Table 2.
Listeriosis in children aged 28 days to < 15 years from 1997 to 2016, characteristics and incidence
| Characteristic of child | Total cases, count (%) n = 22 |
Person-years (× 1,000,000)b | Incidence | IRR (95% CI) | p value |
|---|---|---|---|---|---|
| Age (years) | |||||
| 29 days to < 1 year | 6 (27) | 1.19 | 0.51 (0.23, 1.10) | 1 | 0.006 |
| 1 to 4 | 8 (36) | 4.75 | 0.17 (0.09, 0.33) | 0.33 (0.12, 1.01) | 0.042 |
| 5 to 9 | 4 (18) | 5.97 | 0.07 (0.03, 0.17) | 0.13 (0.03, 0.46) | 0.002 |
| 10 to 14 | 4 (18) | 5.99 | 0.07 (0.03, 0.17) | 0.13 (0.03, 0.46) | 0.002 |
| Sex | |||||
| Female | 10 (45) | 8.72 | 0.11 (0.06, 0.21) | 0 | 0.759 |
| Male | 12 (55) | 9.18 | 0.13 (0.07, 0.23) | 1.14 (0.49, 2.70) | 0.759 |
| Ethnicity a | |||||
| European or other | 7 (32) | 10.29 | 0.07 (0.03, 0.14) | 1 | 0.117 |
| Māori | 5 (23) | 4.34 | 0.12 (0.05, 0.27) | 1.69 (0.50, 5.30) | 0.369 |
| Pacific | 4 (18) | 1.65 | 0.24 (0.09, 0.62) | 3.56 (0.93, 11.78) | 0.043 |
| Asian | 4 (18) | 1.62 | 0.25 (0.10, 0.63) | 3.63 (0.95, 12.01) | 0.040 |
| Unknown | 2 | ||||
| Overall | 22 | 17.90 | 0.12 (0.08, 0.19) | ||
aEthnicity is prioritised in the order Maori, Pacific, Asian, European or other
bPerson years calculated as the sum of the estimated resident population (ERP) for years 1997 to 2016
IRR Incidence rate ratio. P value derived from likelihood ratio test (italics) or comparison with reference group