Fusobacterium necrophorum infections in England and Wales 1990-2000.

In response to a marked increase in both the number of Fusobacterium necrophorum bacteraemia reports to the PHLS Communicable Disease Surveillance Centre and the number of F. necrophorum isolates referred to the PHLS Anaerobe Reference Unit in 1999, the data from both sources on F. necrophorum infections were reviewed for the decade 1990-2000. There were 208 reports of F. necrophorum bacteraemia (average 19/year; range 14-34/year) with a peak in incidence in the late winter months; 68% were from male patients and the peak age range was 16-23 years. Of 205 referred isolates of F. necrophorum, 122 (59%) were from blood cultures and these represented 58% of the bacteraemia reports; the others were from brain and soft tissue abscesses, pleural and joint fluids, eyes, ears and lymphatic tissue. The average number of referrals was 19/year (range 9-37/year). The peak year for bacteraemia reports (34) and isolate referrals (37) was 1999; this increase was not sustained in 2000. All isolates were susceptible to metronidazole, but 2% were resistant to penicillin and 15% to erythromycin. F. necrophorum continues to be a regular but uncommon cause of bacteraemia and metastatic abscesses following an acute sore throat, especially in young, otherwise healthy adults.