Molecular characterisation of group A streptococcus isolates recovered from the north-west of Pretoria, South Africa

Background. Group A streptococcus (GAS) is a human pathogen responsible for a wide range of invasive and non-invasive infections. Pharyngitis caused by GAS may have complications such as acute rheumatic fever subsequently leading to rheumatic heart disease (RHD). RHD continues to have high morbidity and mortality and affects millions of children and young adults, mostly in developing countries. An effective preventive vaccine against GAS may reduce the morbidity and mortality. A 30-valent M-protein-based vaccine is currently at the clinical trials stage of development. Potential vaccine coverage will depend on the geographical distribution of GAS emm (M protein) types.Objectives. To determine the emm types of GAS isolates circulating in the north-west of Pretoria, South Africa.Methods. Throat swabs were collected from patients aged 3 - 20 years presenting with pharyngitis at one local clinic. In addition, GAS clinical isolates were collected from the National Health Laboratory Service diagnostic laboratory. Emm genotyping was done on the GAS isolates by amplification of the emm gene followed by sequencing of the 5′ portion of the gene. The emm types were correlated with the types in the vaccine.Results. A total of 54 GAS isolates were collected, comprising 19 pharyngitis and 35 clinical isolates. We found 15 different emm types among the 43 GAS isolates that were successfully sequenced. Eleven isolates (20%) could not be typed. The most prevalent emm type was 92 (26%), which is part of the 30-valent vaccine. This was followed by emm 25 and 75, each accounting for 12% of the isolates. Up to 67% of the emm types are not covered in the 30-valent vaccine.Conclusions. Fifteen emm types were identified, of which 92 was the most prevalent. It is concerning that 67% of the emm types are not covered in the vaccine currently under development. It is recommended that surveillance studies be extended to include other parts of the country in order to expand knowledge of the circulating emm types

Dynamic cone penetrometer (DCP) relative density correlations for sands

CITATION: MacRobert, C. J., Bernstein, G. S. & Nchabeleng, M. M. 2019. Dynamic cone penetrometer (DCP) relative density correlations for sands. Soils and Rocks, 42(2):201-207, doi:10.28927/SR.422201.The original publication is available at https://www.soilsandrocks.comENGLISH ABSTRACT: The dynamic cone penetrometer (DCP) is a widely used in-situ device to determine the engineering properties of soils. This paper reports a meta-analysis of laboratory calibration studies to establish a relationship between the rate of penetration and relative density for sands. Fourteen (14) different sands from different geographic and geological settings are compared. A direct relationship between the rate of penetration and relative density is proposed with a standard error in relative density predictions of 11%. A relationship incorporating the sand’s median particle size is also proposed with a standard error in relative density predictions of 9%. Whilst there is good agreement between most of these studies, local conditions should be considered before adopting a proposed correlation in engineering design.https://www.soilsandrocks.com/article/1617Publisher's versio

HIV vaccine trial safety and retention among 18-20 year olds in the HVTN 503/Phambili study support the inclusion of adolescents in future trials

Worldwide, many adolescents, especially women, acquire HIV before age 18. Yet to date, no HIV vaccine trials have enrolled adolescents. Reasons for excluding adolescents from these trials include regulations protecting vulnerable subjects and concerns regarding informed consent, social harms, adverse events, and loss to follow-up

Drug-susceptibility Patterns of Mycobacterium tuberculosis in Mpumalanga Province, South Africa: Possible Guiding Design of Retreatment Regimen

Multidrug-resistant tuberculosis (MDR-TB) has been a cause of concern in both developed and developing countries. The prevalence of drug resistance in Mycobacterium tuberculosis (MTB) isolates (n=692) from Mpumalanga province was assessed. In total, 692 (64%) MTB strains from cases with pulmonary TB were tested for susceptibility against rifampicin, isoniazid, ethambutol, and streptomycin using the MGIT 960 instrument. Two hundred and nine (30.2%) strains were resistant to one or more drugs. Resistance to one drug ranged from 1.4% for ethambutol to 17.7% for rifampicin. The prevalence of MDR-TB ranged from 6.7% for three drugs to 34% for four drugs, with significant predictors being patients’ age-groups of 25–54 years (p=0.0012) and >55 years (p=0.007). The result showed a high level (58.4%) of MDR-TB from cases in Mpumalanga province. To achieve a higher cure rate in this province, drug-susceptibility tests must be done for every case

P14-07. Offering new prevention modalities in HIV vaccine trials: experience with male circumcision in the Phambili trial

Background: New prevention options will be added to the 'standard of prevention' offered in HIV vaccine efficacy trials as new methods prove effective. The HVTN503/Phambili trial was initiated in January 2007, shortly after results from 3 randomized controlled trials of male circumcision (MC) demonstrated that MC reduces the risk of HIV acquisition. Thus, HVTN503 investigators made plans to offer MC at no cost to enrolled male participants. Methods: All participants were informed of the benefits of MC as a component of HIV risk reduction counseling, including how and where MC could be accessed. One site offered on-site MC and the others provided referral to local services for men who requested MC. We present data on uptake of MC post-enrollment. Results: Prior to discontinuation of enrolment, 441 men joined the trial, of whom 312 (70.7%) were uncircumcised. Of these, 82 (26.3% of uncircumcised men) requested MC after enrolment. Uptake varied by site, being lower (70%) at the eThekwini site, the site with lowest baseline MC prevalence. Among 3 sites with intermediate baseline MC prevalence, uptake varied from 3.3 to 37.6%, being highest at the site providing MC on site. Uptake was similar in vaccine and placebo arms of the trial [42 (26.1%) vs. 40 (26.5%)]. There was no significant difference by arm in the timing of circumcision relative to randomization assignment being provided to participants following release of the STEP trial results [post-unblinding, vaccine 18 (42.9%) vs. placebo 13 (32.5%), p = 0.37]. Conclusion: MC, a new prevention modality, was offered as part of HIV prevention services in HVTN503. Uptake varied by provision of care model and inversely with baseline MC prevalence, but did not differ between treatment arms, and remained similar even after provision of treatment

Microcystin-LR equivalent concentrations in fish tissue during a postbloom Microcystis exposure in Loskop Dam, South Africa

The effects of a decomposing cyanobacteria bloom on water quality and the accumulation of microcystin-LR equivalent toxin in fish at Loskop Dam were studied in May 2012. Enzyme-linked immunosorbent assay [ELISA] was used to confirm the presence of microcystin-LR equivalent in the water and to determine the microcystin (MCYST) concentration in the liver and muscle of fish. The lowest concentration of extracellular MCYST-LR equivalent was recorded in the lacustrine zone, where no cyanobacterial cells were observed, while the highest concentration (3.25 μg l−1), 3.25 higher than World Health Organization standard, was observed in the riverine zone. Extremely high MCYST-LR equivalent concentrations of 1.72 μg MCYST-LReq kg−1 in the liver and 0.19 μg kg−1 in muscles of Labeo rosae, and 2.14 μg MCYST-LReq kg−1 in the liver and 0.17 μg kg−1 in muscles of Oreochromis mossambicus, indicate that the consumption of sufficient fish biomass might cause severe adverse effects in humans. Microscopic analyses of the stomach content of both fish species revealed low numbers of cyanobacterial Microcystis aeruginosa cells in comparison to other phytoplankton. The extracellular MCYST-LR equivalent of the decomposing bloom may have played a major role in the high levels observed in the livers of the two fish species. These findings are important for all downstream water users.The National Research Foundation (NRF; TTK2006062100013); Council for Scientific and Industrial Research; Department of Genetics, University of Stellenbosch; and the Department of Biodiversity, University of Limpopo as well as the Belgian Vlaamse Interuniversitaire Raad University Development Cooperation funding programme.http://www.tandfonline.com/loi/taas20hb2016Paraclinical Science

What do South African adolescents want in a sexual health service Evidence from the South African Studies on HIV in Adolescents SASHA project

Background. Young people in sub-Saharan Africa (SSA) are disproportionately affected by HIV, sexually transmitted infections and unplanned pregnancies. The provision of accessible sexual and reproductive health services (SRHS) for young people in SSA is vital to reduce this burden.Objectives. To examine the needs of South African (SA) adolescents with regard to differentiated, accessible and adolescent-responsive SRHS.Methods. Data were drawn from a larger project examining the feasibility of conducting HIV vaccine trials in adolescents. Fifteen focus group discussions were conducted across five research sites in four SA provinces with 120 male and female adolescent human papillomavirus vaccine trial participants aged 12 - 19 years from low-income areas with a high incidence of HIV. Transcribed data were double-coded using framework analysis.Results. Three main themes emerged on how best to improve SRHS for adolescents in resource-limited settings: adolescent-friendly services, availability of developmentally appropriate and tailored information, and improved relationships between healthcare workers and clinic attendees. Participants wanted more flexible opening hours at SRHS to account for travel time to clinics from school and home. They suggested that services include contraception, counselling, educational materials, links to adoption services, emergency vehicles, pre- and postnatal care, and improved service quality from clinic staff.Conclusions. While dedicated adolescent SRHS might best meet the needs of young people in SA, the study suggests that failing this, existing SRHS should be more responsive to adolescent use. Innovations such as mobile outreach services, self-testing and flexible hours will help SRHS respond to adolescents’ needs.Â