Hemophilus influenzae and Streptococcus pneumoniae as causative agents of pneumonia in Egyptian preschool children: analysis and serotyping of Hemophilus isolates from hospital patients in Cairo, 1991-93.

The Hemophilus influenzae blood culture and nasopharyngeal isolates, collected during a limited Surveillance of Antimicrobial Resistance in 1991-1993 from 1,635 Egyptian children under 5 years of age, presenting with pneumonia to Embaba and Abbassia Fever Hospitals, were serotyped. The 8 blood culture isolates confirmed H. influenzae to be responsible for 0.5% of the cases of pneumonia, versus 50 Streptococcus pneumoniae blood culture isolates from the same population that confirmed it responsible for 3.1% of the cases. The invasive Hemophilus strains were exclusively isolated from infants below 1 year, from one hospital (Embaba), on one winter season (January to March, 1992). On serotyping, 50% of the blood culture isolates were found to be non-b by latex agglutination. Some 297 nasopharyngeal isolates from cases of pneumonia were also serotyped and 45% were found to be non-b, thus confirming the invasive strains findings. Furthermore, the typing results from ARI-free controls nasopharyngeal isolates--though limited--were consistent with the findings and showed a 43% proportion of non-b. These findings put a question mark on the benefit of a large scale use of the available H. influenzae type b polysaccharide and conjugated vaccines in Egypt. But before interpreting out data in terms of vaccine needs, more specifically designed epidemiological studies need to be conducted to assess the role of H. influenzae as a pathogen in Egypt.