The hiss of the gas lamp and ping of an occasional tropical
beetle on its glass were the only sounds to break the
nightly hum of insects as Richard Johnson leaned back,
shaking his head. A fellow neurologist at Okapa ?eld
station in Papua New Guinea was some yards away, angled
over his beetle collection. Johnson rested the mimeographed
pages on his lap, his thoughts tethered only by the
fascination of the unthinkable: cannibalism.
It was 1964, and Johnson was far from being the authority
he is today on diseases caused by the deviant proteins
called prions—illnesses like mad cow or the lesser
known but equally fatal kuru that devastated New Guinea
in the ’50s and ’60s. But what he saw and
did as a new postdoc in that part of the world marked
the empirical approach—being there, seeing for
himself—that has since stood him in good stead.
For 40 years, he’s continued to land in the thick
of things, to cut to the necessary questions and help
plan minimal yet telling research. It’s given
him perspective on bizarre diseases. And now, it has
put him close to those who plan this country’s
approach to mad cow and its odd relatives.
Johnson had been in Australia on a fellowship, studying
the pathogenesis of herpes, rabies and mosquito-borne
viruses. But when his advisor, who headed the Papua
New Guinea Health Council, found the young researcher
packing for a canoe-based virus hunt in that country’s
swamps, he asked, “Dick, wouldn’t you also
like a week’s detour to see kuru while you’re
So Johnson found a bush pilot to drop him off in PNG’s
tropical highlands. “Harrowing is too kind a word
for that flight,” he says. “Imagine riding
a gnat.” But it was worth it to see, firsthand,
a disease he’d only read about.
By day, Johnson waded through yam patches to the hilltop
villages of the Fore natives. As was customary, he saw
patients in the public square who’d walked or
been carried there. Mostly women, they trembled and
shivered without pause. In the Fore tongue, kuru means
shaking. It causes loss of balance, dementia and, like
the other spongiform encephalopathies such as mad cow
disease, a sure death. The Fore typically died in six
months after symptom onset, believing, while they could
still think, that they’d been victims of sorcery.
“The situation was nothing short of astonishing,”
says Johnson. “In some villages seven out of eight
women would ultimately die. Kuru just annihilated the
By night, having little else to do, Johnson thought
about the disease. He agreed with New Zealander Richard
Hornebrook, the other neurologist there, who acted as
his guide, that kuru primarily attacks the brain’s
cerebellum rather than its basal ganglia. This was a
correction to the original 1957 disease description.
But those evenings, Johnson also read the field notes
and monographs that two cultural anthropologists, Robert
Glasse and Shirley Lindenbaum, had left behind after
living with the Fore. They’d been certain that
kuru spread via the ritual cannibalism that tribe members
practiced on the dead.
“I remember being absolutely stunned by the idea
of cannibalism,” says Johnson, “I’d
never seen anything tying it to kuru. But their data
were totally convincing!” Women ate the tainted
brain and other body parts, unlike men, who thought
such stuff would sap their strength. Kuru’s incidence
varied in the same way that who-ate-what differed from
village to village. Eventually, studies showed the disease
was indeed spread by cannibalism.
Today, Johnson is still caught up in the spongiform
encephalopathies. His opinions are sought widely. He
heads the nation’s foremost committee on the topic,
set up by the Institute of Medicine to advise Congress,
and he is representative neurologist on the FDA’s
committee. Since last December, when news of the first
U.S. “mad cow” got out, he’s also
been the voice for three government agencies, including
the NIH. One especially full week, Johnson’s grainy
bass voice graced all three of NPR’s news programs.
The next morning he was on NBC, mulling over Katie Couric’s
fear of frying—sausage, that is—then back
at his office to answer calls from reporters.
Richard Johnson in New Guinea
What’s odd, Johnson admits with his broad grin,
is that although every year in Hopkins’ neurology
clinic he does see several patients with the prion disease
Creutzfeldt-Jakob disease (CJD), he does no research
on prion diseases or the agents that likely cause them.
Why, then, is Johnson so often picked to play “Mr.
For one thing, he’s done masses of lab and clinical
work on infections of the nervous system. After serving
as director of neurology at Hopkins for almost a decade,
he stepped down in 1996 to help found the National Neuroscience
Institute in Singapore. Now, he edits the Annals of
Neurology. Colleagues speak of him as the “father
But as important, in the years since his session with
the Fore, Johnson has stayed pressed against the window
of prion disease work. He examined, for instance, the
animals that NIH researchers Carleton Gajdusek and Joe
Gibbs inoculated with the finely ground brains of kuru
victims—the required step to prove infectious
agents cause a disease.
“Joe called me and said, ‘A couple of them
might be coming down with kuru. Come see what you think.’
I had a look,” Johnson says. “It was uncanny
how similar the chimps were to the kuru patients I’d
seen. Their tissues looked identical.” All the
spongiform encephalopathies turn brains to lace.
Later, Gibbs and Gajdusek proved that CJD, like kuru,
could be infectious. The work gave Gajdusek a Nobel
Prize in 1976.
Still, says Johnson “nobody in the 1970s knew
about prions.” We thought the ‘unconventional
agents’ causing kuru, scrapie [the prion disease
of sheep] and CJD were mysteriously slow-acting viruses.”
But no researcher then, or now, has ever found viruses
or viral antibodies in humans or animals with these
It took an unknown named Stanley Prusiner to fan everyone’s
interest in prion disease. And it was Prusiner’s
bumpy scientific road that gave Johnson his reputation
as a level-headed observer.
Johnson had just finished a guest lecture at the University
of California, San Francisco, in the early 1980s when
Prusiner, a neurology resident at the time, approached
and asked him to lunch. Prusiner was a bright young
biochemist who groused, while they ate, about the lack
of scientific rigor in scrapie studies, about the slowness
at incubating the “unconventional agent”
in animals and, consequently, at the delay in identifying
it. “I’m going to change this whole field
by getting a rapid test,” he told Johnson. The
elder scientist encouraged him and the two became friends.
Prusiner did develop a quicker assay for scrapie, one
that used hamsters, which sicken faster than mice. He
also found a way to track characteristic brain changes
before the animals’ brain tissue grew spongy.
In April 1982, with unusually noisy fanfare (he’d
hired a PR agency) Prusiner reported in Science that
scrapie was likely caused by an odd protein—and
only a protein—making it the tiniest infectious
agent ever. Boil it, soak it in formaldehyde or alcohol,
subject it to UV light or X-rays—actions that
inactivate bacteria or viruses—and it’s
Prusiner named the protein a “prion,” for
proteinaceous infectious particle (with a vowel switch
for euphony). But he still hadn’t isolated prions.
Sitting wide-eyed on the first new principle of disease
in a century, he’d been desperate to publish.
But many scientists thought Prusiner’s speculations
on how the “organism” works were half-baked.
And the small band of mostly British researchers who’d
slogged for years looking for a slow, elusive virus
they believed caused scrapie must have dreaded missing
“That was enough,” Johnson remembers, “for
all hell to break loose. Editorials about the study
in Nature and The Lancet were scathing.” Many
science writers still consider an article about Prusiner
in the popular magazine Discover the most vitriolic
piece of our age about a scientist. It even included
guest bashings by Prusiner’s postdocs.
Johnson watched from afar: “Stanley didn’t
understand why people were so upset,” he says.
Prusiner also didn’t see that, in anger at what
they thought was a too-early, hyped pronouncement, some
scientists had begun discounting his results. Johnson
finally wrote an editorial in Trends in NeuroSciences
that quietly explained why Prusiner’s research
was sound. From a platform of sympathy for the unhappy
researchers, he zeroed in on what riled them most: that
Prusiner had had the gall to name the infectious agent
before he’d isolated it!
“As a traditional virologist,” Johnson
wrote, “I could question whether enough is known
to adopt a formal name.” But he reminded those
tempted to throw out the baby with the bath water that
Prusiner was still at work and had begun presenting
hard evidence that he had isolated prions.
Since then, Johnson has followed the work coming out
of the prion labs that have now sprouted in the United
States and—with mad cow the impetus for funding—across
Europe. His recent work on HIV neuropathology at the
NIH’s Rocky Mountain Labs in Montana puts him
literally next door to one of the other U.S. camps of
But Johnson still insists he’s called to the
policy committees in Washington because he’s knowledgeable
and doesn’t rile anyone: “I’m older
than most of these guys in research,” he says,
“and I know them well.”
To his fellow scientists, however, Richard Johnson
is a rare commodity: He’s seen it all and doesn’t
ON MAD COW
Q. Are fears of getting a prion disease here
A. The chance is minuscule. But
people are stirred because the diseases are 100 percent
fatal. Also, the long incubation period is frightening,
the time bomb idea. The thought that the sausage you
ate for breakfast could give you a dreadful disease
20 years from now isn’t a happy one.
Q. Is the real difficulty that we can’t
spot mad cow in live animals?
A. Right. Our usual live-animal
tests won’t work with prions because they’re
a self-protein gone wrong. Animals don’t produce
antibodies. And there’s no RNA. Still, it wouldn’t
be unreasonable to follow Europe: Check all downers
and all animals older than 30 months.
Q. What else would you advise?
A. We should watch what gets into
the grocery store. Obviously, you don’t process
brains and spinal cords. But gut and lymphoid tissue
are also infective. Get rid of it! I’d hate to
think what’s in scrapple. Also, we need to monitor
nutritional supplements. People are out there legally
selling raw ground cow brains as health pills!
Q. What worries you most?
A. Chronic wasting disease (CWD).
It’s a spongiform encephalopathy of wildlife,
mostly out West. Only a handful of people in this country
work on it. Mad cow is transferred by feed. There’s
no evidence of transmission from animal to animal. CWD
is different. It apparently crosses species, from mule
deer to regular deer or elk. Deer share pastures with
cattle and sheep. Scary? You bet.
Q. Is this country missing cases of mad cow
A. We could be. If we had a first-rate
autopsy system, we’d be better off. I feel strongly
we’re not going to learn if spongiform encephalopathies
exist here until we do autopsies on every person dying
of a chronic, degenerative nervous system disease.
Q. But isn’t a prion-disease epidemic
here unlikely because we’re aware now?
A. Just because you haven’t
seen something before, doesn’t mean it isn’t
possible. Just in the last few months, there’s
evidence CJD may be spread through transfusions and
that a second strain of mad cow has appeared. With these
diseases, you expect the unexpected.