Dataset Information

Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory.

ABSTRACT: BACKGROUND:Viral load testing is key to monitoring response to anti-retroviral therapy (ART). However, in lower and middle income countries with large epidemics, pre-analytical challenges threaten the quality of testing. It is unknown how much delayed processing and adverse storage affects the validity of results. The aim of this study was to determine the impact of delayed testing and warmer storage conditions on HIV RNA stability in diagnostic samples. METHODS:1194 samples, collected in EDTA or plasma preparation (PPT) tubes, were studied. Immediately after initial testing, primary tubes were stored for 72, 96 or 168 hours at 4°C, 20°C or 30°C. The viral load was then repeated and the 2 results were compared. RESULTS:Viral loads were very stable, with <0.5 log copies/ml median difference noted between paired tests for all storage times and temperatures. The viral load in samples stored for up to a week reliably differentiated between ART-suppressed and failing patients in 98.83% of instances. However, re-centrifugation immediately prior to repeat testing was essential to avoid falsely elevated readings, probably due to contamination of plasma with cell-associated viral nucleic acids. Approximately 20% of samples with initially undetectable viral loads were weakly positive (<100 copies/mL) on repeat. This was not exacerbated by duration or temperature of storage. CONCLUSION:Viral RNA in diagnostic samples is stable well beyond currently recommended limits. However, when testing stored primary samples, contamination of plasma with cellular material easily occurs. Low viral loads (<100copies/mL) in samples stored in this way should be interpreted with caution.

SUBMITTER: Hardie D

PROVIDER: S-EPMC6609026 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

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Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory.

Hardie Diana D Korsman Stephen S Ameer Sharifa S Vojnov Lara L Hsiao Nei-Yuan NY

PloS one 20190703 7

<h4>Background</h4>Viral load testing is key to monitoring response to anti-retroviral therapy (ART). However, in lower and middle income countries with large epidemics, pre-analytical challenges threaten the quality of testing. It is unknown how much delayed processing and adverse storage affects the validity of results. The aim of this study was to determine the impact of delayed testing and warmer storage conditions on HIV RNA stability in diagnostic samples.<h4>Methods</h4>1194 samples, coll ...[more]

PMID: 31269089

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Project description:BackgroundPatient feedback after contact with a hospital is regarded as an important source of information for the improvement of local healthcare services. Routine patient surveys are in widespread use to obtain such feedback. While general principles for the composition of this kind of surveys have been described in the literature, it is unknown which method of contact and topics of feedback are important to patients in postcontact healthcare surveys.Material and methodsWe invited 2931 consecutive patients who had in- or outpatient contact with the Department of Orthopaedics and Traumatology at the University Hospital Basel to an anonymous survey. They were asked whether they were generally in favor of feedback surveys. They also had the opportunity to state their preferred form of contact (text message, app, email, online or letter) and provide up to three topics that they regarded as specifically important in patient surveys.ResultsA total of 745 patients participated in the survey (25.4%), of these 61.9% expressed the preference to be surveyed, and 69.1% selected `letter' as one of the preferred forms of contact. Favoring only `letter' contact increased substantially with age. Overall 54.6% of patients stated at least one topic that they wished to give feedback on. The most frequent topics were related to treatment and rather general aspects regarding staff and overall impression. The wish to include suggestions for improvements was rarely mentioned as specific topic.ConclusionsThe majority of patients seem to be rather indifferent to the existence and content of patient surveys. They mention a wide range of topics from general to specific ones, but do not express interest in the opportunity to suggest changes. There is a need to effectively engage patients in healthcare planning using new approaches to obtain valuable feedback on patients' hospital stay and contact experiences. These new approaches should ideally be more informative and cost-effective than the current practice.

Project description:BackgroundInfectious diseases are of great economic importance in commercial pig production, causing both clinical and subclinical disease, with influence on welfare, productivity, and antibiotic use. The causes of these diseases are often multifactorial and laboratory diagnostics are seldom routinely performed. The aim of the present study was to explore the benefits of monthly pathogen monitoring in nursery and finisher herds and to examine association between laboratory results and observed clinical signs, including coughing and diarrhoea. Three monthly samplings were conducted in three different age groups in six nursery and four finisher production units. For each unit, two pens were randomly selected in each age group and evaluated for coughing and diarrhoea events. Furthermore, faecal sock and oral fluid samples were collected in the selected pens and analysed for 18 respiratory and enteric viral and bacterial pathogens using the high-throughput real-time PCR BioMark HD platform (Fluidigm, South San Francisco, USA).ResultsIn total, 174 pens were sampled in which eight coughing events and 77 diarrhoeic events were observed. The overall findings showed that swine influenza A virus, porcine circovirus 2, porcine cytomegalovirus, Brachyspira pilosicoli, Lawsonia intracellularis, Escherichia coli fimbria types F4 and F18 were found to be prevalent in several of the herds. Association between coughing events and the presence of swine influenza A virus, porcine cytomegalovirus (Cq ≤ 20) or a combination of these were found. Furthermore, an association between diarrhoeic events and the presence of L. intracellularis (Cq ≤ 24) or B. pilosicoli (Cq ≤ 26) was found.ConclusionsThe use of high-throughput real-time PCR analysis for continuous monitoring of pathogens and thereby dynamics of infections in a pig herd, provided the veterinarian and farmer with an objective knowledge on the distribution of pathogens in the herd. In addition, the use of a high-throughput method in combination with information about clinical signs, productivity, health status and antibiotic consumption, presents a new and innovative way of diagnosing and monitoring pig herds and even to a lower cost than the traditional method.

Dataset Information

Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory.

Publications

Reliability of plasma HIV viral load testing beyond 24 hours: Insights gained from a study in a routine diagnostic laboratory.

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