and Prevention with either clinical or radiographic evidence of pneumonia or acute respiratory distress syndrome, without an alternative more likely diagnosis. Sixteen participating states § submitted case investigation forms containing data collected during January 19-June 3, 2020, for 199 COVID-19 patients. Among those patients, 192 (97%) reported experiencing any symptoms, six (3%) reported experiencing no symptoms, and one (<1%) had unknown symptom status. Sufficient symptom data for § States that submitted data include Alaska,

C oronavirus disease (COVID-19) was fi rst identifi ed in Wuhan, China, in December 2019 (1). The fi rst reported case in the United States was identifi ed in January 2020 (2); by mid-March, cases had been reported in all 50 states (3). On March 16, 2020, the White House Coronavirus Task Force published guidance for curbing community spread of COVID-19 (4); soon after, states began to enact stay-at-home orders (5). By late May 2020, all 50 states had begun easing restrictions; reported cases reached new peaks in the summer and then winter months of 2020 (6,7). As restrictions further ease with increased availability of vaccine, and as pandemic fatigue may cause persons to adhere less consistently to recommended guidance such as masking and distancing, it may be informative to look back at exposures and within-household transmission during a period when few mitigation measures were in place. We characterized exposures common among persons with the earliest reported confi rmed COVID-19 cases in the United States (onset mid-January through early April 2020) and identifi ed factors associated with presumed household transmission.This activity was reviewed by the Centers for Disease Control and Prevention (CDC) and was conducted consistent with applicable federal law and CDC policy. Forms were approved under the Offi ce of Management and Budget (no. 0920-1011).

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