TABLE 2.
Risk of infection and severe diarrhea if infected in a cohort of household contacts of index patients with Vibrio cholerae O1 and O139 infection
| V. cholerae serogroup in index patient | Blood group of household contact | Infection in household contacta | OR for infection (95% CI) | P | Severe diarrhea in household contact, if infectedb | OR for severe diarrhea (95% CI) | P |
|---|---|---|---|---|---|---|---|
| O1 & O139 combined | O | 74/264 (28%) | 0.80 (0.65-0.98) | 0.03 | 14/66 (21%) | 2.4 (1.2-4.7) | 0.01 |
| Non-O | 186/529 (35%) | 15/173 (9%) | |||||
| O1 | O | 49/208 (24%) | 0.67 (0.53-0.85) | 0.0008 | 8/43 (19%) | 2.3 (0.98-5.6) | 0.055 |
| Non-O | 151/423 (36%) | 11/139 (8%) | |||||
| O139 | O | 25/56 (45%) | 1.2 (0.80-1.9) | 0.32 | 6/23 (26%) | 2.3 (0.86-6.2) | 0.10 |
| Non-O | 35/106 (33%) | 4/34 (12%) |
a
Number of household contacts infected/number exposed.
b
Number with severe diarrhea/number infected. Severe diarrhea was defined as eight or more large-volume watery stools per 24 hours. Infected patients were excluded if the onset of symptoms was 8 or more days after enrollment.