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Volume 31, Number 7—July 2025
Research Letter
Increasing Predominance of Norovirus GII.17 over GII.4, United States, 2022–2025
Figure 1

Figure 1. Increase in outbreaks of norovirus GII.17 over GII.4, United States, 2022–2025. Seasons are defined as September 1 of one year to August 31 of the next. The 2024–25 season is truncated to September 2024–April 2025. Other genotypes: GI.1, GI.2, GI.3, GI.4, GI.5, GI.5, GI.6, GI.7, GII.1, GII.2, GII.3, GII.6, GII.7, GII.8, GII.10, GII.12, GII.13, GII.14, GII.21, GII.27, and GIX.1.
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