Mediation Analysis of a Theory-Based Culture and Age-Appropriate HIV/STI Prevention

Few studies have investigated mediator effects of HIV prevention interventions on adolescents in sub-Saharan Africa. Herein, we report on a secondary analysis of an intervention that increased intentions to use condoms, abstain from sexual intercourse, and seek safe male circumcision among adolescents in Botswana. In a study conducted in Botswana, 806 grade 9 students from 21 public Junior Secondary Schools were randomly assigned to either the OWN THE FUTURE: Pulling Together We Will” ( PTWW) intervention group or a health promotion control group. Both conditions consisted of 12 1-h modules, with two modules delivered during each of the six sessions on six consecutive school days. The students in both groups completed confidential computer-based surveys at several time points: pre-, immediately post-, 3, 6, and 12 months post-intervention. Mediation was assessed using the product-of-coefficients approach in a generalized estimating equations (GEE) framework. The analyses showed that condom use beliefs were significant mediators of the intervention effect on the intention to consistently use condoms over time. Also, negative socio-cultural beliefs, prevention beliefs, and HIV/STI knowledge were significant mediators of the intervention’s effects on the intention to abstain from sex. Additionally, normative beliefs, prevention beliefs, parental negotiation, and circumcision knowledge were significant mediators of the intervention’s effect on intention to seek safe male circumcision. The mediation analysis delineated a theoretical model and isolated activities that positively impact condom use, abstinence from sex, and circumcision intentions of Batswana middle school adolescents.

     

Efficient estimation of human immunodeficiency virus incidence rate using a pooled cross-sectional cohort study design

Development of methods to accurately estimate human immunodeficiency virus (HIV) incidence rate remains a challenge. Ideally, one would follow a random sample of HIV-negative individuals under a longitudinal study design and identify incident cases as they arise. Such designs can be prohibitively resource intensive and therefore alternative designs may be preferable. We propose such a simple, less resource-intensive study design and develop a weighted log likelihood approach which simultaneously accounts for selection bias and outcome misclassification error. The design is based on a cross-sectional survey which queries individuals' time since last HIV-negative test, validates their test results with formal documentation whenever possible, and tests all persons who do not have documentation of being HIV-positive. To gain efficiency, we update the weighted log likelihood function with potentially misclassified self-reports from individuals who could not produce documentation of a prior HIV-negative test and investigate large sample properties of validated sub-sample only versus pooled sample estimators through extensive Monte Carlo simulations. We illustrate our method by estimating incidence rate for individuals who tested HIV-negative within 1.5 and 5 years prior to Botswana Combination Prevention Project enrolment. This article establishes that accurate estimates of HIV incidence rate can be obtained from individuals' history of testing in a cross-sectional cohort study design by appropriately accounting for selection bias and misclassification error. Moreover, this approach is notably less resource-intensive compared to longitudinal and laboratory-based methods.     

Orphans’ perspectives on grief and loss in Botswana

This paper seeks to examine orphaned children’s experiences on grief and loss in Botswana, and its impact on their well-being and make policy recommendations. A cross sectional design which utilized survey questionnaires was employed. Data were collected from 11 districts (3 urban and 8 rural) among orphan children aged 10–18 years. Chi-squared test was used to identify variables believed to be associated with loss and grief. Unadjusted (simple) and adjusted multiple logistic regression was used to investigate factors associated with loss. Of the 732 participants (53.1%) were females and mean age was 13.5 years (SD?=?2.7); and 44.6% of these children had experienced death of a close family member in the past year which had been communicated. Children had access to education, lower primary (19.5%), upper primary (39.1%), junior secondary (32.5%), senior secondary school (6.6%), and (0.3%) in tertiary institutions. Most children (88.6%) had not experienced stigma and discrimination at school; 55.2% lived with grandparents, aunts (23.4%), siblings (11.8%), uncles (4.0%), other relatives (3.5%) and non-relatives (0.1%). Unadjusted logistic regression indicated that loss was significantly associated with having someone to talk to (OR?=?0.72, 95% CI, 0.53–0.98, p?=?0.03), change of residence (OR?=?3.08, 95% CI, 1.94–4.90, p?p?p?p?p?p?=?0.02). Age-specific interventions aimed at addressing the emotional, psychosocial and economic impacts of grief and loss are critical in preventing negative coping behaviors and improving the quality of life of orphans.     

The cost and impact of male circumcision on HIV/AIDS in Botswana

The HIV/AIDS epidemic continues to be a major issue facing Botswana, with overall adult HIV prevalence estimated to be 25.7 percent in 2007. This paper estimates the cost and impact of the draft Ministry of Health male circumcision strategy using the UNAIDS/WHO Decision-Makers' Programme Planning Tool (DMPPT). Demographic data and HIV prevalence estimates from the recent National AIDS Coordinating Agency estimations are used as input to the DMPPT to estimate the impact of scaling-up male circumcision on the HIV/AIDS epidemic. These data are supplemented by programmatic information from the draft Botswana National Strategy for Safe Male Circumcision, including information on unit cost and program goals. Alternative scenarios were developed in consultation with stakeholders. Results suggest that scaling-up adult and neonatal circumcision to reach 80% coverage by 2012 would result in averting almost 70,000 new HIV infections through 2025, at a total net cost of US$47 million across that same period. This results in an average cost per HIV infection averted of US$689. Changing the target year to 2015 and the scale-up pattern to a linear pattern results in a more evenly-distributed number of MCs required, and averts approximately 60,000 new HIV infections through 2025. Other scenarios explored include the effect of risk compensation and the impact of increasing coverage of general prevention interventions. Scaling-up safe male circumcision has the potential to reduce the impact of HIV/AIDS in Botswana significantly; program design elements such as feasible patterns of scale-up and inclusion of counselling are important in evaluating the overall success of the program.     

Synthesis,physicochemical characterization,toxicity and efficacy of a PEG conjugate and a hybrid PEG conjugate nanoparticle formulation of the antibiotic moxifloxacin

Antibiotic resistance is increasing at such an alarming rate that it is now one of the greatest global health challenges. Undesirable toxic side-effects of the drugs lead to high rates of non-completion of treatment regimens which in turn leads to the development of drug resistance. We report on the development of delivery systems that enable antibiotics to be toxic against bacterial cells while sparing human cells. The broad-spectrum fluoroquinolone antibiotic moxifloxacin (Mox) was successfully conjugated to poly(ethylene glycol) (PEG) which was further encapsulated into the hydrophobic poly(ε-caprolactone) (PCL) nanoparticles (NPs) with high efficiency, average particle size of 241.8 ± 4 nm and negative zeta potential. Toxicity against erythrocytes and MDBK cell lines and drug release in human plasma were evaluated. Hemocompatibility and reduced cytotoxicity of the PEG–Mox and PCL(PEG–Mox) NPs were demonstrated in comparison to free Mox. Antimicrobial activity was assessed against drug sensitive and resistant: Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae. The antibacterial activity of Mox was largely maintained after conjugation. Our data shows that the toxicity of Mox can be effectively attenuated while, in the case of PEG–Mox, retaining significant antibacterial activity. At the conditions employed in this study for antimicrobial activity the encapsulated conjugate (PCL(PEG–Mox) NPs) did not demonstrate, conclusively, significant antibacterial activity. These systems do, however, hold promise if further developed for improved treatment of bacterial infections.

Moxifloxacin was conjugated to polyethylene glycol to segregate host cell toxicity from antimicrobial activity. The conjugate was then encapsulated into a polycaprolactone nanoparticle to assist the simultaneous delivery of multiple drugs to the site of microbial infection.     

Voluntary counseling and testing among post-partum women in Botswana

OBJECTIVE: To determine uptake and socio-demographics predictors of acceptance of voluntary counseling and testing (VCT) among post-partum women in Botswana. METHODS: Women attending maternal and child health clinics for their first post-partum or well baby visit in three sites in Botswana were offered VCT after a written informed consent. A standardized questionnaire was used to collect socio-demographic characteristics and reasons for declining VCT. RESULTS: From March 1999 to November 2000, we approached 1735 post-partum women. Only 937 (54%) of those approached accepted VCT. In multiple logistic regression analysis, younger maternal age, not being married, and less formal education were significant predictors of acceptance of VCT. Thirty percent of women who accepted VCT were HIV-positive. CONCLUSION: Our results indicated that in Botswana prior to the initiation of a government Mother to Child Transmission (MTCT) prevention program, younger, unmarried, and less educated post-partum women were more likely to undergo VCT. PRACTICE IMPLICATIONS: Our results have shown that interventions to improve VCT among post-partum women and more generally among women of reproductive age are warranted in Botswana. These interventions should account for differences such age, marital status, education, and partner involvement to maximize VCT uptake.     

Use of Dual Protection in Botswana

High rates of unintended pregnancy and of HIV and other sexually transmitted infections prompt calls for use of “dual‐protection” strategies, including consistent condom use or dual‐method use. This study examines the use of dual‐protection strategies in a sample of 15–49‐year‐old men and women in Botswana in 2003. Half of sexually active respondents reported consistent condom use in the past year; 2.5 percent reported dual‐method use. Multiple logistic regression analyses showed that urban residence, less than a ten‐year age difference between partners, discussing HIV and contraception with one's partner, not intending to have a child in the next year, having no children, being in a relationship where one or both partners have additional concurrent partners, and supportive condom norms were associated with dual protection—that is, with consistent condom or dual‐method use. In the context of high HIV prevalence, concerns about disease prevention likely influence contraception, and interventions should address childbearing desires and sexual risk simultaneously.     

Missed opportunities in TB diagnosis: a TB Process-Based Performance Review tool to evaluate and improve clinical care

Background  

Traditional tuberculosis (TB) treatment outcome measures, such as cure rate, do not provide insight into the underlying reasons for missing clinical targets. We evaluated a TB Process-Based Performance Review (TB-PBPR) tool, developed to identify "missed opportunities" for timely and accurate diagnosis of TB. The tool enables performance assessment at the level of process and quality of care.