Tennessee preps

Experts see conditions exist to foster flu pandemic

Published 09/10/2006 By J.H. OSBORNE

Second in a series

KINGSPORT - To become a pandemic influenza threat to humans, the avian (or bird) flu that has been making headlines around the world the last couple of years would have to mutate to a strain easily passed from one person to another.

It hasn't done that - yet - pandemic experts told local health officials last week.

"Human-to-human transmission with efficiency hasn't happened yet," said Dr. David Henderson, a Bethesda Md.-based epidemiologist.

He was among several pandemic experts who spoke Friday at a preparedness summit hosted by the Sullivan County Regional Health Department.

To date, there have been no confirmed cases of avian flu, in birds or people, in the United States, Henderson said.

But two major factors have federal, state and local health officials concerned and making preparedness plans: history tells us the world is about due for an influenza pandemic; and past pandemics had their roots in bird flu.

"That's how we got pandemics in the past," Henderson said. "Everything has happened except the efficient transmission from human to human."

Henderson said there has also been an increase in the incidence of bird-to-human transmission, most notably in countries in Asia.

Earlier this year, health officials reported human-to-human transmission of the bird flu among several members of a family in Indonesia, Henderson said.

That cluster of seven cases comprises the bulk of only nine, or maybe 10 at the highest, cases of human-to-human transmission of the virus on record, Henderson said.

That helps explain the World Health Organization's (WHO) current pandemic alert level of "phase 3," which signifies "little to no" reports of human-to-human transmission.‘MIXING VESSELS'

According to the Tennessee Department of Agriculture:

•Avian influenza viruses mutate rapidly. A mutation can cause an outbreak to shift from causing only mild illness in birds to causing rapid high mortality rates. A viral mutation during the course of an epidemic may also alter which species can be infected by the virus. Avian influenza is currently of concern because more than 100 people have been infected with the H5N1 virus over the past 2 years, resulting in 60 human deaths. However, avian influenza will not become widespread in people unless the virus gains the ability to be transmitted from person to person easily. When human or swine populations are infected by more than one strain of influenza virus at the same time, these non-avian species can serve as a "mixing vessel" for the mutation and spread of a strain that can be transmitted easily between humans.FLU TERMS DEFINED

According to the U.S. Department of Health and Human Services, on the Web site www.pandemicflu.gov:

•Seasonal (or common) flu is a respiratory illness that can be transmitted person to person. Most people have some immunity, and a vaccine is available.

•Avian (or bird) flu is caused by influenza viruses that occur naturally among wild birds. The H5N1 variant is deadly to domestic fowl and can be transmitted from birds to humans. There is no human immunity and no vaccine is available.

•Pandemic flu is virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person. Currently, there is no pandemic flu.

President Bush issued the National Strategy for Pandemic Influenza in late 2005.

Its stated intent is "stopping, slowing or otherwise limiting the spread of a pandemic to the United States; limiting the domestic spread of a pandemic, and mitigating disease, suffering and death; and sustaining infrastructure and mitigating impact to the economy and the functioning of society."

It gives the U.S. Department of Health & Human Services (HHS) the leading role in federal pandemic preparedness.

Earlier this year, Bush released an implementation plan for the strategy, outlining more than 300 actions for Federal departments and agencies and setting expectations for state and local governments.

In April, Gov. Phil Bredesen signed a planning resolution detailing HHS' and Tennessee's shared and independent responsibilities for pandemic planning.

Tennessee received nearly $2 million in federal funding for phase one for pandemic planning activities, and the state is scheduled to receive another $4.4 million.

Tennessee's state pandemic preparedness plan is