Projected casualties and deaths
A virus's basic reproduction number helps to determine if a viral outbreak is being contained. A number below 1 shows that the infection rate is dropping. A number above 1 indicates that the infection rate is rising. Using data supplied by the WHO, an August study found that an estimate for this virus was between 1.4 and 1.7 at that time, meaning that each newly infected individual had subsequently infected 1.4 to 1.7 more. The time between initial infection and the infecting of others for this virus is short. The basic reproduction number coupled with a short transfer time for this epidemic is of great concern [97] According to a research paper released in August, in the hypothetical worst-case scenario, if a reproduction number of over 1.0 continues for the remainder of the year we would expect to observe a total of 77,181 to 277,124 additional cases within 2014.[98]On 28 August, the WHO released its first estimate of the possible total cases (20,000) from the outbreak as part of its roadmap for stopping the transmission of the virus.[99][100] The WHO roadmap states "[t]his Roadmap assumes that in many areas of intense transmission the actual number of cases may be 2 - 4 fold higher than that currently reported. It acknowledges that the aggregate case load of EVD could exceed 20,000 over the course of this emergency. The Roadmap assumes that a rapid escalation of the complementary strategies in intense transmission, resource-constrained areas will allow the comprehensive application of more standard containment strategies within 3 months."[100] It does not provide details of how it made this total casualty estimate or a more detailed projection of how Ebola casualty statistics might evolve over time. It includes an assumption that some country or countries will pay the required cost of their plan, estimated at half a billion dollars.[100] However, while the WHO has projected a total of 20,000 cases, some of the United States' leading epidemiologists predict a much higher number. Writing in the NYT on 12 September, Bryan Lewis, an epidemiologist at the Virginia Bioinformatics Institute at Virginia Tech, said that researchers at various universities who have been using computer models to track the growth rate say that at the virus’s present rate of growth, there could easily be close to 20,000 cases in one month, not in nine. [101]
On 3 September, Thomas Kenyon, Director of the US Centers of Disease Control, said "The highly virulent disease, which has claimed more than 1,900 lives so far, is spreading faster than health workers in Guinea, Liberia, Nigeria and Sierra Leone can manage".[102] Similar comments were made by Anthony Fauci, Director of [the US] NIH's National Institute of Allergy and Infectious Diseases, who said that 42 percent of the cases have occurred in the last month and that the outbreak is "completely out of control". He further noted that the rate of infection is exponential: "The number of cases per unit time is dramatically increasing."[103] On 8 September, the WHO warned that the number of new cases in Liberia was increasing exponentially, and would increase by "many thousands" in the following 3 weeks.
On 9 September, Jonas Schmidt-Chanasit of the Bernhard Nocht Institute for Tropical Medicine controversially announced that the containment fight in Sierra Leone and Liberia has already been "lost" and that the disease will "burn itself out" after, eventually, infecting nearly the entire population, with half of them, or around five million, succumbing.[104]
In a 11 September op-ed article printed in the New York Times, Michael Osterholm of the University of Minnesota's Center for Infectious Diseases Research and Policy wrote, "There are two possible future chapters to this story that should keep us up at night. The first possibility is that the Ebola virus spreads from West Africa to megacities in other regions of the developing world...The second possibility is one that virologists are loath to discuss openly but are definitely considering in private: that an Ebola virus could mutate to become transmissible through the air. You can now get Ebola only through direct contact with bodily fluids. But viruses like Ebola are notoriously sloppy in replicating, meaning the virus entering one person may be genetically different from the virus entering the next. The current Ebola virus’s hyper-evolution is unprecedented; there has been more human-to-human transmission in the past four months than most likely occurred in the last 500 to 1,000 years. Each new infection represents trillions of throws of the genetic dice." Osterholm noted that the supervision of relief efforts is, as yet, absent. He suggested that only an international organization such as the United Nations is in the position to take control of the "medical, public health and humanitarian aid that must come from many different countries and nongovernmental groups to smother this epidemic." [105]
end quote from:
No comments:
Post a Comment