Obstetric admissions to intensive care units in Australia and New Zealand: a registry-based cohort study.

OBJECTIVE: Describe the epidemiology of obstetric patients admitted to an Intensive Care Unit (ICU). DESIGN: Registry-based cohort study. SETTING: One hundred and eighty-three ICUs in Australia and New Zealand. POPULATION: Women aged 15-49 years, admitted to ICU between 2008 and 2017, classified as pregnant, postpartum or with an obstetric-related diagnosis. METHODS: Data were extracted from the Australia and New Zealand Intensive Care Society (ANZICS) Adult Patient Database and national agencies. MAIN OUTCOME MEASURES: Incidence of ICU admission, cohort characteristics, maternal outcomes and changes over time. RESULTS: The cohort comprised 16 063 patients. The annual number of obstetric ICU admissions increased, whereas their proportion of total ICU admissions (1.3%) did not change (odds ratio 1.02, 95% CI 0.99-1.04, P = 0.14). There were 10 518 (65%) with an obstetric-related ICU diagnosis, and 5545 (35%) with a non-obstetric ICU diagnosis. Mean (SD) age was 31 (6.4) years, 1463 (9.1%) were Indigenous, 2305 (14%) were transferred from another hospital, and 3008 (19%) received mechanical ventilation. Median [IQR] length of stay in hospital was 5.2 [3.1-7.9] days, which included 1.1 [0.7-1.8] days in ICU. There were 108 (0.7%) maternal deaths, most (n = 97, 90%) having a non-obstetric diagnosis. There was no change in risk-adjusted length of stay or mortality over time. CONCLUSIONS: Obstetric patients account for a stable proportion of ICU admissions in Australia and New Zealand. These patients typically have a short length of ICU stay and low hospital mortality. TWEETABLE ABSTRACT: Obstetric patients in Australia/New Zealand ICUs have a short length of ICU stay and low mortality.

Genetic diversity and stability of the porA allele as a genetic marker in human Campylobacter infection.

The major outer-membrane protein (MOMP) of Campylobacter jejuni and Campylobacter coli, encoded by the porA gene, is extremely genetically diverse. Conformational MOMP epitopes are important in host immunity, and variation in surface-exposed regions probably occurs as a result of positive immune selection during infection. porA diversity has been exploited in genotyping studies using highly discriminatory nucleotide sequences to identify potentially epidemiologically linked cases of human campylobacteriosis. To understand the overall nature and extent of porA diversity and stability in C. jejuni and C. coli we investigated sequences in isolates (n=584) obtained from a defined human population (approx. 600,000) over a defined time period (1 year). A total of 196 distinct porA variants were identified. Regions encoding putative extracellular loops were the most variable in both nucleotide sequence and length. Phylogenetic analysis identified three porA allele clusters that originated in (i) predominantly C. jejuni and a few C. coli, (ii) solely C. jejuni or (iii) predominantly C. coli and a few C. jejuni. The stability of porA within an individual human host was investigated using isolates cultured longitudinally from 64 sporadic cases, 27 of which had prolonged infection lasting between 5 and 98 days (the remainder having illness of normal duration, 0-4 days), and 20 cases from family outbreaks. Evidence of mutation was detected in two patients with prolonged illness. Despite demonstrable positive immune selection in these two unusual cases, the persistence of numerous variants within the population indicated that the porA allele is a valuable tool for use in extended typing schemes.