Bacterial infections and antimicrobal susceptability and outcome in neonates at Muhimbili National Hospital

Abstract

Background: Neonatal septicaemia remains a major cause of morbidity and mortality. More than 5 million neonatal deaths occur worldwide each year, the majority in developing countries where neonatal mortality accounts for 50-70% ofthe infant mortality rate. In Muhimbili National Hospital neonatal bacterial septicaemia ranked number three among causes of neonatal mortality and morbidity in 200712008. The spectrum of organisms causing neonatal septicaemia changes over time, therefore it is important to know the sensitivity pattern of the commonly used antimicrobials. This information is useful in the proper management of neonatal bacteria septicaemia. Objectives: To determine the aetiology, antimicrobial susceptibility pattern and immediate outcome of neonatal bacterial infections among neonates admitted in neonatal unit at Muhimbili National Hospital (MNH) Methods: A hospital based cross sectional study was conducted at the neonatal ward from neonates presenting with clinical feature of infections to Muhimbili National Hospital in Dar es Salaam city from October 2009 to January 2010. A structured questionnaire was used to capture demographic information, neonates presenting of any symptoms and signs of neonatal infections were recruited consecutive daily and included into the study after obtaining a written informed consent from parents/guardians. A thorough physical examination including weight, length and occipital frontal circumference were done. Culture and sensitivity of blood, swabs, and urine were done. Pure colonies were identified based on characteristic morphology, gram stain appearance and standard commercially prepared biochemical tests, and thereafter- antibiotic sensitivities were done. Data analysis was done using SPSS software version 15 (Statistical Package for Social Science) for windows evaluation. A p-value of less than or equal to 0.05 was considered biostatically significant. Results: Three hundred and thirty neonates met inclusion criteria and were recruited into the study. Out of which 170 (51.5%) were male and 160 (48.5%) were females, 253 (76.7%) were o to 6 days while 77 (23.3%) were 7 to 28 days old, with the mean age of 6 days. Common clinical features were umbilical pus discharge with hyperaemia (96.1 %), fever (91.5%) and

Vlll inability to feed (62.4%). Skin rash with pus spots and hypothermia were found to be independent predictors of bacterial infections. The frequency of infections confirmed by cultures in blood was 74 (22.4%), umbilical swabs 285 (89.9%) and skin swabs 28 (90.3%). Overall bacterial isolated were 371 from 330 neonates, 74 (19.9%) isolates from blood and 297 (80.1 %) from pus. In blood, 48.6% of bacteria were gram positive and 51.4% gram negative, of which the common aetiological agents were Staphylococcus aureus (36.5%), Klebsiella spp (29.7%) and Escherichia coli (18.9%). The microorganisms isolated were resistant to ampicillin (88.2%), cloxacillin (85.3%) and moderately resistant to gentamicin (58.8%). Of the 68 bacteria organisms isolated antibacterial susceptibility pattern showed 98.5% were sensitive to amikacin. Overall mortality was 13.9%, of which 14.2% was among neonates aged 0 to 6 days while 13.0% were 7 to 28 days old. In addition, participants with neonatal septicaemia have a higher proportion of mortality than those without septicaemia. (24.3% versus 10.9%, P = 0.003) Conclusion: In this study, the common aetiological agents were S. aureus, Klebsiella spp and E. coli. In early onset septicaemia, Klebsiella spp were the predominant organisms, while S. aureus was predominant in late onset septicaemia. The microorganisms isolated were highly resistant to ampicillin and cloxacillin and moderately resistant to gentamicin (58.8%). Sensitivity to amikacin was high; the orgarusms were also sensitive to ceftriaxone and cefuroxime. Among the neonates with neonatal septicaemia, 11 (61.1 %) died within the first 72 hours of admission Recommendation: The use of ampicillin, cloxacillin and gentamicin as first line treatment of neonatal bacteria septicaemia in the neonatal ward of MNH needs to be re-evaluated. Amikacin should be used as an initial therapy. Antibiotic susceptibility surveillance, evaluation of local pathogens causing neonatal septicaemia and detection of any shift in their antimicrobial susceptibilities