Storyline
US mosquito-borne virus outbreak 2026
One page that accretes the verified record as the story develops. Every fact keeps its date and its sources.
5 DAYS
18 FACTS
3 EVENTS
2 SOURCES
FIRST ENTRY SEP 03
SEP 07 · Day 5
Mosquito-borne virus spreads in one US state
Approximately 97% of U.S. dengue cases in 2024 were travel-associated and roughly 3% were locally acquired.
Florida recorded 85 locally acquired dengue cases across 10 counties in 2024.
As of Sept. 1, there were 33 locally acquired dengue fever cases in Tampa Bay and 41 statewide in Florida in 2026.
SEP 04 · Day 2
Florida fights mosquitoes spreading dengue fever
SEP 03 · Day 1
Deadly mosquito-borne virus claims first life in major US city
CDPH Commissioner Garth Walker said 2026 has seen the rainiest summer in Chicago in years.
Most West Nile cases are reported in August and September.
Several other West Nile cases have been reported throughout Illinois.