The Moving Curve: Episode 26
Hello and welcome to The Moving Curve. I’m Rukmini, a data journalist based in Chennai. Every night on this mini-cast, I consider one question around the novel coronavirus epidemic in India. Tonight, I’m looking at this one — why does the government think that India does not have an asymptomatic transmission problem?
Here are a few recent examples, and I’ve linked to all the studies I’m going to mention here:
- Iceland estimates that 50% of its cases are asymptomatic: https://edition.cnn.com/2020/04/01/europe/iceland-testing-coronavirus-intl/index.html
- In Vo, the small Italian town that tested its whole population, 43% of all cases, across two surveys, were asymptomatic. Most crucially, the viral load was the same in those with and without symptoms: https://www.medrxiv.org/content/10.1101/2020.04.17.20053157v1
- A New York hospital tested all 215 women who were admitted for deliveries between March 22 and April 4. 15% tested positive for SARS-CoV2, and 88% of those who tested positive had no symptoms: https://www.nejm.org/doi/pdf/10.1056/NEJMc2009316?articleTools=true
Wu Zunyou, China’s chief epidemiologist, said in an official briefing in early April that asymptomatic cases accounted for 4.4 percent of the total confirmed patients only in China: https://www.nbcnews.com/news/world/new-chinese-data-asymptomatic-coronavirus-cases-could-help-world-response-n1173896
Two days ago, China released details about the 6764 of its cases who were asymptomatic, which found that a fifth of them developed symptoms later, meaning that about 4,400 did not develop any symptoms at all.: https://www.bloomberg.com/news/articles/2020-04-15/china-s-data-on-symptom-free-cases-reveals-most-never-get-sick
But even China recognises that it hasn’t found all asymptomatic confirmed cases yet; after lifting its lockdown, Wuhan tested 275,400 people from April 8 to April 15 and found 182 asymptomatic positive cases, equivalent to 6.6 asymptomatic cases for every 10,000 people: http://global.chinadaily.com.cn/a/202004/18/WS5e9a97bfa3105d50a3d17277.html
I’m actually someone who doesn’t think the government’s decisions on containing the virus have been wrong on the whole, and I haven’t found the press briefings as unhelpful as many of my colleagues have either. But this was a bad one. To move ahead with effective strategies, our top authorities have to be reading the evidence better, or we’ll really be in trouble.
Thank you for listening. this episode was edited by Anand Krishnamoorthi. Tomorrow — a new question.