Blood Transfusion Blamed for Second 'Mad Cow' Infection in Humans
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This is Gwen Outen with the VOA Special English Health Report.
Blood [A]transfusions[/A] can save lives. But they can also spread [A]diseases[/A]. Researchers believe this is how at least two people in Britain became infected with the [A]human[/A] version of mad cow disease. They say the cases appears to [A]confirm[/A] that eating beef from an infected cow is not the only way the disease can [A]spread[/A].
The first case [A]was reported[/A] at the end of last year; the second was reported earlier this month in the magazine The Lancet. The second [A]patient[/A] had received a blood transfusion five years ago. The unidentified person was one of seventeen known to have received [A]blood[/A] from people who later developed vCJD. The full name is variant Creutzfeldt-Jakob disease.
The disease attacks the brain and [A]central nervous system[/A]. But in this patient, the infection had not spread to those areas. In fact, the report says the elderly person never [A]developed[/A] signs of the disease. The patient died of unrelated causes. Tests later found the [A]infection[/A] in the spleen.
Scientists say the finding suggests that a larger [A]population[/A] of people could become infected. And here is why:
The human [A]genetic map[/A] comes in different versions called genotypes. This patient had the most common genotype in the British population. One hundred fifty deaths from the human form of mad [A]cow disease[/A] have been reported worldwide. But so far, there have been no such cases in people with this common [A]genotype[/A].
James Ironside is an investigator with the CJD Surveillance Unit in Edinburgh. He says [A]infections[/A] might take longer to appear in people with this genotype.
The evidence also suggests that people without signs of the disease could still carry the [A]infection[/A]. And they may be able to pass it to others.
In cows, the official name of the disease is bovine spongiform [A]encephalopathy[/A]. Holes form in the brain. Researchers say the disease is caused by prions, proteins that are [A]deformed[/A] and infectious. No cure is known. But French scientists reported in The Lancet that they have [A]identified[/A] a new way to clean prions off of medical devices.
Also, American scientists reported on a method used in Britain to try to make blood safer for transfusion. White blood cells are [A]removed[/A] to lower the risk of the human form of mad cow disease. But the [A]researchers[/A] say animal tests found that the risk is reduced by only about forty percent.
This VOA Special English Health Report was written by Cynthia Kirk. This is Gwen Outen.
