A COVID-19 Transmission within a family cluster by presymptomatic infectors in China - Clinical Infectious Diseases

Bron: 23-3-2020; https://doi.org/10.1093/cid/ciaa316
By: G. Qian, et al. 

Aim
To report a family cluster of asymptomatic transmission after a temple visit. 

Keys

• COVID-19 from the same index patients can present differently among different patients
• Patients in incubation period (asymptomatic) are transmittable
• Positive patients can stay asymptomatic throughout the entire disease period and be “silent” transmitters
• Children seem to be less affected

Summary

• 19-1 a couple (58 y.o. woman and 60 y.o. man) visit a temple in China
• Woman (index 1) falls ill (fever and fatigue) on 24-1. Man (index 2) asymptomatic. From 20 to 23-1 4 family members (index 3-6) visited the couple. 
• 26-1 Index 1 is admitted to the hospital with COVID-19 diagnosis at 29-1. 
  • Index 2-6 have been tested following index 1 her positive test
    • Index 2: no symptoms, positive test
    • Index 3: positive test, day after: symptoms
    • Index 4: positive test, day after: symptoms
    • Index 5 (child): repetitively negative, no symptoms
    • Index 6 (child): positive, no symptoms
  • Indexes 3-6 had dinner on 23-1 with index 7-9 (parents and grandparents of index 4). On that day none of index 3-6 had symptoms.  
    • All 7-9 were tested positively. Index 7 was even admitted to the ICU.
• Even though all patients from this family got COVID-19 from the same place (all indexed at the temple), symptoms differed a lot between patients. 
• Secondly, this family showed COVID-19 is transmittable during incubation period. 
• Thirdly, positive patients can stay asymptomatic for the whole disease period. 
• These “silent patients” may remain undiagnosed and be able to spread the disease to large number of people.
• Lastly, it appears that children may not be as susceptible to this new virus as adults and elderly, and they may fare better when they have contracted the virus. As reported in this family cluster, the 6-year old child was not infected and the 13-month-old was infected but stay asymptomatic.