Clostridioides difficile infection in a rural New Zealand secondary care centre: an incidence case-control study.

BACKGROUND: Clostridioides difficile infection (CDI) is a form of antibiotic-associated infectious diarrhoea resulting in significant morbidity and mortality. Community-acquired disease in low-risk individuals is increasingly recognised. There are limited New Zealand data published. AIM: To determine the incidence and location of onset of CDI cases in the Manawatu region, and further describe the demographics, risk factors and prevalent C. difficile ribotypes of the population. METHODS: We performed an incidence case-control study of CDI in the Manawatu region between September 2018 and September 2019. Cases were matched to controls with a negative test for C. difficile. Demographic and comorbidity data, location of onset, drug exposure, disease recurrence and 30-day mortality were collected. Ribotype analysis was performed on C. difficile isolates. RESULTS: Thirty-two specimens tested toxin positive over 12 months, yielding an incidence of 18.3 cases per 100 000 person-years. Twenty-five percent of cases had community onset disease. Cases were more likely to have had amoxicillin/clavulanate or ceftriaxone prescribed. Elevated blood white cell count and lower HbA1c were significantly associated with CDI. The dominant ribotype was 014/020. Two cases were RT 023. CONCLUSION: Our data are similar to previous national data. RT 023 has not been previously reported in New Zealand and has been associated with severe colitis. We demonstrated a significant proportion of community-acquired cases and the true incidence might be higher. Vigilance for community onset disease is required. These data may allow observation of temporal changes in incidence and infection patterns of CDI in New Zealand.

A national audit of performance standards for blood cultures in Aotearoa New Zealand: opportunities for improvement.

AIMS: To audit key quality indicators for blood culture (BC) practices across Aotearoa New Zealand to facilitate national BC practice peer review and promote BC quality improvement interventions. METHOD: Microbiology laboratories providing diagnostic services to district health board (DHB) hospitals were invited to participate. Practice was compared against published BC recommendations. Laboratories were required to submit data for BC positivity and contamination rates, BC bottle fill volume and the proportion of BC received as a single set. RESULTS: Laboratories serving 15 of the 20 DHBs participated in the audit. Nine DHBs (60%) demonstrated a positivity rate within the target range of 8% to 15%. Eight DHBs (53%) reported a contamination rate lower than the accepted 3%, but seven (47%) DHBs exceeded this target and two reported a contamination rate greater than 5%. Mean BC bottle fill volumes were generally greater than the target of 8mL, but this volume was not reached by three DHBs and a further three were unable to provide fill volume data. No DHB met the audit standard for single-set BCs representing <20%, and for six DHBs single-set BC comprised more than half of all samples. No DHB failed all audit targets. CONCLUSION: This audit demonstrates wide variation in BC performance across New Zealand. In most instances an inadequate volume of blood is being collected, lowering the chance of culturing a pathogen. A significant opportunity for improvement exists; clinical services and laboratories are encouraged to work together to implement targeted quality improvement processes to correct deficiencies in practice.