- NEW YORK (Reuters Health)
- If introduced into America or Europe, smallpox would spread rapidly at
first, infecting 6 to 12 people for each individual already
- As steps were taken to stymie the spread of the
mass vaccination campaigns, restriction of infected individuals' movement
and quarantines--the rate of disease spread would fall and eventually be
- Nonetheless, "significant epidemics could result,
particularly if there were delays in detecting the first cases or in
up effective public health interventions," Drs. Raymond Gani and Steve
Leach of the Centre for Applied Microbiology and Research in Salisbury,
UK, write in the December 13th issue of Nature.
- Smallpox was eradicated by 1979 and vaccination against
the disease gradually ended around the world. But stockpiles of the
virus remain in laboratories in the US, Russia and possibly other nations.
Recent fears of bioterrorism have ignited concerns that these stockpiles
could be used to introduce the potentially deadly disease into the
which is at present ill-prepared to deal with a potential outbreak,
- In the US, Health and Human Services Secretary Tommy
Thompson announced plans to buy as many as 300 million doses of smallpox
vaccine. But several health experts have warned against a national
program, citing potentially serious side effects including as many as 300
- Other experts argue that once an outbreak has occurred,
restricting mass transportation and informing the public about the nature
of the outbreak and how to minimize the risk of illness may more
prevent the spread of disease than isolating everyone who has been
- The smallpox vaccine can also be used to treat the
if given in the days immediately after exposure.
- The study findings are based on a mathematical model
the researchers created to calculate how fast smallpox would spread in
Western populations that have little natural immunity and in the absence
of public health interventions.
- "This helps scope the potential intensity of the
public health interventions that might subsequently be needed," Leach
told Reuters Health. "The end result would depend on many factors,
including the scale and extent of the outbreak, (but) the most important
aspect will be that the outbreak will have ended."
- SOURCE: Nature 2001;414:748-751.