Characterizing Inflammatory Cell Asthma Associated Phenotypes in Dental Health Workers Using Cytokine Profiling.

Cytokines elicit a pro-inflammatory response by modifying the airway microenvironment in patients with acute or chronic asthma. The expression pattern of several distinct cytokines could be a useful discriminator in asthma. This study aimed to identify asthma subject groupings based on common inflammatory patterns and to determine the relationship between these identified patterns and asthma-associated clinical indices. A sub-group of 76 dental healthcare workers (HCWs) identified from a larger cross-sectional study of 454 dental HCWs in five dental institutions were evaluated further. A self-administered questionnaire elicited the health and employment history of subjects. Sera were analyzed for atopic status, latex sensitization, and 12 cytokines (IL-1ß, 3, 4, 5, 6, 7, 8, 10, 12p70, eotaxin, GM-CSF, TNF-α). Pre and post-bronchodilator spirometry was performed on all HCWs. Data clustering and factor analysis were used to identify inflammatory cluster patterns of cytokines. Associations between the cytokine cluster groupings and relevant asthma-associated clinical indices were determined using multivariate logistic regression. The classification of asthma subtype based on cytokine patterns demonstrated both eosinophilic and neutrophilic inflammatory responses. Four phenotypically distinct subgroups relating to the severity of inflammation (acute or chronic) of the cell types were identified. Cytokine determinants for the neutrophilic subtype included IL-1ß, 6, 8, 10, 12p70, and TNF-α whereas for the eosinophilic subtype these included IL-3, 4, 5, 7, eotaxin, and GM-CSF. The multivariate models showed a significant association between work-related chest symptoms and all four inflammatory patterns. However, stronger associations were observed for the acute neutrophilic (OR = 6.00, p < 0.05) compared to acute and chronic eosinophilic responses (OR = 4.30, p < 0.05; OR = 4.93, p < 0.05), respectively. Subjects with airway obstruction were more likely to have a mixed cellular infiltrate. The odds of work-exacerbated asthma were increased in acute or chronic eosinophilia (OR = 7.75 and 8.12; p < 0.05), respectively as well as with acute neutrophilia (OR = 6) sub-type. This study demonstrated that neutrophilic inflammatory cell asthma phenotypes coexist with eosinophilic inflammatory phenotypes suggesting a possible dual pathway for asthma in dental health workers, probably due to mixed exposures to high molecular weight (e.g., latex) and low molecular weight (e.g., acrylates) agents.

Risk Factors of In-Hospital Mortality in Patients Treated for Pneumonia at a Tertiary Care Centre in Switzerland.

BACKGROUND: Little is known about risk factors upon hospital admission that are associated with in-hospital death of patients hospitalized for bacterial pneumonia. Identifying such factors may help to optimize the treatment and lower the mortality of these patients. OBJECTIVES: The aim of the study was to characterize baseline characteristics of patients hospitalized for bacterial pneumonia in Switzerland and to identify risk factors associated with all-cause in-hospital mortality. METHODS: Routinely collected electronic health record data of patients discharged from a large Swiss tertiary care hospital between August 2009 and 2017 were analysed. Potential risk factors such as patient demographics, physical examination findings, vital signs, laboratory results, and comorbidities were considered within ±24 h of admission. Univariable and multivariable logistic regression models identified risk factors for in-hospital death. The area under the receiver operating characteristic (ROC) curve was used to compare the identified factors to existing pneumonia scoring systems. RESULTS: Out of 1,781 hospital stays with initial and main diagnosis of bacterial pneumonia, 85 patients (4.85%) died (33.9% female, median age 62.3 years [interquartile range, 52-75]). Age, low systolic blood pressure, underweight, a missing value for body mass index, decreased haemoglobin level, raised C-reactive protein, high urea, high lactate dehydrogenase, concomitant pleural effusion, and cancer were independently associated with in-hospital death. The area under the ROC curve was 0.89 for the multivariable model containing the identified predictors. CONCLUSIONS: Our data are consistent with previous trials characterizing patients hospitalized for pneumonia. Additionally, we identified new and independent risk factors associated with in-hospital death among patients treated for bacterial pneumonia. Findings need to be further validated in larger multicentre cohorts.

Mining laboratory data to describe prostate specific antigen testing and prostate cancer in Johannesburg, South Africa.

INTRODUCTION: guidelines issued by different organizations worldwide differ on the use of prostate specific antigen (PSA) in prostate cancer. However, no local data is available describing how PSA testing is offered by our healthcare facilities in the country. The objectives of this study were to describe PSA testing and subsequent prostate biopsy uptake in a South African urban population. METHODS: this was a descriptive retrospective study. Data of all PSA tests and prostate biopsies performed at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) laboratory for 2013 calendar year was extracted from the laboratory information system. RESULTS: a total of 20 365 PSA tests were performed on 17 481 men during the study period. The majority of men were Black African (79%). The mean age for Black Africans (55.5 years, SD 13.3) was significantly lower than other racial groups (62.9 years, SD 12.6, p < 0.0005). PSA level was lower in Black Africans compared to others. Prostate biopsy uptake across all age groups was lower in Black African men compared to others (2% versus 4%, p = 0.01). Of the 423 men who had a prostate biopsy, 50% had prostate cancer. More Black African men were diagnosed with prostate cancer on biopsy compared to men of other racial groups (54% versus 43%, p = 0.03). CONCLUSION: our study confirms that PSA testing is prevalent in healthcare facilities in South Africa. Black African men are tested for PSA levels but have low biopsy uptake and are more likely to be diagnosed with prostate cancer.

Alcohol use and sexual risk behaviour among men and women in inner-city Johannesburg, South Africa.

BACKGROUND: Alcohol misuse is a key factor underlying the remarkable vulnerability to HIV infection among men and women in sub-Saharan Africa, especially within urban settings. Its effects, however, vary by type of drinking, population group and are modified by socio-cultural co-factors. METHODS: We interviewed a random sample of 1465 men living in single-sex hostels and 1008 women in adjacent informal settlements in inner-city, Johannesburg, South Africa. Being drunk in the past week was used as an indicator of heavy episodic drinking, and frequency of drinking and number of alcohol units/week used as measures of volume. Associations between dimensions of alcohol use (current drinking, volume of alcohol consumed and heavy episodic drinking patterns) and sexual behaviours were assessed using multivariate logistic regression. RESULTS: Most participants were internal migrants from KwaZulu Natal province. About half of men were current drinkers, as were 13% of women. Of current male drinkers, 18% drank daily and 23% were drunk in the past week (women: 14% and 29% respectively). Among men, associations between heavy episodic drinking and sexual behaviour were especially pronounced. Compared with non-drinkers, episodic ones were 2.6 fold more likely to have transactional sex (95%CI = 1.7-4.1) and 2.2 fold more likely to have a concurrent partner (95%CI = 1.5-3.2). Alcohol use in men, regardless of measure, was strongly associated with having used physical force to have sex. Overall effects of alcohol on sexual behaviour were larger in women than men, and associations were detected between all alcohol measures in women, and concurrency, transactional sex and having been forced to have sex. CONCLUSIONS: Alcohol use and sexual behaviours are strongly linked among male and female migrant populations in inner-city Johannesburg. More rigorous interventions at both local and macro level are needed to alleviate alcohol harms and mitigate the alcohol-HIV nexus, especially among already vulnerable groups. These should target the specific dimensions of alcohol use that are harmful, assist women who drink to do so more safely and address the linkages between alcohol and sexual violence.

Increased time-to-pregnancy is associated with domestic work in South Africa.

BACKGROUND: The effects of female occupational exposures on fecundity have not been evaluated in South Africa. The aim of this study was to assess the effects of three specific occupational groups on time-to-pregnancy (TTP). METHODS: This cross-sectional study collected data, by means of a questionnaire, on 1210 women representative of a South African population, and sought information on: TTP for the most recent pregnancy, time-specific information on maternal factors and occupational exposures, as well as some paternal factors. Occupational exposure groups were determined using employment profile prior to the pregnancy. In the risk analysis, domestic workers and teachers were compared to administrative staff. Accidental and unplanned pregnancies were excluded from the analysis and participants who were never pregnant were censored. Discrete-time Cox regression models were built to estimate fecundability ratios (FR). RESULTS: The median TTP in administrative workers, domestic workers and teachers was 4, 12 and 3 months respectively. After adjusting for a number of potential confounders, TTP was significantly related to occupation at the time of pregnancy attempt. Compared to administrative workers, domestic workers had a significantly lower per-cycle probability of conception (adjusted FR = 0.53; 95 CI 0.32-0.88). The per-cycle probability of conception in teachers compared to administrative workers was not significantly different (adjusted FR = 1.14; 95 CI: 0.75-1.72). CONCLUSION: Domestic work was associated with prolonged TTP. Working as a domestic worker in South Africa may affect fecundity.

Maternal risk exposure during pregnancy and infant birth weight.

BACKGROUND: Birth weight is an important determinant of an infant's immediate and future health. AIM: This study examined associations between selected maternal psychosocial and environmental risk factors during pregnancy and subsequent infant birth weight, utilising data from the South African Birth to Twenty Plus (Bt20+) birth cohort study. SUBJECTS: Exposure to nine maternal risks were assessed in 1228 women who completed an antenatal questionnaire and whose infants were delivered within a seven-week period. OUTCOME MEASURES: The outcome of interest was infant birth weight. Birth weight z-scores (BWZ) were calculated using the World Health Organization Child Growth Standards. Bivariate analyses and multiple regression models were used to identify significant risk factors. RESULTS: The mean infant birth weight was 3139g (SD 486g), with a significant advantage in mean birth weight for male infants of 73g (p=0.008). Being unsure or not wanting the pregnancy was associated with a ~156g reduction in infant birth weight (ß=-0.32; 95% CI -0.51; -0.14). Tobacco use during pregnancy was also negatively associated with BWZ (ß=-0.32; 95% CI -0.59; -0.05). Exposure to both significant risk factors (tobacco use and pregnancy wantedness) was associated with cumulative reductions in birth weight, particularly among boys. CONCLUSIONS: This study reinforces the importance of risks related to maternal attitudes and behaviours during pregnancy, namely unwanted pregnancy and tobacco use, which significantly lowered birth weight. Both identified risks are amenable to public health policy and programme intervention.

HIV prevalence and risk in long-distance truck drivers in South Africa: a national cross-sectional survey.

We estimated the prevalence of HIV and assessed correlates of HIV infection in long-distance truck drivers in South Africa. Between October 2003 and July 2004, 1900 long-distance truck drivers aged ≥18 years consented to interview and for testing for HIV. Participants were selected from a 10% stratified random sample of registered truck depots. A proximate-determinants framework was used to assess the hierarchical relationship between risk factors and HIV infection using logistic regression. HIV prevalence was 26% (95% confidence interval 24% to 28%). In multivariate analyses, HIV infection was associated with spending 2-4 weeks on the road (adjusted odds ratio 1.4; 95% confidence interval 1.1 to 1.9). There was modest evidence of a dose-response relationship between time on the road and HIV risk. Mobility increased risk by creating conditions for unsafe sex and reducing access to health services. Targeted HIV interventions for long-distance truck drivers are needed.

Risk factors associated with asthma phenotypes in dental healthcare workers.

BACKGROUND: Exposure in the dental environment can increase the risk of respiratory disease in dental healthcare workers (HCWs). This study investigated the prevalence of asthma phenotypes in dental HCWs and associated risk factors. METHODS: A cross-sectional study of 454 dental HCWs in five dental institutions in South Africa was conducted. A self-administered questionnaire elicited the health and employment history of subjects. Sera was analyzed for atopic status and latex sensitization. Pre- and post-bronchodilator spirometry was performed. RESULTS: The prevalence of atopic asthma was 6.9%, non-atopic asthma 5.9% and work-exacerbated asthma (WEA) 4.0%. Atopy and work-related ocular-nasal symptoms were strong predictors of WEA (OR: 3.4; 95% CI: 1.07-10.8; OR: 6.7, 95% CI: 2.4-19.1), respectively. Regular use of personal protective equipment (PPE) was associated with a protective affect (OR: 0.23, 95% CI: 0.1-0.7) among non-atopic asthmatics, while glove use and respiratory protection was protective among atopic asthmatics (OR: 0.39, 95% CI: 0.17-0.89). CONCLUSION: Identification of risk factors associated with specific asthma phenotypes in dental HCWs can be used to focus preventive strategies for asthmatics.

Trends in lung cancer mortality in South Africa: 1995-2006.

BACKGROUND: Cancer remains a major cause of morbidity and mortality worldwide. In developing countries, data on lung cancer mortality are scarce. METHODS: Using South Africa's annual mortality and population estimates data, we calculated lung cancer age-standardised mortality rates for the period 1995 to 2006. The WHO world standard population was used as the reference population. Scatter plots and regression models were used to assess linear trends in mortality rates. To better characterise emerging trends, regression models were also partitioned for defined periods. RESULTS: Lung cancer caused 52,217 deaths during the study period. There were 4,525 deaths for the most recent year (2006), with men accounting for 67% of deaths. For the entire South African population, the age-standardised mortality rate of 24.3 per 100,000 persons in 1995 was similar to the rate of 23.8 per 100,000 persons in 2006. Overall, there was no significant decline in lung cancer mortality in South Africa from 1995 to 2006 (slope = -0.15, p = 0.923). In men, there was a statistically non-significant annual decline of 0.21 deaths per 100,000 persons (p = 0.433) for the study period. However, from 2001 to 2006, the annual decline of 1.29 deaths per 100,000 persons was statistically significant (p = 0.009). In women, the mortality rate increased significantly at an annual rate of 0.19 per 100,000 persons (p = 0.043) for the study period, and at a higher rate of 0.34 per 100,000 persons (p = 0.007) from 1999 to 2006. CONCLUSION: The more recent declining lung cancer mortality rate in men is welcome but the increasing rate in women is a public health concern that warrants intervention. Smoking intervention policies and programmes need to be strengthened to further reduce lung cancer mortality in men and to address the increasing rates in women.

Time-to-pregnancy and pregnancy outcomes in a South African population.

BACKGROUND: Time-to-pregnancy (TTP) has never been studied in an African setting and there are no data on the rates of adverse pregnancy outcomes in South Africa. The study objectives were to measure TTP and the rates of adverse pregnancy outcomes in South Africa, and to determine the reliability of the questionnaire tool. METHODS: The study was cross-sectional and applied systematic stratified sampling to obtain a representative sample of reproductive age women for a South African population. Data on socio-demographic, work, health and reproductive variables were collected on 1121 women using a standardized questionnaire. A small number (n = 73) of randomly selected questionnaires was repeated to determine reliability of the questionnaire. Data was described using simple summary statistics while Kappa and intra-class correlation statistics were calculated for reliability. RESULTS: Of the 1121 women, 47 (4.2%) had never been pregnant. Mean gravidity was 2.3 while mean parity was 2.0 There were a total of 2467 pregnancies; most (87%) resulted in live births, 9.5% in spontaneous abortion and 2.2% in still births. The proportion of planned pregnancies was 39% and the median TTP was 6 months. The reliability of the questionnaire for TTP data was good; 63% for all participants and 97% when censored at 14 months. Overall reliability of reporting adverse pregnancy outcomes was very high, ranging from 90 - 98% for most outcomes. CONCLUSION: This is the first comprehensive population-based reproductive health study in South Africa, to describe the biologic fertility of the population, and provides rates for planned pregnancies and adverse pregnancy outcomes. The reliability of the study questionnaire was substantial, with most outcomes within 70 - 100% reliability index. The study provides important public information for health practitioners and researchers in reproductive health. It also highlights the need for public health intervention programmes and epidemiological research on biologic fertility and adverse pregnancy outcomes in the population.

Workplace determinants of endotoxin exposure in dental healthcare facilities in South Africa.

OBJECTIVES: Aerosols generated during dental procedures have been reported to contain endotoxin as a result of bacterial contamination of dental unit water lines. This study investigated the determinants of airborne endotoxin exposure in dental healthcare settings. METHODS: The study population included dental personnel (n = 454) from five academic dental institutions in South Africa. Personal air samples (n = 413) in various dental jobs and water samples (n = 403) from dental handpieces and basin taps were collected. The chromogenic-1000 limulus amebocyte lysate assay was used to determine endotoxin levels. Exposure metrics were developed on the basis of individually measured exposures and average levels within each job category. Analysis of variance and multivariate linear regression models were constructed to ascertain the determinants of exposure in the dental group. RESULTS: There was a 2-fold variation in personal airborne endotoxin from the least exposed (administration) to the most exposed (laboratory) jobs (geometric mean levels: 2.38 versus 5.63 EU m(-3)). Three percent of personal samples were above DECOS recommended exposure limit (50 EU m(-3)). In the univariate linear models, the age of the dental units explained the most variability observed in the personal air samples (R(2) = 0.20, P < 0.001), followed by the season of the year (R(2) = 0.11, P < 0.001). Other variables such as institution and total number of dental units per institution also explained a modest degree of variability. A multivariate model explaining the greatest variability (adjusted R(2) = 0.40, P < 0.001) included: the age of institution buildings, total number of dental units per institution, ambient temperature, ambient air velocity, endotoxin levels in water, job category (staff versus students), dental unit model type and age of dental unit. CONCLUSIONS: Apart from job type, dental unit characteristics are important predictors of airborne endotoxin levels in this setting.

Allergenicity of latex rubber products used in South African dental schools.

BACKGROUND: Latex sensitisation is recognised as a health problem among health care workers (HCWs) using latex products. The aim of this study was to quantify specific latex allergens in latex devices used in South African academic dental schools. The current study also compared the total protein content and the levels of specific allergens in these products. METHODS: Fourteen latex examination gloves (powdered and non-powdered) and five dental rubber dams, representing 6 brands, from five dental academic institutions were analysed for latex allergens and total protein. Total protein content was determined using the BioRad DC protein assay kit and natural rubber allergen levels using a capture enyme-linked immunosorbent assay (ELISA) specific for Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02. RESULTS: Hev b 6.02 was found in higher concentrations than other natural rubber latex (NRL) allergens in the products analysed. Hev b 5 content ranged from 0 to 9.2 microg/g and Hev b 6.02 from 0.09 to 61.5 microg/g of sample. Hev b 1 levels were below the detection limit (DL) for 79% of the samples (15/19). Dental dams showed higher allergen levels (median 80.91 microg/g) than latex gloves (median 11.34 microg/g). Powdered rubber samples also showed higher allergen levels (median 40.54 microg/g) than non-powdered samples (median 5.31 microg/g). A statistically significant correlation was observed between total protein and total allergen (r=0.74, p<0.001) concentrations. CONCLUSION: NRL allergen concentrations differ significantly by product and brand. This study has demonstrated that NRL allergens in latex-containing products used in South African dental institutions are present at sufficiently high levels to pose an allergic health risk.