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Biomedical subjects

Landon Myer

Publications and source records attributed to Landon Myer.

At least 19 recordsLinked to original sources
PubMed2006

Brief report: methods for collecting sexual behaviour information from South African adolescents--a comparison of paper versus personal digital assistant questionnaires.

Reporting bias in adolescent behavioural research may be overcome with the use of personal digital assistants (PDA) or other computer based technologies. However, there is little insight into the use of these tools among adolescents in low resource settings. We compared self-administered paper questionnaires with PDA questionnaires to collect sexual behaviour data from a sample of 11-19 year olds living in a periurban, Xhosa-speaking community in South Africa. There was a high level of agreement between sexual risk behaviour data collected via each method (kappas> or = 0.50). Data collected from the PDA questionnaires were more complete. Subjectively, adolescents found the use of PDA to be simple and confidential. PDA may be a useful method to collect sensitive, self-reported information from adolescents in resource-limited settings.

Adolescent↗
PubMed2006

Prospective study of hormonal contraception and women's risk of HIV infection in South Africa.

BACKGROUND: Many women using hormonal contraceptives are also at risk of sexually transmitted HIV infection, but data are mixed on whether hormonal contraception increases women's risk of HIV. We investigated associations between HIV incidence and use of combined oral contraceptives (COC), norethindrone enanthate (NET-EN) or depot medroxyprogesterone acetate (DMPA) in a cohort of South African women. METHODS: Participants were 4200 HIV-negative women aged 35-49 years enrolled into a cervical cancer screening trial. At enrollment, women were tested for sexually transmitted infections and reported on their sexual behaviour and contraceptive use. During the 24 months of follow-up, women reported on their sexual behaviours and contraceptive use and underwent repeat HIV testing. RESULTS: During the 5010 person-years of follow-up, 111 incident HIV infections were observed (HIV incidence, 2.2 infections/100 person-years). At enrollment, 21% of women reported using hormonal contraception, primarily DMPA (14% of all women) or NET-EN (5%). After adjusting for sexual risk behaviours and sexually transmitted infections, the incidence of HIV was similar among women using COC, NET-EN or DMPA compared with women not using any hormonal method [incidence rate ratios and 95% confidence intervals, 0.65, 0.16-2.66; 0.79, 0.31-2.02 and 0.96, 0.58-1.59, respectively]. There was also no association between increased duration of DMPA use and HIV incidence (P-value for trend, 0.51). CONCLUSIONS: These findings contribute to the evidence from general population cohorts of women that hormonal contraceptive use is not associated with increased risk of HIV acquisition. Nonetheless, family planning services are an important venue for HIV prevention activities.

Adult↗
PubMed2006

Undiagnosed tuberculosis in a community with high HIV prevalence: implications for tuberculosis control.

BACKGROUND: Although failure of tuberculosis (TB) control in sub-Saharan Africa is attributed to the HIV epidemic, it is unclear why the directly observed therapy short-course (DOTS) strategy is insufficient in this setting. We conducted a cross-sectional survey of pulmonary TB (PTB) and HIV infection in a community of 13,000 with high HIV prevalence and high TB notification rate and a well-functioning DOTS TB control program. METHODS: Active case finding for PTB was performed in 762 adults using sputum microscopy and Mycobacterium tuberculosis culture, testing for HIV, and a symptom and risk factor questionnaire. Survey findings were correlated with notification data extracted from the TB treatment register. RESULTS: Of those surveyed, 174 (23%) tested HIV positive, 11 (7 HIV positive) were receiving TB therapy, 6 (5 HIV positive) had previously undiagnosed smear-positive PTB, and 6 (4 HIV positive) had smear-negative/culture-positive PTB. Symptoms were not a useful screen for PTB. Among HIV-positive and -negative individuals, prevalence of notified smear-positive PTB was 1,563/100,000 and 352/100,000, undiagnosed smear-positive PTB prevalence was 2,837/100,000 and 175/100,000, and case-finding proportions were 37 and 67%, respectively. Estimated duration of infectiousness was similar for HIV-positive and HIV-negative individuals. However, 87% of total person-years of undiagnosed smear-positive TB in the community were among HIV-infected individuals. CONCLUSIONS: PTB was identified in 9% of HIV-infected individuals, with 5% being previously undiagnosed. Lack of symptoms suggestive of PTB may contribute to low case-finding rates. DOTS strategy based on passive case finding should be supplemented by active case finding targeting HIV-infected individuals.

Adolescent↗
PubMed2006

Determinants of mortality and nondeath losses from an antiretroviral treatment service in South Africa: implications for program evaluation.

BACKGROUND: The scale-up of antiretroviral treatment (ART) services in resource-limited settings requires a programmatic model to deliver care to large numbers of people. Understanding the determinants of key outcome measures--including death and nondeath losses--would assist in program evaluation and development. METHODS: Between September 2002 and August 2005, all in-program (pretreatment and on-treatment) deaths and nondeath losses were prospectively ascertained among treatment-naive adults (n=1235) who were enrolled in a community-based ART program in South Africa. RESULTS: At study censorship, 927 patients had initiated ART after a median of 34 days after enrollment in the program. One hundred twenty-one (9.8%) patients died. Mortality rates were 33.3 (95% CI, 25.5-43.0), 19.1 (95% CI, 14.4-25.2), and 2.9 (95% CI, 1.8-4.8) deaths/100 person-years in the pretreatment interval, during the first 4 months of ART (early deaths), and after 4 months of ART (late deaths), respectively. Pretreatment and early treatment deaths together accounted for 87% of deaths, and were independently associated with advanced immunodeficiency at enrollment. Late deaths were comparatively few and were only associated with the response to ART at 4 months. Nondeath program losses (loss to follow-up, 2.3%; transfer-out, 1.9%; relocation, 0.7%) were not associated with immune status and were evenly distributed during the study period. CONCLUSIONS: Loss to follow-up and late mortality rates were low, reflecting good cohort retention and treatment response. However, the extremely high pretreatment and early mortality rates indicate that patients are enrolling in ART programs with far too advanced immunodeficiency. Causes of late access to the ART program, such as delays in health care access, health system delays, or inappropriate treatment criteria, need to be addressed.

Adult↗
PubMed2006

Knowledge of the abortion legislation among South African women: a cross-sectional study.

BACKGROUND: In order to ensure that legalized abortion in South Africa improves reproductive health, women must know that abortion is a legal option in the case of unwanted pregnancy. This study investigated knowledge of abortion legislation eight years after the introduction of legal abortion services in one province of South Africa. METHODS: In 2004/2005, we conducted a cross-sectional study among 831 sexually-active women attending 26 public health clinics in one urban and one rural health region of the Western Cape Province. RESULTS: Thirty-two percent of women did not know that abortion is currently legal. Among those who knew of legal abortion, few had knowledge of the time restrictions involved. CONCLUSION: In South Africa there is an unmet need among women for information on abortion. Strategies should be developed to address this gap so that women are fully informed of their rights to a safe and legal termination of pregnancy.

Journal Article↗
PubMed2006

Burden of tuberculosis in an antiretroviral treatment programme in sub-Saharan Africa: impact on treatment outcomes and implications for tuberculosis control.

OBJECTIVES: To determine burden and risk factors for tuberculosis (TB) in an antiretroviral treatment (ART) programme and its impact on ART outcomes. DESIGN: Prospective cohort study. METHODS: Prevalent TB was assessed at baseline and incident TB was ascertained prospectively over 3 years among 944 patients accessing a community-based ART programme in South Africa. RESULTS: At enrollment, median CD4 cell count was 96 cells/microl and 52% of patients had a previous history of TB. Prevalent TB (current antituberculosis treatment or active TB) was present in 25% and was strongly associated with advanced immunodeficiency. During 782 person-years of ART, 81 cases of TB were diagnosed. The incidence was 22.1/100 person-years during the first 3 months of ART and decreased to an average of 4.5/100 person-years during the second and third years. In multivariate analysis, risk of incident TB during follow-up was only associated with the current absolute CD4 cell count at that time point; an increase of 100 cells/mul was associated with a 25% lower risk (P = 0.007). Although prevalent and incident TB were associated with greater than two-fold increased mortality risk, they did not compromise immunological and virological outcomes among survivors at 48 weeks. CONCLUSIONS: Late initiation of ART was associated with a major burden of TB in this ART programme. TB reduced survival but did not impair immunovirological outcomes. Reductions in TB incidence during ART were dependent on CD4 cell count; however, after 3 years of treatment, rates were still 5- to 10-fold higher than among non-HIV-infected people. Earlier initiation of ART may reduce this burden of TB.

Adult↗
PubMed2006

Adolescent HIV prevalence, sexual risk, and willingness to participate in HIV vaccine trials.

PURPOSE: To determine human immunodeficiency virus (HIV) prevalence, sexual risk behaviors, and attitudes toward HIV vaccine trials among 11-19 year-olds in a peri-urban community near Cape Town, South Africa. METHODS: We performed HIV antibody testing on oral transudate, and assessed sexual risk behaviors and willingness to participate in HIV vaccine trials using self-administered questionnaires. RESULTS: Of the 510 adolescents selected, 356 (73%) participated. The HIV prevalence of the group was 10.6% (95% confidence interval [CI] 7.5-14.4). One-third of adolescents had experienced sexual debut, with a mean age of 14.6 years. Number of lifetime sexual partners was independently associated with HIV infection (odds ratio [OR] = 1.62; 95% CI 1.1-2.3). In a multivariate analysis, increasing age, female gender, and attending school were independently associated with having had sex. The majority of adolescents (79%) were willing to participate in an HIV vaccine trial. Increasing age and length of residence in the community were significantly associated with willingness to participate (OR = 1.19; 95% CI 1.01-1.4 and OR = 1.14; 95% CI 1.03-1.26, respectively). CONCLUSIONS: The prevalence of HIV and risk behavior among adolescents in this community is high. HIV vaccines are required that target preadolescents. HIV vaccine trials in adolescents in this setting will be facilitated by their willingness to participate.

AIDS Vaccines↗
PubMed2006

"We have our protector": misperceptions of protection against HIV among participants in a microbicide efficacy trial.

OBJECTIVES: We examined perceptions of the effectiveness and acceptability of a candidate microbicide among 94 South African female sex workers who had participated in a phase 3 microbicide trial for HIV prevention. METHODS: Sixteen focus groups were conducted in 2001, 12 to 15 months after participants were informed that the candidate microbicide had been determined to be ineffective in preventing HIV and other sexually transmitted infections (STIs). RESULTS: Participants clearly indicated that they understood the experimental nature of the candidate microbicide, and they recognized that they had been informed after the trial that the product was ineffective. Nevertheless, most continued to believe that the candidate microbicide helped prevent HIV and other STIs, alleviated reproductive tract pain and STI symptoms, and helped to clean the vagina. CONCLUSIONS: These findings underscore the importance of understanding women's perceptions of the efficacy of candidate microbicides and the rationale for these beliefs. These issues need to be addressed in counseling throughout microbicide trials for HIV prevention. These results also demonstrate how desperate many women at high risk of HIV infection may be for new HIV prevention technologies.

Adolescent↗
PubMed2006

Preferences between injectable contraceptive methods among South African women.

OBJECTIVE: To examine South African women's preferences between depot medroxyprogesterone acetate (DMPA) and norethisterone enanthate (NET-EN), as well as the reasons for and correlates of these preferences. STUDY DESIGN: A cross-sectional study among women attending 26 primary health care clinics across the Western Cape Province. RESULTS: Of 893 women participating in the survey, 57% (n=511) and 45% (n=399) had ever used DMPA and NET-EN, respectively. Among women who knew of both injectables, 46% stated a preference for DMPA (n=365) and 37% stated a preference for NET-EN (n=297). Most women who preferred DMPA thought that it was more effective in preventing pregnancy, while women who preferred NET-EN stated that it was preferable for women who wanted children in the future. Preferences for NET-EN were independently associated with younger age, higher education and living in an urban area. CONCLUSION: These findings suggest that there are significant misperceptions among women regarding the differences between DMPA and NET-EN, which may have important resource implications for contraceptive services. It is likely that these misperceptions arise from popular discourse and individual user experiences, as well as poor communication with and counseling of women on the part of providers. Interventions aimed at both users and providers are required to dispel the myths and misinformation regarding progestogen-only injectable methods.

Adolescent↗
PubMed2006

CD4 cell count recovery among HIV-infected patients with very advanced immunodeficiency commencing antiretroviral treatment in sub-Saharan Africa.

BACKGROUND: Patients accessing antiretroviral treatment (ART) programmes in sub-Saharan Africa frequently have very advanced immunodeficiency. Previous data suggest that such patients may have diminished capacity for CD4 cell count recovery. METHODS: Rates of CD4 cell increase were determined over 48 weeks among ART-naïve individuals (n = 596) commencing ART in a South African community-based ART programme. RESULTS: The CD4 cell count increased from a median of 97 cells/microl at baseline to 261 cells/microl at 48 weeks and the proportion of patients with a CD4 cell count < 100 cells/microl decreased from 51% at baseline to just 4% at 48 weeks. A rapid first phase of recovery (0-16 weeks, median rate = 25.5 cells/microl/month) was followed by a slower second phase (16-48 weeks, median rate = 7.7 cells/microl/month). Compared to patients with higher baseline counts, multivariate analysis showed that those with baseline CD4 counts < 50 cells/microl had similar rates of phase 1 CD4 cell recovery (P = 0.42), greater rates of phase 2 recovery (P = 0.007) and a lower risk of immunological non-response (P = 0.016). Among those that achieved a CD4 cell count > 500 cells/microl at 48 weeks, 19% had baseline CD4 cell counts < 50 cells/microl. However, the proportion of these patients that attained a CD4 count 200 cells/microl at 48 weeks was lower than those with higher baseline CD4 cell counts. CONCLUSION: Patients in this cohort with baseline CD4 cell counts < 50 cells/microl have equivalent or greater capacity for immunological recovery during 48 weeks of ART compared to those with higher baseline CD4 cell counts. However, their CD4 counts remain < 200 cells/microl for a longer period, potentially increasing their risk of morbidity and mortality in the first year of ART.

Adult↗
PubMed2006

Healthcare providers' perspectives on discussing HIV status with infected children.

The disclosure of HIV status to infected children has received relatively little attention to date in sub-Saharan Africa. We conducted 40 semi-structured interviews with healthcare providers working in a large paediatric HIV clinic in Cape Town, South Africa regarding attitudes and experiences around discussing HIV with infected children. Most providers felt that the optimal age for general discussions about an HIV-infected child's health should happen around age 6, but that specific discussions regarding HIV infection should be delayed to a median of 10 years. Though most providers said that primary caregivers were the most appropriate individuals to lead disclosure discussions, there were strong views that caregivers require support from healthcare providers. These findings indicate the complexities involved in the disclosure of HIV status to infected children, and point to the need for interventions to support caregivers and providers in disclosure discussions.

Adolescent↗
PubMed2006

Impact of HIV infection on the epidemiology of tuberculosis in a peri-urban community in South Africa: the need for age-specific interventions.

BACKGROUND: In August 2005, the World Health Organization declared the tuberculosis (TB) epidemic in Africa to be a regional emergency. Current TB-control measures are failing, largely as a result of the human immunodeficiency virus (HIV) epidemic. Evaluation of additional control interventions requires detailed understanding of the epidemiological relationship between these diseases at the community level. METHODS: We examined age- and sex-specific trends in TB notifications and their association with the prevalence of HIV infection in a peri-urban township in South Africa during 1996-2004. Denominators for TB notifications were derived from population census data. The local TB-control program used the World Health Organization directly observed treatment, short-course (DOTS) strategy. RESULTS: TB notification rates increased 2.5-fold during the period, reaching a rate of 1468 cases per 100,000 persons in 2004 (P=.007, by test for trend); the estimated population prevalence of HIV infection increased from 6% to 22% during the same period. After stabilization of prevalence of HIV infection, the TB notification rate continued to increase steeply, indicating ongoing amplification of the TB epidemic. In 2004, at least 50% of children aged 0-9 years who developed TB were HIV infected. Annual TB notification rates among adolescents increased from 0 cases in 1996-1997 to 436 cases per 100,000 persons in 2003-2004, and these increases were predominantly among female. However, 20-39-year-old persons were affected most, with TB notification rates increasing from 706 to 2600 cases per 100,000 persons among subjects in their 30s. In contrast, TB rates among persons aged >50 years did not change. CONCLUSIONS: HIV infection is driving the TB epidemic in this population, and use of the DOTS strategy alone is insufficient. TB notifications have reached unprecedented levels, and additional targeted, age-specific interventions for control of TB and HIV infection in such populations are needed.

Adolescent↗
PubMed2006

Distinguishing the temporal association between women's intravaginal practices and risk of human immunodeficiency virus infection: a prospective study of South African women.

Cross-sectional studies have suggested that intravaginal practices, such as douching or "dry sex," may increase women's susceptibility to infection with human immunodeficiency virus (HIV). The authors examined the temporal nature of this association in a cohort of South African women. At enrollment (2001-2002), 4,089 women were tested for HIV infection. Participants reported their intravaginal practices at a 6-month follow-up visit and were followed with repeat HIV testing for up to 24 months. Among the 3,570 women who were HIV-negative at enrollment, 26% reported some type of intravaginal practice, mostly washing inside the vagina with water and/or cloth as part of daily hygiene. During follow-up, 85 incident HIV infections were observed. Intravaginal practices were associated with prevalent HIV at enrollment (adjusted odds ratio = 1.50, 95% confidence interval: 1.22, 1.85), but during follow-up there was no association between intravaginal practices and incident HIV (adjusted hazard ratio = 1.04, 95% confidence interval: 0.65, 1.68). These findings may be explained by a reversal of the causal sequence assumed for this association, since intravaginal practices may be undertaken in response to vaginal infections that occur more commonly among HIV-infected women. Intravaginal practices appear unlikely to be a cofactor in the male-to-female transmission of HIV in this setting.

Adult↗
PubMed2006

Nested case-control study of cervical mucosal lesions, ectopy, and incident HIV infection among women in Cape Town, South Africa.

OBJECTIVE: The objective of this study was to test whether cervical mucosal lesions and ectopy increase women's susceptibility to HIV infection. STUDY DESIGN: HIV-seronegative women ages 35 to 65 years (n = 5773) enrolled into a cervical cancer screening trial were followed for up to 36 months. All HIV seroconverters (n = 86) in the cohort were compared with randomly selected controls (n = 324) who did not seroconvert. Magnified photographs of the cervix taken during speculum examination at enrollment were evaluated for cervical mucosal lesions and ectopy using standard criteria. RESULTS: The presence of mucosal lesions (observed among 19% of controls) was associated with increased risk of HIV seroconversion (adjusted odds ratio [AOR] = 1.93; 95% confidence interval [CI] = 1.07-3.48). Ectopy extending over >20% of the cervix was also associated with HIV seroconversion (AOR = 2.18; 95% CI = 1.01-4.69). CONCLUSIONS: Visible lesions of cervical mucosa and cervical ectopy may be markers of increased susceptibility to HIV infection among women. Protection of the mucosa of the cervix may provide an important approach for new HIV prevention technologies.

Adult↗
PubMed2006

Design and evaluation of a drama-based intervention to promote voluntary counseling and HIV testing in a South African community.

BACKGROUND: Voluntary counseling and testing (VCT) services are a major component of HIV prevention and treatment efforts. We developed a drama-based intervention to promote VCT services in a peri-urban community in South Africa. METHODS: Young adults from the community received training in HIV/AIDS and drama, and developed sketches to address perceived barriers to VCT. Over 12 months, 80 performances were held in busy community settings. The intervention was evaluated through changes in VCT uptake at the local clinic compared with comparable communities nearby. RESULTS: After the start of the intervention in August 2003, a 172% increase in the uptake of VCT services was observed in the intervention community. This was significantly greater than demand for VCT in either of the control communities during the same period (P < 0.0001). CONCLUSION: A structured, community-based education program based on drama can lead to substantial increases in the demand for VCT services in resource-limited settings.

Adult↗
PubMed2006

TB patients' perspectives on integrated TB/HIV services in South Africa.

There are few data describing patients' attitudes towards the integration of antiretroviral therapy for HIV-infected patients into existing TB services. We investigated this issue among patients receiving TB treatment at a primary care facility in Cape Town, South Africa. Of 85 patients interviewed, the vast majority (92%, n = 78) stated they would be willing to attend an integrated TB/HIV service; perceived stigmatization of TB and HIV was a significant predictor of negative attitudes towards a combined TB/HIV programme (adjusted odds ratio, 19.90, P = 0.02). While integrated TB/HIV services appear generally acceptable in this setting, continuing efforts to combat stigmatization are necessary to ensure maximum uptake.

Adolescent↗
PubMed2006

Rapid scale-up of a community-based HIV treatment service: programme performance over 3 consecutive years in Guguletu, South Africa.

BACKGROUND: Despite rapid expansion of antiretroviral therapy (ART) in sub-Saharan Africa there are few longitudinal data describing programme performance during rapid scale-up. METHODS: We compared mortality, viral suppression and programme retention in 3 consecutive years of a public sector community-based ART clinic in a South African township. Data were collected prospectively from establishment of services in October 2002 to the censoring date in September 2005. Viral load and CD4 counts were monitored at 4-monthly intervals. Community-based counsellors provided adherence and programme support. RESULTS: During the study period 1139 ART-naïve patients received ART (161, 280 and 698 in the 1st, 2nd and 3rd years respectively). The median CD4 cell counts were 84 cells/microl (interquartile range (IQR) 42-139), 89 cells/microl (IQR 490-149), and 110 cells/microl (IQR 55-172), and the proportions of patients with World Health Organization (WHO) clinical stages 3 and 4 were 90%, 79% and 76% in each sequential year respectively. The number of counsellors increased from 6 to 28 and the median number of clients allocated to each counsellor increased from 13 to 33. The overall loss to follow-up was .9%. At the date of censoring, the Kaplan-Meier estimates of the proportion of patients still on the programme were 82%, 86% and 91%, and the proportion who were virally suppressed (< 400 copies/ml) were 100%, 92% and 98% for the 2002, 2003 and 2004 cohorts respectively. CONCLUSIONS: While further operational research is required into optimal models of care in different populations across sub-Saharan Africa, these results demonstrate that a single community-based public sector ART clinic can extend care to over 1000 patients in an urban setting without compromising programme performance.

Adolescent↗