The Threat From China's Pigs

In an outbreak reminiscent of the early stages of SARS and bird flu, pigs are growing sick and dying across China's southeastern Guangdong province. Roughly 3,000 pigs have been infected on hundreds of family farms and about 300 have died. Early reports from Chinese scientists attribute the outbreak to porcine respiratory and reproductive syndrome (PRRS), which first appeared 18 years ago and was originally called Mystery Swine Disease. But certain symptoms of the current outbreak, including massive hemorrhaging, are not consistent with PRRS, and might indicate that the disease—most likely caused by a virus—has mutated. The outbreak has renewed fears that a viral pandemic is in the making in southern China. Richard Webby, an influenza researcher at St. Jude Research Hospital in Memphis, Tenn., and Marie Gramer, a veterinarian and expert on swine influenza at the University of Minnesota, spoke by phone with NEWSWEEK's Barrett Sheridan on the risks of the recent outbreak, and China's response. Excerpts:

NEWSWEEK: Is an epidemic in pigs more dangerous to humans than one in, say, birds?
Richard Webby:
We think so. We think that if a virus does replicate in pigs it probably is adapted more toward humans.

Is China adequately responding to the outbreak?
Marie Gramer:
Although they have a few good laboratories, they don't have enough of them. They especially don't have enough of them where the pigs are. They have difficulty in getting timely, accurate diagnoses because of the lack of laboratories, lack of diagnosticians and lack of pathologists. So it doesn't surprise me that things are undiagnosed.

China has been criticized for being close-lipped during the early stages of the SARS and avian-flu outbreaks. Has that changed?
To China's credit, they are reporting more things to the OIE [the World Organization for Animal Health], which is the World Health Organization for animals, and trying to get things diagnosed, especially in the wake of SARS and bird flu and things like that. Since SARS, I've been seeing more reports from every country on what's going on with undiagnosed outbreaks. I think all countries are doing a little bit better reporting, and China's certainly trying to maintain a status as good reporter. They're cooperating.

How much should we be concerned about an outbreak like this one?
With the standard strains of flu in pigs there's not much of a concern because these viruses really are endemic [to the pig population] globally. It depends, of course, on what subtype [of influenza]. If it is an H5 [the same strain as bird flu], then yes, that is strange, and yes, that is a concern, and yes, the world needs to know about it yesterday.

Is there a danger of a pig epidemic such as this one jumping species?
There are a number of reports in the literature—and obviously many more not in the literature—giving examples of influenza viruses from pigs that have gone to humans and also the other way, influenza viruses from humans that have gone to pigs. Generally when it occurs, though, it's only a few cases. It never really spreads.

Gramer: Yes, that's a possibility with any disease in any animal. And the more animals you have dying, and the more contact you have with those animals, which increases the chance of it infecting the human taking care of those animals.

Is that the case in China? Do they have closer contact with their animals?
In China, [pigs] are very labor-intensive. [The Chinese] are hands-on with their pigs quite a bit. And as a source of food, everybody would have a pig and two chickens on their farms. From what I've seen and what's been reported by other people over there, there's a lot more intimate contact with your farm animals than there would be in the United States. And there's more swine in total.

What's the impact of poverty on a situation like this? Does that increase the risks?
We live in a country where we can afford, if a pig is sick or a pig dies, to not eat that pig. In China, if your pig died and your family was still hungry, you'd eat the dead pig, even though it might have been sick when it died. In [developed countries] we don't have a lot of food-borne diseases because we have an excellent safety inspection system and no sick animals can be consumed for food. That's a luxury we have that a lot of countries don't have.

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