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Explore the crucial variables - Infectivity, Severity, Susceptible Population, Persistence, Duration of Infective Stage, Mixing Coefficient, and Terror Factor - in controlling epidemics and biosecurity threats. Understand the implications for policy-making in managing smallpox, flu, SARS, anthrax, and other diseases. Delve into the ethical and logistical challenges of vaccination, quarantine enforcement, healthcare access, and emergency response strategies.
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The Law and Politics of Smallpox Edward P. Richards
Modeling Infectious Diseases • What makes a disease a plague? • Which plagues make good bioterrorism agents? • You can predict this from a core set of variables • You manage a natural epidemic or bioterrorism event by modifying these variables
I = Infectivity • How easy is it to catch the disease? • The flu is easy • Respiratory spread (you rub stuff in your eyes) • Causes coughing which sheds virus • Same as smallpox • HIV versus Gonorrhea • Anthrax – can be pneumonic, but not often • Bioengineering to increase infectivity
S = Severity of illness • The usual flu is a massive world wide epidemic each year but it is not severe so we do not care • In 1918-1919 flu was deadly • That is why SARS scared the epidemiologists so much • Severity includes treatablity • Treatability only matters if you can do it • Creates terrible justice issues if limited
T = Susceptible population • How many people can catch the disease? • Vaccinations attack disease by reducing the number of susceptible persons • Direct protection • Herd Immunity • Jacobson v. MA • People need to fear the disease • Tort law has undermined faith in vaccination • The CDC and many states have lost the will to say vaccination will be mandatory
P = Persistence • Does the disease persist in the environment? • Anthrax spores stick around • Probably not nearly as dangerous as people think • We have created such fear that cleanup will be difficult • Smallpox can linger on personal effects but not in the general environment • Cholera, typhoid, plague, SARS, and many diseases have non-human hosts which makes eradication impossible
D = Duration of infective Stage • How long can you spread the disease? • Makes a huge difference in the ability to restrict individuals • Tuberculosis can be months or more • SARS was 10 days • Smallpox is about 2 weeks on the outside • The longer the period • The more demand for due process • The higher the cost of providing for people
M = Mixing coefficient • How many people can you infect? • Depends on the number of people you contact in a way that can spread the disease • HIV – took the bathhouses in the US • Smallpox in NYC is much more dangerous than in a small town in Maine • Key issue in quarantine and restrictions
TF = Terror Factor • The product of the other factors • These can be manipulated to change perceptions • Smallpox • 2002 – seen as terrible threat • 2003 – CDC pushes models that reduce I and M so smallpox does not spread quickly • Why?
What does this mean for Emergency Response? • Which variables can you affect? • Anthrax • Pre-exposure antibiotics • Limit exposure by limiting movement • Smallpox • Vaccinate • Quarantine
Smallpox demands massive restrictions and mandatory vaccination in a hurry • CDC now downplays the time factor • Official policy says no mandatory vaccinations • No realistic plans for mass immunization • Feds completely ignore the problem of immunosuppressed communities because of AIDS politics
No serious discussion of whether smallpox is a real threat • Why are suddenly worried? • If it is real, should we do routine immunizations? • How would we change these decisions if the vaccine was safer?
Making the hard choicesWhat did TOPOFF ignore? • How do we enforce quarantine when people resist? • How do we force people to be vaccinated? • How do we keep people out of health care facilities? • How do we defend vaccine centers from people who do not want to wait? • How do we keep core services working when people do not go to work?