What are you going to say to the astute patient who wants to know
whether their prion gene codes for methionine or valine at position 129, or to
the anxious person who wants the answer before they accept a blood transfusion,
graft, embryo, or organ? If you don't understand the question you didn't see this
two part Horizon special. Whatever you do, don't mention "cost," "can t," or "no
risk," particularly if the patient is a sheep breeder who has just used a similar
test on a ram. I presume that transferable human products are already being
screened, for if there is one message in this documentary it is that scientists,
portrayed in goldfish bowls, chain mail, white coat, and wellies but protected
most of all by knowledge have a duty to make this available to the meat mincing,
burger munching, public. Professor Richard Southwood (who appears in this
documentary), and his government working party on bovine spongiform
encephalopathy (BSE) had the opportunity to do this but favoured "not being
alarmist and upsetting the beef industry" whereas Professor Richard Lacey (who
doesn't appear) came over the hillside with a bugle only to find that the cavalry
were all cowboys. Science didn't "fail to predict" the transmission of BSE to
people; as the programme suggests. some scientists allowed hope and politics to
dominate reason, hypothesis, and experimentation.
The first programme, BSE:
the invisible enemy, set the scene with poignant, monochrome footage of women and
children with Kuru and cattle with BSE. Infected nervous tissue rises from a -70
degree mist, and is planted, sliced, autoclaved, irradiated, and given waiter
service by scientists against a variety of backdrops - microscopes, computers,
and appropriately sitting on a fence. BSE is good television and sausages,
sonatas, silence, and computer simulation are used to maximum effect. The prion
theory is given skilful coverage and the paradox of an infectious protein
explained in detail. Micro-organisms that live in volcanic conditions and
scientists who took almost 20 years to identify the Herpesvirus associated with
Kaposi's sarcoma may smile quietly at the dismissal of a conventional infectious
agent. Transgenic mice needed a mention but there was little indication of their
contribution. Just as the programme seemed to be losing its thread it reached
March 1996 and "New variant Creutzfeldt-Jakob disease."
The second programme,
BSE: the human experiment, describes the intensive search and identification of
new variant CJD, the rapid process by which its findings were conveyed to an
"astonished and gasping" Spongiform Encephalopathy Advisory Committee and the
British public but apparently not to a close relative of one of the 14 cases.
Faced with an epidemic the questions cascaded from "could it?" to "how big would
it be?" We hear estimates of the number of cows consumed before the specified
offal ban and the "surprise, grave concern and horror" that the ban was not being
implemented correctly. John Snow would have waved his pump handle angrily. Where
was the consistency in the message? The British public and its abattoir workers
were assured that there was no link between BSE and CJD and then asked to carry
out a difficult and thankless task apparently to satisfy the "balmy brigade" and
the Germans. If anyone should be "horrified" it is the people who were asked to
remove the bovine CNS with a rubber apron, marigold gloves, and cloth cap for
protection.
But this is a programme about the future, about the public health
sciences of prediction and risk, so poorly utilised in this epidemic to date, and
the home turf of medicine, treatments. An eloquent dental student gives a brave
and vivid description of the clinical signs of CJD in her 18 year old brother and
with the audacity of youth poses key questions: "Why him and not me?" "How are we
going to care for each affected individual in the future?" She might have also
asked if this variant CJD really was new. What position would CJD have been on
the list of differential diagnoses of a disturbed 18 year old in 1980?
Television is about images and the programme finished with a steeplechase
anatomy review in tomography, endoscopy, fluoroscopy, and a soundtrack of
speculation. A key issue in evaluating the risk to people has always been dose
and species barrier. A disturbing feature of the BSE agent is that it seems to
like the oral route and with the question of the dose required to infect people
the images shift from sausages to steak. We are presented with depressing flashes
of the chief veterinary officer in denial and the reassuring picture of the
veterinary epidemiologist who has led the team from the Ministry of Agriculture
Fisheries and Food over the past 10 years.
Looking relaxed after what must
have been intense pressure, his work now validated by an independent source, he
sits on a straw bale in shirt sleeves and tan slip on shoes and tells us that a
gram of brain can infect a cow. It's worrying but should draw not a gasp of
horror but a sigh of relief. In being able to talk freely about his work he
signals that this McCarthyite era of British veterinary and medical science, that
spawned one of the biggest experiments on a human population, is over. This
disease is at last open to rational scientific investigation.
KENTON MORGAN,
professor of epidemiology,
Faculty of Veterinary Science,
Liverpool University
From a
less complicated time: former agriculture minister John Gummer feeds his daughter
a hamburger to allay public disquiet about BSE