Overview

• New York State is investigating a preliminary positive chikungunya result in a 60-year-old Nassau County woman with no recent travel, with samples submitted to the state lab for confirmation.
• Health officials say routine mosquito surveillance on Long Island has not detected chikungunya and they assess the current public risk as very low.
• Massachusetts confirmed two additional West Nile virus infections, bringing the season total to eight and elevating risk to high in Arlington, Chelsea, Medford and Waltham as 445 mosquito samples have tested positive statewide.
• Rhode Island reported its first probable human West Nile case of 2025 in a hospitalized Providence County resident in their 60s, now awaiting CDC confirmation, with 13 mosquito samples testing positive this season.
• Wisconsin officials confirmed a West Nile–positive blood donor in Shawano County, indicating local infected mosquitoes and noting that any positive blood donations are removed from the supply.