United States COVID-19 Prevalence and Mortality as of 3–17–2020

Summary

Projection of Positive COVID-19 Cases in NH: Using the rates of transmission and methodologies described in this analysis, it is estimated that in New Hampshire:

✦Positive cases of COVID-19 will range from 200 to 800 by March 25th and up to 1,400 cases by March 30th, 2020.

✦By April 15th, it is possible that over 120,000 NH residents would theoretically test positive for COVID-19.

Projection of Intensive Care Bed Need: Based on Chinese data[1], it is possible that 5% or 6,000 of the positive NH cases (estimated 120,000 people) will require intensive care treatment within 30 days. According to the NH Hospital Association,[2] the state has a total of 3,051 staffed hospital beds.

Projection of Mortality: The Centers for Disease Control (CDC) has determined that risk factors for mortality from COVID-19 include age and comorbid conditions.[3]

✦Comorbid conditions: The mortality (death) rates for people in China who are critically ill is 49% or higher.[4] This would equate to more than approximately 3,000 deaths of critically ill people in NH based on the projections above.

✦Age Cohort: Eighteen percent (234,000 people) of the NH population is over the age of 65[5] or about 1 out of every 5 people are in the high-risk group for age. Using the 4% mortality rate that would equate to 9,340 deaths in people over the age of 65 in NH.

Recommendations

With such high transmission rates, the State of NH needs to shift to containment and mitigation measures immediately.

1. Strictly enforce social distancing measures.

2. Develop consistent messaging and modeling to help the public understand the gravity of this threat.

South Korea COVID-19 Prevalence and Mortality as of March 17, 2020

3. Aggressively implement additional testing to test every single suspected case as recommended by the WHO.[6] Implementing drive-through testing like in South Korea and parts of New York will provide the most rapid testing while limiting transmission. (Only about 380 tests have been done of the 1.3M residents in NH. This is a critical piece of understanding mitigation.)

4. Acquire critical medical supplies from federal stockpiles and suppliers, such as respirators and personal protective gear, to treat patients and protect healthcare workers.

5. Prepare staffing plans for hospitals and healthcare professionals for the eventuality that our healthcare system will be overwhelmed in less than 30 days.

6. State emergency management should include constructing temporary healthcare facilities to treat high rates of infected individuals in less than 30 days.

7. Request help from the federal government to identify locations and setup emergency healthcare treatment centers to handle the critically ill, as well as, obtain stockpiled equipment.

The situation in South Korea indicates that quick, consistent, and clear action will likely flatten the curve and lower incident cases to prevent deaths. However, the healthcare system will be overwhelmed in less than 30 days and steps need to be taken right now in NH to prepare for the eventuality.

Background

Infectious outbreaks are usually tracked by incidence rate to understand whether mitigation efforts are effective. In the case of the COVID-19 virus, the spread is so fast it is more informative to track the prevalence or the number of people living with the virus to understand the trajectory (the spread) and the impact to our medical system. According to the Centers for Disease Control (CDC) every infected person infects approximately 2 to 3 others.

On March 2nd, 2020, NHDHHS confirmed the first case of COVID-19 in NH. As of March 15th, 2020, there are 13 (3.4%) confirmed cases of COVID-19 out of 380 tests in NH. The State is waiting for results from an additional 100 tests.[7] According to publicly available information, about 480 of the approximate 1.3M people have been tested for COVID-19 in NH which represents a rate of 0.04%.

About 4,500 to 8,000 children live with their grandparents,[8] in part due to the opioid epidemic. This is why school closures are important in NH because we think children are carriers for the virus and are likely to bring it home, without symptoms, to their elderly caregivers. NH has taken action to limit the transmission rate by closing public schools on March 15th, 2020, for three weeks.

Methods

Prevalence data collected from online news reports for China[9], South Korea[10], New York[11][12], Italy[13][14][15][16][17], and New Hampshire. Trendlines were used to project 10- and 15-day estimates of positive cases.

Italy COVID-19 Prevalence and Mortality as of March 17, 2020

Results

In all cases, positive cases of COVID-19 began exponential increase 20 days or less from the initial case identification causing an inflection point (Figures 1a and 1b). The transmission rates for each of the countries follow approximately the same rate of increase after the inflection point among these locations.

Figure 1a. NH COVID-19 Projected Prevalence Data 10 Days from March 15, 2020.

Figure 1b. NH COVID-19 Projected Prevalence Data 30 Days from March 15, 2020.

Using these rates, it is estimated that the positive COVID-19 cases will range from 200 to over 300 by March 25th (Figure 1a) and up to 1,400 cases by March 30th, 2020. By April 15th, it is possible that over 120,000 people would theoretically test positive for COVID-19 in NH (Figure 1b).

Importantly, reduced incidence of COVID-19 in South Korea[18] appears to be slowing the rate of infection as shown on Figures 1a and 1b. It is likely that steps taken to mitigate the spread of the virus including widescale testing and strict social distancing and protective measures have been successful.

Discussion

South Korea has implemented the most comprehensive testing program. On February 26th, South Korea implemented drive-through testing that has resulted in about 109,600 citizens tested. However, only approximately 0.2% of the over 51 million South Koreans have been tested. Therefore, the prevalence rates may not be truly representative of the population rate.

Approximately 4.4% (4,812) of the tests were positive COVID-19 for South Koreans tested. Of the testing conducted by to date in NH, 3.4% of the 380 had positives tests for COVID-19. This is similar to the rate observed for South Korea.

Even though South Korea has achieved the highest test rate, it is unlikely that the testing has fully identified all positive cases, and it is likely that the current prevalence is much higher than realized.

The citizens of NH need to understand how critical it is to minimize transfer of this deadly virus and carefully implement social distancing and self-quarantine. The Centers for Disease Control (CDC) has said that transmission has occurred over a few hours during a small dinner gathering.

With testing rates so low in NH and the US overall, others have suggested that true COVID-19 prevalence may be 10 to 100 times higher than realized.[19] In this case, the true number of COVID-19 cases could be approximately 400 as of March 15th and would spread to the entire State within about 45 days. The State of NH is currently monitoring 450 people; therefore, this estimate may be realistic.[20]

Based on Chinese data[21], it is possible that 5% or 6,000 of the positive cases (estimated 120,000 people) will require intensive care treatment within 30 days. According to the NH Hospital Association,[22] the state has a total of 3,051 staffed hospital beds.

Mortality

The CDC has determined that risk factors for mortality from COVID-19 include age and comorbid conditions.[23] The mortality (death) rates for people in China who are critically ill is 49% or higher.[24] This would equate to more than approximately 3,000 deaths of critically ill people in NH based on the projections above.

Eighteen percent (234,000 people) of the NH population is over the age of 65[25] or about 1 out of every 5 people are in the high-risk group for age. Using the 4% mortality rate that would equate to 9,340 deaths in people over the age of 65 in NH.

Mortality rates for Chinese people over the age of 65 range from about 4 to almost 15%[26] (see Figure 2). The World Health Organization has indicated an overall mortality rate of approximately 3 to 4%[27] which would equate to 3,000 to 4,000 people.

Figure 2. Mortality by age group in Mainland China.

The situation in South Korea indicates that quick, consistent, and clear action will likely flatten the curve and lower incident cases to prevent deaths. However, the healthcare system will be overwhelmed in less than 30 days and steps need to be taken right now in NH to prepare for the eventuality. As Dr. Fauci said, he would rather we are criticized for being too aggressive responding to this pandemic.

References

[1]https://jamanetwork.com/journals/jama/fullarticle/2762996

[2]https://nhha.org/images/Data/2018_Health_System_Report.pdf

[3]https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/high-risk-complications.html

[4]http://www.cidrap.umn.edu/news-perspective/2020/02/study-72000-covid-19-patients-finds-23-death-rate

[5]https://www.census.gov/quickfacts/NH

[6]https://www.cnbc.com/2020/03/16/who-says-some-nations-arent-running-enough-coronavirus-tests-test-every-suspected-case.html

[7]https://www.nh.gov/covid19/

[8]https://www.dhhs.nh.gov/dcyf/documents/relativecaregivers.pdf?fbclid=IwAR0N_fVr2IvPr9ivxS0G7IfsJX29kJowCoJSGpXcaPD3IqhBNsbzo9wX6wI

[9]https://www.ecdc.europa.eu/en/publications-data/download-todays-data-geographic-distribution-covid-19-cases-worldwide

[10]https://thegroundtruthproject.org/timeline-how-south-korea-reacted-to-the-covid-19-outbreak/

[11]https://www.nbcnewyork.com/news/local/timeline-tracking-the-spread-of-covid-19-in-tri-state/2313123/

[12]https://www.nytimes.com/2020/03/14/nyregion/coronavirus-ny.html

[13]https://www.ecdc.europa.eu/sites/default/files/documents/novel-coronavirus-threat-assessment-brief-23-feb-2020.pdf

[14]https://en.wikipedia.org/wiki/Timeline_of_the_2019–20_coronavirus_pandemic_in_March_2020

[15]https://time.com/5788661/italy-coronavirus-cases/

[16]https://www.healio.com/infectious-disease/emerging-diseases/news/online/%7B830328bb-8a5a-487d-85d0-cc99eef84a45%7D/italy-races-to-contain-covid-19-outbreak

[17]https://www.statista.com/statistics/1101680/coronavirus-cases-development-italy/

[18]https://www.euractiv.com/section/coronavirus/news/commitment-transparency-pay-off-as-south-korea-limits-covid-19-spread/

[19]https://medium.com/@tomaspueyo/coronavirus-act-today-or-people-will-die-f4d3d9cd99ca

[20]https://www.nh.gov/covid19/

[21]https://jamanetwork.com/journals/jama/fullarticle/2762996

[22]https://nhha.org/images/Data/2018_Health_System_Report.pdf

[23]https://www.cdc.gov/coronavirus/2019-ncov/specific-groups/high-risk-complications.html

[24]http://www.cidrap.umn.edu/news-perspective/2020/02/study-72000-covid-19-patients-finds-23-death-rate

[25]https://www.census.gov/quickfacts/NH

[26]http://www.cidrap.umn.edu/news-perspective/2020/02/study-72000-covid-19-patients-finds-23-death-rate

[27]https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200306-sitrep-46-covid-19.pdf?sfvrsn=96b04adf_2