1996 - The Island of the Colorblind (29 page)

60
A frightful picture of leprosy on Guam is to be found in Arago’s description of the Freycinet voyage:

A few hundred yards from Anigua are several houses, in which are kept lepers of both sexes, whose disease is so virulent that it commonly deprives them of the tongue or some of their limbs, and is said to become a contagious distemper. I have delineated two of these unfortunate creatures, exhibiting to the eye the most hideous aspect of human misery. One shudders with horror on approaching these houses of desolation and despair. I am persuaded, that by enlarging these paltry buildings, collecting in them all the persons in the island severely attacked by the leprosy, and prohibiting all communication with them from without, they might expel from the country this frightful disease; which, if it do not quickly cause the death of the patient, at least shortens his days, and perhaps leads him to curse them. (It is here called the disease of St. Lazarus.) What a scene, to behold an infant, a few days old, calmly reposing in the arms of a woman devoured by the leprosy, who imprudently lavishes on it her caresses! Yet this occurs in almost every house; government opposes no obstacle to it; and the infant, while sucking in its mother’s milk, inhales with it death and disease.

61
The rarity of Safford’s understanding and sympathy is brought out by comparison with the almost contemporary account of Antoine- Alfred Marche. The Chamorros, Marche reported,

…do not engage in any serious work…The indigenes today are intelligent but very lazy, proud, and dishonest, incapable of gratitude, and, like their ancestors, without any moral sense…All that is frivolous…attracts them…without limit or decency…One finds a few individuals who have learned how to benefit from our civilization, but they are the few.

62
The little village of Umatac is strangely peaceful, a backwater now – though there is a memorial to Magellan just outside town, remembering that momentous day in the spring of 1521 when he landed at Guam. For Julia Steele, a journalist and historian (and John’s daughter), the village is symbolic of that moment of first contact:

The more I thought about Umatac, the more I liked thinking about Umatac, this little town of such significance, a minor understudy thrust into a major role on history’s stage: the first spot where island and Western cultures had clashed, in the first of thousands of conflicts that would be played out time and again throughout the Pacific and bring with them a cataclysm of change in island societies. Just as the Indies had been for Magellan, from that point on Umatac became for me a concept, a vehicle for thinking about the world and its structure.

63
Though Lake Fena is the largest above-ground reservoir on Guam, most of the fresh water is provided by an exceptionally large water lens which floats above the saltwater aquifer underlying the northern end of the island. Fena is a manmade lake whose waters add to this supply. It is rumored that the lake was built as a ‘quenching facility’ to stop a chain reaction should an accident occur in the surrounding nuclear storage area.

64
In hindsight, John feels, it is far from clear whether these few non-Chamorro immigrants had true lytico-bodig or classic ALS or parkinsonism. But some of their offspring, half Chamorro, have gone on to develop lytico-bodig. And though Kurland could not pursue the genetic hypothesis with the technology of the 1950
s
, he and his colleague W.C. Wiederholt are now looking at the children of the Californian Chamorros, to see if lytico-bodig appears in any of them.

65
Kuru, a fatal neurological disease which had been endemic in the area for a century or more, could be transmitted, Gajdusek found, by the ritual practice of eating the brains of the dead. The disease agent was a newly discovered form of virus, a so-called slow virus which could remain latent in the tissues for years before giving rise to actual symptoms. The elucidation of kuru might not have been accomplished, one feels, had Gajdusek not combined a very sharp and sophisticated medical curiosity with a deep and sympathetic knowledge of the cultural beliefs and traditions of the indigenous tribes in the region. Such a combination of medical, biological, and ethological passions has underlain almost all of his work and has driven him to investigate geographical isolates throughout the world – not only the kuru and lytico-bodig in New Guinea, but the endemic goitrous cretinism, the cysticercosis with epidemic epilepsy, and the pseudohermaphroditism there; the muscular dystrophy in New Britain; the congenital orthopedic deformities in the New Hebrides; the Viliuisk encephalitis in Siberia; the hemorrhagic fever with renal syndrome in Korea; the genetic diseases of Australian aborigines; and dozens of others (during his 1972 expedition on the research vessel
Alpha Helix
, he paid a brief visit to Pingelap). Besides his hundreds of technical articles, Gajdusek has kept immensely detailed journals for the last forty years, which combine the hard science of his investigations with vivid evocations of places and people, and form a unique record of the life-work of one of the most extraordinary physician-naturalists of our time.

66
A very full discussion of the ecological disaster in Guam has recently been provided by David Quammen in his book
The Song of the Dodo: Island Biogeography in an Age of Extinction
. He describes how the native bird populations, which had been numerous and varied in 1960, were brought to the verge of extinction little more than twenty years later. No one at the time had any idea what was causing this:

Where had the birds gone? What was killing them? Had they been devastated by an exotic disease, as in Hawaii? Had they been poisoned by cumulative doses of DDT? Had they been eaten by feral cats and tree-climbing pigs and Japanese soldiers who refused to surrender?

It was only in 1986 that Guam’s ‘ecological murder mystery’ was solved and the bird-eating tree snake,
Boiga irregularis
, was proved to be the culprit. There had been a spreading explosion of these snakes, starting in the southern savannahs in the 1950
s
, reaching the northern forests by 1980, correlating precisely with the wave of bird extinctions. It was estimated in the mid-eighties that there were now thirteen thousand snakes to the square mile, three million on the whole island. Having consumed all the birds by this time, the snakes turned to other prey – skinks, geckos, other lizards, and even small mammals – and these too have shown catastrophic declines. Going with this there has been a vast increase in the numbers of orb-weaving spiders (I saw their intricate webs everywhere), probably due to the decline of the lizards. Thus the inauguration of what ecologists call a trophic cascade, the accelerating imbalance of a previously balanced ecosystem.

67
Lynn Raulerson had told me of something even rarer, an immense tassel fern,
Lycopodium phlegmaria
, which used to be common in the forest, but had now almost vanished, because most specimens had been poached for cultivation as house plants. Both this and the great ribbon fern are also to be found in Australia, and Chamberlain, while cycad hunting there, was fascinated by these and wrote of them in his 1919 book
The Living Cycads
:

The immense
Lycopodium phlegmaria
, the ‘tassel fern,’ with tassel-like cluster of cones, and
Ophioglossum pendulum
, the ‘ribbon fern,’ were the most interesting features of the epiphytic vegetation of the treetops. If a tree with such specimens was a foot or less in diameter the bushmen were likely to cut it down; if larger they would climb; but when they found that fine, uninjured specimens were worth three pence or even six pence, a climb of eighty feet was not at all objectionable.

68
It is sometimes said (the term goes back to Charcot) that patients with Parkinson’s disease have a ‘reptilian’ stare. This is not just a picturesque (or pejorative) metaphor; normal access to the motor functions, which gives mammals their delicate motor flexibility, is impaired in parkinsonism; this leads to alternations of extreme immobility with sudden, almost explosive motion, which are reminiscent of some reptiles.

Parkinson himself was a paleontologist, as well as a physician, and his 1804 book,
Organic Remains of a Former World
, is one of the great pioneer texts of paleontology. One wonders whether he may have partly regarded parkinsonism as an atavism, a reversion, the uncovering, through disease, of an ancestral, ‘antediluvian’ mode of function dating from the ancient past.

Whether or not this is so of parkinsonism is arguable, but one can certainly see reversion to, or disclosure of, a variety of primitive behaviors in post-encephalitic syndromes on occasion, and in a rare condition, branchial myoclonus, arising from lesions in the brain stem. Here there occur rhythmic movements of the palate, middle-ear muscles, and certain muscles in the neck – an odd and unintelligible pattern, until one realizes that these are the only vestiges of the gill arches, the branchial musculature, in man. Branchial myoclonus is, in effect, a gill movement in man, a revelation of the fact that we still carry our fishy ancestors, our evolutionary precursors, within us.

69
About five years ago, John became intrigued by the number of lytico-bodig patients with gaze palsies. His colleague Terry Cox, a neuro-ophthalmologist, confirmed this with further eye examinations and found that half of these patients also showed strange tortuous tracks in the retina (these cannot easily be seen with an ordinary ophthalmoscope, but only with indirect ophthalmoscopy – and thus would escape notice on a routine eye exam). The tracks seem to affect just the upper layer of retinal pigment, and to cause no symptoms.

‘This retinal pigmentary epitheliopathy,’ John said, ‘is confined to the Chamorros – it has never been observed in a Caucasian immigrant, or in Filipinos, who have lived here since the 1940
s
. It’s rare in anyone under fifty – the youngest person we’ve seen with it was born in 1957. It’s present in twenty percent of Chamorros over the age of fifty; but in fifty percent of those with lytico-bodig. We have been following patients who showed RPE in the early 1980
s
, and more than two-thirds of them have gone on to develop lytico-bodig within ten years.

‘The condition doesn’t seem to be progressive; it’s more like the scar of some trauma to the eye many decades ago. We wonder if it could be a marker for the lytico-bodig, something which came on at the same time as the disease – even though we are only picking it up now. We are checking now to see if there are any similar findings in patients with PSP or post-encephalitic parkinsonism.

‘The tracks have some resemblance to those made by the larvae of a botfly, but we don’t have any botflies on Guam. Maybe the tracks are made by the larvae of some other fly – perhaps one which transmitted a virus that caused the lytico-bodig. Or maybe it’s an effect of a toxin. We don’t yet know if it is unique to the lytico-bodig or not, or whether it is significant at all. But all these coincidences are tantalizing, and this is another thing that makes me think that the lytico-bodig could be caused by an organism, a virus – perhaps one transmitted by an otherwise unobjectionable parasite.’

70
The term ‘cynomolgus’ means, literally, ‘dog-milking.’ The Cy-nomolgi were an ancient human tribe in Libya. Why this name should be given to some macaques (which are also known as ‘crab-eating macaques’) is unclear, though John Clay suggests that a better translation might be ‘dog-suckling,’ as macaques may indeed suckle other animals.

71
There was one report in a Japanese journal in the 1920
s
regarding an unusually high incidence of bulbar palsy in Saipan, though it is unclear whether this could have been a manifestation of lytico. Of the fifteen cases of lytico-bodig in Saipan described by Gajdusek et al., all but two had been born before the First World War and the youngest had been born in 1929. In several cases, according to John, the parents of these patients had been born in Guam or Rota.

72
Research on cycad neurotoxicity, somewhat dormant since the 1960
s
, has again become very active in several places. Tom Mabry and Delia Brownson at the University of Texas at Austin are working on the relation between cycads and lytico-bodig, looking at the effect of the putative Guam neurotoxins on rat brain-cell preparations. And Alan Seawright at the (Australian) National Research Centre for Environmental Toxicity has been investigating the effects of MAM and BMAA in experimental animals.

73
Zhang and his colleagues, re-examining the geographic variation of lytico-bodig on Guam over a twenty-year period, have confirmed the very close correlation of local cycasin levels with the disease. But such ‘correlations,’ they point out, however close, do not necessarily imply a simple cause-and-effect relationship. Though there are rare forms of Alzheimer’s disease, Parkinson’s disease, and ALS with a simple Mendelian pattern, these are the exception and not the rule. Ordinary Alzheimer’s, Parkinson’s, and ALS, it seems, are complex disorders in which the actual expression of disease is contingent on a variety of genetic and environmental factors. Indeed we are now discovering, as Spencer points out, that such gene-environment interactions are involved in many other conditions. Thus a rare but terrible side effect of streptomycin – which was introduced for the treatment of tuberculosis, but caused a total and irremediable nerve deafness in some patients – has now been found to depend on the presence of a mitochondrial DNA defect that gives no hint of its existence unless streptomycin is given.

A variety of disorders, sometimes familial but lacking the usual Mendelian patterns of inheritance, may arise, similarly, from mutations in the mitochondrial DNA. This seems to be the case in a rare syndrome in which deafness is combined with diabetes, nephropathy, photomyoclonus, and cerebral degeneration (this syndrome, or a very similar one, was originally described in 1964 by Herrmann, Aguilar, and Sacks). Mitochondrial DNA is transmitted only maternally, and Wiederholt and others have wondered whether, in the critical period between 1670 and 1710, when the Chamorro males were virtually exterminated and the population reduced, in effect, to a few hundred females, such a mitochondrial mutation may have arisen and spread in the generations that followed, especially in certain families. Such a mutation may have sensitized those in whom it occurred so that otherwise benign environmental agents might, in them, set off the fatal degenerative processes of lytico-bodig.