Bovine spongiform encephalopathy from India?

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Hi All,

Articles relating to the below are pdf-available and suggest that bovine

spongiform

encephalopathy (BSE) originated from India.

Did BSE in the UK originate from the Indian subcontinent?

Susarla K Shankar and P Satishchandra

Lancet, 366, Iss 9488, Sept 3-9 2005, 790-791

In today's Lancet, Alan and Colchester1 put forward a scientific

hypothesis

that bovine spongiform encephalopathy (BSE), which has affected mostly the UK

and to

a lesser extent European dairy cattle, is the result of feeding vegetarian

animals

with an imported carnivorous diet. They further hypothesise that imported

meat-bone

meal from the Indian subcontinent was contaminated with human carcasses infected

with Creutzfeldt-Jakob disease (CJD).

BSE has occurred in imported and indigenous cattle of several countries other

than

the UK.2 and 3 The origin of such cases has been attributed directly or

indirectly

to the export of infected cattle or infected meat-bone meal from countries with

BSE.

The incidence of the epidemic in most European countries where efficient

surveillance or monitoring systems are in place implies indigenous exposure

rather

than direct linkage with imported cattle feed. Epidemiological studies in the UK

have revealed a greater risk of developing the disease in the offspring of

clinical

cases of BSE (although risk perception has been downgraded recently on the basis

of

estimates and extrapolations).4

The probable spread of disease to human beings manifested as variant CJD has

been

proposed to be due to molecular similarities of the disease-related isoform of

abnormal prion protease-resistant protein (PrPres) from human patients and

certain

animal species with naturally acquired or experimentally transmitted BSE. The

biological behaviour of transmissible spongiform encephalopathy strains during

their

transit from one species to another and their adaptive behaviour when passed

into

secondary species from the primary source is still to be elucidated. It is

appropriate and important to address all sources of meat-bone meal imported to

the

UK, from the Indian subcontinent and other countries, which could have

contributed

to the so-called human disease being transmitted to cattle by contaminated

cattle

feed. This broad analysis is vital for a better understanding of the evolution

of

this disease.

The Colchesters assume the prevalence of sporadic CJD to be uniform worldwide.

However, one should also consider the role of geographic variations and genetic

polymorphisms (panel). To date, India has had 85 recorded cases of sporadic CJD

reported over the past 37 years.5 and 6 In India, all clinical and pathological

specimens (biopsies and autopsies) are referred to the CJD Registry at the

National

Institute of Mental Health and Neurosciences, Bangalore, India. When the

diagnosis

is suspected, relatives are persuaded to undertake deep burial or cremation,

respecting religious sentiments. Most Hindus do not eat beef, except for a few

specific communities in India. Histopathologically verified CJD has been

observed in

vegetarians, suggesting that their disease belongs to a sporadic variant of CJD

unrelated to dietary habits.

Panel. A few ground realities

• 85 cases of CJD have been recorded over past 37 years (1968–2005)5 and 6

(definite

40, probable 45 cases, according to Master's criteria).7 85 cases in population

of 1

billion (0·085/million) is less than 0·5–1·0 in a million population worldwide.8

The

CJD registry was established at National Institute of Mental Health and

Neurosciences in 1988. Nationwide survey was done with predesigned comprehensive

questionnaire (32% of cases aged 55–65 years; 25% of cases aged 35–45 years).

Ten of

25 cases where dietary history was available were vegetarians.

• The Registry confirmed cases by immunohistochemistry on brain tissues from

suspected cases of CJD.9 No case of iatrogenic CJD or variant CJD has been

reported

from India.

• No case of BSE has been recorded from India. Five Regional Disease Diagnostic

Laboratories in India did surveillance for Ministry of Agriculture, Department

of

Animal Husbandry Dairying, New Delhi, from 2001 to 2004.10 Cattle and buffaloes

from

slaughter houses and fallen animals (ailing cattle with neurological deficits

and

dead are screened, and have been found negative for BSE).10 No case of scrapie

has

been identified from India (except for one anecdotal case).11

• Indian meat exported to international markets is declared safe by Organization

Internationale Des Epizooties on Animal and Animal Product Trade. It is

difficult to

obtain official information about export and import practices and magnitude

during

1960–80 from India.

By the Colchesters' extrapolation, 150 deaths in India are related to CJD. In

most

of the hospital-related deaths, the bodies are not taken to Varanasi, the holy

city

on the banks of the Ganges in North India, but cremated or buried in community

burial grounds. Even in Varanasi, most Hindus do not put half-burnt bodies into

the

river. The Colchesters have drawn heavily from pictures on the internet and

other

sources.12 A human body put into the river undergoes substantial putrefaction,

unlike fallen cattle. No study has been done to establish whether or not

putrefied

human cadaver brain and spinal cord tissue from the Ganges contains CJD, and

experimental transmission from this human source into animals has not been

attempted. Successful transmission by feeding animals with this purportedly

infective tissue seems unjustified, especially as pooling with other animal

protein

would have occurred in the meat-bone meal exported to the UK, and could

conceivably

result in an enormous and unspecified dilution that would greatly reduce

infectivity. One approach would be to characterise the PrPsc (the

disease-causing

protein) strain from the brains of CJD cases in India and show homology with

PrPsc

in the afflicted British cows. If the bodies found in the Ganges were found to

have

CJD, there should have been a major epidemic in north India.

So far not a single case of BSE or scrapie has been reported from India, except

for

one case of scrapie from the Himalayan foothills in a sheep, which was probably

imported.11 In India, the prevalence of CJD spreads far beyond the banks of the

Ganges. Scientists must proceed cautiously when hypothesising about a disease

that

has such wide geographic, cultural, and religious implications. We agree that

the

idea proposed by the Colchesters needs to be probed further. Facts to support or

refute their hypothesis now need to be gathered with urgency and great care.

Refers to: The origin of bovine spongiform encephalopathy: the human prion

disease

hypothesis, The Lancet, Volume 366, Issue 9488, 3 September 2005-9 September

2005,

Pages 856-861

Alan CF Colchestera, , and TH Colchesterb

SummaryPlus | Full Text + Links | PDF (81 K)

Referred to by: The origin of bovine spongiform encephalopathy: the human prion

disease hypothesis, The Lancet, Volume 366, Issue 9488, 3 September 2005-9

September

2005, Pages 856-861

Alan CF Colchestera, , and TH Colchesterb

SummaryPlus | Full Text + Links | PDF (81 K)

Al Pater, PhD; email: old542000@...

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