# Presentation: 737378

## Epidemiology of Neonatal Sepsis caused by Group B Streptococci and other Bacterial Pathogens Among Alaska Newborns

- M. Soriano-Gabarró, MD., MSc.,
- Respiratory Diseases Branch, DBMD, NCID

## Incidence Rates Early-onset GBS Neonatal Disease by Race  USA 1993-1998

- Schrag et al. NEJM  2000; 342: 15-20

## Early-onset Neonatal Sepsis Caused by Group B Streptococcus among Australian Native Populations  1991-1997 

- Non aboriginal infections: chi square, 33.0; p<0.0001
- Aboriginal infections: chi square, 6.2; p<0.05

- Isaacs D, et al.
- Pediatr Infect Dis J 1999; 18:524-8

## Neonatal GBS Disease  Burden Among Native Populations

- Neonatal GBS disease burden is not known among Native American and / or Alaska Native populations

## Objectives

- To determine the incidence rates and trends of neonatal GBS sepsis among Alaska newborns
- To determine the incidence rates of neonatal sepsis caused by other bacterial pathogens
- To compare neonatal GBS sepsis with the Alaska birth cohort

## Case Definition

- Neonatal sepsis:  isolation of a bacterial pathogen from blood or cerebrospinal fluid (CSF)
- Early-onset sepsis: isolation of  a bacterial pathogen  in an infant < 7 days old
- Late-onset disease: isolation of a bacterial pathogen in an infant  7-30 days old

## Case Ascertainment

- Retrospective review of clinical records of infants admitted to the three hospitals with level 2 and 3 Neonatal Intensive Care Units (NICUs) in Alaska (1991-1998)
- Microbiology records reviewed in each facility to confirm complete case ascertainment
-  Denominator data for Alaska newborns obtained through birth certificate records

## Organisms Causing Neonatal Sepsis Alaska, 1991-1998

##  Incidence Rates Early-onset GBS by Race, Alaska 1993-1998

## Early-onset GBS Incidence Rates by Hospital, Alaska 1993-1998

- IAP 1989

- IAP 1993

- IAP  revised 1995

- Hospital 1 : 71.3% of admissions were Alaska Natives
- Hospital 2 : 12% of admissions were Alaska Natives

## Cohort Analysis: Factors Associated with Early-onset GBS Sepsis,  Alaska 1991-1998

## Incidence Rates GBS and Other Neonatal Sepsis by Race,  Alaska 1993-1998

- * Prematurity rates higher for Alaska Natives than for Non Natives
-  ( 87.8/1000live births versus 65.6/100 live births, p<0.0001)

## Incidence Rates Early-onset  Sepsis by Other Pathogens by Race, Alaska 1993-1998

## Cohort Analysis: Factors Associated with Early-onset Sepsis Caused by Other Pathogens,  Alaska 1991-1998

## Summary

- GBS is the main cause of neonatal sepsis among newborns in Alaska, affecting both Alaska Native and Non-Native populations
- Maternal risk factors for early onset GBS disease consistent with other studies
- Alaska Natives are at higher risk of early-onset sepsis caused by other pathogens
- Decreasing  rates of early-onset GBS sepsis among infants in Alaska  may be related to the introduction of IAP policies

## Limitations

- Ascertainment of cases limited to hospitals with level 2 and 3 NICUS in Alaska
- Early introduction of IAP guidelines

## Implications

- Healthy People Goal 2010 (0.5 cases early-onset GBS sepsis /1000 live births) achieved for Alaska Natives. Sustainability needs to be monitored
- Need to monitor trends of early-onset sepsis caused by other pathogens
- Evaluate the potential preventability of early-onset sepsis caused by other pathogens

## Acknowledgments 

- Alaska Native Medical Center
- N. Murphy
- Medical Records Staff
- Alaska Department of Health and Social Services
-  B. Gessner
- D. Ingle
- Arctic Investigations Program
- J. C. Butler
- D. Bruden,
-  D. Hurlburt

- Providence Alaska Medical Hospital
- J. Jacob
- S. Hulman
- Medical Records Staff
- CDC
- A. Schuchat
- E. Zell
- C. Wright
- F. Gimenez
- Fairbanks General Hospital
- S Galvin
- Medical Records Staff

## Prematurity among all Alaska newborns by Race 1991-1998

- N birth cohort=82528

## Factors Associated with Early-onset GBS and Other Neonatal Sepsis, Alaska 1991-1998

- Factors Associated with Early-onset GBS and Other Neonatal Sepsis, Alaska 1991-1998

## Factors Associated with Early-onset GBS and Other Neonatal Sepsis, Alaska 1991-1998

## Incidence Rates GBS and Other Neonatal Sepsis by Race,  Alaska 1993-1998

- * Prematurity rates higher for Alaska Natives than for Non Natives
-  ( 87.8/1000live births versus 65.6/100 live births, p<0.0001)

## Cohort Analysis: Factors associated with Early-onset GBS Disease.  Alaska 1993-1998

## Cohort Analysis: Factors Associated with Early-onset GBS Sepsis,  Alaska 1991-1998