Trend, features and outcome of meningitis in the Communicable Diseases hospital, Alexandria, Egypt, 1997-2006

Abstract

Background: Following vaccine introduction, long-term epidemiological changes have been occurred in meningitis. Studying these changes is of practical importance for both public health planning and clinical management.

Objectives: To study trend in meningitis in Alexandria, Egypt (1997-2006) as well patients' characteristics and outcome.

Materials and methods: The descriptive epidemiologic approach was adopted. Study population was all discharge records and computer files of meningitis admissions to the Communicable Diseases Hospital in Alexandria, Egypt, 1997-2006. Outcome measures were age, number and percentage of patients, organisms proportions and case fatality.

Results: The study included 1210 recorded meningitis cases. Patients had a mean age of 22.26 years and a male to female ratio of 1.8 : 1. Study started with a sharp descent of yearly admissions (1997-1999) and ended by a sharp increase (2004-2006). Cases insignificantly increased during autumn through spring. Neisseria meningitidis was the dominant pathogen (28.9%) in all years. Mycobacterium tuberculosis (MTB) was the second common agent (11.6%) with a decreasing frequency till 2000. Streptococcus pneumoniae was responsible for 8.9% of cases. Group B Streptococci and Haemophilus influenzae type b caused 2.8% and 2.4% of cases respectively. Both had a declining trend. Other bacteria (gram negative bacteria, non specific streptococci and staphylococci) was isolated in 2.7% whereas no organism could be identified in 45.6% of specimens. All agent differences were statistically significant where P<0.001. The mean hospital stay was 14.95 days. Overall case fatality was 17.6%. The most lethal was other bacteria [Odds Ratio=6.0, 95% Confidence interval=3.0-12.2]. Fatal outcome was predicted by short hospital stay (regression coefficient(r)=-0.17, P<0.001), diagnosis of other bacterial (r=1.75, P<0.001), pneumococcal (r=0.66, P=0.02) or tuberculous meningitis (r=0.59, P=0.04) and being an elderly (r=1.80, P<0.001) or an adult (r=1.03, P<0.001).

Conclusion: Neisseria remained the main etiologic agent of meningitis. TB emerged as the second pathogen. Rate of bacterial un-detection was high. Mean age of meningitis had shifted to adult age. Other bacteria, pneumococci, MTB and advanced age were important predictors for mortality.