The Rate Of Diamond Princess Infections Suggest Worldwide Infections Are Much Higher Than Official Reports

by Tyler DurdenThu, 02/20/2020

Submitted by Eric Ross, Chief Investment Strategist of Cascend

SummaryThe Diamond Princess cruise ship is the largest controlled COVID-19 coronavirus infected population outside of China

  • 20% of the ship were infected over three weeks
  • From this, it suggests the rate of official reported infections (largely in China) is likely too low
  • This corroborates well with what our models have been saying: official reported infections are likely too low
  • From our models, far more people have likely been infected, but the death rate is also (thankfully) coming in lower than expected – worse than the flu, but perhaps in-line or lower than SARS, and definitely not a death sentence
  • Two passengers died last night from the Diamond Princess (male 87 and female 84) after being airlifted from the ship to a hospital a week ago, which implies a 1-2% death rate
  • And 14 days might not be long enough to conclusively prevent COVID-19 transmission, from the Diamond Princess experience, although passengers have now been released

The rate of Diamond Princess infections suggest worldwide infections are likely much higher than official reports

  • From the log scale chart below, the rate of Diamond Princess infections is much higher than infections suggested by official data (on log charts, lines with the same slope have the same growth rates)
  • Additionally, the Diamond Princess growth is very stable along the growth line versus the official data which doesn’t seem to follow a growth trend
  • Extending the fitted Diamond Princess line back to Patient Zero shows the first patient likely occurred on 21 January 2020 – in very good agreement with the actual assumed Patient Zero arriving on the cruise on the afternoon of 20 January
  • There is a slight possibility that massive quarantines in Hubei and China overall have dramatically slowed the infections rate, but we believe other possibilities are more likely

Cruise ships give us some of the best looks of the COVID-19 coronavirus

  • This is as close to a clinical trial as we will likely get
  • We can study rates of infections directly
  • An isolated, fixed-number population
  • No interaction with other populations (different from, say, Wuhan where 5m people were said to have fled before quarantine)
  • And free from lack of testing kits, medical staff, Chinese government determinations of “acceptable diagnosis techniques”, self-treating patients, and other data influences (organic or political)

Actually, the Diamond Princess cruise infection rates should be much lower than in normal cities

  • Passengers who have tested positive for COVID-19 have been evacuated to onshore quarantined medical facilities (so only spread before symptoms manifest)
  • Cruise passengers have been largely quarantined in their rooms (except for short breaks for fresh air, much like prison), thus likely keeping measured spread rates much lower than in a city where there are many modes of interactions (and thus transmission)
  • Passengers can’t get off the ship without permission (unlike in Wuhan where 5m people were said to have left just before quarantine)
  • Everyone on the ship is being closely monitored
  • And passengers and staff are keenly aware of any slight symptoms, and quick to report
  • Additionally, passengers with medical need are quickly ferried off the ship to an onshore quarantined medical facility

Several medical professionals have criticized the Japanese efforts on the Diamond Princess

  • The World Health Organization (WHO) and the U.S. Centers for Disease Control (CDC) both commended Japan’s handling of the cruise ship quarantine
  • As of 12 February 2020 all infections (174 at that point) were deemed to have been contracted BEFORE quarantine
  • However no update to this has been provided
  • Did the next 447 infections occur from a longer infectious timeframe? (i.e longer than 14 days?)
  • Or did these infections occur because of a breakdown of quarantine
  • Kentaro Iwata (an infectious diseases expert at Kobe University) visited the ship and assessed the quarantined process was flawed
  • David Shu-Cheong Hui (director of the Stanley Ho Centre for Emerging Infections Diseases in Hong Kong) suggested a far better quarantine would be to have moved all passengers and staff to an onshore quarantine, rather than keep everyone in close quarters
  • Anthony Fauci (director of the U.S. National Institute of Allergy and Infectious Diseases) stated that the quarantine process had failed

From our model we see the number of infections are likely much higher than official reports (for a variety of reasons)

  • But the death rate is likely not very high either; We expect the number of infections to crest in late March 2020 and subside from there
  • With careful measures, the outbreak will be contained mainly in China
  • Although we caution it is still very early in this outbreak to have an absolute answer

Why could China’s numbers be much lower than the actual infections?

  • China’s Hubei province acknowledged there methods for classifying infections was not counting many infections
  • They relied only on a nucleotide analysis and most of China is short of nucleotide tests
  • Hubei is the ONLY province which has announced an official change in diagnosis techniques
  • Medical staff and CT scans are below demand as well
  • For those taking the tests, there are false negatives for these tests (a normal issue)
  • Many patients are unwilling or unable to go to the hospitals to be tested – fear of being quarantined, or of catching the virus there
  • Many people who are infected will ride it out and be fine, regardless if they show up to be tested (this doesn’t seem to be like Ebola where 60+% of patients die, and even more without medical intervention)
  • Additionally it could be intentional:
    • It is possible many infected patients are not being tested to keep official numbers low
    • And there is little incentive for Chinese officials (who want to portray a sense of calm) to test patients who have already died (although this would be wise to help learn more about the virus)

About the Diamond Princess cruise ship

  • 2,670 passengers and 1,100 crew for a total of 3,770
  • Diamond Princess travels mainly between Japan, South Korea, Singapore, Vietnam, Taiwan and Malaysia
  • Plans to maintain this route through early 2021 (via cruise schedules)

Timeline of events

  • On 20 January 2020 an 80-year-old guest from Hong Kong embarked in Yokohama and disembarked in Hong Kong on 25 January – this guest tested positive for COVID-19 on 1 February 2020 and is suspected to be “Patient Zero” of the ship
  • 3 February the ship was quarantined in Japanese waters – it had stopped in 14 ports over the prior month
  • On 4 February 2020 when 10 passengers were diagnosed with COVID-19
  • 3,700 passengers and crew were then quarantined by the Japanese Ministry of Health, Labour and Welfare for 14 days, moored off the Port of Yokohama
  • On 11 February 2020 a quarantine officer was diagnosed
  • On 18 February 2020 the U.S. government 300 American passengers to the U.S., and quarantined them at military bases in California and Texas (except 14 of them who tested positive for COVID-19 are in hospitals)
  • On 19 February 2020 quarantine lifted and another 300 passengers left the Diamond Princess cruise ship

COVID-19Diamond Princess infection rate suggests China’s reported infections are too

A floating clinical trial?Quarantined cruise ships give us some of the best looks at the COVID-19 coronavirusThis is as close to a clinical trial as we will likely getWe can study rates of infections directlyAn isolated, fixed-number populationNo interaction with other populations (different from, say, Wuhan where 5m people were said to have fled before quarantine)And free from lack of testing kits, medical staff, Chinese government determinations of “acceptable diagnosis techniques”, self -treating patients, and other data influences

The Diamond Princess cruise ship was the largest controlled COVID-19 coronavirusinfected population outside of China20% of the ship were infected over three weeksThis suggests the rate of official reported infections (largely in China) is likely too lowThis corroborates well with whatour models have already been sayingTwo passengers died last night from the Diamond Princess (male 87, female 84) after being airlifted to a hospital –implies a 1-2% death rateAnd 14 days might not be long enough to conclusively prevent COVID-19 transmission, from the Diamond Princess experience (although passengers have now been released)

Growth rates of Chinese infections and Diamond Princess don’t matchDiamond Princess infections grow at this rateWhy don’t the Chinese infections grow at this rate??(if they’re the same virus, slopes should match)

The rate of Diamond Princess infections suggest worldwide infections are likely much higher than official reports(On log charts, lines with the same slope have the same growth rates)The Diamond Princess growth is very stable along the growth line versus the official data which doesn’t seem to follow a growth trendAnd extending the fitted Diamond Princess line back to Patient Zero shows the first patient likely occurred on 21 January 2020  –in very good agreement with the actual assumed Patient Zero arriving on the cruise on the afternoon of 20 January

Our model fits the data well (log scale)(this is just Hubei Province, the region in China which contains Wuhan, and thus has the most local data)The rate is changing?Hubei (China) 

Cascendhas modeled Wuhan coronavirus(2019-nCoV) outcomes in data format AND research commentary:Over 21,000 rows each with infections, deaths and recoveriesDaily projections each scenario through February 26th 202227 different scenarios regarding quarantines and effectivenessBased on official reported dataUpdated at least weekly (and currently daily) as inputs changeCSV or SQL formats

Fundamental data-driven

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