THE BIG HEALTH ISSUE OF 2005???

[Guest guest]

Hi folks:

This may turn out to be REALLY important in 2005 or 2006. The

precautions that brought SARS under control (isolation of cases) are

unlikely to be adequate ( " would not be effective " ) to control a bird

flu epidemic.

In Asia the fatality rate of bird flu in humans has been greater than

70%. It becomes transmissible within two days of infection (unlike

SARS), well before symptoms appear:

" Future flu epidemic 'controllable' through rapid vaccination

If a flu pandemic similar to the deadly one that spread in 1918

occurs, it may be possible to keep the pandemic in check through

vaccinations, a new study suggests. The infamous 1918 pandemic killed

up to 40 million people worldwide, but the virus strain was not

unusually contagious compared with other infectious diseases such as

measles, according to a new analysis by researchers at the Harvard

School of Public Health (HSPH). However, the 1918 flu was quite

lethal once contracted, believed to be 10 times more lethal than

other pandemic strains.

Epidemiologists analyzed historical epidemic data in 45 U.S. cities

and found that the transmissibility of the 1918 strain as measured by

the number of people infected by a single case was only about 2 to 4,

making the strain about as transmissible as the recent SARS

coronavirus. Because people with influenza can transmit the infection

before the appearance of symptoms, strategies for transmission

reduction, including vaccination, would need to be implemented more

rapidly than measures for the control of the recent SARS outbreak.

Isolation methods alone, such as those used for controlling SARS,

would not be effective.

The analysis, " Transmissibility of 1918 Pandemic Influenza, " by

Mills, doctoral student in the HSPH Department of

Epidemiology, and faculty co-authors appears in the Dec. 16 issue of

Nature.

World Health Organization officials have warned that we are closer

now to another pandemic than in any other recent time because of the

persistent bird flu epidemic in East Asia that threatens to jump to

humans.

" Our study suggests that if you could vaccinate a reasonable number

of people before exposure, a future flu epidemic could be

controlled, " said Mills. " But flu takes just a couple of days to

become contagious in a person, unlike the almost weeklong latency

period we experienced with SARS. Isolation would be only partially

effective. Rapid vaccination is essential. "

" Before this study, estimates were all over the map on the

transmissibility of pandemic flu, " said co-author Marc Lipsitch,

associate professor of epidemiology at HSPH. " Some thought it was so

transmissible that vaccines would be unlikely to stop it. This study

is optimistic, except we don't have the vaccine. It is now even more

important to put resources into the development of vaccine

technology, manufacture and distribution systems to make possible a

rapid response to the next outbreak of an entirely new flu strain. "

" This year we found out how bad our system is currently with the

contamination of flu vaccine at one manufacturer and the consequent

shortage, " said Lipsitch. " We are lucky this is happening in a year

when the flu is not so terrible. We need to have our manufacturing

system functional quickly. " "

Rodney.