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Transplants from animals raise question of spreading disease
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Text 2
Exercise 1. Read the text:
Transplants from animals raise question of spreading disease
In 1993, an official with the Centre for Disease Control and Prevention (CDC) called a few employees into her office and asked the question: What was the CDC doing about the risk that animal-to-people transplants might introduce new germs into the human population? 'My first reaction was - nothing, ' recalled Louisa Chapman, an expert on animal viruses that infect humans. Transplants from animals were so rare and recipients lived so briefly that it didn't seem a threat. ' But as she looked into the situation, she changed her mind. Interest in xenotransplants was heating up. Animals could not only ease the shortage of kidneys, hearts and livers for transplantation, but also supply brain tissue for treating diseases like Parkinson's. These days, drug and biotech companies have poured more than J100 million into xenotransplant research. Scientists report progress in overcoming rejection of animal organs. But the concern Chapman heard in that 1993 meeting has not gone away: Would xenotransplants give new germs a sneaky entree into the human population? In March, scientists at the Institute of Cancer Research in London reported that a virus - one that might be found even in healthy pigs - sprang out of pig tissue and infected human cells in a lab experiment. That showed that the idea of such infection in a pig-to- human transplant 'is more plausible than a fanciful scare story, ' the researchers said. And federal regulators in the United States are now refining draft guidelines to minimise the risk to public health. Here's why Chapman and others say there's reason to worry:
• Animals do have germs that can infect people and then spread from person-to-person.
• The AIDS virus apparently came from monkeys long ago.
• Dangerous germs can hide in healthy-looking animals.
• People getting animal organs would be on drugs to suppress their immune systems. • Genes from an animal virus could mingle with those of a human virus, creating a hybrid virus with unpredictable behaviour.
• Keeping animals isolated from infection may not be enough. Some viruses aren't caught, they're inherited. They're just part of being a pig, for example.
So far, however, the limited experience with xenotransplants is encouraging. Dr Alan Dimick, who's put pigskin on severe burns since 1970, says there's no evidence treatment has infected anybody with pig germs. But Dimick notes that pigskin stays on for only a day or two. An implanted organ might pose more of a risk, he said. For instance, transgenic pigs may provide donor organs for humans.
Dr dames M. Schumacher, a neurosurgeon who has put foetal pig tissue into the brains of a dozen people with Parkinson's or Huntington's disease over the past two years, also reports no sign of infection. 'We are extremely overzealous about studying these effects and looking for viruses in the long and short run, and we haven't to date found any problem, ' he said. While scientists ponder the risk of xenotransplantation, thousands of people die each year because they can't get a human organ. It's a difficult issue, ' said virus expert Jonathan Allan. There are people dying. You want to do everything possible to prevent that. But you certainly don't want to foster new infectious diseases that would make even greater suffering in the population. '
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Exercise 2. Answer the questions to the text.
1. What was Louisa Chapman’s first reaction to the risk of animal transplants?
2. Why did she feel animal transplants weren’t a threat?
3. Why did she change her mind?
4. How could animal transplants be used?
5. What are the possible dangers of animal to human transplant?
6. What is Dr Schumacher's opinion?
Exercise 3. Answer the questions and give your own ideas based on your knowledge.
1. How can people be encouraged to become organ donors? For what reasons might people not wish to donate their organs?
2. Pigs are now being genetically manipulated to carry human genes. Do you think this is ethical? Why, why not?
3. What possible alternatives do you think there are to using animal transplants?
4. Having read the article, do you think animal transplants seem too risky? Why, why not?
5. Who should make the decision to go ahead with research into animal transplants - doctors, lawyers, politicians?
6. Most research is being done by commercial. pharmaceutical and biotechnology companies. One estimate suggests a potential market of $5 billion for sales of drugs associated with animal transplants. Do you think other organisations should be doing the research? Why, why not?
7. In what other ways do animals help the advance of human medicine? Should we continue to use them? Do animals have any rights themselves?
8. Would you be happy to receive an animal’s organ if you were seriously ill?
9. What animals are used as donors and what for?
10. What social and ethical problems do you think animal transplants raise?
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