Thread by @peripatetical

Where are we now in Australia and what might we expect next? Over the last week, there have been about 20 cases/day reported across Australia, but jurisdictions other than NSW and VIC have very small numbers of cases.

NSW cases relate mainly to the outbreak at Newmarch House aged care facility, and Victoria to Cedar Meats, with secondary transmissions from this cluster.
abc.net.au/news/2020-05-0…

The PM has announced a 3 step plan to start easing restrictions, with the jurisdictions setting the timeline. It is likely that we'll have to wait at least 3-4 weeks between steps to monitor on what's going on.

https://twitter.com/mariemcinerney/status/1258585678385868802?s=20

One issue is that with such small numbers of cases, it will be difficult to know if infection is spreading. If we are starting from a handful of cases, a doubling of cases over the next week or two may not be detectable.

An analogy is that it is like a fire danger rating - if restrictions have been relaxed too far, we might have the conditions for a major fire, but an actual fire requires a flame to set it off.

Mobility data suggests that people are getting about more in the last week than before. It's much less than at baseline, but how much mobility is too much is difficult to say - it isn't a direct measure of physical distancing.
gstatic.com/covid19/mobili…
apple.com/covid19/mobili…

The current clusters in NSW and VIC reinforce that any problems are likely to show up as outbreaks, especially in settings with vulnerable populations.

In the US, the most common outbreak settings have been in aged care facilities, meat works and detention facilities. A CDC report highlighted difficulties in workplace physical distancing and hygiene, and crowded living and transportation conditions.
cdc.gov/mmwr/volumes/6…

Singapore have had ongoing problems with foreign worker dormitories - there have been more than 19,000 cases in the 320,000 foreign workers housed mainly in 43 crowded dormitories
moh.gov.sg/docs/libraries…

In Australia, not everyone is getting tested. In the most recent FluTracking report, only 44% of respondents who reported having fever and cough got tested for COVID.
info.flutracking.net/reports-2/aust…

It is notable that the people who participate in FluTracking are generally highly educated and motivated (eg 78% were vaccinated last year). More than 60% have university qualifications (vs 27% in the general population) info.flutracking.net/wp-content/upl…

We can only wonder how many people with mild illness are being tested who might have a disincentive to be tested (eg casual workers), or those with poor access to health care (eg homeless) or may not have gotten the message (eg English not primary language)

What should we do now? We need sustainable suppression, which is easy to say but hard to do. Some things will be part of the new normal - personal hygiene measures, limited sizes of gatherings, enhanced cleaning, working from home where feasible.

Outdoor settings seem to be safer, and this may be a key to some businesses reopening in the future - outdoor activities, outdoor cafes, pop-up shops, markets perhaps?
wellcomeopenresearch.org/articles/5-83/…
medrxiv.org/content/10.110…

We need good surveillance to "spot and stop" outbreaks - hospitals, aged care, detention facilities, workplaces where physical distancing is difficult, and in vulnerable populations.

We're in a reasonably good place now. But we still need to prepare for what would happen if we lost control - imposition of restrictions, strengthening our public health workforce and efficiently tracing contacts, enough hospital beds and PPE to treat cases