Table 1.
Genetic Relatedness of 640 New Clostridium difficile Infection Cases to Any Previous Isolate
| Type of Relationship/Contact | Same Ribotype | 0 SNV | 0–2 SNV | 3–10 SNV | 0–10 SNV |
|---|---|---|---|---|---|
| Relationship to all previous study isolates at this threshold | 567 (89%) | 162 (25%) | 227 (35%) | 127 (20%) | 354 (55%) |
| Genetically linked to any previous case on the same ward at the same time | 164 (26%) | 91 (14%) | 115 (18%) | 9 (1%) | 124 (19%) |
| Within plausible infectious and incubation periodsa | 139 (22%) | 84 (13%) | 105 (16%) | 6 (1%) | 111 (17%) |
| Genetically linked to any previous case on the same ward at a different time | 144 (23%) | 20 (3%) | 30 (5%) | 34 (5%) | 64 (10%) |
| Within 4 wk | 54 (8%) | 13 (2%) | 16 (3%) | 9 (1%) | 25 (4%) |
| Plausible community contact | 83 (13%) | 8 (1%) | 13 (2%) | 8 (1%) | 21 (3%) |
| Shared general practice | 27 (4%) | 4 (1%) | 10 (2%) | 1 (0%) | 11 (2%) |
| Postcode district | 77 (12%) | 8 (1%) | 11 (2%) | 9 (1%) | 20 (3%) |
| Genetically related but no contact of any kind identified | 176 (28%) | 43 (7%) | 69 (11%) | 76 (12%) | 145 (23%) |
| CA/I | 67 (10%) | 12 (2%) | 21 (3%) | 32 (5%) | 53 (8%) |
Prior contact considered in order shown (same ward same time (direct), same ward different time (spore), community) with the exception of any spore contamination lasting <28 days which was considered more plausible than direct transmission outside 56-day donor infectious period and 90-day recipient incubation periods.
Abbreviations: CA, community associated; CDI, Clostridium difficile infection; I, indeterminate; SNV, single nucleotide variants.
aFifty-six–day donor infectious period and 90-day recipient incubation [18].