A Model Describing COVID-19 Community Transmission Taking into Account Asymptomatic Carriers and Risk Mitigation

Abstract

Coronavirus disease 2019 (COVID-19) is a novel human respiratory disease caused by the SARS-CoV-2 virus. Asymptomatic carriers of the virus display no clinical symptoms but are known to be contagious. Recent evidence reveals that this sub-population, as well as persons with mild disease, are a major contributor in the propagation of COVID-19. The asymptomatic sub-population frequently escapes detection by public health surveillance systems. Because of this, the currently accepted estimates of the basic reproduction number (R 0 ) of the disease are inaccurate. It is unlikely that a pathogen can blanket the planet in three months with an R 0 in the 1 . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

A mathematical model to investigate the transmission of COVID-19 in the Kingdom of Saudi Arabia

“…At the initial time t = 0, if we set the initial population N Table 1. I assumed that the mean asymptomatic infectious period is the same as the mean symptomatic infectious period because there is no estimation available in the literature [9,29]. Based on those estimated, assumed and measured values, the basic reproduction number R 0 is estimated to range from 2.87 to 4.9.…”

“…In reality, R 0 is not a biological constant; it could fluctuate daily depending on environmental and social factors such as percentage of entire susceptible 6 population wearing suitable medical mask and practicing physical distancing. In the literature, estimates of R 0 vary greatly: from 1 to 6 [18][19][20][21][22][23][24] up to 26.5 [9]. This variation is because of different assumptions and factors they had considered in the calculations.…”

Lies, Gosh Darn Lies, and Not Enough Good Statistics: Why Epidemic Model Parameter Estimation Fails

“…For example, from time of infection to the time the person can transmit disease has a time distribution, that, for enough people in the compartment, will tend to center on an average by the central limit theorem for large enough samples drawn from any given distribution. There is evidence that COVID-19 presents symptomatic cases and asymptomatic cases, with asymptomatic cases [10][11][12] less likely to be identified and isolated [13][14][15][16][17] . There is an incubation period after infection that lasts until the incubating individuals become infectious.…”

“…There is an incubation period after infection that lasts until the incubating individuals become infectious. There has been some early estimates based on confirmed cases 13,18 with more evidence of pre-symptomatic transmission being noted 19,20 yielding faster incubation. Incubation partly accounts for the observed lag when social distancing or other viral spread prevention policies are imposed.…”

A COVID-19 Risk Assessment for the US Labor Force

“…We propose three stages of risk at which society can mitigate the emergence and consequences of a new disease: (1) the risk that a pathogen will spill over into the human population, (2) the risk of transmission among humans once a disease has spilled over, and (3) 20 the risk of hospitalization or death of an infected individual. Currently, most country-wide efforts to mitigate COVID-19 focus on reducing human-to-human transmission largely through distancing policies (9,10), aimed at reducing the rate of increase in severe cases, and therefore of overwhelming hospital capacity (flattening the curve).…”