Table 3.
Adjusted Hazard Ratios Denoting Homotypic and Heterotypic Protection or Cross-reactivity Between Norovirus Genotypes Among 194 Children in Peru
| Prior Infection | Adjusted Hazard Ratio (95% CI) | |||||||
|---|---|---|---|---|---|---|---|---|
| GI.3 (n = 73) | GI.5 (n = 51) | GI.7 (n = 58) | GII.2 (n = 45) | GII.4 (n = 195) | GII.6 (n = 150) | GII.17 (n = 53) | GII.23 (n = 49) | |
| GI.3 | 0.35 a (.15–.82) | 0.64 (.28–1.48) | 0.60 (.27–1.34) | 0.89 (.37–2.37) | 1.57a (1.08–2.28) | 1.75b,c (1.18–2.59) | 0.73 (.32–1.67) | 0.18 (.03–1.23) |
| GI.5 | 1.47 (.80–2.71) | 0.89 (.31–2.51) | 0.89 (.44–1.82) | 0.67 (.22–2.07) | 1.17 (.76–1.80) | 0.81 (.42–1.57) | 1.29 (.66–2.53) | 1.30 (.42–4.07) |
| GI.7 | 1.17 (.72–1.90) | 0.90 (.44–1.81) | 0.19 a (.04–.79) | 0.85 (.33–2.33) | 1.10 (.76–1.60) | 1.06 (.71–1.57) | 0.94 (.44–2.00) | 1.09 (.48–2.48) |
| GII.2 | 1.36 (.79–2.33) | 0.27 (.07–1.07) | 0.53 (.21–1.29) | 0.74 (.30–1.86) | 1.16 (.78–1.72) | 1.33 (.88–2.01) | 3.42b,c (2.00–5.82) | 1.05 (.44–2.51) |
| GII.4 | 0.52b,c (.33–.82) | 1.03 (.52–2.03) | 0.74 (.44–1.24) | 0.41a (.20–.84) | 0.39 b,c (.27–.54) | 0.91 (.66–1.27) | 0.79 (.43–1.45) | 1.13 (.67–1.92) |
| GII.6 | 1.09 (.71–1.70) | 1.18 (.64–2.18) | 0.73 (.43–1.26) | 1.61 (.84–3.09) | 0.96 (.70–1.33) | 0.52 b,c (.32–.82) | 1.73a (1.03–2.91) | 2.19a (1.19–4.03) |
| GII.17 | 2.06b,c (1.29–3.30) | 0.61 (.17–1.23) | 0.77 (.39–1.52) | 0.94 (.39–1.26) | 0.71 (.43–1.17) | 1.06 (.69–1.61) | 0.38 (.12–1.20) | 0.91 (.32–2.58) |
| GII.23 | 0.76 (.41–1.41) | 1.22 (.61–2.44) | 0.72 (.32–1.62) | 0.43 (.14–1.29) | 0.83 (.54–1.27) | 1.03 (.72–1.47) | 0.90 (.42–1.95) | 1.14 (.49–2.65) |
Hazard ratios of being infected with the same genotype (highlighted with bold text) or a different genotype among children with vs without prior infection with genotypes are listed in the left-hand column. Values between 0 and 1 denote reduced risk of subsequent infection among the previously exposed; values > 1 denote increased risk of subsequent infection among the previously exposed. Hazard ratios included adjustment for length-for-age z score and the duration of exclusive breastfeeding.
Abbreviation: CI, confidence interval.
a P < .05 (significantly different from the null hypothesis that there is no relationship between prior and future infection).
b P < .01 (strong significant finding).
cHolds after Holm correction (P < .007).