Table 3.
Age-Specific Case:Infection Ratios Observed During a Poliomyelitis Outbreak Among Children Under Age 15 Years, North Carolina, 1948a
| Age Group, years | Total Population | Proportion of Seroconverters | No. of Seroconverters | No. of Paralytic Cases | No. of Cases Per 100 Seroconverters |
| <1 | 1,800 | 5/20 | 450 | 3 | 0.66 |
| 1–2 | 3,900 | 10/39 | 1,000 | 10 | 1.00 |
| 3–4 | 3,600 | 7/34 | 741 | 12 | 1.62 |
| 5–9 | 7,300 | 8/56 | 1,042 | 25 | 2.40 |
| 10–14 | 6,300 | 5/44 | 716 | 13 | 1.82 |
a
The proportion of seroconverters is the ratio of the number of seroconverters to the total number of subjects tested and was multiplied by the age-specific population for estimation of the number of seroconverters in the population. Data were obtained from Melnick and Ledinko (41).