An outbreak of HIV infection among people who inject drugs linked to injection of propofol in Taiwan

Simple quantification of propofol and its metabolites in blood and urine using gas chromatography-tandem mass spectrometry (GC-MS/MS)

An analytical method which was used for the simultaneous detection and quantification of propofol and its metabolites in human blood and urine by gas chromatography-tandem mass spectrometry (GC-MS/MS) was newly established and applied to authentic human samples obtained from the deceased. The QuEChERS method was employed, and then analyzed by GC-MS/MS. We separately used sulfatase and β-glucuronidase to hydrolyze the urine sample and calculated the increase of propofol and 4-hydroxypropofol before and after the hydrolysis. The results of urinary concentrations in urine from the subject were: 4.88 μg/mL for propofol, 0.53 μg/mL for 4-hydroxypropofol, 3.35 μg/mL for propofol-glucuronide, 0.31 μg/mL for the total concentration of 1-(2,6-diisopropyl-1,4-quinol)-glucuronide plus 4-(2,6-diisopropyl-1,4-quinol)-glucuronide, and 0.39 μg/mL for 4-(2,6- diisopropyl-1,4-quinol)-sulfate. The lower limit of quantification was 10 ng/mL for all determined compounds; the extraction recoveries were not less than 57.2 %. Intraday and interday precisions and accuracies were all less than 10 %. The calibration curves for propofol and 4-hydroxypropofol in human urine showed the correlation values of not less than 0.999; propofol and 4-hydroxypropofol in blood also presented good linearities in the concentration ranges of 0.1-10 μg/mL. The two compounds had good stability within 7 days at 25, 4, and -20 ℃. To our knowledge, this is the first trial to establish a simple and reliable method to simultaneously detect and quantify of propofol and its phase I and II metabolites in human blood and urine samples by GC-MS/MS.

Use of HIV Recency Assays for HIV Incidence Estimation and Other Surveillance Use Cases: Systematic Review

BACKGROUND

HIV assays designed to detect recent infection, also known as "recency assays," are often used to estimate HIV incidence in a specific country, region, or subpopulation, alone or as part of recent infection testing algorithms (RITAs). Recently, many countries and organizations have become interested in using recency assays within case surveillance systems and routine HIV testing services to measure other indicators beyond incidence, generally referred to as "non-incidence surveillance use cases."

OBJECTIVE

This review aims to identify published evidence that can be used to validate methodological approaches to recency-based incidence estimation and non-incidence use cases. The evidence identified through this review will be used in the forthcoming technical guidance by the World Health Organization (WHO) and United Nations Programme on HIV/AIDS (UNAIDS) on the use of HIV recency assays for identification of epidemic trends, whether for HIV incidence estimation or non-incidence indicators of recency.

METHODS

To identify the best methodological and field implementation practices for the use of recency assays to estimate HIV incidence and trends in recent infections for specific populations or geographic areas, we conducted a systematic review of the literature to (1) understand the use of recency testing for surveillance in programmatic and laboratory settings, (2) review methodologies for implementing recency testing for both incidence estimation and non-incidence use cases, and (3) assess the field performance characteristics of commercially available recency assays.

RESULTS

Among the 167 documents included in the final review, 91 (54.5%) focused on assay or algorithm performance or methodological descriptions, with high-quality evidence of accurate age- and sex-disaggregated HIV incidence estimation at national or regional levels in general population settings, but not at finer geographic levels for prevention prioritization. The remaining 76 (45.5%) described the field use of incidence assays including field-derived incidence (n=45), non-incidence (n=25), and both incidence and non-incidence use cases (n=6). The field use of incidence assays included integrating RITAs into routine surveillance and assisting with molecular genetic analyses, but evidence was generally weaker or only reported on what was done, without validation data or findings related to effectiveness of using non-incidence indicators calculated through the use of recency assays as a proxy for HIV incidence.

CONCLUSIONS

HIV recency assays have been widely validated for estimating HIV incidence in age- and sex-specific populations at national and subnational regional levels; however, there is a lack of evidence validating the accuracy and effectiveness of using recency assays to identify epidemic trends in non-incidence surveillance use cases. More research is needed to validate the use of recency assays within HIV testing services, to ensure findings can be accurately interpreted to guide prioritization of public health programming.

A Multistage Process Model of How a Person Who Currently Injects Drugs Comes to Assist Persons Who Do not Inject with Their First Injections

Injecting drugs for the first time almost always requires assistance from an experienced person who injects drugs (PWID). While there has been moderate amount of research on PWID who assist with first injections, most of this research has focused on identifying characteristics of PWID who assist with first injections. We do not have a formal model that describes how the minority of PWID come to assist do so, while the majority never assist. Through comparison of persons who did or did not recently assist with first injections using data from PWID in Tallinn, Estonia (N = 286) and Staten Island, New York City (N = 101), we developed a formal multi-stage model of how PWID come to assist with first injections. The model had a primary pathway 1) of engaging in "injection promoting" behaviors, 2) being asked to assist, and 3) assisting. Statistical testing using odds ratios showed participation in each stage was strongly associated with participation in the next stage (all odds ratios >3.0) and the probabilities of assisting significantly increased with participation in the successive stages. We then used the model to compare engagement in the stages pre-vs. post participation in an intervention, and to compare persons who recently assisted to persons who had assisted in the past but had not recently assisted and to persons who had never assisted. Advantages of a formal model for how current PWID come to assist with first injections include: facilitating comparisons across different PWID populations and assessing strengths and limitations of interventions to reduce assisting with first injections.