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1.  Discontinuation of cART postpartum in a high prevalence district of South Africa in 2014 
Combination antiretroviral therapy (cART) is the current strategy to prevent mother-to-child transmission (PMTCT) of HIV. Women initiated on cART should continue taking treatment life-long or stop after cessation of breastfeeding depending on their CD4 cell count or on their World Health Organization (WHO) staging. Keeping people living with HIV on treatment is essential for the success of any antiretroviral therapy (ART) programme. There has been a rapid scale-up of cART in the PMTCT programme in South Africa. cART is supposed to be taken life-long or until cessation of breastfeeding, but premature or unmanaged discontinuation of cART postpartum is not unusual in South Africa and is confirmed by studies from around the world. Discontinuation of cART can lead to mother-to-child transmission (MTCT), drug resistance and poor maternal outcomes. The extent of this problem in the South African context however is unclear. This study aims to determine the prevalence of and identify risk factors associated with discontinuation of cART postpartum amongst women who were initiated on antiretroviral treatment during their index pregnancy.
An observational analytic cross-sectional study design will be conducted in six health facilities in a high prevalence district in KwaZulu-Natal, South Africa over a period of 3 months in 2014. An interviewer-administered questionnaire will be used to collect data from mothers who initiated cART during their index pregnancy. The prevalence of discontinuation of cART postpartum will be measured, and the association between those who discontinue cART postpartum and independent variables will be estimated using multivariable-adjusted prevalence odds ratios for discontinuation.
PMCID: PMC4198759  PMID: 25278351
Prevention of mother-to-child transmission; cART; Discontinuation; Risk factors postpartum
2.  A paediatric X-ray exposure chart 
The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-seconds (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes.
PMCID: PMC4175850
Exposure; imaging; paediatric; radiography; technique
3.  Understanding the Profile of Tuberculosis and Human Immunodeficiency Virus Coinfection: Insights from Expanded HIV Surveillance at a Tuberculosis Facility in Durban, South Africa 
ISRN AIDS  2014;2014:260329.
Background. Expanded HIV surveillance in TB patients forms part of the World Health Organization framework for strategic collaborative activity. Surveillance helps understand the epidemiology of the local dual epidemic and enables design of a tailored response to these challenges. Methods. We conducted an observational, cross-sectional study of anonymous unlinked HIV testing for 741 consecutive TB suspects attending an urban TB facility during a seven-week period in 2008. Results. A total of 512 patients were found to have TB. The mean age was 35.7 years, and 63% were male. The prevalence of HIV was 72.2% (95% CI: 68.2–75.9) in all TB cases, 69.8% (95% CI: 65.3–74.2) in pulmonary tuberculosis (PTB), 81.6% (95% CI: 72.9–90.3) in extrapulmonary disease, and 66.8% (95% CI: 60.7–72.9) in those without TB disease. HIV prevalence in TB patients was higher in females than males and in younger age groups (18–29 years). The sex ratio of PTB patients correlated with the sex ratio of the prevalence of HIV in the respective age groups (P < 0.05). Conclusion. The use of a rapid HIV test performed on sputum anonymously provides an opportunity for HIV surveillance in this high-burdened setting, which has the potential to lend valuable insight into the coepidemics.
PMCID: PMC4004112  PMID: 25006526
4.  A retrospective study of Human Immunodeficiency Virus transmission, mortality and loss to follow-up among infants in the first 18 months of life in a prevention of mother-to-child transmission programme in an urban hospital in KwaZulu-Natal, South Africa 
BMC Pediatrics  2012;12:146.
Follow up of Human Immunodeficiency Virus (HIV)-exposed infants is an important component of Prevention of Mother-to-Child Transmission (PMTCT) programmes in order to ascertain infant outcomes post delivery. We determined HIV transmission, mortality and loss to follow-up (LTFU) of HIV-exposed infants attending a postnatal clinic in an urban hospital in Durban, South Africa.
We conducted a retrospective cohort study of infants born to women in the PMTCT programme at McCord Hospital, where mothers paid a fee for service. Data were abstracted from patient records for live-born infants delivered between 1 May 2008 and 31 May 2009. The infants’ LTFU status and age was based on the date of the last visit. HIV transmission was calculated as a proportion of infants followed and tested at six weeks. Mortality rates were analyzed using Kaplan-Meier (K-M), with censoring on 15 January 2010, LTFU or death.
Of 260 infants, 155 (59.6%) remained in care at McCord beyond 28 weeks: one died at < 28 days, three died between one to six months; 34 were LTFU within seven days, 60 were LTFU by six months. K-M mortality rate: 1.7% at six months (95% confidence interval (CI): 0.6% to 4.3%). Of 220 (83%) infants tested for HIV at six weeks, six (2.7%, 95% CI: 1.1% to 5.8%) were HIV-infected. In Cox regression analysis, late antenatal attendance (≥ 28 weeks gestation) relative to attending in the first trimester was a predictor for infant LTFU (adjusted hazards ratio = 2.3; 95% CI: 1.0 to 5.1; p = 0.044).
This urban PMTCT programme achieved low transmission rates at six weeks, but LTFU in the first six months limited our ability to examine HIV transmission up to 18 months and determinants of mortality. The LTFU of infants born to women who attended antenatal care at 28 weeks gestation or later emphasizes the need to identify late antenatal attendees for follow up care to educate and support them regarding the importance of follow up care for themselves and their infants.
PMCID: PMC3468389  PMID: 22963527
HIV-exposed infants; LTFU; Prevention-of-Mother-to-Child Transmission; Postnatal clinic
5.  Total Hip Arthroplasty - over 100 years of operative history 
Orthopedic Reviews  2011;3(2):e16.
Total hip arthroplasty (THA) has completely revolutionized the nature in which the arthritic hip is treated, and is considered to be one of the most successful orthopaedic interventions of its generation. With over 100 years of operative history, this review examines the progression of the operation from its origins, together with highlighting the materials and techniques that have contributed to its development. Knowledge of its history contributes to a greater understanding of THA, such as the reasons behind selection of prosthetic materials in certain patient groups, while demonstrating the importance of critically analyzing research to continually determine best operative practice. Finally, we describe current areas of research being undertaken to further advance techniques and improve outcomes.
PMCID: PMC3257425  PMID: 22355482
total hip arthroplasty; polyethylene; Metal-on-metal; ceramic; minimally-invasive.
6.  Primary Cultures of Female Swine Genital Epithelial Cells In Vitro: a New Approach for the Study of Hormonal Modulation of Chlamydia Infection  
Infection and Immunity  2003;71(8):4700-4710.
Previous studies have demonstrated that female reproductive hormones influence chlamydial infection both in vivo and in vitro. Due to the reduced availability of human genital tissues for research purposes, an alternative hormone-responsive model system was sought to study chlamydial pathogenesis. Mature female swine eliminated from breeding programs were selected as the animals of choice because of the similarity of a sexually transmitted disease syndrome and sequelae in swine to a disease syndrome and sequelae found in humans, because of the near identity of a natural infectious chlamydial isolate from swine to Chlamydia trachomatis serovar D from humans, and because a pig's epithelial cell physiology and the mean length of its estrous cycle are similar to those in humans. Epithelial cells from the cervix, uterus, and horns of the uterus were isolated, cultivated in vitro in Dulbecco's minimum essential medium-Hanks' F-12 (DMEM-F-12) medium with and without exogenous hormone supplementation, and analyzed for Chlamydia suis S-45 infectivity. The distribution of chlamydial inclusions in swine epithelial cells was uneven and was influenced by the genital tract site and hormone status. This study confirmed that, like primary human endometrial epithelial cells, estrogen-dominant swine epithelial cells are more susceptible to chlamydial infection than are progesterone-dominant cells. Further, the more differentiated luminal epithelial cells were more susceptible to infection than were glandular epithelial cells. Interestingly, chlamydial growth in mature luminal epithelia was morphologically more active than in glandular epithelia, where persistent chlamydial forms predominated. Attempts to reprogram epithelial cell physiology and thereby susceptibility to chlamydial infection by reverse-stage, exogenous hormonal supplementation were unsuccessful. Freshly isolated primary pig epithelial cells frozen at −80°C in DMEM-F-12 medium with 10% dimethyl sulfoxide for several weeks can, after thawing, reform characteristic polarized monolayers in 3 to 5 days. Thus, primary swine genital epithelia cultured ex vivo appear to be an excellent cell model for dissecting the hormonal modulation of several aspects of chlamydial pathogenesis and infection.
PMCID: PMC166018  PMID: 12874351
7.  Localization of Chlamydia trachomatis Heat Shock Proteins 60 and 70 during Infection of a Human Endometrial Epithelial Cell Line In Vitro 
Infection and Immunity  1998;66(5):2323-2329.
Unlike chlamydial lipopolysaccharide, which is released from the developing inclusion to the surface of infected genital epithelial cells, both Chlamydia trachomatis heat shock protein (hsp) 60 and 70 antigens remained confined within the inclusion during the course of the chlamydial developmental cycle. Exposure of the infected cells to penicillin to induce a persistent infection or to a lipophilic microbicide did not potentiate secretion or exocytosis of the chlamydial hsp.
PMCID: PMC108198  PMID: 9573124

Results 1-7 (7)