Browsing by Author "Mark, Daniella"

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    Indoor social networks in a South African township: potential contribution of location to tuberculosis transmission
    (Public Library of Science, 2012) Wood, Robin; Racow, Kimberly; Bekker, Linda-Gail; Morrow, Carl; Middelkoop, Keren; Mark, Daniella; Lawn, Stephen D
    BACKGROUND: We hypothesized that in South Africa, with a generalized tuberculosis (TB) epidemic, TB infection is predominantly acquired indoors and transmission potential is determined by the number and duration of social contacts made in locations that are conducive to TB transmission. We therefore quantified time spent and contacts met in indoor locations and public transport by residents of a South African township with a very high TB burden. METHODS: A diary-based community social mixing survey was performed in 2010. Randomly selected participants (n = 571) prospectively recorded numbers of contacts and time spent in specified locations over 24-hour periods. To better characterize age-related social networks, participants were stratified into ten 5-year age strata and locations were classified into 11 types. RESULTS: Five location types (own-household, other-households, transport, crèche/school, and work) contributed 97.2% of total indoor time and 80.4% of total indoor contacts. Median time spent indoors was 19.1 hours/day (IQR:14.3-22.7), which was consistent across age strata. Median daily contacts increased from 16 (IQR:9-40) in 0-4 year-olds to 40 (IQR:18-60) in 15-19 year-olds and declined to 18 (IQR:10-41) in ≥45 year-olds. Mean daily own-household contacts was 8.8 (95%CI:8.2-9.4), which decreased with increasing age. Mean crèche/school contacts increased from 6.2/day (95%CI:2.7-9.7) in 0-4 year-olds to 28.1/day (95%CI:8.1-48.1) in 15-19 year-olds. Mean transport contacts increased from 4.9/day (95%CI:1.6-8.2) in 0-4 year-olds to 25.5/day (95%CI:12.1-38.9) in 25-29 year-olds. CONCLUSIONS: A limited number of location types contributed the majority of indoor social contacts in this community. Increasing numbers of social contacts occurred throughout childhood, adolescence, and young adulthood, predominantly in school and public transport. This rapid increase in non-home socialization parallels the increasing TB infection rates during childhood and young adulthood reported in this community. Further studies of the environmental conditions in schools and public transport, as potentially important locations for ongoing TB infection, are indicated.
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    The neuropsychological effects of pituitary macroadenomas and their treatment
    (2005) Mark, Daniella; Solms, Mark
    Pituitary adenomas account for roughly 12% of all intracranial tumours and are treated either surgically or medically. Due to the prevalence, there have been many articles focusing on their treatment. Recently, a few studies have been published suggesting a link between pituitary tumours, their treatment and cognitive dysfunction. These articles challenge the texts put forward to date, texts that demarcate adenoma treatment effects to the realm of the physicaL The mechanism(s) behind these supposed deficits have not yet been identified, largely because of problematic research designs and sampling. In the South African context, practitioners tend to encounter a greater proportion of macroadenomas than developed countries. Working on the assumption that the effects of adenomas are magnified in macroadenoma patients, the South African situation provides a base of extreme cases in which any potential dysfunction has the best chance to declare itself. This is particularly valuable given the controversy surrounding the presence of these cognitive deficits.
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    Predicting adherence to antiretroviral therapy and retention to HIV care : effects of baseline biopsychosocial status and neuropsychological functioning
    (2011) Mark, Daniella; Solms, Mark; Bekker, Linda-Gail
    These drugs have demonstrated efficacy in improving immune function and reducing HIV-related morbidity and mortality, and while a cure is not available, patients on treatment may live longer, healthier lives. However, early optimism has been tempered by the growing recognition that meticulous adherence is a prerequisite for optimal clinical response and prevention of drug resistance.
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    Treatment outcomes in HIV-infected adolescents attending a community-based antiretroviral therapy clinic in South Africa
    (BioMed Central Ltd, 2012) Nglazi, Mweete; Kranzer, Katharina; Holele, Pearl; Kaplan, Richard; Mark, Daniella; Jaspan, Heather; Lawn, Stephen; Wood, Robin; Bekker, Linda-Gail
    BACKGROUND: Very few data are available on treatment outcomes of adolescents living with HIV infection (whether perinatally acquired or sexually acquired) in sub-Saharan Africa. The present study therefore compared the treatment outcomes in adolescents with those of young adults at a public sector community-based ART programme in Cape Town, South Africa. METHODS: Treatment outcomes of adolescents (9-19 years) were compared with those of young adults (20-28 years), enrolled in a prospective cohort between September 2002 and June 2009. Kaplan-Meier estimates and Cox proportional hazard models were used to assess outcomes and determine associations with age, while adjusting for potential confounders. The treatment outcomes were mortality, loss to follow-up (LTFU), immunological response, virological suppression and virological failure. RESULTS: 883 patients, including 65 adolescents (47 perinatally infected and 17 sexually infected) and 818 young adults, received ART. There was no difference in median baseline CD4 cell count between adolescents and young adults (133.5 vs 116 cells/muL; p = 0.31). Overall mortality rates in adolescents and young adults were 1.2 (0.3-4.8) and 3.1 (2.4-3.9) deaths per 100 person-years, respectively. Adolescents had lower rates of virological suppression (< 400 copies/mL) at 48 weeks (27.3% vs 63.1%; p < 0.001). Despite this, however, the median change in CD4 count from baseline at 48 weeks of ART was significantly greater for adolescents than young adults (373 vs 187 cells/muL; p = 0.0001). Treatment failure rates were 8.2 (4.6-14.4) and 5.0 (4.1-6.1) per 100 person-years in the two groups. In multivariate analyses, there was no significant difference in LTFU and mortality between age groups but increased risk in virological failure [AHR 2.06 (95% CI 1.11-3.81; p = 0.002)] in adolescents. CONCLUSIONS: Despite lower virological suppression rates and higher rates of virological failure, immunological responses were nevertheless greater in adolescents than young adults whereas rates of mortality and LTFU were similar. Further studies to determine the reasons for poorer virological outcomes are needed.