Tracking spread of H1N1 flu
The Times has tracked H1N1 swine flu cases since the never-before-seen strain was first detected in Southern California last month. Our interactive map shows daily developments by U.S. counties and Canadian provinces. Globally, cases are reported by country.
Epidemiologists have traced the first known case to a 4-year-old boy who lived near a pig farm in Perote, a mountainous town east of Mexico City. He fell ill April 1. A week and a half later, a 39-year-old woman died in Oaxaca, about 175 miles to the south.
On April 23, a Canadian lab confirmed that the woman had the new strain of the flu. By then, U.S. officials had detected the first cases of H1N1 virus in Southern California.
Fears about the strain began to rise April 24, the first full day after Mexican officials ordered the capital city’s schools shut. Concern about the strain appeared to peak last week as Mexican officials reported more than 1,500 suspected flu cases. Later that week, concern about the flu in the United States reached panicked levels in some places, with calls for a closure of the U.S.-Mexico border.
At the end of last week, U.S. health officials recommended the closure of schools that have had lab-confirmed cases of the new virus, disrupting Advanced Placement and SAT testing, athletic events and proms.
This week, fears lessened as it became clear that the flu strain was causing relatively mild illness in most people who contracted it.
Two deaths have been reported in the United States, both in individuals who had other underlying health problems; there have been no deaths reported in countries outside the U.S. and Mexico.
On Tuesday, the U.S. Centers for Disease Control and Prevention lifted advisories to close schools. Street vendors in Mexico City returned to work Wednesday after a week and a half of voluntary confinement.
In all, more than 2,000 cases of swine flu have been confirmed globally; about 680 in the U.S. and more than 100 in California.
—Rong-Gong Lin II