BackgroundDiagnostic investigations using radiation have become a critical feature of medical practice in recent times. However, the possibility of doctors’ underestimation of risks of over-exposure of patients to diagnostic radiation still warrants further evaluation.ObjectivesTo investigate doctors’ awareness of diagnostic radiation exposure at Dr George Mukhari Academic Hospital, South Africa.MethodsThis was a cross-sectional, analytical investigation of the awareness of doctors about radiation exposure in diagnostic radiology investigations. A cluster sampling technique was employed to recruit 217 participants. Consent and approval of the participants were sought and obtained before questionnaire administration during departmental meetings between October 2017 and March 2018.ResultsOf the participants, 80% had no formal training on radiation exposure and 33.8% of them correctly estimated natural background radiation. Correct estimates of the effective dose from a single-view abdominal X-ray (AXR) were expressed by 7.5%, quantity of radiation of a single-phase computed tomography (CT) abdomen by 30.3% and dosage from a two-view unilateral mammogram by 29.1% of the participants. More than 75% of participants agreed that children are more sensitive to radiation, but only 10.5% suggested medical termination of pregnancy for a woman who had CT abdomen and pelvis with contrast. Dosage and risk of inducing fatal cancer from common but more complex imaging procedures were poorly understood. Only the doctors of the radiology department showed a statistically significant (p < 0.0001) association with regards to their radiation awareness.ConclusionBecause of the high rate of poor awareness of radiation risks observed in this study, it is important to initiate, early in the medical curriculum for medical students, the need for a rotation in the Department of Radiology, similar to such rotations in other medical specialties.

Semen analysis still remains an important diagnostic procedure in male infertility evaluation. For the purpose of standardization and uniformity in the interpretation of sperm count results, the accuracy of three different counting chambers (improved Neubauer (IMN), Makler, and Horwells) were evaluated. Semen samples produced by 50 men were analyzed with the three different counting chambers using World Health Organization guidelines. The overall precision values of sperm count were: IMN 9.7%, Makler 5.9%, and Horwells 7.1%. The mean sperm counts (+/- SEM) were 78.6 (+/- 10.1), 119.1 (+/- 14.1), and 211.5 (+/- 27.5) million spermatozoa/ml respectively. Statistically significant differences were revealed when the sperm count results obtained with the different counting chambers were compared, i.e., IMN vs Makler (P < 0.05), IMN vs Horwells (P < 0.001), and Makler vs Horwells (P < 0.01). The sperm count results obtained from the 50 samples were classified into four subgroups (A = 1-20, B = 21-50, C = 51-100, and D = > 100 million spermatozoa/ml) using IMN as a reference chamber. Errors reflected as progressively poor SEM of sperm count (A = 1.1, 3.2, 4.1; B = 3.0, 6.1, 12.4; C = 3.4, 17.0, 23.9; and D = 14.1, 21.3, 46.3) were observed for IMN, Makler, and Horwells counting chamber respectively in each group. This study revealed that inherent errors abound when different counting chambers are used for sperm count. While IMN gave the lowest sperm count, Horwells recorded the highest. Makler counting chamber gave midway values and conforms with recommendations in the literature about its accuracy.

The rapid scale-up of global HIV antiretroviral therapy (ART) in resource-limited settings has resulted in the successful enrolment of millions of HIV-infected children into care and treatment programmes. [1] South Africa (SA) has made great strides in HIV treatment, and has the largest ART programme in the world, with ~4.4 million people receiving ART. [2] The scale-up of ART has resulted in improvements in virological and immunological parameters, as well as reductions in mortality, morbidity and comorbidities. [3,4] However, viral load rebound may still occur in some patients, despite an initial good response to ART. Maintenance of maximal and durable suppression of plasma viraemia has been particularly challenging for HIV-infected children, and nonadherence is often the strongest predictor of failure to achieve viral suppression. [5-7] The challenges that limit high adherence in children include complex ART regimens, significant side-effects, limited availability of paediatric formulations, the lifelong duration ART, and dependence on a caregiver to administer the medication. [8-10] A systematic review of resistance data in children from developing world settings found that 90% of those failing first-line regimens had at least one detectable resistance mutation. [11] Virological failure rates of up to 50% have been reported in African children during the 12-24 months after ART initiation. [12-14] Studies that include long-term follow-up of children on combination ART (cART) are limited; it is therefore difficult to generate reliable estimates of the incidence of first-line failure in large paediatric cohorts in public sector settings and to identify the factors associated with virological failure. We therefore analysed data from a large cohort of HIV-positive children and adolescents receiving care in one of the largest public sector ART programmes in SA to estimate the cumulative incidence of virological failure, identify the determinants of virological failure, and evaluate the emergence of drug resistance. Methods Study population A retrospective cohort study of HIV-1 perinatally infected children was conducted at the Dr George Mukhari Academic Hospital (DGMAH) in Pretoria, SA. Patients included in the study were aged <17 years, initiated first-line ART between 1 January 2004 and 31 December 2013, and had at least 5 years of HIV viral load measurements. Longitudinal clinical and demographic data were collected from the clinical files until last follow-up review or up to a 5-year time point following the initiation of ART. Failure to achieve an HIV viral load below the limit of detection was assessed at multiple time points during a 5-year period. For the purposes of this study, virological failure was defined as a viral load of >1 000 copies/ mL 1 year after ART initiation. HIV drug resistance HIV genotyping was performed using an in-house drug resistance assay. Briefly, a 1.7 kb amplicon was generated by reverse transcriptase (RT)-initiated polymerase chain reaction of the entire protease (PR) and partial...

Background: Available evidence suggest that the optimum prothrombin time-international normalised ratio (PT-INR) intensities recommended for anticoagulation of patients with mechanical heart valve prosthesis may not apply to all race groups. Optimal PT-INR target ranges and effectiveness of warfarin oral anticoagulation were determined among black South African patients fitted with St Jude bileaflet mechanical heart valve prosthesis (SJBMHVP) at Dr George Mukhari Academic Hospital (DGMAH). Methods: A convenience sample of 95 medical records of patients fitted with SJBMHVP from 1994 until 2013 was reviewed. Optimum PT-INR target ranges were estimated using two different methods: the classical two PT-INR target level method and the alternative, PT-INR specific incident rate method. The quality of warfarin anticoagulation was assessed using the fraction in therapeutic range method.Results: Optimum PT-INR target ranges for all participants fitted with SJBMHVP in the aortic position was estimated to be 2.0–3.5 and 2.6–3.5, respectively, by the classical and alternative methods. That of the patients with mitral valve replacement was estimated to be in the range 2.6–3.5 by the classical method and that of patients with double heart valve replacement was estimated to be 3.5 by both methods. The quality of warfarin anticoagulation of participants with SJBMHVP replacement was found to be inadequate as indicated by percentage time in treatment range (TTR) of 49.7% for all study participants compared with the ideal TTR of 70% and above.Conclusion: Optimum Caucasian-based PT-INR intensities recommended for oral anticoagulation of patients fitted with mechanical heart valve prosthesis are applicable to black patients fitted with SJBMHVP at DGMAH.

The findings demonstrate that the fetuses exposed to stress during labor produce higher progesterone secretion. This could be one possible way the fetus protects itself against the sequelae of hypoxia.