OBJECTIVEStreptococcus pneumoniae (SP) is a major causative agent of community-acquired pneumonia. In children older than 2 months, SP is also the most common cause of invasive bacterial infections. Invasive pneumococcal diseases (IPD) have become a severe problem of public health worldwide. The aim of this study was to summarize the clinical characteristics and antimicrobial resistance of IPD in children, and to raise the level of diagnosis and treatment of this disease.

METHODThe clinical data from 55 cases of IPD younger than 12 years old seen from January 2004 to June 2009 in Yuying Children's Hospital Affiliated to Wenzhou Medical College were analyzed retrospectively. Blood, cerebrospinal fluid (CSF), seroperitoneum, mediastinum and soft tissue aspirate specimens were collected from these children, and 64 SP strains were cultured, isolated and confirmed and the antibiotics susceptibility to penicillin and other antibiotics of these strains were assessed.

RESULTThe 55 cases of IPD were identified, among whom 32 were male and 23 female, the ratio was 1.39. The ages ranged from 47 days to 12 years. Most (62%) of the cases were aged less than 2 years, and 16% were aged from 2 to 5 years. Overall, 38 (69%) had septicemia, of whom 8 cases were complicated with meningitis, 2 with pneumonia complicated with empyema, 1 had pneumonia complicated with mediastinal abscess and 11 with pneumonia. Nine cases (16%) were diagnosed as meningitis. Seven cases (13%) had hip or neck abscess and 1 case had purulent peritonitis. Thirteen cases (24%) had an underlying disease, including mainly leukemia (31%), followed by congenital heart disease (23%) and head trauma (15%). Three cases (5%) had received a surgical operation; 3 cases (5%) had combined virus infections and 2 cases (4%) had mycoplasma infection. Most (73%) episodes occurred in winter and spring. The main origin of infection was community (89%). Forty of the patients were cured, 12 improved and 3 died (5%). Nine cases (16%) developed neurologic complications. There was a statistically significant differences in the annual detection rate of invasive SP (chi(2) = 33.93, P < 0.01). The incidence of penicillin-intermediate S. pneumoniae (PISP) and penicillin-resistant S. pneumoniae (PRSP) were 30% and 41%, respectively; the resistance to erythromycin and lincomycin were found in as high as 94% and 88% of isolates, respectively; while the resistant rate to chloramphenicol and cefotaxime were low, 26% and 22%, respectively. The multidrug resistance rate was 89%.

CONCLUSIONChildren aged less than 5 years, especially younger than 2 years are prone to IPD and the underlying diseases are found in 24% of cases; septicemia and meningitis are the common diseases.