TOPICS > Health

The Hong Kong Flu

December 16, 1997 at 12:00 AM EDT


PHIL PONCE: That new flu is a virus never before seen in humans and one which apparently was transmitted to humans by chickens. But scientists now worry the virus is being transmitted by humans. While the outbreak in Hong Kong is still in early stages, the fear of a possible epidemic is prompting the medical community to take action. For more were joined by Dr. David Heymann, director of emerging and other communicable diseases for the World Health Organization. Welcome, Dr. Heymann. Again, a small group of people in Hong Kong. Why is it that the world’s health community is so interested, so concerned?

DR. DAVID HEYMANN, World Health Organization: Well, Phil, this is a new virus in humans. This is the first time, as far as we know, that this virus has entered the human population. And whenever a new virus enters a human population, we’re worried. We need to find out what’s going to happen now that humans are infected.

PHIL PONCE: It’s a new virus, and yet, what does the world scientific community know about it so far?

DR. DAVID HEYMANN: Well, what we know is that this is a very lethal virus, not only a lethal virus in poultry but also in humans. Two of the first four cases have died from the disease, and now we have two people who are on ventilators with the disease in Hong Kong. So it’s a disease which appears to be more lethal than the usual influenza.

PHIL PONCE: And as far as symptoms go, are they similar to what–the kind of flu that most people are familiar with?

DR. DAVID HEYMANN: Absolutely. These are the same symptoms–the high fever, muscle aches, just feeling very bad, and then developing influenza.

PHIL PONCE: And how did it come to people’s attention? Where did it come from? When was it first noticed?

DR. DAVID HEYMANN: Well, throughout the world there’s a series of laboratories which are constantly monitoring influenza, under 10 laboratories throughout the world. And these laboratories monitor cases of influenza. In Hong Kong back in May they isolated from a patient with influenza who died a new virus, the H-5 N-1 virus, which is the same virus that has infected poultry and was first identified in 1961 in Turns in South Africa.

PHIL PONCE: Turns being a form of bird.

DR. DAVID HEYMANN: That’s correct, yes.

PHIL PONCE: Reports today indicate that two cousins of somebody who had been previously infected presumably by exposure to a chicken, that these two cousins now may have this virus. Do you believe now that it’s being transmitted from human to human?

DR. DAVID HEYMANN: Certainly, this is more concern that there might be human to human transmission, but these two people, these two cousins could have also been exposed to the same source of the virus, and, therefore, been infected at the same time, because they’ve fallen ill within five days of each other.

PHIL PONCE: But is that the key concern, just how communicable this virus might be from person to person?

DR. DAVID HEYMANN: That’s right. If this virus is very communicable from person to person, then we’ll see it spread rapidly throughout Hong Kong, and with international travel, it will spread farther. What we know, though, is that hospital workers who have taken care of patients during this period have not themselves become ill with the disease. Some have become ill, and they’ve been put under observation, but they’ve not been ill with the virus, itself.

PHIL PONCE: Most of the people who’ve gotten the virus to date have been children. Why is that?

DR. DAVID HEYMANN: That’s a good question and that we can’t answer. That’s some of the questions that must be answered in what’s called an epidemiological investigation. We need to know who is at risk of this disease, why is it coming from animals to man? Will man pass it from man to man?

PHIL PONCE: What about this 11-year cycle that viruses sometimes seem to follow, could you tell us about that?

DR. DAVID HEYMANN: In recent years there have been influenza pandemics; that is, influenza epidemics that have covered the whole world every eleven to fifteen years. In 1958, for example, there was an epidemic of Asian flu. Then in 1968, there was an epidemic of Hong Kong flu. Then, as you know, in 1976 here in the U.S. there was fear that flu had crossed the barrier from pigs into man, and that there might be an epidemic of what was called swine flu, and measures were taken, vaccines were developed, and people were immunized in the hopes of preventing an epidemic, which never did occur. But at least the population was prepared.

PHIL PONCE: And in that case you talk about with the swine flu, there were–the epidemic did not happen, and yet, some people suffered some adverse consequences as a result of the vaccination.

DR. DAVID HEYMANN: That’s right. People who were vaccinated, a certain number of those people developed a paralysis after vaccination, what’s called Gionne Beret Syndrome, related to the vaccine.

PHIL PONCE: So what’s being done with regards to this virus in terms of a vaccine?

DR. DAVID HEYMANN: Well, this virus is a very lethal virus, and, therefore, it can’t be grown on eggs, which normally viruses grow on to produce vaccines. So we’re doing–the scientific community is doing what now is called looking for a reassortment; that is, a virus which will grow on eggs, so that a vaccine can be prepared. The virus is being manipulated to see if we can make it grow on eggs. And if that’s the case, then this will serve as a seed virus to develop a new vaccine.

PHIL PONCE: And how long might that take?

DR. DAVID HEYMANN: Well, we hope that by January, early January, this reassortment will have been found, and then it would fit into the actual normal cycle for preparation of influenza vaccines because each year in February there is a meeting which determines what strains of influenza should be put into the vaccine, and this is the time when this new reassortment will be available and can be put into vaccine.

PHIL PONCE: But typically, the lag period for the introduction of a new vaccine is what, about six months or so?

DR. DAVID HEYMANN: That’s right. The lag period is six months, and right now we are working with industry to see what the minimum amount of time could be. This is called pandemic preparedness, trying to find out what the minimum time will be for development of a new vaccine.

PHIL PONCE: So for those people who’ve already had a flu vaccine this season, what do you say to them?

DR. DAVID HEYMANN: Those people are protected from what we know will be an epidemic this year, from the strains of virus which will cause an epidemic this year. What we don’t know is if this new strain will also cause an epidemic.

PHIL PONCE: So if one has been–if one has already received a flu vaccine, that’s for a strain that people were already familiar with in the past, not for this one.

DR. DAVID HEYMANN: That’s correct. This is a new strain. We need to develop a new vaccine.

PHIL PONCE: What exactly constitutes a pandemic, or an epidemic?

DR. DAVID HEYMANN: A pandemic is a disease which starts localized and then spreads worldwide, a very simple definition.

PHIL PONCE: In this case how concerned should people in this country be about what’s happening in Hong Kong?

DR. DAVID HEYMANN: People should be very concerned and make sure that the laboratories in the U.S., which are supporting the investigations in this outbreak, are supported. And those laboratories are the Centers for Disease Control in Atlanta and St. Jude’s Hospital in Memphis.

PHIL PONCE: You’re coordinating some of those, at least they’re reporting to you. Are you satisfied those laboratories and sufficient resources are being committed to this?

DR. DAVID HEYMANN: Yes. Every day we’re sending more teams out to look not only at the human disease but also disease in poultry in neighboring Canton, because we know that that’s where they’re having epidemics in poultry. And we know that poultry from that area are coming into Hong Kong for sale.

PHIL PONCE: Dr. Heymann, thank you very much.