Purpose

Although most medical schools and residency programs offer international medical electives (IMEs), little guidance on the educational objectives for these rotations exists; thus, the authors reviewed the literature to compile and categorize a comprehensive set of educational objectives for IMEs.

Method

In February and July 2012, the authors searched SciVerse Scopus online, which includes the Embase and MEDLINE databases, using specified terms. From the articles that met their inclusion criteria, they extracted the educational objectives of IMEs and sorted them into preelective, intraelective, and postelective objectives.

Results

The authors identified and reviewed 255 articles, 11 (4%) of which described 22 educational objectives. Among those 22 objectives, 5 (23%), 15 (68%), and 2 (9%) were, respectively, preelective, intraelective, and postelective objectives. Among preelective objectives, only cultural awareness appeared in more than 2 articles (3/11; 27%). Among intraelective objectives, the most commonly defined were enhancing clinical skills and understanding different health care systems (9/11; 82%). Learning to manage diseases rarely seen at home and increasing cultural awareness appeared in nearly half (5/11; 45%) of all articles. Among postelective objectives, reflecting on experiences through a written project was most common (9/11; 82%).

Conclusions

The authors identified 22 educational objectives for IMEs in the published literature, some of which were consistent across institutions. These consistencies, in conjunction with future research, can be used as a framework on which institutions can build their own IME curricula, ultimately helping to ensure that their medical trainees have a meaningful learning experience while abroad.

BACKGROUND: People living with HIV (PLHIV) may have concurrent Hepatitis B Virus (HBV) infection, and certain antiretroviral therapies are recommended for HBV-HIV co-infected individuals. Routine screening for Hepatitis B virus may influence management of antiretroviral therapy for PLHIV, but risk factors for co-infection have not been well defined. The objective of this study was to identify risk factors for HBV infection among PLHIV in South Africa. METHODS: We conducted a cross-sectional analysis of a prospective, clinic-based cohort study of adults seeking HIV testing from 2013-2017 in Umlazi township, South Africa. Patients newly diagnosed with HIV were enrolled and subsequently tested for Hepatitis B surface antigen positive (HBsAg +). We used a Poisson linear regression model to assess which factors, pertaining to sociodemographic status, medical history, clinical symptoms, mental health were associated with HBV. RESULTS: Among 3,105 PLHIV participants in South Africa, 6% were positive for HBV. Males had a higher HBV prevalence (10.4%) than females (5.2%). Within the HBV-positive group, the mean age was 33.2 years, with 38.3% females and 43.9% having completed high school or higher. About 39.9% reported alcohol use, 24.7% had a smoking history, and 8.3% reported substance use in the past year. Older participants born before 1995, when routine infant HBV vaccination was introduced, were more likely to have HBV. In multivariable analyses, smoking history increased HBV risk in females (aPR = 2.58; 95% CI 1.47-2.52), while alcohol use decreased HBV risk in males (aPR = 0.36; 95% CI 0.19-0.70). CONCLUSIONS: In a South African cohort, roughly one in 16 PLHIV had HBV co-infection, and this rate was higher in males. The most prominent risk factors for HBV infection in PLHIV were alcohol use, higher income, and smoking history, which may help inform targeted treatment and prevention strategies. Creating HBV-specific screening and prevention strategies for PLHIV may be useful for reducing HBV infections.

We examined the impact of past-year intimate partner violence (IPV) on HIV outcomes among women living with HIV (WLHIV) in Durban, South Africa. We assessed past-year IPV using the WHO Violence Against Women Questionnaire. We conducted logistic regression to assess associations between demographic variables and IPV at baseline, and between IPV at baseline and longitudinal HIV outcomes. Among 235 WLHIV, 17% reported past-year emotional, physical, or sexual IPV. At baseline, HIV-disclosure to partner was associated with 4.35-fold odds of past-year IPV (95% CI 1.17-16.10) after controlling for children, education, and harmful alcohol use. In the prospective analysis, IPV was associated with not achieving the co-primary outcome of retention in care and viral suppression in univariate (OR = 2.32, 95% CI 1.04-5.18), but not in the multivariate model. In the context of rapid treatment scale-up, the high burden of IPV among WLHIV needs to be prioritized, with an emphasis on disclosure support.

Background

Current pharmacologic adherence monitoring for antiretrovirals involves expensive, labor-intensive liquid chromatography/tandem mass spectrometry (LC-MS/MS)-based methods. Antibody-based assays can monitor and support adherence in real time. We developed a tenofovir (TFV)-based immunoassay and further validated it in a directly observed therapy (DOT) study.

Design

Pharmacologic DOT study of TFV disoproxil fumarate (TDF)/emtricitabine (FTC) administered to HIV-noninfected volunteers.

Methods

The TARGET study provided directly observed TDF 300 mg/FTC 200 mg 7 (high adherence), 4 (moderate), and 2 doses/week (low) to 30 volunteers (10/group) in Thailand, collecting a total of 637 urine samples over 6 weeks of administration and during washout. ELISA measured urine TFV levels by the immunoassay and LC-MS/MS-based concentrations served as the gold standard. A mixed-effects regression model evaluated cutoffs for a point-of-care assay. Performance characteristics of the immunoassay were compared with LC-MS/MS at a chosen cutoff.

Results

Median TFV levels were 12,000 ng/mL by the immunoassay 1 day after dosing; 5000 ng/mL 2 days after dosing; 1500 ng/mL 3 days after dosing; and below the lower limit of quantification thereafter (≥4 days). An immunoassay cutoff of 1500 ng/mL accurately classified 98% of patients who took a dose 24 hours ago as adherent. The specificity and sensitivity of the immunoassay compared with LC-MS/MS at the 1500 ng/mL cutoff were 99% and 94%; the correlation between TFV levels by the 2 assays was high (0.92, P < 0.00001).

Conclusions

We have developed a novel TFV immunoassay that is highly specific, sensitive, and correlates strongly with LC-MS/MS measurements in a large DOT study. Adherence benchmarks from this DOT study will guide the development of a low-cost rapid point-of-care test for pre-exposure prophylaxis and antiretroviral treatment adherence monitoring and interventions.

Background

Direct measurement of tenofovir (TFV) in urine could be an objective measure to monitor adherence to preexposure prophylaxis (PrEP) or TFV-based antiretroviral therapy (ART).

Methods

We conducted a 3-arm randomized, pharmacokinetic study of tenofovir disoproxil fumarate (TDF) 300 mg/emtricitabine (FTC) 200 mg among adults living with human immunodeficiency virus. Participants were randomized to receive controlled TDF/FTC dosing as (1) "perfect" adherence (daily); (2) "moderate" adherence (4 doses/week); or (3) "low" adherence (2 doses/week). We obtained trough spot urine and plasma samples during a 6-week directly observed therapy period and a 4-week washout period. TFV concentrations were compared between adherence arms using 1-way analysis of variance.

Results

Among 28 participants, the median age was 33 years and 16 (57%) were male. Correlation between TFV plasma and urine concentrations was strong (ρ = 0.78; P < .0001). Median (interquartile range) steady-state trough TFV concentrations (ng/mL) for perfect, moderate, and low TDF adherence were 41 (26-52), 16 (14-19), and 4 (3-5) in plasma; and 6480 (3940-14 300), 3405 (2210-5020), and 448 (228-675) in urine. Trough TFV concentrations at steady state were significantly different between the 3 adherence arms for plasma (P < .0001) and urine (P = .0002). Following drug cessation, TFV concentrations persisted longer in urine than plasma samples. Washout urine TFV concentrations and time to undetectable concentrations did not differ between the 3 randomized adherence groups.

Conclusions

Urine TFV concentrations can inform interpretation of novel point-of-care urine-based TFV assays to assess recent TDF adherence.

Clinical trials registration

NCT03012607

Background

Pharmacologic adherence measures were critical to the interpretation of the tenofovir (TFV)-disoproxil-fumarate/emtricitabine (TDF/FTC) PrEP trials. These measures are being incorporated into PrEP demonstration projects, but currently-available metrics in plasma, cells, hair or urine involve expensive and time-intensive mass-spectrometry (MS)-based methods. No point-of-care method to assess PrEP adherence in real-time has yet been implemented. Antibody-based tests allow for low-cost, easy-to-perform, point-of-care drug detection. In this study, we developed an antibody-based TFV immunoassay and evaluated its test characteristics among individuals taking TDF/FTC.

Methods

We synthesized possible immunogens based on TFV's molecular structure, injected rabbits with the conjugated derivatives, and bled them monthly for subsequent ELISA-testing for TFV-specific antibodies. We purified an antibody with specific TFV binding and created dose-response curves for ELISA-quantification. We then quantified TFV in urine from human participants not taking TDF/FTC and from individuals taking daily TDF/FTC 300 mg/200 mg for 7 days with a 7-day washout period using ELISA with this TFV-specific antibody. ELISA results were compared with the gold-standard test for TFV detection/quantification using liquid-chromatography-tandem-MS (LC-MS/MS).

Findings

None of the urine samples from 115 participants not taking TDF/FTC showed ELISA- reactivity, indicating 100% specificity (95% CI 97-100%) of the immunoassay. Among participants taking TDF/FTC, 67 of 70 samples positive by LC-MS/MS were positive by the ELISA-immunoassay for an estimated diagnostic sensitivity of 96% (95% CI 88-99%). The precision of the assay was high (coefficient of variationb15%). The rank correlation between ELISA and LC-MS/MS values in the 70 quantitative urine TFV levels positive by LC-MS/MS across a wide range of concentrations among participants on TDF/FTC was high (r = 0.96).

Interpretation

Our antibody-based immunoassay for measuring TFV in urine performed well compared to the gold-standard of LC-MS/MS among individuals taking TDF/FTC. A sensitive and specific immunoassay paves the way for real-time monitoring/feedback on recent adherence to TFV-based regimens, which should optimize interpretation and outcomes during PrEP and ART roll-out.

From directly observed therapy studies, urine tenofovir (TFV) levels were 74% lower when taking tenofovir alafenamide (TAF) vs tenofovir disoproxil fumarate. Urine TFV remains quantifiable across a range of TAF adherence patterns, but a separate point-of-care lateral flow immunoassay with a lower TFV threshold will be needed to support TAF adherence monitoring.

Objective

HIV prevention and treatment studies demonstrate that pharmacologic adherence metrics are more accurate than self-report. Currently available metrics use liquid-chromatography/tandem-mass-spectrometry (LC-MS/MS), which is expensive and laboratory-based. We developed a specific and sensitive antibody against tenofovir, the backbone of treatment and prevention, but conversion to a lateral flow assay (LFA) - analogous to a urine pregnancy test - is required for point-of-care testing. We describe the development of the first LFA to measure antiretroviral adherence in real-time.

Methods

Previous work in a directly observed therapy study of providing tenofovir disoproxil fumarate (TDF) to HIV-noninfected volunteers at various simulated adherence patterns defined the appropriate cut-off for the LFA (1500 ng tenofovir/ml urine). We developed the LFA using a sample pad for urine; a conjugate pad coated with TFV-specific antibodies conjugated to colloidal gold nanoparticles; a nitrocellulose membrane striped with tenofovir-antigen (test line) and a control line; with an absorbent pad to draw urine across the reaction membrane.

Results

We tested 300 urine samples collected from the directly observed therapy study by this LFA and the gold-standard method of LC-MS/MS. The LFA demonstrated 97% specificity (95% CI 93-99%) and 99% sensitivity (94-100%) compared with LC-MS/MS. The LFA accurately classified 98% of patients who took a dose within 24 h as adherent.

Conclusion

We describe the development and validation of the first point-of-care assay to measure short-term adherence to HIV prevention and treatment in routine settings. The assay is low-cost, easy-to-perform and measures the breakdown product (tenofovir) of both TDF and tenofovir alafenamide (TAF). This assay has the potential to improve HIV and PrEP outcomes worldwide by triggering differentiated service delivery with further study merited.

Background

The World Health Organization (WHO) recommends that outpatient people living with HIV (PLHIV) undergo tuberculosis screening with the WHO four-symptom screen (W4SS) or C-reactive protein (CRP) (5 mg·L^-1 cut-off) followed by confirmatory testing if screen positive. We conducted an individual participant data meta-analysis to determine the performance of WHO-recommended screening tools and two newly developed clinical prediction models (CPMs).

Methods

Following a systematic review, we identified studies that recruited adult outpatient PLHIV irrespective of tuberculosis signs and symptoms or with a positive W4SS, evaluated CRP and collected sputum for culture. We used logistic regression to develop an extended CPM (which included CRP and other predictors) and a CRP-only CPM. We used internal-external cross-validation to evaluate performance.

Results

We pooled data from eight cohorts (n=4315 participants). The extended CPM had excellent discrimination (C-statistic 0.81); the CRP-only CPM had similar discrimination. The C-statistics for WHO-recommended tools were lower. Both CPMs had equivalent or higher net benefit compared with the WHO-recommended tools. Compared with both CPMs, CRP (5 mg·L^-1 cut-off) had equivalent net benefit across a clinically useful range of threshold probabilities, while the W4SS had a lower net benefit. The W4SS would capture 91% of tuberculosis cases and require confirmatory testing for 78% of participants. CRP (5 mg·L^-1 cut-off), the extended CPM (4.2% threshold) and the CRP-only CPM (3.6% threshold) would capture similar percentages of cases but reduce confirmatory tests required by 24, 27 and 36%, respectively.

Conclusions

CRP sets the standard for tuberculosis screening among outpatient PLHIV. The choice between using CRP at 5 mg·L^-1 cut-off or in a CPM depends on available resources.