ALL ABOUT BASIC REPRODUCTION NUMBER R 0 < 1 A newly infected person is likely to spread the infection to less than one person on average. �This means the number of those infected will decline and the infection may eventually cease to exist. Infected Uninfected R 0 = 1 A newly infected person is likely to spread the infection to one more person on average. This means the infection is likely to continue to exist in a population but there will not be a widespread outbreak or epidemic. © Bethany Lau R 0 > 1 A newly infected person is likely to spread the infection to more than one person on average. This means the infection is likely to spread throughout a population and there may be a widespread outbreak or epidemic. �The greater the R 0 value, the harder it will be to control an epidemic. R0 Limitations Scientists use data (infectious period, contact rate, mode of transmission) to calculate or estimate R 0 but as the virus moves through different populations with different environmental conditions, R 0 can change. If some members of the population have been exposed to the virus before or some have been vaccinated, the viral infection rate will be reduced. Scientists use a basic reproduction number (or R 0 “R Naught”) to describe how many other people that a newly infected person is likely to infect. R 0 is useful because it helps scientists and doctors estimate whether an infection will die out or spread much further in the population. BASIC REPRODUCTION NUMBER, R 0 Example Viruses and Estimated R 0 values Virus Measles Smallpox Pertussis Ebola Seasonal Flu 2019-nCoV R0 12-18 5-7 5.5 1.5-2.5 1.3 1.4-6.49 Airborne Airborne droplet Airborne droplet Bodily fluids Airborne droplet Unknown Mode of Transmission ALL ABOUT Wuhan Coronavirus 2019-nCoV * As of February 29th, 2020, there have been 86,960 confirmed people known to be infected in the world. In Mainland China alone, there have been 79,822 confirmed cases; in the United States, there have been 70 cases confirmed. There have been a total of 2,977 deaths attributed to the virus, including 2,761 deaths in Mainland China and 1 death in the United States. * The incubation period for the virus (the amount of time between the time of infection and the time an infected person shows symptoms) may be 10-14 days. The virus is contagious and can be passed between people. The fatality rate varies between age groups. The elderly are most at risk. * Symptoms of Wuhan coronavirus include fever, dry cough, and trouble breathing. Serious symptoms can progress to kidney failure, pneumonia, and death in severe infections. * Animals sold for food at the Huanan Seafood Market in Wuhan, China, are believed to be the initial carriers of the virus. The virus is suspected to be able to infect more than one type of animal as well as humans. What we know as of 2/29/2020 What can we do to prevent spread * Wash your hands frequently and thoroughly. This is the most important thing you can do to prevent spread. * Use alcohol-based hand sanitizer when you cannot wash your hands. * Avoid contact with anyone with a fever or a cough. * If you have a fever or cough, seek medical care. * Cook meat and eggs thoroughly These are important ways to prevent other viruses, not just Wuhan coronavirus! You can visit the CDC’s webpage here: https://www.cdc.gov/coronavirus/2019-ncov /summary.html And the World Health Organization’s page here: https://www.who.int/emergencies/diseases /novel-coronavirus-2019 To learn more about 2019-nCoV: © Bethany Lau