Performance of commercial SARS-CoV-2 wild-type and Omicron BA.1 antibody assays compared with pseudovirus neutralization tests.

BACKGROUND: Commercially available ELISA-based antibody tests are used to approximate vaccination success against SARS-CoV-2 in at-risk patients, but it is unclear whether they correlate with neutralization of the Omicron variant. METHODS: 269 serum samples of a cohort of 44 non-immunosuppressed participants and 65 MTX-treated rheumatic patients taken before and after COVID-19 booster vaccinations were measured using COVID-19 antibody testing systems with wild-type and Omicron BA.1 antigens developed by three different manufacturers (surrogate virus neutralization test cPass, and binding antibody tests QuantiVac and SeraSpot), as well as with a pseudovirus neutralization test (pVNT). The pVNT was considered the gold standard for determining the presence and level of anti-SARS-CoV-2 antibodies. RESULTS: All three wild-type ELISAs showed excellent test performance compared with wild-type neutralization in pVNT. However, out of 56 samples without Omicron BA.1 neutralization in pVNT, 71.4% showed positive results in at least one and 28.6% in all three wild-type ELISAs at the manufacturer-defined cut-offs. Omicron ELISAs showed either decreased specificity (57.1% and 55.4% for binding ELISAs) or sensitivity (51.2% in cPass) compared to Omicron neutralization in pVNT. The proportion of any false positive results among all samples decreased from 26.5% before to 3.2% after booster vaccination, however binding antibody test specificities remained below 70%. CONCLUSIONS: We found a poorer test performance of new Omicron antibody test systems compared to wild-type tests in detecting neutralizing antibodies against the corresponding SARS-CoV-2 variants. Decisions for booster vaccination or passive immunization of at-risk patients should not be based solely on antibody test results.

Study protocol: a pilot randomized controlled trial to evaluate the acceptability and feasibility of a counseling intervention, delivered by nurses, for those who have attempted self-poisoning in Sri Lanka.

BACKGROUND: Deliberate self-harm in the form of non-fatal self-poisoning is a major public health problem in Sri Lanka. Previous work suggests that many nurses in Sri Lanka-particularly those who work in primary care in the medical treatment of persons who attempt self-poisoning-already approach their role in a holistic fashion and consider "advising" or "counseling" patients after self-poisoning to be a part of their nursing role. But there is no formal training given to such nurses at present nor has the efficacy or feasibility of such an intervention been assessed in Sri Lanka. The aims of this pilot study are to explore the potential efficacy, acceptability, and feasibility of carrying out a counseling intervention that could be delivered by nurses for persons who present to hospital for medical management of non-fatal self-poisoning. METHODS/DESIGN: The study will be carried out at the Toxicology Unit of Teaching Hospital Peradeniya, Sri Lanka. A pilot randomized controlled trial will be carried out among participants admitted to Teaching Hospital Peradeniya for medical management of non-fatal self-poisoning. The primary objective of this study is to explore the acceptability and feasibility of a counseling intervention being delivered by nurses. The secondary objectives are to explore the efficacy of the intervention for the improvement of skills to cope with situations of acute emotional distress, and to reduce rates of anxiety, depression, and future repetition and suicidal ideation. A nurse's experiences and attitudes regarding the acceptability and feasibility of implementing this intervention and participant experiences of the intervention and its effects will be explored via qualitative interviews and focus group discussions. DISCUSSION: It is anticipated that the findings of this pilot study will help determine and assess the acceptability and feasibility of this counseling intervention, as well as indicate the more useful aspects of this intervention in order to develop it for further exploration in a larger trial. TRIAL REGISTRATION: SLCTR/2017/008 Registered on 21st March 2017.

Improving peri-operative fluid management in a large teaching hospital: pragmatic studies on the effects of changing practice.

Concerns about the over-prescription of peri-operative fluids, particularly normal saline, culminated in the recent publication of UK national guidelines on fluid prescription during and after surgery. A working group comprising members of the nutrition support team, surgeons, anaesthetists and pharmacists therefore sought to reduce the overall levels of fluid prescription and to limit normal saline usage in our large Teaching Hospital by producing written local fluid prescribing guidelines and holding a series of fluid prescription education sessions for consultants and junior staff. Ideally, the success of such measures would have been determined by studies on fluid balance, body weight and/or measured body water in large numbers of individual patients in a large cluster-randomised controlled trial. However, this would have proved logistically difficult and very costly especially as it is notoriously difficult to rely on the accuracy of daily fluid balance charts in large numbers of patients on busy post-operative surgical wards. We therefore undertook a pragmatic study, comparing historical data on fluid type/volume prescribed (from both individual and ward level pharmacy records), oedema status and clinical outcomes from 2002 with two prospective audits of similar data carried out during 2008 and 2009. Our data showed that in the comparable, elective surgical patients within each audit, there was a decline in total intravenous fluids prescribed over the first 5 post-operative days from 21·1 litres per patient in 2002 to 14·2 litres per patient in 2009 (P<0·05), while pharmacy records showed that the proportion of 0·9% saline supplied declined from 60% to 35% of all fluids supplied to the surgical wards involved, with a concomitant increase in the use of 4%/0·18% dextrose-saline and Hartmann's solution. Alongside these changes in fluid prescribing, the number of patients with clinically apparent oedema declined from 53% in 2002 to 36% in 2009; gut function returned more quickly (6 d in 2002 v. 4 d in 2009, P<0·05) and the length of stay improved from 13 d in 2002 to 10 d in 2009, P<0·05). Although we accept that other factors might have contributed to the observed changes in these clinical parameters, we believe that the measures to reduce fluid and saline administration were the major contributors to these improved clinical outcomes.