Prof: What I want to do this morning is first of all
begin by recapitulating a couple of points that we made last
time.
You'll recognize our friend here, having her blood feast,
and last time we talked about the importance of malaria in
human history for a little bit, from ancient times to the
contemporary world, and we tried to suggest that
malaria continues to impose an extraordinary burden of
suffering and death, along with those consequences
that follow in its train: poverty,
low productivity, illiteracy, a low level of
political, social and education
participation.
We also talked, as you'll remember,
about the transmission of the disease, with the complex
lifecycle of plasmodia and Anopheles mosquitoes.
We talked about the effect of the disease on the human body of
the patient and symptoms that result from malaria,
and we tried to deal also with the great years of discovery at
the end of the 1890s, between 1898 and 1901,
when the great mysteries of this disease were largely
unraveled in two different places.
First in India, with the collaboration of
Ronald Ross and Patrick Manson, they demonstrated the mosquito
transmission of malaria with regard to avian malaria--
that is, among birds.
And then the other place, even more importantly,
was Italy, where Giovanni Battista Grassi and other
scientists of what was called the Italian School,
or the Rome School, proved the mosquito theory of
transmission for human beings.
I hope that in that discussion, it was apparent to all of you
that malaria is by far the most complex of all the diseases that
we've studied, or will study, in our course.
And that point is important and underlies the fact that we spent
a lot of time talking about the complexity of the disease.
It's important because it helps us to understand a great deal of
the history.
One point is that if we understand that,
we're in a position to understand also why research on
malaria generated such intense intellectual excitement in the
1890s.
It was then that malariology because the centerpiece for the
new medical discipline of tropical medicine.
Here was one of the world's oldest and most important public
health problems, and suddenly it was yielding
its secrets.
There was a tremendous excitement intellectually,
and malariology attracted some of the world's leading
scientists and public health officials.
We also wanted to talk about the complexity of malaria,
because a second reason is that it helps us to understand why
the public health strategies that we've examined so far
haven't worked in dealing with malaria.
If we think, for example,
what are the main public health strategies that we've discussed
so far--one was plague measures.
You know the drill by now: sanitary cordons,
quarantines, isolation.
These, however, prove to be powerless against a
disease that's borne by vectors as efficient and mobile as
Anopheles mosquitoes.
In high malarial endemicity areas, mosquitoes are infinitely
numerous and infinitely mobile.
Plague measures would be no help at all.
We can understand also why another form of public health
was useless.
The sanitary movement was irrelevant.
Malaria is not like cholera.
It's not a disease of filth or the bacteria that thrive in it.
Places that are immaculately clean can be lethally infested
with mosquitoes and the plasmodia that they bear.
Furthermore, malaria is a disease of rural
areas, primarily, and urban cleanups were
therefore largely irrelevant in combating it.
So, a second strategy of public health that we've confronted so
far was powerless in dealing with this disease.
Another public health strategy that we've examined was the
strategy of vaccination, and we've seen that pioneered
by Edward Jenner, and developed much more by
Louis Pasteur.
And this too, thus far, has proved unavailing
with regard to malaria.
Let's think for a moment about vaccines,
and I'd like to argue that they're effective primarily
under certain conditions, that they aren't universal
panaceas for all diseases.
They're helpful primarily, first of all,
in combating diseases against which the body develops a robust
acquired immunity.
Smallpox is a perfect example.
A patient who has once suffered from smallpox,
but then recovers, is then immune for the rest of
his or her life.
And, so, the strategy for vaccination is to produce
artificially the same effective immune response that was
generated by the naturally occurring infection.
The strategy then is to reproduce what nature does on
her own.
But in malaria, the immune response of the body
is limited, and it takes multiple
infections and recovery there from to acquire a partial
immunity, and that immunity even then is
short-lived.
It's partial and short-lived.
If you have painfully acquired an immunity from malaria and
then you move away from the malarial area,
in a couple of years your immunity fades away,
and if you return to the malaria area you're susceptible
all over again.
So, this is one factor that makes vaccine development so
very complicated.
Another point about vaccine development is that vaccines
haven't so far been developed against a pathogen with a
lifecycle as complex as that of a plasmodium.
In targeting a virus or bacterium, a vaccine is always
dealing quite simply with the virus or the bacterium.
But the point about studying about--one of the points about
investigating the lifecycle of the plasmodium is that they're
different.
They go through a series of complicated life stages.
Sometimes they're sporozoites.
Sometimes they're merozoites.
Sometimes they're gametocytes.
And the problem with a vaccine is that in order to be viable,
it has to be effective against all of those phases in the
lifecycle of the plasmodium.
And then also another feature, as I said, is that malaria is
not a single disease.
It's a family of four different parasitic diseases,
and the vaccine has to be effective against not simply
one, but against numerous,
therefore, species of parasite.
Now, I don't want to argue that therefore the development of a
vaccine against malaria is impossible.
In fact, as we're speaking, scientists are hard at work
trying to develop such a vaccine, and indeed,
they have come up with one.
You read some rather silly things in the press.
The vaccine developers came up with a vaccine in the last few
years that's about thirty-percent effective.
I remember reading in places like the New York Times
that malaria would therefore be eradicated globally in five to
seven years.
This is a sort of rather silly prediction,
and even the people--I know because I've talked to them--
who are developing the vaccine have no such illusion about its
efficacy.
They're thrilled because it's thirty-percent effective,
but that means that it's seventy-percent not effective.
Well, in order to understand the evolution of public health
strategies against malaria and the problem facing the world
today in dealing with this disease,
then we need to know that the very complexity of malaria has
led to a wide array of different strategies to combat it,
as well as to an ongoing debate on which course is likely to be
most effective.
And as yet there's no consensus in the international health
community on the best and most effective strategy,
despite the fact that since the turn of the twentieth century,
at the least, malaria is a disease,
paradoxically, that has such extraordinary
ravages on the global population,
and yet, paradoxically, it's a disease that's both
treatable and preventable.
There is an amazing paradox.
This morning, then, I want to talk about not
the effects, the nature of the plasmodium,
the nature of mosquitoes, the lifecycle or symptomatology
of malaria, but I'd like to look instead at
the disease from the societal point of view,
and in particular on efforts to development a successful
antimalarial strategy.
But developing a strategy or thinking about the proper
strategy against malaria is easier if we think of a number
of ways in which this disease might be characterized,
the ways in which it has been seen by leading scientists,
physician, and public health officials who've dealt with it.
So, I'm wondering if we could think of malaria--we might ask a
number of questions about it.
How should we describe this disease?
Is it a disease of poverty, and what's the evidence for
that?
That would entail dealing with--and in a particular way
that might be different from other ways.
One of the leading world malariologists in the early
twentieth century defined malaria as a house disease.
In other words, it's primarily defined by poor
housing conditions in which people are crowded in order to
work in agricultural occupations,
and those houses are porous to insects,
and it's in the house that the disease is transmitted,
and both mosquitoes and human beings are infected.
Or should we see it instead as an occupational disease?
We've talked about the relationship of malaria to
agriculture, and it's quite clear that
certain forms of agricultural production create and generate
high risk for those who practice them,
and malaria is contracted overwhelmingly by people who
work in fields under certain conditions.
Another way of thinking about it is,
in that case, one way of attacking a malaria
then would be to have occupation improve the conditions of
farming, of agriculture,
to regulate rice fields and all the rest of it.
That would be what you would do, perhaps, if you define it as
an occupational disease.
Should we think of it instead as an environmental disease,
that it's a disease that flourishes where the environment
has been degraded?
Where there's been deforestation,
for example.
Where the hydrology of rivers has been undermined.
Where there's flooding of places where there are swamps
and impounded water.
In that case, the way of dealing with
malaria, you might think,
might be to have land drainage, reclamation,
environmental sanitation-- quite a different strategy for
dealing with the disease.
What should we call this particular disease?
Is it an endemic disease, or is it an epidemic disease?
And here I think that malaria is one of those diseases that
we're studying in our course that's actually both.
That is to say, in a particular locality,
it is an endemic disease.
For example, if you were to go to the
tropical areas of Africa today, malaria is present throughout
the year.
It's highly, even hyper endemic.
But it's also capable of being an epidemic disease.
First of all, that's easiest to see,
perhaps, it temperate zones where malaria has also been
prevalent, because then it's seasonal and
you have the winter when the disease--
it's too cold for the plasmodium to be transmitted,
but you have an annual summer epidemic.
But in addition, under certain conditions we
would say that the epidemic is intensified in conditions,
for example, of years of exceptionally heavy
rainfall.
Or, say, in tropical Africa, it becomes an epidemic disease
when something happens to the environment,
where there are complex emergencies or famines that
cause people to move in large numbers--
who lack immunity to move to areas where the disease is
prevalent.
So, malaria can cause extraordinarily intense
epidemics against a background of being also an endemic
disease.
I would like to argue, and I will be arguing that part
of the complexity of malaria-- and if I were asked the
question--although you may want to disagree with me,
because people are still arguing about how one defines a
malaria and how one deals with it.
But I'd like to suggest that perhaps it's all of those.
It's a disease of poverty.
This is part of its complexity, its biological,
social, and environmental complexity.
It is a disease of poverty.
It's also a house disease.
It's an occupational disease.
It's an environmental disease.
It's an endemic disease.
And it's an epidemic disease as well.
Well, what are the kinds of strategies that have been
deployed against this dreadful disease?
One was since we now know that it's transmitted by vectors,
Ronald Ross, who was one of the people who
won the Nobel Prize, in fact for establishing that
very idea, developed very question the
idea then if it's a disease that's transmitted by vectors,
perhaps the right course for dealing with malaria is vector
control.
Kill mosquitoes by insecticides,
or remove their breeding grounds by environmental
sanitation, by dealing with an unregulated
hydrology of an area, by land drainage,
by removing uncovered water.
A different strategy would be to deal with not the mosquito
but with the plasmodium.
And so there have been--and here I've talked about the
Italian School of malariology, and Giovanni Battista Grassi
had the idea that you would be able to eradicate malaria by the
use of antiplasmodial-- that is, quinine--one the first
effective magic bullets.
He thought the idea was that if we know what causes malaria and
there is an effective treatment for it,
if you can use it prophylactically to prevent
people from being infected for a number of seasons in a
particular geographical area, or if you can destroy the
plasmodia in the bloodstreams of all of the sufferers,
then you can prevent mosquitoes from being infected for the
following year.
And if you do that for several seasons, then you could break
the cycle of transmission and eradicate malaria.
Both of the people who discovered the mosquito theory
of transmission very quickly came to the idea of malarial
eradication.
Ross did so, and Grassi immediately thought
that malaria had what he called--
it was the "colossus with feet of clay"--
and that quinine would be the instrument that would enable the
world to eradicate it.
But if you think of it as a disease of poverty,
you might think instead--and a disease of housing,
and an occupation disease--then you might think of a different
strategy of social uplift, that what you need to do to
deal with malaria is to practice social medicine to deal with
poor diet, poor wages, child labor--those
whole series of complex factors that create the substratum in
which malaria thrives.
And then there is another strategy which is quite commonly
thought of.
It has not made much progress, at least to date,
though who knows, maybe it will in the future,
and that's the Jenner/Pasteurian strategy of
hoping to develop an effective antimalarial vaccine.
So vaccine development is one of the great hopes in the
antimalarial struggle, and enormous amounts of
resources are being invested in antimalarial vaccine development
as we speak.
Well, I want to give an example of a particular place.
It's the one you're reading about this week,
which was the impact of malaria on a particular country.
And I've chosen Italy for particular reasons.
One is that Italy had a special relationship to malaria.
It was the only Western European country where it wasn't
a colonial issue, but rather the most important
domestic public health problem.
It was also the international center of malariology from about
1900 until the Second World War.
In other words, we've talked about the hegemony
of powers in international medicine in the early nineteenth
century down the middle of the nineteenth century.
In the smaller domain of malariology, Italy was the
center of the action from 1900 until World War II.
This is the place where people went to be trained in
malariology.
People traveled--physicians from all over the world--
to study with those people who were called the Rome School,
or the Italian School of malariology--
Giovanni Battista Grassi most prominent.
But other names were extremely prominent also,
like Angelo Celli, and we could list a whole
series of others.
And it was Italians primarily who were responsible for
unraveling the mysteries of malaria.
And finally, Italy was a place that did
something quite extraordinary.
It was the first place to have a successful strategy of
antimalarial campaigning.
In other words, a campaign began in 1900 and
was successful in a eradicating malaria by 1962.
The last indigenous case of malaria in Italy was in Sicily
in 1962.
So, this means that Italy has lessons,
and there are not many places where there have been campaigns
that have succeeded intentionally in eradicating the
disease.
This leads to a message of hope--what can be accomplished
by doing it, and it also means that I think
it's useful to look at the this successful campaign in order to
draw lessons from it, but to beware also of the
misuse of history, because a lot of what I think
are the wrong lessons have also been drawn from it.
Well, in any case, let's look just very,
very quickly at the Italian experience.
As you know, Italy was united in the middle
of the nineteenth century, and by the 1880s the new
liberal regime became aware of the prevalence of the disease
throughout the country, and this is the map that
was--it's not the best map artistically or even in terms of
clarity, or I would even say in terms of
accuracy; and, so, you're wondering why
do I show you this map of malaria in Italy when there are
actually better maps that are more colorful and all the rest?
But for historians, this is the important one,
because this is the one that shook Italians up and convinced
them of the enormity of the problem in their country.
One of the things that's quite clear, even in looking at this
map, is that malaria was present everywhere virtually.
There are areas that are yellow, pink,
and red of prominence or extreme prominence of malaria.
And it was the case also that after unification,
instead of the problem--unification seen as a
foundational moment for this new regime that's supposed to
deliver civilization, economic betterment,
progress, and also public health--
but instead, the years at the end of the
nineteenth century see the malarial problem,
already intense, getting worse.
Worse because of things like deforestation of the Apennines.
The railroad era actually had a devastating impact,
because it led to the demand for trees to make the railroad
ties and the stations and all the rest,
and therefore led to massive deforestation and deregulation
of the hydrology of the entire peninsula,
which was turned topsy-turvy.
It was also a time then of economic difficulties and
crises, and malaria feeds on human misfortune,
and it did so in the late nineteenth century.
Well, in any case, Italy also provided--
we've talked about malaria as a housing disease--
I thought I'd just show you a representative type of peasant
housing, even down through the 1930s and
'40s, and when you live in places
like this, in a malarial area,
you're highly vulnerable because this is almost like
being outdoors.
In fact, it's probably worse in terms of mosquitoes.
It's entirely vulnerable and open to flying insects,
and having numerous people sleeping in conditions like this
helps to promote the disease and transmission.
Similarly, we talked about it being an occupational disease.
It wasn't by chance that Italy is also a place of rice fields,
and rice fields are actually wonderful places for mosquitoes,
and the rice workers were among those people who were most
vulnerable, and became symbolic as the
victims of the plasmodia.
So, in any case then, there was an epidemic and
endemic condition in Italy.
And Italy showed all of those terrible consequences of malaria
that we've been talking about: absenteeism in agriculture;
waste--whole areas that weren't cultivated because they were so
dangerous, and those who did work on them sickened and died;
an area of low productivity, of illiteracy;
the underdevelopment of civil society;
low participation in politics; mass emigration.
And I would argue indeed that one of the features of Italy is
that we've talked about North and South,
and I talked about agriculture being a determinant of malaria,
and that the global North had advanced forms of agriculture
that were intensive and not conducive to malaria;
and the South, the global South,
had the opposite.
Well, this was reproduced in a microcosm in Italy in that the
North of Italy was much less vulnerable to malaria,
and the form of malaria was the milder vivax malaria,
while the South of Italy was riddled with malaria,
and it was malaria that predominantly falciparum;
that is, the most devastating and lethal form of the disease.
Well, there was a time of great scientific discoveries that
we've talked about.
Oh, this is a famous picture, just to show you.
This is a painting called "Malaria,"
and as you see, it's sort of like a
piet�, or a deposition from the cross,
and I think it conveys, in a moving,
emotional way, the reaction of a society to
intense malarial transmission.
This is the prime minister at the turn of the century until
the First World War, under whom the antimalarial
campaign gets started.
And this is Giovanni Battista Grassi--
I tried to show him last time--who was the person who
proves the mosquito transmission among human beings,
the leading representative of the Rome School of malariology,
and his work was--we've talked about institutions--
this is the Santo Spirito Hospital,
where he conducted his research, because there were an
enormous, almost unending supply,
of malarial patients.
And it was here that he first successfully infected human
beings with malaria with a number of scientific
experiments, that you might consider
ethically problematic, but in any case,
there weren't rules about such things at the turn of the
twentieth century.
Well, the pillars of the eradication program--the pillar
of it was initially going to be quinine.
And so Italy passed a series of quinine laws from 1900 to 1907,
with support from the liberal prime minister.
And the idea was that you could kill the plasmodia,
break the cycle of transmission,
and eradicate the disease.
Grassi thought it would be merely a matter of a few years.
In fact, it then turned out to be impossible to eradicate the
disease so easily that people were not used to contact with
physicians.
There wasn't access, in other words,
to medical care.
Distributing quinine was tremendously problematic.
It also has to be followed according to a very complex
regimen, and it has to be followed for
months at a time, and you can't get people to do
that unless they understand the disease.
And, so, actually to have an effective antimalarial program,
turned out you have also to deal with poverty and with
illiteracy, which are the allies of the
mosquito and of malaria.
And so it was important to teach people the discipline of
quinine and the reasons for it so very quickly,
and also health access was important.
And, so, new parts of the program turned out to be rural
health stations.
It's expanding now beyond quinine to include rural health
stations, education and rural schools.
In other words, a whole panoply of things that
we might call social medicine, improved housing.
Actually, Celli argues that trade unions were a powerful
antimalarial tool because they helped deliver better wages,
and with that, better diet and better
clothing, and child labor laws--and we
know that children are particularly susceptible to
malaria-- and the regulation of
occupations that were particularly dangerous,
such as working in rice fields.
Well, the results of the liberal program,
which has expanded well beyond distributing quinine--
in other words, it starts with the vision of a
magic bullet and moves very quickly to a whole panoply of
things that we might, for shorthand,
call social uplift, with having to do with access
to medical care, improved housing,
civil liberties, education,
and all of those sorts of measures.
The results of the liberal program,
by the eve of the First World War, were a massive decline in
mortality, at least, but still the
persistence of the disease.
And then comes World War I, which was an extraordinary
setback for malaria.
And I've talked about the way that malaria is a disease that
thrives on human misfortune, and there is no misfortune that
is better for malaria than war.
I thought I would show you a few paintings of the First World
War to show you the kinds of conditions that led in Italy
that destroyed, almost, the first fifteen,
sixteen years of antimalarial efforts,
and created this huge explosion of epidemic malaria during the
First World War.
And this is a famous painter--Sartorio is his name--
who was a combatant in the First World War,
but then was wounded, and returned to the front as a
painter-- rather, as a photographer--and
he took photographs of the conditions at the fighting
front, and then he did paintings from
his photographs.
And these are some of the most impressive, I think,
moving pictures of the sorts of conditions.
You can see exactly how mosquitoes would thrive in
conditions of this sort.
This is not dead soldiers.
These are soldiers bivouacking after a battle,
and I think you can imagine them being from non-malarial
areas and not having resistance, and you can see that they are a
wonderful feast for Anopheles mosquitoes,
and the soldiers from non-malarial areas fell sick and
died in enormous measures.
We've talked about malaria as a housing disease.
Well, also the destruction of housing renders people
vulnerable; if you have to move into tents
or into the open fields to bivouac,
to move from area to area, from cities to the rural areas
and all the rest of it, you become extraordinarily
vulnerable.
And, so, the destruction of housing and the housing stock
was extremely important.
So, there was this tremendous upsurge of malaria during the
First World War.
After the First World War, in 1922, we have a new regime,
and this was the fascist regime of Benito Mussolini.
We won't talk about the conditions that brought
Mussolini to power, but we now have a totalitarian,
one-party dictatorship-- the end of elections,
police repression, violence, the secret police,
and a foreign policy of expansion to restore an empire
and to pursue broad European and African conquest.
By the end of the 1920s, Mussolini is fully in power,
and he institutes some antimalarial measures that
became extremely famous, and he's often thought as a
hero of the antimalarial movement because of what he did
in this area-- the Pontine Marshes--which is
just outside of Rome, and you'll be reading about
that.
This was done, however, for political purposes
more than for medical ones, because the point about the
Pontine Marshes was that only a couple of thousand people lived
there in 1930, and this became the height of
the regime's antimalarial measures,
which were to drain the swamps, to build new housing,
and to settle the land.
But it doesn't actually confront malaria in the parts of
Italy where the most numerous people were getting ill and
dying.
It was an enormous propaganda effort to demonstrate,
more than health, the power of the regime:
that Mussolini could succeed where liberals had failed,
where the popes had failed.
The sorts of measures that were undertaken, this is the kinds of
conditions that he found--the swamp conditions.
I guess I'm overdoing it, but I'm showing you there was
plenty of water and there were plenty of mosquitoes,
and it was estimated that you had an eighty percent chance of
contracting malaria if you spent a single night in this area in
the summer, before the drainage of the
swamps.
Well, this is the construction of something modestly called the
Mussolini Canal, and we'll see also it went
pumping stations, land drainage;
you see canals being constructed;
water being raised to be harmlessly diverted to the sea
went with it as well; the distribution of
quinine--I'm showing quinine being distributed;
education and literacy, and the teaching about the
mosquito theory of transmission--all of that was
important.
We see fascist Boy Scouts learning about larvae and their
collection, and taking that information home to their
families, was part of the idea.
Here they're doing the same thing.
There were sanatoria.
And you see the improved housing.
These are sturdy houses.
They have screened windows and all the rest of it.
You see screens going up.
So, this was really a huge, huge project.
It also included things that weren't so--the building of new
cities.
Suddenly an area that was a swamp, you see modern cities
going up.
The display of power is enormous.
This was really an idea that had as much to do with the power
of the regime as with public health.
I'm not saying that it's my view that fascism is in fact bad
for your health rather than good for it.
Here are some of the propaganda pictures of the first peasant of
Italy here, among his smiling, happy crowds,
and all the rest of it.
So, this was used in that way.
Well then, part of fascism, however, you can't understand
it without its impetus to expansion and to war.
And the Second World War, again, led to a major
destruction and to devastation, repeating even a worse scale
what had happened during the First World War.
So, I won't talk about that.
I won't talk either this morning about a war crime that I
do discuss in the book, that will see the use of
malaria as an instrument of bioterrorism.
But my theme this morning is what are the tools for dealing
with malaria, and the lessons that can be
learned.
And, so, I'd like to look then--with the downfall of
fascism and another terrible upsurge of malaria during the
Second World War, there is a campaign to
eradicate malaria that gets underway 1945-1946,
and succeeds by 1962.
And it's done with Allied cooperation,
the leadership of the Rockefeller Foundation and money
from this country, and it involves the idea of a
powerful new weapon to destroy mosquitoes--
a technological weapon.
DDT was discovered during the war and is now used as an
instrument, a powerful insecticide, to destroy malaria.
And this is thought, in fact, to be--and becomes--a
premise, if we like.
The lesson is drawn that malaria was eradicated in Italy
after the use of DDT, and so DDT is thought to be the
cause of the destruction of malaria,
the successful campaign.
And this becomes the premise for an international campaign,
a global campaign, of the World Health
Organization from 1955 until 1969 to use DDT worldwide to
eradicate malaria globally.
I want to argue that this is in fact misleading,
because the wrong lessons were drawn from what happened in
Italy.
In actual fact, the eradication after World War
II was possible in part because it marked not only the use of
DDT, but it also meant a massive
investment of American aid to provide food,
clothing, housing and employment, that becomes,
first, UNRA, and then the Marshall Aid Plan.
And so there is an enormous campaign to improve housing and
conditions of people.
In other words, there's a massive social
uplift, if we like, that's going along at the same
time as the use of DDT.
At the same time, you have the reestablishment of
healthcare services and rural health stations,
and the massive distribution of quinine and artificial quinines
developed during the war-- Atabrine and chloroquine.
So, it's not a simple, unidimensional program that
succeeds.
By 1962, Italy becomes malaria-free,
and I think that's one of the factors that led to the
possibility of the economic miracle,
and Italy's becoming after, by our day,
the world's seventh industrial power.
So, there's an amazing measure of hope of what can be done.
When you eradicate malaria, you unleash productivity and
development.
But in addition, this example then becomes the
basis of the post World War II program of global eradication
that believed that it would be possible simply to have a
panacea, a technological intervention
with DDT, and this is an experiment that
by 1969 collapses in failure, and I would like to argue that
this ought to lead us to enormous questions about today's
antimalarial program of the World Health Organization,
Roll Back Malaria, and very often it's thought
that the development of using some sort of magic bullet would
be adequate.
I want to argue that this was partly based on a
misunderstanding of the Italian lesson,
and I think we're dealing with, in our own world,
the consequences of that in the form,
now, of either DDT- or insecticide-treated bed nets as
being the most useful instruments;
and I think the campaign is having enormous difficulties,
and I think we need to think about how we define this
disease--what is its substratum; what conditions promote it;
and what kinds of strategies are effective in combating it.
So, thank you.