Serotype and antimicrobial susceptibility patterns of isolates of Streptococcus pneumoniae causing invasive disease in The Gambia 1996-2003.
OBJECTIVE
To describe the characteristics of pneumococcal isolates obtained from patients with invasive pneumococcal disease in The Gambia.


METHODS
Pneumococcal isolates were obtained from children aged < or =6 years with invasive pneumococcal disease during a Haemophilus influenzae vaccine effectiveness study (1997-2002) and from patients with invasive pneumococcal disease admitted to the MRC hospital, Fajara, for routine care (1996-2003). Isolates were identified, serotyped and tested for antibiotic susceptibility.


RESULTS
Five hundred and thirty one pneumococcal isolates were obtained from 518 patients; 55 (10.6%) patients died; 415 isolates (79%) were from blood culture, 84 (16%) from CSF, and 42 (8%) from lung aspirates. Forty serogroups and serotypes were identified; six accounted for 64% and 16 for 86% of all episodes; 33.7% were of serotypes 1 and 5. 23.5% were of a 7-valent vaccine serotype, 57.1% were of a 9-valent vaccine serotype; 56% were of a 7-valent serogroup and 78% were of a 9-valent serogroup. There was a significant increase in the proportion of isolates of non-vaccine serogroup with increasing age (P < 0.0001). Antibiotic resistance had not significantly increased over time; but intermediate non-susceptibility to penicillin had risen and resistance to chloramphenicol had fallen in isolates of vaccine serotype compared with those of non-vaccine serotype.


CONCLUSIONS
The majority of invasive pneumococcal disease in The Gambia is caused by pneumococci of relatively few serogroups. A conjugate vaccine would be expected to reduce the pneumococcal disease burden substantially and to have a beneficial effect on pneumococcal antibiotic resistance to penicillins.
Adegbola
Richard A
RA
Bacterial Diseases Programme, Medical Research Council Laboratories, PO Box 273, Banjul, The Gambia. radegbola@mrc.gm
Hill
Philip C
PC
Secka
Ousman
O
Ikumapayi
Usman N
UN
Lahai
George
G
Greenwood
Brian M
BM
Corrah
Tumani
T
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002701:Chloramphenicol / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D005714:Gambia / Q000453:epidemiology; D006679:HIV Seropositivity / Q000175:diagnosis / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D010406:Penicillins / Q000627:therapeutic use; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D012703:Serotyping / Q000379:methods; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D000962:Antimalarials; D010406:Penicillins; D002701:Chloramphenicol