TY - JOUR
T1 - Critical care services and the H1N1 (2009) influenza epidemic in Australia and New Zealand in 2010: the impact of the second winter epidemic
AU - Webb, Steven
AU - Aubron, Cecile
AU - Bailey, Michael John
AU - Bellomo, Rinaldo
AU - Howe, Belinda Duval
AU - McArthur, Colin
AU - Morrison, Siouxzy
AU - Seppelt, Ian M
PY - 2011
Y1 - 2011
N2 - During the first winter of exposure, the H1N1 2009 influenza virus placed considerable strain on intensive care unit (ICU) services in Australia and New Zealand (ANZ). We assessed the impact of the H1N1 2009 influenza virus on ICU services during the second (2010) winter, following the implementation of vaccination. A prospective, cohort study was conducted in all ANZ ICUs during the southern hemisphere winter of 2010. Data on demographic and clinical characteristics, including vaccination status and outcomes, were collected. The characteristics of patients admitted during the 2010 and 2009 seasons were compared. From 1 June to 15 October 2010, there were 315 patients with confirmed influenza A, of whom 283 patients (90 ) had H1N1 2009 (10.6 cases per million inhabitants; 95 confidence interval (CI), 9.4 to 11.9) which was an observed incidence of 33 of that in 2009 (P <0.001). The maximum daily ICU occupancy was 2.4 beds (95 CI, 1.8 to 3) per million inhabitants in 2010 compared with 7.5 (95 CI, 6.5 to 8.6) in 2009, (P <0.001). The onset of the epidemic in 2010 was delayed by five weeks compared with 2009. The clinical characteristics were similar in 2010 and 2009 with no difference in the age distribution, proportion of patients treated with mechanical ventilation, duration of ICU admission, or hospital mortality. Unlike 2009 the incidence of critical illness was significantly greater in New Zealand (18.8 cases per million inhabitants compared with 9 in Australia, P <0.001). Of 170 patients with known vaccination status, 26 (15.3 ) had been vaccinated against H1N1 2009. During the 2010 ANZ winter, the impact of H1N1 2009 on ICU services was still appreciable in Australia and substantial in New Zealand. Vaccination failure occurred.
AB - During the first winter of exposure, the H1N1 2009 influenza virus placed considerable strain on intensive care unit (ICU) services in Australia and New Zealand (ANZ). We assessed the impact of the H1N1 2009 influenza virus on ICU services during the second (2010) winter, following the implementation of vaccination. A prospective, cohort study was conducted in all ANZ ICUs during the southern hemisphere winter of 2010. Data on demographic and clinical characteristics, including vaccination status and outcomes, were collected. The characteristics of patients admitted during the 2010 and 2009 seasons were compared. From 1 June to 15 October 2010, there were 315 patients with confirmed influenza A, of whom 283 patients (90 ) had H1N1 2009 (10.6 cases per million inhabitants; 95 confidence interval (CI), 9.4 to 11.9) which was an observed incidence of 33 of that in 2009 (P <0.001). The maximum daily ICU occupancy was 2.4 beds (95 CI, 1.8 to 3) per million inhabitants in 2010 compared with 7.5 (95 CI, 6.5 to 8.6) in 2009, (P <0.001). The onset of the epidemic in 2010 was delayed by five weeks compared with 2009. The clinical characteristics were similar in 2010 and 2009 with no difference in the age distribution, proportion of patients treated with mechanical ventilation, duration of ICU admission, or hospital mortality. Unlike 2009 the incidence of critical illness was significantly greater in New Zealand (18.8 cases per million inhabitants compared with 9 in Australia, P <0.001). Of 170 patients with known vaccination status, 26 (15.3 ) had been vaccinated against H1N1 2009. During the 2010 ANZ winter, the impact of H1N1 2009 on ICU services was still appreciable in Australia and substantial in New Zealand. Vaccination failure occurred.
UR - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3219015/pdf/cc10266.pdf
U2 - 10.1186/cc10266
DO - 10.1186/cc10266
M3 - Article
SN - 1364-8535
VL - 15
SP - 1
EP - 7
JO - Critical Care
JF - Critical Care
IS - 3
ER -