The average time it took for coronavirus cases to double in the U.S. was about 6.5 days, a study released Friday by the Centers for Disease Control and Prevention found.
Doubling time ranged from 5.5 days in Louisiana to eight days in New York City among the 10 jurisdictions reporting the most cases as of April 7.
The CDC analysis includes all lab-confirmed COVID-19 cases from Feb. 12 to April 7 from health departments in all 50 states and eight U.S. territories, the District of Columbia and New York City. Cases and deaths reported by New York state exclude those reported by New York City.
Two-thirds of the 395,926 cases reported to the CDC as of Tuesday were in eight jurisdictions: New York City (76,876), New York state (61,897), New Jersey (44,416), Michigan (18,970), Louisiana (16,284), California (15,865), Massachusetts (15,202) and Pennsylvania (14,559).
By Tuesday, 55 of 56 jurisdictions with COVID-19 cases had reported at least one death from the respiratory infection. About half of those deaths were in New York City, New York state and New Jersey.
The national coronavirus rate was 199.6 cases per 100,000 people as of Tuesday, with Minnesota reporting the lowest rate at 20.6 and New York City reporting the highest at 915.3.
Eight other jurisdictions had rates higher than the national average: New York (555.5), New Jersey (498.6), Louisiana (349.4), Massachusetts (220.3), Connecticut (217.8), Michigan (189.8), the District (172.4) and Rhode Island (133.7).
The incidence rate rose by 63.4 per 100,000 people from March 31 to April 7, ranging from 8.3 in Minnesota to 418 in New York City. New Jersey (288.7), New York (262.4), Louisiana (237.1), Connecticut (130.2), Massachusetts (124.3), Michigan (113.6), the District (101.9), Rhode Island (84.6), Pennsylvania (75.9) and Maryland (64) all had increases that surpassed the national climb.
“Epidemiologic and population factors as well as clinical and public health practices” likely explain the differences among the states, the CDC report said.
The variation in the timing and implementation of community mitigation strategies across jurisdictions and the availability and approaches to testing could also play a role, it said.
New York state, not including New York City, gave 4.9 tests per 1,000 people, higher than the national average of 1.6, which could partially explain the state’s higher case count.
• Shen Wu Tan can be reached at stan@washingtontimes.com.
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