Braimoh Bello

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.

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

BackgroundCancer remains a major cause of morbidity and mortality worldwide. In developing countries, data on lung cancer mortality are scarce.MethodsUsing South Africas 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.ResultsLung 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.ConclusionThe 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.

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.

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

BackgroundTime-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.MethodsThe 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.ResultsOf 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.ConclusionThis 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.

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.

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.

Maternal risk exposure during pregnancy and infant birth weight

BACKGROUND Birth weight is an important determinant of an infants 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 (β=-0.32; 95% CI -0.51; -0.14). Tobacco use during pregnancy was also negatively associated with BWZ (β=-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.