2009 swine flu pandemic in the United States by state
2009 H1N1 pandemic in the United States (short version)
A new flu strain, H1N1 (often called “swine flu”), began spreading in the United States in spring 2009. The first US cases appeared in California in late March, then spread to Texas, New York, and many other states by mid‑April. Early cases were linked to travel to Mexico, and many involved students who had visited Mexico for Spring Break. By the end of May, outbreaks had occurred in states across the country. The first official US death occurred on April 27, a 23‑month‑old child visiting Texas from Mexico. By late June, dozens of deaths were reported, and by January 2010 the virus had caused thousands of deaths worldwide and more than 12,000 confirmed in the United States. Health officials believed the true US death toll was higher than the confirmed number because some deaths were not confirmed as H1N1.
Governments and schools responded with alerts and temporary closures, and a vaccine campaign began in fall 2009. The pandemic affected the whole country, with many communities experiencing school closures, hospitalizations, and ongoing vaccination efforts throughout 2009 and into 2010.
State highlights (selected examples)
- California: Early cases in April; by late July 2009 there were about 2,655 confirmed cases and 61 deaths, rising to roughly 479 deaths and thousands of cases statewide by January 2010.
- Texas: Among the hardest hit early on; by July 24, 2009, about 4,998 cases and 27 deaths were reported, with more hospitalizations. The first US death was a toddler who had traveled from Mexico.
- New York: Early cases linked to New York City schools; by July 24, 2009, 2,738 confirmed cases and several deaths, including the state’s first pediatric death in May.
- Alabama: First confirmed case on May 2, 2009; by December 5, 2009, 2,453 confirmed cases and 36 deaths.
- Alaska: First probable case in May 2009; by December 2009 there were about 460 cases and 11 deaths; a death was later reported.
- Arizona: First cases in April; by late October 2009, 6,302 confirmed cases and 81 deaths; first death reported in May.
- Colorado: Early spread in April; by mid‑July 2009, 171 cases and more; first death reported in July.
- Connecticut: By July 2009 there were over 1,700 confirmed cases; by early 2010 several thousand cases in all, with about 31 deaths overall.
- Delaware: About 381 cases by July 24, 2009; 6 deaths by January 2010.
- Florida: First cases in May; by July 30, 2009, about 3,221 cases; several deaths, including early pediatric cases.
- Georgia: About 222 cases by July 24, 2009; a number of schools and campuses reported cases.
- Hawaii: By July 24, 2009 there were about 1,424 cases; 13 deaths by January 2010.
- Idaho: By late 2009 there were several hundred deaths and hundreds of cases; vaccine distribution and public health responses were underway.
- Illinois: By July 24, 2009, 3,366 cases and 17 deaths; by January 2010, about 2,931 hospitalizations and 97 deaths.
- Indiana: By July 24, 2009, 291 cases; by early 2010, dozens of deaths.
- Kansas: By July 24, 2009, about 213 cases; several deaths by early 2010.
- Kentucky: First cases in late April 2009; by mid‑summer hundreds of cases and multiple hospitalizations.
- Louisiana: By January 2010, about 1,973 cases and 43 deaths.
- Maine: Early cases in April; by mid‑2010 hundreds of cases and dozens of hospitalizations, with several dozen deaths reported during the period.
- Maryland: By fall 2009, about 954 confirmed cases; around 43 deaths by January 2010.
- Massachusetts: About 1,398 cases and 172 hospitalizations by mid‑to‑late 2009; several deaths.
- Michigan: First cases in April 2009; by mid‑summer hundreds of cases and several dozen deaths; many schools closed briefly in fall 2009.
- Minnesota: About 684 cases by July 23, 2009; several dozen deaths by late 2009 and 2010 (about 55 deaths by January 2010).
- Missouri: Early cases in spring; by July 2009 dozens of cases and one death; cases continued to be confirmed through the summer.
- Mississippi: Hundreds of cases with several deaths reported by early 2010.
- Montana: By late July 2009 there were about 122 cases; by January 2010 several hundred cases and some deaths.
- Nebraska: About 313 confirmed cases by July 23, 2009; 16 hospitalizations and 3 deaths noted by late 2009.
- Nevada: By October 2009, about 1,871 total cases and 15 deaths across counties, with higher activity in some urban areas.
- New Hampshire: About 232 confirmed cases by early July 2009; several deaths by late 2009.
- New Jersey: By July 22, 2009, 936 confirmed cases and 480 probable; 14 deaths by January 2010.
- New Mexico: Hundreds of cases reported in spring to summer 2009; several deaths.
- New York (state): Early cases in New York City; by July 24, 2009, thousands of cases and multiple deaths; some early cases tied to schools.
- North Carolina: About 483 confirmed cases by July 22, with several deaths.
- North Dakota: Dozens to a few dozen confirmed cases by mid‑summer 2009.
- Ohio: Initial cases in late April 2009; by July 24, 2009, 186 confirmed cases; follow‑up deaths occurred later in 2009.
- Oklahoma: By July 22, about 203 cases; at least one death reported.
- Oregon: By July 24, about 530 people tested positive; several deaths occurred by mid‑2009.
- Pennsylvania: By January 2010, about 2,997 confirmed or probable cases; at least 14 deaths.
- Rhode Island: By August 2009, about 203 confirmed cases and two deaths.
- South Carolina: By July 24, 2009, about 313 confirmed cases; first death reported late August.
- South Dakota: A smaller number of cases, with early deaths in 2009.
- Tennessee: At least one death reported in 2009; additional cases occurred through 2010.
- Utah: Early cases in May 2009; by October 2009, about 30 deaths and hundreds of cases statewide.
- Vermont: A few dozen confirmed cases by mid‑to‑late 2009.
- Virginia: Several dozen deaths by fall 2009 (dozens across districts).
- Washington: By July 22, 2009, hundreds of cases and multiple deaths; state later focused on hospitalizations and deaths rather than daily case counts.
- Wisconsin: Thousands of cases by July 2009, with several deaths; Milwaukee area had a large share of cases.
- Wyoming: By July 2010, over 100 confirmed cases; first death reported in August 2009.
Note on the numbers: The counts above reflect the best available totals reported for the 2009–2010 period. They show how the virus spread from a few pockets to widespread activity across most states, with the illness and its impact varying by place and over time. Vaccination campaigns and public health responses continued through the 2009–2010 season, helping to reduce severe illness and deaths as the pandemic progressed.
This page was last edited on 2 February 2026, at 09:15 (CET).