Guidance
Diphtheria: laboratory isolates of C. diphtheriae and C. ulcerans
Laboratory isolates of Corynebacterium diphtheriae and Corynebacterium ulcerans in England and Wales from 1986 to 2014.
Pharyngeal or cutaneous diphtheria is caused by toxigenic strains of C. diphtheriae and occasionally by C. ulcerans. The table below shows the isolates received by the Respiratory and Vaccine Preventable Bacteria Reference Unit (RVPBRU) for toxigenicity testing.
| Year | Toxigenic C. diphtheriae | Toxigenic C. ulcerans | Non-toxigenic C. diphtheriae | Total Corynebacteria Isolates |
|---|---|---|---|---|
| 1986 | 8 | 1 | 4 | 13 |
| 1987 | 2 | 2 | 8 | 12 |
| 1988 | 4 | 1 | 6 | 11 |
| 1989 | 6 | 2 | 12 | 20 |
| 1990 | 4 | 0 | 17 | 21 |
| 1991 | 1 | 2 | 11 | 14 |
| 1992 | 3 | 1 | 55 | 59 |
| 1993 | 5 | 4 | 51 | 60 |
| 1994 | 4 | 4 | 48 | 56 |
| 1995 | 1 | 4 | 137 | 142 |
| 1996 | 3 | 5 | 130 | 138 |
| 1997 | 5 | 5 | 178 | 188 |
| 1998 | 3 | 2 | 162 | 167 |
| 1999 | 0 | 2 | 255 | 256 |
| 2000 | 1 | 7 | 294 | 301 |
| 2001 | 0 | 3 | 205 | 209 |
| 2002 | 6 | 2 | 143 | 152 |
| 2003 | 3 | 2 | 147 | 152 |
| 2004 | 0 | 1 | 130 | 131 |
| 2005 | 0 | 2 | 123 | 125 |
| 2006 | 1 | 2 | 68 | 71 |
| 2007 | 0 | 3 | 79 | 82 |
| 2008 | 2 | 4* | 68 | 73 |
| 2009 | 2 | 2 | 37 | 41 |
| 2010 | 1 | 1 | 45 | 47 |
| 2011 | 0 | 2 | 54 | 56 |
| 2012 | 0 | 1 | 66 | 67 |
| 2013 | 3 | 0 | 69 | 72 |
| 2014 | 0 | 1 | 69† | 70 |
- Including 1 isolate which was previously identified as toxigenic C. pseudotuberculosis
† Including 5 non-toxigenic tox gene bearing C. diphtheriae isolates