The case of a man in his seventies that may have contracted sporadic Creutz feldt-Jakob disease (sporadic CJD) in southern Taiwan could be causally related to atypical Bovine Spongiform Encephalopathy (BSE, also known as mad cow disease), a psychiatrist said yesterday.
The Centers for Disease Control (CDC) on Thursday announced a new possible case of the disease was identified by the Taiwan Neurological Society’s Task Force on CJD.
According to the center there have been 279 cases deemed highly probable or confirmed out of the 456 cases of suspected CJD identified in Taiwan since 1996, adding that out of these cases, 274 of them were thought to be sporadic CJD.
The CDC stressed that sporadic CJD differed from variant Creutz feldt-Jakob disease (vCJD), which is related to mad cow disease and that the average annual occurrence of CJD in Taiwan in the past decade was about 0.5 to 1 per million, which is about the same rate as in other countries.
However, citing academic research reports from different countries, psychiatrist Su Wei-shuo (蘇偉碩) said “the CDC should at least tell the truth about the possibility of sporadic CJD caused by mad cow disease.”
According to Su, animal experimental research published in England in 2002 indicated that sporadic CJD in humans may be caused by mad cow disease, and a cross-national research paper published in 2004 discovered that atypical BSE had molecular similarities to sporadic CJD.
Another research report published in the US in 2006 suggested conducting an epidemiological investigation on the correlation between sporadic CJD and atypical mad cow disease, he said, adding that an animal research experiment in 2008 also showed the transmission of atypical mad cow disease to a primate with biochemical symptoms similar to sporadic CJD.
“It is very likely that sporadic CJD is caused by atypical mad cow disease,” Su said.
“It is also highly possible that sporadic CJD in humans has been caused by ingesting infected food in the past or by other means,” she added.
CJD is an incurable and fatal disease, which can be vertically transmitted from mother to infant and horizontally transmitted through blood transfusion. It can have very long incubation period of 10 to even 50 years, depending on the type of CJD, Su added.
“We should be more cautious in clarifying the relationship between mad cow disease and the two types of CJDs and in analyzing the risk of US beef ingestion,” he said, adding that the government should not mislead the public by denying a possible causal relation.
In response, CDC Deputy Director-General Chou Jih-haw (周志浩) said: “It may be because there are limitations in each research paper that so far there is not sufficient evidence to prove there is a causal relation between mad cow disease and sporadic CJD.”
“But the WHO as well as other countries will give warnings if they find sufficient evidence,” he added.