The attack rate peaked in the third period and substantially declined afterwards across geographic regions, sex and age groups, except for children (age <20) whose attack rate continued to increase. Healthcare workers and elderly people had higher attack rates and severity risk increased with age. The effective reproductive number dropped from 3.86 (95% credible interval 3.74 to 3.97) before interventions to 0.32 (0.28 to 0.37) post interventions. The interventions were estimated to prevent 94.5% (93.7 to 95.2%) infections till February 18. We found that at least 59% of infected cases were unascertained in Wuhan, potentially including asymptomatic and mild-symptomatic cases. CONCLUSIONS Considerable countermeasures have effectively controlled the Covid-19 outbreak in Wuhan. Special efforts are needed to protect vulnerable populations, including healthcare workers, elderly and children. Estimation of unascertained cases has important implications on continuing surveillance and interventions.
Статья (препринт) в пдф формате, так же содержит эпидемиологичсекие данные по Ковид-19 в Китае.
Кстати, по их данным,
" we found that the attack rate continued to increase over time for those aged under 20 years. In particularly, infants under the age of 1 year had the highest attack rate than the other age groups of children, probably because they cannot wear masks and have low immunity. Children had a lower chance of getting infected probably because they had less frequent social activities during the school winter break starting in early or middle January, but the attack rate increased when all people were required to stay at home and risk of familial clustering of infection started to increase."
Так что американцам не стоит себя утешать что дети мало болеют.
"The outbreak quickly spread from the urban areas to the suburban and rural areas. The attack rate in the healthcare workers was substantially higher between January 11 and February 1, indicating a high risk of nosocomial infections. This was probably due to lower awareness of protection before January 20, and later severe shortage of medical resources including designated wards and personal protective equipment in hospitals confronting overwhelmed patients."
- думаю, тут ситуация повторится. Не всесмопобны учиться на чужих ошибках.
"Increasing evidence also suggested that the asymptomatic and presymptomatic cases can be infectious to the susceptible population, imposing a substantial challenge to the epidemic control."
К тому же, по мнению авторов, в других старанх ловится всего лишь 3 случаев занесения инфекций (из Китая)
Therefore, understanding the proportion of unascertained cases and the rate of asymptomatic spread will be critical for pandemic prevention of Covid-19, including prioritization the surveillance and control measures.