Infection vs. Gestational age

59 3.9.4 Types of Infecting Organism The commonest organism identified was the Coagulase Negative Staphylococcus CONS, overall as well as in the Late Infections after 3 days category. The second commonest organism was Klebsiella followed by Group B Streptococcus GBS. Figure 42. Percentage of babies vs. type of infecting organism Early and Late Infections: The majority of infections were Late Infections 61.5, ie occurring later than 3 days after admission. These are indicative of nosocomial Hospital acquired infections. Figure 43. Early vs late infections 50 100 150 200 250 300 350 N o . o f In fe ct io n s Type of Organism Infecting Organisms All Infections Late Infections 38.5 61.5 Early Vs Late Infections Less than 3 days After 3 days 60 Infection-Associated Mortality: The overall mortality associated with infection was 23.6, ranging from the highest 33.5 in the less than 28 weeks gestation group, corresponding to the 32.1 in the less than 1000 g birthweight group. Figure 44. Mortality associated with infection according to gestational age Figure 45. Mortality associated with infection according to birth weight groups The overall infection-associated mortality was 20 for nosocomial infection amongst inborn babies, varying widely from centre to centre. 33.5 23.4 18 19.4 29.1 22 23.6 5 10 15 20 25 30 35 40 28 weeks 28-30 weeks 31-32 weeks 33-35 weeks 36-37 weeks 37 weeks OVERALL M o rt a li ty Gestation Mortality associated with Infection vs Gestation 32.1 21.4 22.3 20.6 23.6 5 10 15 20 25 30 35 1000gm 1001-1500gm 1501-2500gm 2501gm TOTAL M o rt a li ty Birthweight Mortality from Infection vs Birthweight 61 Figure 46. Infection-associated mortality by cent 3.10 Outcome 3.10.1 Survival according to birthweight and gestational age The overall survival at discharge of this high risk group of babies was 9190 survivors out of 11219 i.e. 82, similar to the rate in 2007 Tables 27a and 27c. Survival is dependant on many factors including gestational age and birthweight. For outborn babies, mortality was attributed to the referring unit if the baby died within the first 24 hours of life. There was marked improvement in survival at above 700 g birthweight i.e. from 23 survival rate at 601-700 g birthweight group to 43 survival rate at 701-800 g birthweight Figure 47. This may be a reflection of the NICU policies in terms of conservative management in the lower birthweight group. 5 10 15 20 25 30 35 40 45 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 P e rc e n ta g e Centre Number Fig. 46 Infection associated mortality by centre 62 Figure 47. Survival rate according to birth weight Less than half 48 of babies of 26 weeks’ gestation survived while survival was better at 68 for 27 weeks’ gestation Figure 49. Survival of babies up to 31 weeks’ gestation and of birthweight up to 1500 g improved progressively with increasing gestation and birth weight. The survival of babies in the Australian-New Zealand Network were about 75-85 for babies 26 weeks gestational age and over 95 for babies above 29 weeks’ gestation. Thus, better survival rates are possible as neonatal care services advance. Babies who were 32 weeks’ gestation and above and babies of BW 1500 g were entered into the study only if they had required ventilatory support or had died, hence the survival rate appeared lower in these more mature and bigger babies Figure . 10 20 30 40 50 60 70 80 90 100 P e rc e n ta g e o f b a b ie s Birth weight grams Fig. 47 Survival according to birth weight 2005 2006 2007 2008