Study population and setting
This study was an outbreak investigation of cases associated with a confirmed case of COVID-19 among students in Austin, Texas, United States, with the first case identified on March 28, 2020. Contact tracing was conducted to identify additional cases as well as establish control measures to prevent future onward transmission. Contract tracing linked infections to a spring break trip to Cabo San Lucas, Mexico, from March 14 to 19, 2020. SARS-CoV-2 reverse transcription–polymerase chain reaction (RT-PCR) testing was conducted to identify cases among those recommended for testing.
Summary of Main Findings
Among 298 persons identified during the investigation, 289 (97%) were interviewed. Among those tested (n=231), 28% (n=64) tested positive for SARS-CoV-2. Among the 183 Cabo San Lucas travelers 33% (n=60) tested positive; 8% (1/13) of household contacts of Cabo San Lucas travelers and 9% (3/35) of community contacts of Cabo San Lucas travelers tested positive. Of cases identified, 22% (n=14) were asymptomatic and 78% (n=50) were symptomatic at the time of testing. No identified cases were hospitalized or died. No differences were observed in smoking status among persons with positive and negative test results.
Contact tracing was used to actively identify individuals with potential exposure.
The study did not distinguish between pre-symptomatic and asymptomatic cases, and therefore may be subject to misclassification bias. Missing data was present, with 17% missing underlying health conditions and smoking status, and 14% on symptom presentation. Most individuals were only tested once during the investigation, and therefore infection results are subject to test limitations or stage of infection.
Outbreak investigation of a cluster associated with travel among a young group of students provides insights on transmission among young adults.
This review was posted on: 12 August 2020