Streptococcus pyogenes bacteraemia - The impact of previous radiation and clindamycin resistance

Thirty-six patients with bacteraemia due to Lancefield Group A Streptococcus (LGAS) infection were hospitalized at National Taiwan University Hospital, Taiwan, from January 1982 to September 1994. Infection in 29 of these patients was community-acquired. Thirty patients were adults. Solid tumour was present in 30%. Local complications caused by radiation therapy were found to be the most common predisposing factor for developing LGAS bacteraemia in these cancer patients. Resistance rates to tetracycline, erythromycin, clindamycin, and chloramphenicol were 33, 29, 19 and 16 per cent, respectively. Cross-resistance to erythromycin and tetracycline was detected in all seven clindamycin-resistant strains. The mortality rate directly related to bacteraemia was 16.7% and 84% of these died within 2 days of onset of septicaemia. Five adult patients had streptococcal toxic shock syndrome, all of whom died. This study revealed unique predisposing host factors for LGAS bacteraemia and high resistance rates to non-β-lactam antimicrobial agents.