Table 1.
Comparison of key variables from the earlier post-elimination years (2001– 2008) with the later post-elimination years (2009– 2014)a
| 2001– 2008 | 2009– 2014 | p-value | |
|---|---|---|---|
| Reported case-patients annuallyb | 56 (37– 140) | 130 (55– 667) | 0.08 |
| Sex (male)c | 269/554 (49) | 682/1252 (55) | 0.02 |
| Median age (years)b | 15 (0– 89) | 14 (0– 84) | 0.53 |
| U.S. resident case-patientsc | 438/557 (79) | 1173/1263 (93) | <0.0001 |
| U.S. resident case-patients who were unvaccinated or had unknown vaccination statusc | 361/438f (83) | 1053/1173 (90) | <0.0001 |
| U.S. resident case-patients with philosophical or religious objections to vaccinationc,d | 110/162 (68) | 600/917 (65) | 0.54 |
| Preventable case-patientsce | 285/438 (65) | 917/1171 (78) | <0.01 |
| Complicationsc | 106/557 (19) | 109/1264 (9) | <0.0001 |
| Hospitalizationsc | 126/557 (23) | 211/1264 (17) | 0.003 |
| Imported cases annuallyb | 26 (18– 54) | 45 (21– 80) | 0.32 |
| Outbreaks annuallyb | 4 (2– 10) | 10 (4– 23) | 0.04 |
| Outbreak-related case-patientsb | 4 (3– 34)g | 5 (3– 383) | 0.71 |
| Outbreak durationb | 27 (3– 79) | 17 (3– 121) | 0.40 |
Data are median (range) for Wilcoxon rank sum results or n/N (%) for chi-squared results.
Differences in medians were calculated by Wilcoxon rank sums.
Differences in proportions were calculated by Mantel-Haenszel chi square.
Data on philosophical or religious objections were not routinely collected until 2004. Thus, for earlier post-elimination years, the numerator and denominator for this variable reflect data from 2004–2008. The denominator only includes vaccine-eligible U.S. resident case-patients.
Case-patients with preventable measles were case-patients for whom vaccination was recommended by the Advisory Committee on Immunization Practices but who had not received ≥1 dose of measles-containing vaccine.
In the previously published summary of measles epidemiological data from 2001– 2008 [10], the numerator was 358. In that paper, there were 3 individuals who were categorized as vaccinated, because they had a “yes” under the vaccinated variable, but they had an unknown number of doses. We re-categorized those individuals as having unknown vaccination status in this paper.
In the previously published summary of measles epidemiological data from 2001– 2008 [10], the annual median number of outbreak-related case-patients was 5. In that paper, there were 3 smaller outbreaks that were re-categorized as 1 larger outbreak by the health department after the paper was published. This resulted in a slight shift in the median number of outbreak-related case-patients.