The latest local dengue case in Los Angeles county isn't related to the cluster reported earlier this month.
At least one household member and six healthcare workers who encountered the index case-patient are being investigated after showing symptoms of viral infection.
The scientists examined outbreaks in European fur farms, South American marine mammals, and US dairy cattle.
California now has 40 avian flu outbreaks in dairy herds, and the US total has reached 238.
In other developments, CDC and Ohio partners launched a serosurvey among bovine veterinary workers who attended a recent professional conference.
The source of the girl's infection isn't known, though H9N2 has been reported in the country's poultry before.
California now has the nation's second most dairy farm outbreaks.
In other H5N1 developments, the FDA's vaccine advisory group said it will discuss the composition of H5 vaccines when it meets next month.
Massachusetts is the only state to test all dairies, which involved bulk-milk tank sampling in August.
Like most other H9N2 cases, China's latest illness involves a young child.
