Clinical Research Directory

Antimicrobial Stewardship Effects of Interpretive Comments for Faecal PCR Tests

Bacterial gastroenteritis is a common condition seen in Aotearoa New Zealand, which is typically diagnosed by PCR testing on a stool sample. Most causes of bacterial gastroenteritis (e.g. Campylobacter spp, Salmonella spp, Yersinia spp) cause a self-limiting illness and antibiotic therapy is not required. Indeed, guidelines available for community healthcare providers in Aotearoa (e.g. Community HealthPathways, recently released national antimicrobial guidelines Te Whata Kura) recommend against antibiotic therapy for the vast majority of cases. A recent internal analysis at Awanui Laboratories of community faecal pathogen PCR testing revealed that antibiotic prescribing was very common after a positive result (ranging between 20-40% for the various individual pathogens), which suggests many community healthcare providers may not be following the recommended approach for the management of these infections. Given how common infectious gastroenteritis is in Aotearoa, and the volume of tests performed (approximately 100,000 through the Awanui network per year), this prescribing behaviour may represent a large volume of unnecessary antibiotic use in our communities, with resultant potential harmful effects at the individual patient level and population level via side effects, disruption to the faecal microbiome, and impacts on antimicrobial resistance (AMR). In previous work we have demonstrated that interpretive comments, when added to laboratory reports, can have a significant positive effect on prescriber behaviour (https://doi.org/10.1093/jac/dkad384), but this has not been examined in relation to faecal pathogen testing.

Balanced Crystalloid vs Normal Saline in Pediatric Acute Gastroenteritis

Acute gastroenteritis (AGE) is among the most common reasons for paediatric emergency visits. Children with significant dehydration often require intravenous (IV) fluid therapy. Two main types of IV crystalloid solutions are currently used in clinical practice: 0.9% sodium chloride (normal saline, NS) and balanced crystalloids such as Isolyte-S, which contain acetate and gluconate as bicarbonate precursors. Normal saline has a high chloride content (154 mEq/L), which may worsen the metabolic acidosis already present in many children with acute gastroenteritis. Balanced crystalloids have a chloride content closer to that of plasma (98 mEq/L) and additionally contain acetate and gluconate, which are metabolised in peripheral tissues to consume hydrogen ions and thereby raise serum bicarbonate - a mechanism distinct from simply avoiding chloride overload. This study prospectively observes and compares early biochemical and clinical outcomes in children with acute gastroenteritis who receive one of these two fluid types as part of their routine clinical care. The treating physician independently decides which fluid to use; the research team does not influence this decision and does not order any additional tests or procedures. Laboratory values used as outcomes are drawn solely from blood tests obtained as part of standard care. The primary aim is to determine whether, at approximately 4 hours after IV fluid start, serum bicarbonate has changed more in children who received a balanced crystalloid compared with those who received normal saline. Secondary aims include comparing blood pH, chloride levels, need for additional IV boluses, time to first oral fluid intake, hospitalisation rate, and 72-hour return visits.

Diagnostic PCR Panel in Children With Acute Gastrointestinal Symptoms

This investigator-initiated randomized controlled trial compares the clinical impact of real time PCR of fecal samples in children with acute gastrointestinal symptoms at a pediatric emergency room. Specifically, the trial compares immediate testing of fecal samples using a multiplex PCR panel to a a control group with delayed test results.