Assessment of precision and reliability of a novel computerized heterophoria test.

Purpose: To assess the precision and reliability of a novel computerized heterophoria test (CHT). Methods: One hundred and three subjects aged 20 to 48 (27.37 ± 5.15) were recruited from Wenzhou Medical University. All subjects with corrected spectacles were examined with CHT and a prism-neutralized objective cover test (POCT) in a randomized order. They were then re-examined with CHT within 1 week. Their heterophoria was measured at three different distances (3 m, 0.77 m and 0.4 m); the average was recorded after three consecutive measurements. Inter-examiner repeatability, intra-examiner repeatability of CHT and agreement between CHT and POCT were evaluated. Results: There was no significant difference among repeated measurements using CHT (all p > 0.05). The difference between POCT and CHT was statistically significant at three distances (all p < 0.001). However, the mean absolute difference was 1.20△, 1.93△, and 2.41△, all of which were significantly smaller than the permissible range of error (4△) at three different distances (all p < 0.001). Conclusion: The CHT demonstrated excellent inter- and intra-examiner repeatability, as well as good correlation with POCT. The differences between CHT and POCT were within the permissible range of error, indicating that CHT could provide a precise and reliable measurement for clinical applications.

Knowledge, attitudes and practices of undergraduate health sciences students on hepatitis B vaccination at a South African university highlight the need for improvement of policies, implementation and co-ordination.

BACKGROUND: Hepatitis B virus (HBV) infection causes nearly 300 million chronic infections globally. Healthcare workers face up to four times the risk of HBV infection through occupational exposure to contaminated blood and bodily fluids. Health sciences students (HSSs) are regarded as at an even greater risk as they embark on their clinical training journey. While chronic hepatitis B is incurable, it can be prevented by the safe and effective hepatitis B vaccine (HepB). The South African National Department of Health recommends at least three doses of vaccine (HepB3) for HSSs before patient contact. However, data on policy implementation at training institutions, vaccine coverage and HBV immunity in HSSs are lacking or limited. OBJECTIVES: To investigate knowledge, attitudes and practices of HSSs at the University of the Witwatersrand (Wits) in relation to international guidelines and institutional HepB programmes included in the Wits vaccination policy. Sociodemographic factors predicting HepB uptake were also investigated. METHODS: A cross-sectional study was conducted between February and June 2021. An electronic, self-administered survey was emailed to all current HSSs (N=3 785). The survey included questions on sociodemographic characteristics, knowledge of and attitudes towards HepB- related international guidelines and Wits policies, and HepB uptake and vaccine practices at Wits. Descriptive statistical analyses, followed by multivariable regression modelling, were used to identify factors associated with HepB uptake. RESULTS: A response rate of only 7.1% yielded 269 returned surveys, of which 221 were adequate for analysis. Most respondents were female (69.2%), with a mean (standard deviation) age of 22.5 (3.5) years, and were studying a Bachelor of Medicine and Surgery (MB BCh) degree (76.9%). Only 78% of those students who reported a history of vaccination (89.1% of study sample) reported a completed vaccine series. The only significant predictor, when adjusted for interactions, was being enrolled in MB BCh compared with other courses (odds ratio 4.69; p=0.026). Students displayed higher levels of knowledge around institutional (Wits) vaccine recommendations (94.1%) compared with international recommendations (75.6%). Most students were in favour of mandatory vaccination (91.4%), but not of serological testing following vaccination (42.5%). Half of our students received vaccinations in private facilities, but no follow-up or record was made of this by the designated Wits Campus Health and Wellness Centre. CONCLUSION: Institutional HepB policies are suboptimal, with no centralised co-ordination or implementation strategy. Urgent efforts are required to create awareness around policy and management, ensure vaccination coverage in this high-risk group, and foster positive practices with adequate monitoring.

Statistical analysis of the reproducibility and predictive capacity of MCTT HCE™ eye irritation test, a me-too test method for OECD TG 492.

We aimed to conduct additional statistical analysis of the reproducibility and predictive capacity of MCTT HCE™ eye irritation test (EIT), a me-too test method for OECD TG 492 with the data generated during the validation study in which 30 reference chemicals were tested in three repeated runs by three independent laboratories. We evaluated the within-laboratory reproducibility (WLR) and the between-laboratory reproducibility (BLR) through tabulation and graphs and presented the concordance of eye irritancy prediction with 95% Wilson's confidence intervals (CIs). Also, the analyses of the Intra-Class Correlation Coefficient (ICC) and Bland-Altman plot were applied to confirm the reproducibility and the comparability, referring to the validated methods of OECD TG 492. Kappa analysis was also performed to check the degree of agreement of the within- and between-laboratory reproducibility and agreement between MCTT HCE™ EIT and the reference methods. We calculated the predictive capacity via misprediction over total prediction method. The predictive capacity (sensitivity, specificity, and accuracy) was presented with 95% of Wilson's CIs. Also, bootstrap resampling was performed to express the 95% CI by the simple percentile methods for 30 chemicals and 141 reference chemicals additionally tested. Collectively, WLR (92.2%) and BLR (93.3%) met the criteria of the performance standards (WLR ≥ 90% and BLR ≥ 85%), and the results of ICC analysis and the Bland-Altman plot suggested an acceptable WLR and BLR and comparability to other validated methods of OECD TG 492. Also, the predictive capacity results for the 30 reference chemicals confirmed the good performance of the MCTT HCE™ EIT by satisfying the criteria of sensitivity, specificity, and the accuracy stated in the PS. The bootstrap resampling method showed a predictive capacity, sufficiently satisfying the criteria stated in the Performance Standards.

South African guideline for the management of chronic hepatitis B: 2013.

Hepatitis B remains a significant yet preventable health issue in South Africa. The introduction of the hepatitis B vaccine into the country some 18 years ago has demonstrated benefit, but the exposure to, and prevalence of chronic HBsAg positivity remain unacceptably high. Those with chronic hepatitis B virus infection have an elevated risk of developing cirrhosis with end-stage liver disease and a markedly elevated risk of hepatocellular carcinoma, independent of the presence of cirrhosis. The challenge in South Africa remains prevention through the universal vaccination coverage of all children and the identification of those with chronic hepatitis B virus infection. Over the last decade our understanding of hepatitis B and its behaviour and natural history in those with chronic infection has significantly improved. This understanding is key to identifying those who warrant further evaluation and therapy. A number of global societies have updated their guidelines in recent years. This document draws on these guidelines and serves to contextualise, for South Africa, practice guidelines for the management of chronic hepatitis B.

Impact of cytochrome P450 3A and ATP-binding cassette subfamily B member 1 polymorphisms on tacrolimus dose-adjusted trough concentrations among Korean renal transplant recipients.

BACKGROUND: Tacrolimus is a substrate of cytochrome P450 3A (CYP3A) and P-glycoprotein (P-gp), encoded by the CYP3A and ATP-binding cassette subfamily B member 1 (ABCB1) genes, respectively. This study was aimed to investigate the impact of CYP3A and ABCB1 polymorphisms on the tacrolimus pharmacokinetics and clinical outcomes in Korean renal transplant recipients. METHODS: We analyzed data from a cohort of 70 renal transplant recipients receiving tacrolimus. CYP3A4*4, CYP3A4*5, CYP3A4*18, CYP3A5*3, ABCB1 C1236>T, ABCB1 G2677>T/A, and ABCB1 C3435>T polymorphisms were genotyped and correlated to dose-adjusted tacrolimus trough concentration at months 1, 3, 6, and 12 after transplantation. RESULTS: Patients with the CYP3A5*3 alleles showed higher dose-adjusted tacrolimus concentrations for 12 months and higher trough levels until 6 months after transplantation. ABCB1 polymorphisms and haplotypes were not associated with tacrolimus concentrations. In a multivariate analysis, the presence of ≥1 CYP3A5*3 allele was a significant independent variable affecting dose-adjusted tacrolimus concentrations. Glomerular filtration rate, acute rejection, opportunistic infection, and graft survival were not affected by CYP3A5 polymorphisms. Calcineurin inhibitor toxicity, which showed higher tendency in patients with CYP3A5*1 alleles, might be associated with higher tacrolimus dose per kilogram. CONCLUSIONS: The CYP3A5 genotype is a major factor in determining the dose requirement of tacrolimus, and genotyping may be of value in individualization of immunosuppressive therapy of renal transplant patients.

Managed care, school health programs, and adolescent health services: opportunities for health promotion.

The rapid expansion of managed care creates opportunities and dilemmas for those involved in school health and adolescent health promotion. Managed care organizations (MCOs), public health agencies, and school and adolescent health providers share certain common goals and priorities including an emphasis on prevention, cost-effectiveness, and quality of care--and a willingness to explore innovative approaches to health promotion and disease prevention. However, MCOs often face conflicting challenges, balancing the goals of cost containment and investment in prevention. In considering support for school health programs, MCOs will be interested in evidence about the effectiveness of services in improving health and/or reducing medical expenditures. Mechanisms for improving prevention efforts within MCOs include quality assurance systems to monitor the performance of health plans, practice guidelines from professional organizations, and the contracting process between payers and health care providers. Development of partnerships between MCOs and schools will be a challenge given competing priorities, variation in managed care arrangements, structural differences between MCOs and schools, and variability in services provided by school health programs.

Should pregnant urban south African women be screened for hepatitis B?

The prevalence of hepatitis B virus (HBV) infection in the South African urban obstetric population, which consists of white, black, coloured and Asian patients from different socio-economic, cultural and geographical backgrounds, is unknown. Routine screening performed in 3,469 urban pregnant women revealed that 42 patients were HBV surface antigen-positive (a prevalence of 1.21%). Only 2 patients (4.6%) were hepatitis B e antigen (HBeAg)-positive (0.06% of the entire cohort), whereas the remaining 40 were identified as hepatitis B e antibody-positive. Despite a significant increase in the numbers of black patients, there has not been an accompanying increase in the number of HBV carriers. Replicative infection was equally distributed among white and black pregnant women. Because the low prevalence of HBeAg results in lack of perinatal transmission and the prevention of a single case of neonatal hepatitis B infection is costly, we conclude that in South African urban hospitals, routine screening for hepatitis B is not cost-effective.