PAHO is tracking a rise in dengue serogroup 3 activity, which could raise the risk of severe illness as countries approach the peak of the season.
The WHO said the increasing XEC COVID-19 variant isn't likely to burden healthcare systems as much as earlier variants.
The case was reported in a resident of Cameron County, located on the state's southern tip.
San Diego County officials said an area around 60 homes in Vista will be treated.
To date, 442,855 children under 10 years have been successfully vaccinated in central and south Gaza.
Cluster cases now total five, in addition to a detection in Panorama City and previous detections in El Monte and San Diego County.
Cases in the region have topped 11.7 million and continue to rise in the Central American Isthmus and Mexico, as the South America faces the start another season.
The latest case is from El Monte and doesn't appear to be related to the county's earlier four illnesses.
California has reported 63 West Nile virus infections this year, including many in the Central Valley.
The latest local dengue case in Los Angeles county isn't related to the cluster reported earlier this month.