Hantavirus in Louisiana.
Louisiana is the principal endemic zone for Bayou virus, which causes HPS with renal involvement more prominent than Sin Nombre HPS. Cases concentrate in the southeast — particularly the parishes around the Atchafalaya Basin. Louisiana Department of Health works with LSU and CDC on serosurveillance of rice-rat populations after major flood years.
Frequently asked
How many hantavirus cases has Louisiana reported?
Louisiana has reported 1 confirmed hantavirus pulmonary syndrome cases year-to-date in 2026, against a 5-year average of 0.8 per year. Case counts vary year-on-year with rodent population cycles.
What rodent carries hantavirus in Louisiana?
Rice rat (Oryzomys palustris). Coastal marshes and wet pine flatwoods; year-round transmission risk.
Which strain causes hantavirus in Louisiana?
Bayou virus is the dominant hantavirus strain in Louisiana. It causes hantavirus pulmonary syndrome (HPS) with case fatality typically 30–40%.
Related
Disclaimer. State case counts reflect what CDC NNDSS publishes. The state health department is the authoritative real-time source.