Hi Elizabeth,
Just cleaning up my records, and came across your post.

> Could it be that the reason that a particular section of people
> get Parkinsons more then a different section, due to the lack of
> a standard medical system for all?  Is it that there are fewer
> Parkinsons people, or is it that there are the same percentages
> but many remain undiagnosed?

I was carrying out a document search for our PD Research Group, and found
some data in the World Health Organisation (WHO) epidemiological statistics
to be published next year. I quote below the relevant figures.

WHO Region              Incidence per 100,000
Americas                        10.00
Europe                          12.24
Eastern Mediterranean             3.96
South-East Asia                   3.44
Western Pacific                   2.50
Africa                            2.22

Level of Development    Incidence per 100,000
Developed                       16.52
Economies in transition           9.72
Developing                        2.98
Least developed                   2.38

The reasons for the disparity between, say, the Americas and Africa, can be
manifold. Some possibilities:

1. There is better data collection and reportage from developed economies.
2. There is a higher rate of diagnosis in developed economies.
3. There is a lower availability of medical services in less developed
economies.
4. There are environmental, genetic or cultural precursors that are more
prevalent in developed economies than in less developed economies.
5. There are environmental, genetic or cultural prophylactics pervasive in
less-developed economies.

In other words, the low rates may be:
1. Genuinely low, due to lack of causative agents, or presence of
protective factors.
2. Due to lack of data, because of inadequate reportage or diagnosis.

The higher rates may be
1. Genuinely high, due to presence of causative factors, or lack of
protective factors.
2. Due to misdiagnosis of similar conditions.

There is not enough differentiation in the raw figures to support any
conclusion, as the following factors can cloud the issue:
1. Is it predominantly a 'white' disease, since the populations of the
Americas and Europe are predominantly white? Do Asiatic and Negroid peoples
have protective genetic factors?
2. Is it a disease of advanced economies? Does diet play a part? Are
cultural differences an issue.
3. How would the figures vary if the US and Canada data were separated from
Mexico, Central America and South America?  If South Africa were separated
from the rest of Africa? If Australia and New Zealand were separated from
the Western Pacific? If separate figures from within countries were
obtained for ethnic or cultural groups?
4. Is poverty a factor?

Any theory advanced as to a cause or causes must take into account the fact
that PD was described in the early 1800's by James Parkinson, and was known
before then by the name Shaking Palsy.

The problems can be demonstrated by comparison with lead poisoning.

In Roman times, lead poisoning was a disease of the higher socio-economic
groups, who had water piped-in to their houses by lead pipes. (The 'plumb'
in 'plumbing' comes from the Latin 'plumbum', meaning lead.) The lower
groups had no piping, the middle group used pottery or wooden pipes and
utensils.

In the Middle Ages, it was a disease of the middle socio-economic groups,
who used pewter mugs and pewter plates. Pewter then was a 3:1 alloy of tin
and lead. (Modern pewter contains no lead. The upper groups used other
metals, the lower groups used pottery or wood.

In the Eighteenth and Nineteenth centuries, it became a disease of the
lower socio-economic groups, as they moved to lead pipes and pewter
utensils, while the more well-to-do moved to iron pipes and pottery
utensils.

In this century, lead poisoning is endemic where lead is used as a
constituent of petrol, or as a whitening agent in some paints.

So you can see that the problem, as well as being possibly multi-factorial
in terms of cause, has to be examined on a cross-cultural basis as well.

This is one of the factors our group is examining in its combined research
with our Chinese colleagues.  We carrying out an epidemiological study of
ethnic Chinese in mainland China, Hong Kong, and Sydney, Australia, both
indigenous and immigrant.

Factors being considered include diet, exposure to chemicals, environment
(eg, urban, rural, etc.), lifestyle, availability of medical facilities,
medications, genetic factors, etc.

So you can see the job is a big one for all of us.  Any discoveries that we
may make  will almost certainly not help those of us who are PWP's or
carers, as the correlation, interpretation and application of our data will
take some years to bear fruit. But we are buoyed-up by the knowledge that
we are kept alive in the present by the dedication of researchers in the
past, and the hope that current research may find answers for us in the
near future.

Jim

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 James F. Slattery, J.P., M.A.C.S.
 JandA Computing Consultancy
 E-mail: [log in to unmask]
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