Various places got a lot of traffic from Wuhan before it was shut down: Singapore, Thailand, the US, Europe, Korea, Australia, etc. It’s clear that Europe’s outbreak is worse than the US/Australia/Singapore. It seems likely that things are worse in the colder parts of the US (vs. Texas or Florida).
Iran was not testing/reporting. There are many tropical / Southern Hemisphere places that could have had an Iran style outbreak and which had a lot more traffic from Wuhan than Iran does. Why Iran?
(I’m mostly replying to this entire thread rather than Owain’s comment.)
I’m failry confident in the following two claims:
Warm climate slows down transmissions substantially.
But not enough to prevent large outbreaks.
My reasoning being:
As commenters have pointed out, we see striking correlations between countries that report large numbers of cases and cold-ish temperatures.
The alternative hypothesis (poorer testing and detection) seems likely true to me, but not strong enough to overcome this point:
Now granted there could be a higher spread in these countries that is underreported, but if they had it bad as in Italy or Iran it wouldn’t go unnoticed.
That said, I think there is circumstantial evidence for a somewhat large underreported outbreak in Indonesia (avg temperature of 31+ Celsius for the last two months), and maybe also the Philippines (but I haven’t been following the latter at all). For Indonesia I think it’s likely they have upward of 2,500 infections. It seems implausible to me that they’d already be anywhere near Italy or Iran’s level of infections, but if one is really cynical, I admit that it can’t be ruled out completely.
Some relevant data points:
When Indonesia had <20 confirmed diagnoses, 3 Indonesians were tested positive abroad: a married couple in Singapore and an Indonesian woman who travelled to Australia. The Singapore case seems to have been motivated by seeking quality hospital care, which admittedly makes this evidence consistent with a smaller outbreak than if Indonesians who travelled to Singapore for non-health-related reasons had tested positively. Still, I think 2 instances of testing positive abroad at a time when the official count is <20 is quite telling.
Indonesia also reported 4 deaths by now. For the first death, a British woman age 53 with several serious previous health conditions, Indonesian authorities labelled the case “imported” because the woman had only been to Indonesia for a couple of days by the point she died. However, I’m not sure whether I should believe the conclusion because there were reports (US nursing home and one from Italy) of people going from symptomatic to dead in <30h. In any case, 3 further deaths were announced yesterday, and no indication was given that they might be imported cases. Even just 3 deaths usually correspond to true rates of infection well above 1,000. The ratio of confirmed diagnoses to deaths is now exceptionally high in Indonesia. (The same applies even more strongly to the Philippines, but I could imagine that some deaths there were definitely imported.)
There was this entire discussion about expert modelling suggesting that indonesia’s long count of zero diagnoses is evidence for them missing cases throughout February.
(Indonesia was one of the last countries to ban incoming travel from Italy or Iran, I believe.)
According to this tweet, testing in Indonesia was 970 people. Indonesia’s population is >>200 million.
In addition, the incentives for reporting cases diligently seem to be suboptimal, as evidenced by some data points:
Indonesian ministers install even less confidence than Trump. Just one example of communication: About the Australia exported case, the Indonesian health official claimed that the woman most likely got infected in Australia because she had travelled for quite a while and because she also visited a Vietnamese restaurant there (implication: Vietnamese restaurants in Australia are risky). However, the Australian source (link above) says clearly that the woman in question started showing symptoms 2 days after leaving Jakarta (so much for “she travelled for quite a while”), and the only reason a Vietnamese restaurant was mentioned anywhere is because the Australian authorities obviously traced the Indonesian woman’s contacts in order to interrupt a potentially newly started chain.
Maybe the time lag confuses me, but I’m pretty sure there was one time when Indonesia skipped a day of reporting case numbers, and then numbers double and deaths went from 1 to 4. (Could be totally benign if there’s some disorganization during a time of crisis, of course.)
Indonesian officials seem to be under enormous pressure because the economy is doing very poorly already. Some unusual measures have already been taken a while back, such as disallowing shorting and pledges for government-owned companies to buy back shares.
And here’s a concerning but speculative hypothesis:
Singapore doctors gave out a warning that patients who tested positive for Dengue fever with a quick-testing kit actually turned out to have Covid-19. They say the diseases are clinically similar and that the widely used quick-test kits may not have failed isolatedly due to extraordinary circumstances. Indonesia currently has a somewhat large Dengue outbreak (and the same goes for the Philippines).
UPDATE: 18 days after I made this comment, Reuters reports that Jakarta’s funeral count for March was 1,300 funerals higher than any preceding month since 2018. This looks highly statistically significant because the previous record was only 3,100 (compared to 4,400). (And there was no natural disaster or other unusual disease outbreak.)
I wrote the above before checking today’s news: Only 27 further cases, but a government official infected and 1 more death. The article also says that cases were in many different parts of Jakarta, and some in other parts of the country. At the same time, the Indonesian authorities say that the reason why they detected all those cases is because they did “massive contact tracing,” suggesting between the lines that this isn’t yet evidence of even more widespread community transmission than already acknowledged.
Edit2: Australia may have caught another infected person with Indonesia as travel history. (I say may have because there’s a small chance that this refers to the initial case from 5 days ago; however, some of the wording somewhat strongly suggests it’s a second, new case.)
A competing hypothesis (this time I am specifically replying to Owain’s comment) is that it’s easier to catch infected travellers coming from the location where one expects them to come from. Asian countries certainly had it harder in phase 1 when the goal was to detect all the infections with Chinese travel history. However, as soon as even just one country in Europe failed at detection, the traveling dynamics changed and in phase 2 it subsequently became easier for the Asian countries, because they had basically zero incoming travel from Europe by that point. So while everyone was still focused on catching infections with Chinese travel history, Europeans were infecting other places in Europe, but less so places in Asia.
It’s maybe some supporting evidence that the Italy outbreak was connected to the early Germany outbreak, and that it only became clear that many countries were going to lose control of the situation once infected travellers had come from many different places. (At the same time, the Seattle outbreak is evidence against.)
Very hot countries have it easier to do contact-tracing. It’s plausible that the virus deactivates at 30 degrees Celsius (I think I may have read that in the often-cited Lipsitch article). In the hottest countries, public transport can be 30+ degrees and even grocery stores can be that warm. If infections happen primarily in indoor settings (e.g., business contacts or partying or household), contact tracing is easier, giving hot countries an initial advantage at preventing outbreaks early on. However, once contact tracing fails, that advantage shrinks. What remains is only that the r0 is lowered somewhat by heat interrupting certain types of of transmissions, but not all types. It wouldn’t surprise me therefore if hotter countries also need extreme measures to contain the case count from growing exponentionally, even if the doubling time might be generally lower for hot countries.
Various places got a lot of traffic from Wuhan before it was shut down: Singapore, Thailand, the US, Europe, Korea, Australia, etc. It’s clear that Europe’s outbreak is worse than the US/Australia/Singapore. It seems likely that things are worse in the colder parts of the US (vs. Texas or Florida).
Iran was not testing/reporting. There are many tropical / Southern Hemisphere places that could have had an Iran style outbreak and which had a lot more traffic from Wuhan than Iran does. Why Iran?
(I’m mostly replying to this entire thread rather than Owain’s comment.)
I’m failry confident in the following two claims:
Warm climate slows down transmissions substantially.
But not enough to prevent large outbreaks.
My reasoning being:
As commenters have pointed out, we see striking correlations between countries that report large numbers of cases and cold-ish temperatures.
The alternative hypothesis (poorer testing and detection) seems likely true to me, but not strong enough to overcome this point:
That said, I think there is circumstantial evidence for a somewhat large underreported outbreak in Indonesia (avg temperature of 31+ Celsius for the last two months), and maybe also the Philippines (but I haven’t been following the latter at all). For Indonesia I think it’s likely they have upward of 2,500 infections. It seems implausible to me that they’d already be anywhere near Italy or Iran’s level of infections, but if one is really cynical, I admit that it can’t be ruled out completely.
Some relevant data points:
When Indonesia had <20 confirmed diagnoses, 3 Indonesians were tested positive abroad: a married couple in Singapore and an Indonesian woman who travelled to Australia. The Singapore case seems to have been motivated by seeking quality hospital care, which admittedly makes this evidence consistent with a smaller outbreak than if Indonesians who travelled to Singapore for non-health-related reasons had tested positively. Still, I think 2 instances of testing positive abroad at a time when the official count is <20 is quite telling.
Indonesia also reported 4 deaths by now. For the first death, a British woman age 53 with several serious previous health conditions, Indonesian authorities labelled the case “imported” because the woman had only been to Indonesia for a couple of days by the point she died. However, I’m not sure whether I should believe the conclusion because there were reports (US nursing home and one from Italy) of people going from symptomatic to dead in <30h. In any case, 3 further deaths were announced yesterday, and no indication was given that they might be imported cases. Even just 3 deaths usually correspond to true rates of infection well above 1,000. The ratio of confirmed diagnoses to deaths is now exceptionally high in Indonesia. (The same applies even more strongly to the Philippines, but I could imagine that some deaths there were definitely imported.)
There was this entire discussion about expert modelling suggesting that indonesia’s long count of zero diagnoses is evidence for them missing cases throughout February.
(Indonesia was one of the last countries to ban incoming travel from Italy or Iran, I believe.)
According to this tweet, testing in Indonesia was 970 people. Indonesia’s population is >>200 million.
In addition, the incentives for reporting cases diligently seem to be suboptimal, as evidenced by some data points:
Indonesian ministers install even less confidence than Trump. Just one example of communication: About the Australia exported case, the Indonesian health official claimed that the woman most likely got infected in Australia because she had travelled for quite a while and because she also visited a Vietnamese restaurant there (implication: Vietnamese restaurants in Australia are risky). However, the Australian source (link above) says clearly that the woman in question started showing symptoms 2 days after leaving Jakarta (so much for “she travelled for quite a while”), and the only reason a Vietnamese restaurant was mentioned anywhere is because the Australian authorities obviously traced the Indonesian woman’s contacts in order to interrupt a potentially newly started chain.
Maybe the time lag confuses me, but I’m pretty sure there was one time when Indonesia skipped a day of reporting case numbers, and then numbers double and deaths went from 1 to 4. (Could be totally benign if there’s some disorganization during a time of crisis, of course.)
Indonesian officials seem to be under enormous pressure because the economy is doing very poorly already. Some unusual measures have already been taken a while back, such as disallowing shorting and pledges for government-owned companies to buy back shares.
And here’s a concerning but speculative hypothesis:
Singapore doctors gave out a warning that patients who tested positive for Dengue fever with a quick-testing kit actually turned out to have Covid-19. They say the diseases are clinically similar and that the widely used quick-test kits may not have failed isolatedly due to extraordinary circumstances. Indonesia currently has a somewhat large Dengue outbreak (and the same goes for the Philippines).
UPDATE: 18 days after I made this comment, Reuters reports that Jakarta’s funeral count for March was 1,300 funerals higher than any preceding month since 2018. This looks highly statistically significant because the previous record was only 3,100 (compared to 4,400). (And there was no natural disaster or other unusual disease outbreak.)
Malaysia is up to 428 cases now and rising rapidly: https://www.bloomberg.com/news/articles/2020-03-15/malaysia-virus-cases-spike-after-outbreak-at-16-000-strong-event They’ve been averaging 24C with peaks of 36C. Not looking good for the heat hypothesis.
I wrote the above before checking today’s news: Only 27 further cases, but a government official infected and 1 more death. The article also says that cases were in many different parts of Jakarta, and some in other parts of the country. At the same time, the Indonesian authorities say that the reason why they detected all those cases is because they did “massive contact tracing,” suggesting between the lines that this isn’t yet evidence of even more widespread community transmission than already acknowledged.
Edit: On the same day, Singapore gets 2 positive tests with a direct connection to Indonesia.
Edit2: Australia may have caught another infected person with Indonesia as travel history. (I say may have because there’s a small chance that this refers to the initial case from 5 days ago; however, some of the wording somewhat strongly suggests it’s a second, new case.)
A competing hypothesis (this time I am specifically replying to Owain’s comment) is that it’s easier to catch infected travellers coming from the location where one expects them to come from. Asian countries certainly had it harder in phase 1 when the goal was to detect all the infections with Chinese travel history. However, as soon as even just one country in Europe failed at detection, the traveling dynamics changed and in phase 2 it subsequently became easier for the Asian countries, because they had basically zero incoming travel from Europe by that point. So while everyone was still focused on catching infections with Chinese travel history, Europeans were infecting other places in Europe, but less so places in Asia.
It’s maybe some supporting evidence that the Italy outbreak was connected to the early Germany outbreak, and that it only became clear that many countries were going to lose control of the situation once infected travellers had come from many different places. (At the same time, the Seattle outbreak is evidence against.)
Another hypothesis:
Very hot countries have it easier to do contact-tracing. It’s plausible that the virus deactivates at 30 degrees Celsius (I think I may have read that in the often-cited Lipsitch article). In the hottest countries, public transport can be 30+ degrees and even grocery stores can be that warm. If infections happen primarily in indoor settings (e.g., business contacts or partying or household), contact tracing is easier, giving hot countries an initial advantage at preventing outbreaks early on. However, once contact tracing fails, that advantage shrinks. What remains is only that the r0 is lowered somewhat by heat interrupting certain types of of transmissions, but not all types. It wouldn’t surprise me therefore if hotter countries also need extreme measures to contain the case count from growing exponentionally, even if the doubling time might be generally lower for hot countries.