Invasive group A streptococcal infection in injecting drug users and non-drug users in a single UK city.
OBJECTIVE
Injecting drug users (IDU) represent an increasing proportion of patients with invasive group A streptococcal (GAS) disease. Our aims were to characterise the clinical presentation and strains causing GAS bacteremia in IDU from a single UK city (Brighton and Hove), and to compare this patient group with non-drug users (non-DU) with GAS bacteremia.


METHODS
Consecutive GAS blood culture isolates from twenty-two IDU and twenty-two non-DU presenting to the city hospital were studied. Clinical features, strain emm typing and superantigen toxin genotyping were investigated.


RESULTS
GAS invasive disease presented differently in IDU compared to non-DU with a predominance of injection site abscesses and lower mortality in IDU. GAS strains from IDU were predominantly emm82 and emm83 types, which are uncommon in the UK and emm82 strains appeared clonal. The non-DU GAS strains demonstrated a broader range of emm types including most frequently emm1 and emm89. There was no major difference in superantigen gene profile between the isolate groups.


CONCLUSIONS
The distinct presentation of invasive GAS disease in IDU compared with non-DU was associated with distinct emm types, a predominance of abscesses, and low mortality, although the small numbers preclude definitive conclusions. Further study is required to establish if these findings reflect strain differences or epidemiological differences in colonisation patterns and injecting practice.
Curtis
S J
SJ
Department of Infectious Diseases, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
Tanna
A
A
Russell
H H
HH
Efstratiou
A
A
Paul
J
J
Cubbon
M
M
Sriskandan
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000145:classification / Q000235:genetics; D016470:Bacteremia / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D001425:Bacterial Outer Membrane Proteins / Q000145:classification / Q000235:genetics; D015373:Bacterial Typing Techniques; D001769:Blood / Q000382:microbiology; D002352:Carrier Proteins / Q000145:classification / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D003470:Culture Media; D005838:Genotype; D006786:Hospitals, Urban; D006801:Humans; D007223:Infant; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods; D013290:Streptococcal Infections / Q000382:microbiology / Q000401:mortality / Q000473:pathology; D013297:Streptococcus pyogenes / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015819:Substance Abuse, Intravenous / Q000150:complications* / Q000401:mortality; D018089:Superantigens / Q000235:genetics; D006113:United Kingdom / Q000453:epidemiology
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D003470:Culture Media; D018089:Superantigens; C014689:streptococcal M protein