Some encouraging news from northern Italy:
Real-time evidence of flattening the curve. Lodi had the first Covid-19 case in Italy, and implemented a shutdown on Feb 23. Bergamo waited until March 8.
Look at the difference.
— Don Moynihan (@donmoyn) March 15, 2020
This paper from scientists in the UK lays out the story in more detail.
This section is particularly interesting, noting how Italy seems uniquely vulnerable to COVID-19 due to their generally older population and the high amount of inter-generational contact between people. It also notes that countries with younger populations may be less vulnerable to COVID-19:
The rapid spread of COVID-19 has revealed the need to understand how population dynamics interact with pandemics now and in the future. Population ageing is currently more pronounced in wealthier countries, which mercifully may lessen the impact of this pandemic on poorer countries with weaker health systems but younger age structures. It is plausible that poor general health status and co-infections such as tuberculosis may still increase the danger of COVID-19 among younger cases in these countries.
Thus far, the lower than expected number of cases detected in Africa (despite extensive trade and travel links with China), suggests that the young age structure of the continent may be protective of severe and thus detectable cases, or it may be undetected. Beyond age structure, there are large sex differences in mortality that need to be understood – with men at higher risk – some of which may be accounted for by the stark differences in smoking rates by sex in Asia.
Distributions of underlying co-morbidities such as diabetes, hypertension and COPD will likewise refine risk estimates. Until these more nuanced data are available, the concentration of mortality risk in the oldest old ages remains one of the best tools we have to predict the burden of critical cases and thus more precise planning of availability of hospital beds, staff and other resources.
As of March 13th, the most affected province of Bergamo (2,368 cases) has largely overcome the province of Lodi (1,133 cases) where the outbreak started and the containment measures were introduced first. We note that social distancing interventions were invoked on Feb 23rd in Lodi but until March 8th in Bergamo, providing some empirical evidence for the potential of “flattening the curve” interventions.