Investigation of a family cluster outbreak of COVID-19 indicates the necessity of CT screening for asymptomatic family members in close contact with confirmed patients

BACKGROUND: To investigate whether asymptomatic close-contact family members of patients diagnosed with coronavirus disease (COVID-19) should immediately undergo CT screening in addition to the viral nucleic acid test. METHODS: We retrospectively analyzed the data of a family cluster of 8 individuals, of whom 1 family member (Patient 3) had an epidemiologic history of having visited Guangzhou from Hubei Province on January 20, 2020. Her father (Patient 1) developed a fever and respiratory system symptoms and was confirmed COVID-19-positive on February 4–5, 2020 at Zengcheng People’s Hospital, Guangzhou, China. Seven close-contact family members of the patients were then screened for COVID-19 on February 5–6 at the hospital. The CT imaging manifestation and laboratory tests of this family cluster were investigated and reported. RESULTS: Five (62.5%) of the 8 family members were confirmed COVID-19-positive. Except for Patient 1, who had fever, cough, fatigue, and dizziness, the remaining four (4/5, 80%) COVID-19-positive family members (Patients 2–5) had no clinical symptoms. Among the 5 patients, 2 had leukopenia (2/5, 40%), 1 had low absolute neutrophil counts (1/5, 20%), and 2 had increased high-sensitivity C-reactive protein (2/5, 40%). Ground-glass opacity (GGO) was found on chest CT imaging in all 5 patients (5/5, 100%), with interlobular septal thickening. Thickened blood vessel shadows were seen in 3 patients (3/5, 60%). The 3 COVID-19-negative family members (Family Members 1–3) did not have CT abnormalities, and they showed negative reverse transcription-polymerase chain reaction (RT-PCR) results twice. CONCLUSIONS: CT screening is necessary in close-contact family members of a confirmed COVID-19 pneumonia case, regardless of the presence of clinical symptoms.