Severity and frequency of sequelae of bacterial meningitis in Alaska Native infants. Correlation with a scoring system for severity of sequelae
G. W. Letson, B. G. Gellin, L. R. Bulkow, D. J. Parks and J. I. Ward
UCLA Center for Vaccine Research, Harbor-UCLA Medical Center, Torrance.
OBJECTIVES--To (1) determine the frequency and severity of sequelae of
Haemophilus influenzae type b and Streptococcus pneumoniae meningitis in
Alaska Native children, (2) compare morbidity and mortality of H influenzae
b and S pneumoniae meningitis, and (3) evaluate the applicability of the
Herson-Todd prognostic score (HTPS) to both H influenzae b and S pneumoniae
meningitis in this population. DESIGN--A retrospective study of all cases
of H influenzae b and S pneumoniae meningitis in Alaska Native children
younger than age 5 years. Data on meningitis sequelae, obtained from
medical charts and records of the Infant Learning Program, were collected,
and incidence of sequelae tabulated. Data obtained on admission to the
hospital were used to calculate HTPS. SETTING--Indian Health Service
facility for the Yukon-Kuskokwin Delta region of southwest Alaska. STUDY
SUBJECTS--51 of 63 Alaska Native children with H influenzae b meningitis
and 13 of the same 63 Alaska Native children with S pneumoniae meningitis
occurring between 1980 and 1988. One child was infected with both
organisms, producing a total of 64 cases for study. SELECTION
PROCEDURES--Cases were identified by surveillance for these diseases
between January 1, 1980, and December 31, 1988, maintained by the Arctic
Investigations Program, Centers for Disease Control. MEASUREMENTS AND
RESULTS--Sequelae of bacterial meningitis caused by H influenzae b were
equal to or exceeded rates of sequelae described in other children in the
United States. After H influenzae b meningitis, motor abnormalities (29%)
and hydrocephalus (7%) occurred two to four times more often in Alaska
Native children than in children in other parts of the United States.
Differences in severity of H influenzae b sequelae could not be accounted
for by microbiologic markers of the H influenzae b strain, including
ampicillin sensitivity, biotype, outer membrane protein type, or
electropherotype. Numbers of cases of S pneumoniae meningitis were too
small for statistically valid comparison, but sequelae of S pneumoniae
meningitis occurred in roughly equal proportion as sequelae of H influenzae
b meningitis. The HTPS was applied to Alaska Native children with H
influenzae b meningitis and was found to be very accurate in predicting
children with major sequelae. Analysis of the prognostic factors used in
deriving the HTPS revealed a unique set of predictors for sequelae in
Alaska Native children: seizures at admission, glucose levels in
cerebrospinal fluid of less than 1.1 mmol/L; and male gender, with a
significant predictive interaction between male gender and age less than 6
months at admission. CONCLUSIONS--Alaska Native children suffer greater
neurologic morbidity as a result of H influenzae b meningitis than do their
non-Native counterparts. The HTPS was a good predictor of major sequelae in
Alaska Native children with H influenzae b or S pneumoniae meningitis and
could be useful in determining which patients need referral to a tertiary
care center.
