• Two serotypes, uncommon in pediatric infections, accounted for a disproportionately large number of cases of pneumococcal empyema at the Children's Hospital of Pittsburgh. Eight of ten empyemas were caused by types 1 or 3, and two additional cases of mixed infection involved the type 3 pneumococcus. The type 3 pneumococcal empyemas tended to be more severe than those due to other serotypes. Counterimmunoelectrophoresis (CIE) appeared to be more useful than culture in establishing the cause of this condition; in seven of ten cases, the pleural fluid was CIE positive while cultures of blood and pleural fluid were negative. In each of the seven culture-negative cases, antibiotics had been given prior to hospitalization. One case of type 7 pneumococcal empyema illustrated the potential value of the Ouchterlony test for the etiologic diagnosis of this condition.
(Am J Dis Child 132:1094-1096, 1978)