Studies on ozone initiated inactivation of pathogenic bacteria in aqueous systems

Thesis (M.Sc.)-University of KwaZulu-Natal, 2008.The effect of ozone on the inactivation of two Gram-negative strains (Escherichia coli and Pseudomonas aeruginosa) and one Gram-positive endospore (Bacillus subtilis) bacteria, often present in water and the cause of some waterborne diseases was investigated as a function of ozone concentration and ozonation duration. Ozone was generated in situ using corona discharge methods where the ozone concentration ranged from 0.906 - 4.724 mg/L and the inactivation of the three microbes followed pseudo-first order kinetics with respect to the microbes. Three microbes were cultured and the influence of temperature and pH of the aqueous systems on the ozone initiated inactivation rate of the three microbes was also investigated. This study reports that molecular ozone is more effective than hydroxyl radicals initiated by the ozone chain reactions. Two suggested mechanisms for the antimicrobial effectiveness of ozone in water systems from the literature is discussed. The study also found that ozonation significantly decreased the Biological Oxygen Demand (BOD) value of natural water

Age at sexual debut: A determinant of multiple partnership among South African youth

Age at sexual debut is an important determinant of HIV infection. The paper investigates the effects of age at sexual debut on sexual behaviour among South African youth. Among 2 875 respondents who ever had sexual intercourse, 39% had early sexual debut (sexual debut at age 16 years and below). Males (44.6%) were significantly more likely than females (35.1%) to report early sexual debut (odds ratio (OR)=1.45, p-value <0.001). Multiple sexual partners are significantly more common among those that had early sexual debut (10.4% vs. 4.8%) than those who had late sexual debut, (OR=2.29, p-value<0.001). Those aged 15 to 19 years were 1.4 times more likely to report multiple partners compared to those aged 20 to 24 years. Delaying sexual debut is a strategy many national programmes are promoting. The results of this study provide additional arguments to support such initiatives and show the need to strengthen intervention targeting youth (Afr. J. Reprod. Health 2010; 14[2]:47-54)

Addressing challenges in scaling up TB and HIV treatment integration in rural primary healthcare clinics in South Africa (SUTHI): a cluster randomized controlled trial protocol

Background A large and compelling clinical evidence base has shown that integrated TB and HIV services leads to reduction in human immunodeficiency virus (HIV)- and tuberculosis (TB)-associated mortality and morbidity. Despite official policies and guidelines recommending TB and HIV care integration, its poor implementation has resulted in TB and HIV remaining the commonest causes of death in several countries in sub-Saharan Africa, including South Africa. This study aims to reduce mortality due to TB-HIV co-infection through a quality improvement strategy for scaling up of TB and HIV treatment integration in rural primary healthcare clinics in South Africa. Methods The study is designed as an open-label cluster randomized controlled trial. Sixteen clinic supervisors who oversee 40 primary health care (PHC) clinics in two rural districts of KwaZulu-Natal, South Africa will be randomized to either the control group (provision of standard government guidance for TB-HIV integration) or the intervention group (provision of standard government guidance with active enhancement of TB-HIV care integration through a quality improvement approach). The primary outcome is all-cause mortality among TB-HIV patients. Secondary outcomes include time to antiretroviral therapy (ART) initiation among TB-HIV co-infected patients, as well as TB and HIV treatment outcomes at 12 months. In addition, factors that may affect the intervention, such as conditions in the clinic and staff availability, will be closely monitored and documented. Discussion This study has the potential to address the gap between the establishment of TB-HIV care integration policies and guidelines and their implementation in the provision of integrated care in PHC clinics. If successful, an evidence-based intervention comprising change ideas, tools, and approaches for quality improvement could inform the future rapid scale up, implementation, and sustainability of improved TB-HIV integration across sub-Sahara Africa and other resource-constrained settings. Trial registration Clinicaltrials.gov, NCT02654613. Registered 01 June 2015

HIV risk perception and behavior among medically and traditionally circumcised males in South Africa

Abstract Background In South Africa, voluntary medical male circumcision (VMMC) has recently been implemented as a strategy for reducing the risk of heterosexual HIV acquisition among men. However, there is some concern that VMMC may lead to low risk perception and more risky sexual behavior. This study investigated HIV risk perception and risk behaviors among men who have undergone either VMMC or traditional male circumcision (TMC) compared to those that had not been circumcised. Methods Data collected from the 2012 South African national population-based household survey for males aged 15 years and older were analyzed using bivariate and multivariate multinomial logistic regression, and relative risk ratios (RRRs) with 95 % confidence interval (CI) were used to assess factors associated with each type of circumcision relative no circumcision. Results Of the 11,086 males that indicated that they were circumcised or not, 19.5 % (95 % CI: 17.9–21.4) were medically circumcised, 27.2 % (95 % CI: 24.7–29.8) were traditionally circumcised and 53.3 % (95 % CI: 50.9–55.6) were not circumcised. In the final multivariate models, relative to uncircumcised males, males who reported VMMC were significantly more likely to have had more than two sexual partners (RRR = 1.67, p = 0.009), and males who reported TMC were significantly less likely to be low risk alcohol users (RRR = 0.72, p < 0.001). Conclusion There is a need to strengthen and improve the quality of the counselling component of VMMC with the focus on education about the real and present risk for HIV infection associated with multiple sexual partners and alcohol abuse following circumcision

Marital status and risk of HIV infection in South Africa

Objective. Available evidence on the relationship between marital status and HIV is contradictory. The objective of this study was to determine HIV prevalence among married people and to identify potential risk factors for HIV infection related to marital status in South Africa. Methods. A multistage probability sample involving 6 090 male and female respondents, aged 15 years or older was selected. The sample was representative of the South African population by age, race, province and type of living area, e.g. urban formal, urban informal, etc. Oral fluid specimens were collected to determine HIV status. A detailed questionnaire eliciting information on socio-demographic, sex behaviour and biomedical factors was administered through face-to-face interviews from May to September 2002. Results. HIV prevalence among married people was 10.5% compared with 15.7% among unmarried people (p-value < 0.001). The risk of HIV infection did not differ significantly between married and unmarried people (odds ratio (OR) = 0.85, 95% confidence interval (CI): 0.71 - 1.02) when age, sex, socio-economic status, race, type of locality, and diagnosis of a sexually transmitted infection (STI) were included in the logistical regression model. However, the risk of HIV infection remained significantly high among unmarried compared with married people when only sex behaviour factors were controlled for in the model (OR 0.55; 95% CI: 0.47 - 0.66). Conclusions. The relationship between marital status and HIV is complex. The risk depends on various demographic factors and sex behaviour practices. Increased prevention strategies that take socio-cultural context into account are needed for married people. S Afr Med J 2004; 94: 537-543

Using joint models to study the association between CD4 count and the risk of death in TB/HIV data

BACKGROUND: The association structure linking the longitudinal and survival sub-models is of fundamental importance in the joint modeling framework and the choice of this structure should be made based on the clinical background of the study. However, this information may not always be accessible and rationale for selecting this association structure has received relatively little attention in the literature. To this end, we aim to explore four alternative functional forms of the association structure between the CD4 count and the risk of death and provide rationale for selecting the optimal association structure for our data. We also aim to compare the results obtained from the joint model to those obtained from the time-varying Cox model. METHODS: We used data from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) AIDS Treatment programme, the Starting Antiretroviral Therapy at Three Points in Tuberculosis (SAPiT) study, an open-label, three armed randomised, controlled trial between June 2005 and July 2010 (N=642). In our analysis, we combined the early and late integrated arms and compared results to the sequential arm. We utilized the Deviance Information Criterion (DIC) to select the final model with the best structure, with smaller values indicating better model adjustments to the data. RESULTS: Patient characteristics were similar across the study arms. Combined integrated therapy arms had a reduction of 55% in mortality (HR:0.45, 95% CI:0.28-0.72) compared to the sequential therapy arm. The joint model with a cumulative effects functional form was chosen as the best association structure. In particular, our joint model found that the area under the longitudinal profile of CD4 count was strongly associated with a 21% reduction in mortality (HR:0.79, 95% CI:0.72-0.86). Where as results from the time-varying Cox model showed a 19% reduction in mortality (HR:0.81, 95% CI:0.77-0.84). CONCLUSIONS: In this paper we have shown that the “current value” association structure is not always the best structure that expresses the correct relationship between the outcomes in all settings, which is why it is crucial to explore alternative clinically meaningful association structures that links the longitudinal and survival processes

Young people's experiences of sexual and reproductive health interventions in rural KwaZulu-Natal, South Africa

Despite efforts to address HIV-infection, adolescents and young peoples’ (AYP) engagement in interventions remain suboptimal. Guided by a risk protection framework we describe factors that support positive and negative experiences of HIV and SRH interventions among AYP in rural KwaZulu-Natal, South Africa, using data from: community mapping; repeat semi-structured individual interviews (n = 58 in 2017, n = 50 in 2018, n = 37 in 2019–2020); and group discussions (n = 13). AYP who had appropriate and accurate HIV-and SRH-related information were reported to use health-care services. Responsive health-care workers, good family and peer relationships were seen to be protective through building close connections and improving self-efficacy to access care. In contrast to cross-generational relationships with men, alcohol and drug use and early pregnancy were seen to put AYP at risk. Policies and interventions are needed that promote stable and supportive relationships with caregivers and peers, positive social norms and non-judgemental behaviour within clinical services