Reduction of secondary transmission of SARS-CoV-2 in households by face mask use, disinfection and social distancing: a cohort study in Beijing, China


  1. Yu Wang1,

  2. Huaiyu Tian2,

  3. Li Zhang1,

  4. Man Zhang3,

  5. Dandan Guo4,

  6. Wenting Wu1,

  7. Xingxing Zhang3,

  8. Ge Lin Kan5,

  9. Lei Jia1,

  10. Da Huo1,

  11. Baiwei Liu1,

  12. Xiaoli Wang1,

  13. Ying Sun1,

  14. Quanyi Wang1,

  15. Peng Yang3,

  16. C. Raina MacIntyre6,5


In the absence of a vaccine for COVID-19, non-pharmaceutical interventions (NPIs) are the only available disease control measures. We have shown that population level NPIs, including travel bans and the national emergency response, were effective in flattening the COVID-19 epidemic curve in China.1

However, the effect of other NPIs such as mask use and hygiene practices have not been well studied in the COVID-19 pandemic. In the United States, the use of face masks in the community has been recommended.2 It is thought that universal face mask use (UFMU) may reduce outward transmission from asymptomatically infected people and protect well people from becoming infected. However, the World Health Organization (WHO) and Public Health England recommend against UFMU on the grounds that there is little evidence from randomized controlled trials to support this. Some experts suggest that in a pandemic the precautionary principle should be used and universal face masks use encouraged as it is unlikely to cause harm and may result in public health gain.3,4 In countries where personal protective equipment is scarce, people are making their own masks.

In China, over 70% of human-to-human transmission of SARS-CoV-2 occurred in families.5,6However, data to inform COVID-19 risk reduction in households is unavailable. Given epidemic growth is dominated by household transmission,5,6 studying the use of NPIs such as face masks, social distancing and disinfection in the household setting may inform community epidemic control and prevent transmission of COVID-19 in households.