China appears to have limited transmission of COVID-19 outside of Hubei Province through rapid and intensive containment and mitigation interventions. Most countries only attempt to carry out social distancing and hygiene interventions when widespread transmission is evident.
This gives the virus many weeks to propagate with a higher basic reproduction number (R0) than would be recorded if these interventions were implemented before the transmission was detected or propagated. In the context of the imminent transmission in the community of the new coronavirus causing COVID-19, low-cost preventive measures of social distancing and hygiene improvement should be considered.
Early interventions to reduce the average frequency and intensity of exposure to the virus could reduce the risk of infection, decrease the average viral infectious dose of those who have been exposed, and lead to less severe and less infectious cases. A pre-emptive phase would also assist government, workplaces, schools, and businesses to prepare for a more rigorous phase. Countries, and sub-regions of countries, that do not have recognized transmission of COVID-19 should assume that it is present and consider applying low-cost hygiene and social distancing measures.
Dalton CB1, Corbett SJ2, Katelaris AL3 1. Facultad de Medicina y Salud Pública, Universidad de Newcastle, Callaghan, NSW, Australia, 2308 2. Facultad de Salud de la Población y Facultad Clínica Occidental, Universidad de Sydney, Sydney, NSW, Australia, 2151 3. Centro Nacional de Epidemiología y Salud de la Población, Universidad Nacional de Australia, Canberra, ACT, Australia