concurrent smoking and drinking, than Han participants (p<0.01). Participants with a higher education level had a higher prevalence of smoking, drinking, and concurrent smoking and drinking than their counterparts (p<0.01). In contrast, participants with a lower education level had a higher prevalence of SHS exposure than their counterparts (p<0.01). Multivariate logistic regression analysis found that smokers (AOR=1.31; 95% CI: 1.13-1.51), individuals exposed to SHS (AOR=1.24; 95% CI: 1.11-1.43), drinkers (AOR=1.31; 95%: CI: 1.15-1.50), and concurrent smokers and drinkers (AOR=1.45; 95% CI: 1.25-1.67) all had a higher probability of having hypertension (p<0.01). Additionally, concurrent smoking and drinking had the strongest association with the prevalence of hypertension (AOR=1.45; 95% CI: 1.25-1.67; p<0.01). CONCLUSIONS: Socioeconomic factors play an important role in influencing the prevalence of smoking, exposure to SHS, and drinking in rural southwest China. Interventions to prevent and reduce hypertension should, in particular, focus on smokers, individuals exposed to SHS, drinkers, and, in particular, concurrent smokers and drinkers.

Association of socioeconomic and lifestyle factors with prevalence of diabetes in rural southwest China: a structural equation modelling approach.

OBJECTIVES: This study aimed to investigate the prevalence of diabetes using structural equation modelling (SEM) to examine the pathways and associations of socioeconomic and lifestyle factors on diabetes in rural southwest China. DESIGN: Data were collected from a cross-sectional health interview and examination survey among individuals aged ≥35 years in rural southwest China. Fasting blood glucose, blood pressure, height, weight and waist circumference (WC) were measured for each participant. SEM was employed to assess the relationships between demographic characteristics (sex, age and ethnicity), socioeconomic position (SEP; annual household income, education level and access to medical services), lifestyle factors (obesity status (body mass index and WC) and physical inactivity), hypertension, hyperlipidaemia and family history of diabetes. SETTING: This study was conducted in rural Yunnan Province of China. PARTICIPANTS: 7536 individuals aged ≥35 years consented to participate in the study. RESULTS: The overall prevalence of diabetes in the present study was 8.3%. Prevalence did not differ by gender (prevalence for both men and women was 8.3% (p>0.05)). The results of SEM indicated that SEP, age, ethnicity, obesity status and physical inactivity had both significant direct and indirect effects on diabetes, with total effect size of 0.091, 0.149, -0.094, 0.212 and 0.089, respectively (p<0.01). Family history of diabetes (0.128, p<0.01), hypertension (0.135, p<0.01) and hyperlipidaemia (0.137, p<0.01) were directly associated with diabetes. CONCLUSIONS: Socioeconomic and lifestyle factors have both direct and indirect effects on prevalence of diabetes in rural southwest China. Future efforts to implement comprehensive interventions to promote the prevention and control of diabetes should in particular focus on obese individuals.

Analytical Sensitivity Analysis and Clinical Impact Modeling of Rapigen Rapid Diagnostic Tests for Malaria.

Laboratory benchmarking allows objective analysis of the analytical performance of malaria rapid diagnostic tests (RDTs). We present the analytical detection limits of the Rapigen BIOCREDIT Malaria Ag Pf/Pv (pLDH/pLDH), the Rapigen BIOCREDIT Malaria Ag Pf (pLDH/HRPII), and two best-in-class WHO-prequalified comparator RDTs, generated using standardized panels containing recombinant antigen, in vitro cultured parasites, international standards, and clinical samples. Detection limit antigen concentrations of HRP2, PfLDH, and PvLDH were determined for the Rapigen and comparator RDTs. Detection of antigens in international units (IU)/mL was also evaluated. The Rapigen Ag Pf (pLDH/HRPII) detected 3.9 and 3.9 IU/mL for PfLDH and HRP2, respectively, and the Ag Pf/Pv (pLDH/pLDH) detected 3.9 and 5.0 IU/mL for PfLDH and PvLDH, respectively. The comparator HRP2/PfLDH and HRP2/PvLDH detected 15.6 and 31.3 IU/mL for HRP2 and PfLDH and 15.6 and 50.0 IU/mL for HRP2 and PvLDH, respectively. The RDT clinical sensitivity was predicted through application of analytical detection limits to antigen concentration distributions from clinical symptomatic and asymptomatic cases. Febrile cases would be detected in a majority by both standard and Rapigen RDTs, but incremental increases in sensitivity in the Rapigen RDTs may be important for clinical cases currently missed by microscopy. Rapigen RDTs were predicted to have improved detection of asymptomatic cases and infections with parasites carrying hrp2 deletions through more sensitive PfLDH detection. Through the benchmarking and simulation of clinical sensitivity, a method for rapidly assessing the ability of new RDTs to meet clinical needs using high-sensitivity antigen distribution data is presented.