Epidemiology of First U.S. Cases
On January 21, 2020, the first person in the United States with diagnosed 2019-nCoV infection was reported. As of February 4, a total of 293 persons from 36 states, the District of Columbia, and the U.S. Virgin Islands were under investigation based on current patient under investigation (PUI) definitions,¶ and also included those being evaluated because they are close contacts. Of these PUIs, 11 patients have confirmed 2019-nCoV infection using a real-time reverse transcription–polymerase chain reaction (RT-PCR) assay developed by CDC. These 11 cases were diagnosed in the following states: Arizona (one), California (six), Illinois (two), Massachusetts (one), and Washington (one) (Table). Nine cases were in travelers from Wuhan. Eight of these nine cases were identified as a result of patients seeking clinical care for symptoms and clinicians connecting with the appropriate public health systems. Two cases (one each in California and Illinois) occurred in close contacts of two confirmed cases and were diagnosed as part of routine monitoring of case contacts. All patients are being monitored closely for progressing illness. No deaths have been reported in the United States.
TABLE  Characteristics of initial 2019 novel coronavirus cases (N = 11) — United States, January 21–February 4, 2020
Case  State  Approximate age (yrs)  Sex  Place of exposure  Date laboratory confirmation announced
1  Washington  30s  M  Wuhan  1/21/2020
2  Illinois  60s  F  Wuhan  1/24/2020
3  Arizona  20s  M  Wuhan  1/26/2020
4  California  30s  M  Wuhan  1/27/2020
5  California  50s  M  Wuhan  1/27/2020
6  Illinois  60s  M  Household Illinois  1/30/2020
7  California  40s  M  Wuhan  1/31/2020
8  Massachusetts  20s  M  Wuhan  2/01/2020
9  California  50s  F  Wuhan  2/02/2020
10  California  50s  M  Wuhan  2/02/2020
11  California  50s  F  Household California  2/02/2020
Abbreviations: F = female; M = male.