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COLLABORATIVE
RESEARCH ON TROPICAL DISEASES (1985) p. 2 of 12
E. THE SEVENTH PANDEMIC AND THE U.S. RESPONSE
Pandemic number seven broke out in 1961 in Celebes (Sulawesi),
Indonesia, and hit China and the Philippines the same year. At first it was called para-cholera, because the infecting
organism was not the classical vibrio but a variety called El Tor. The El Tor vibrio had been discovered at a quarantine station of
that name on the Sinai peninsula in 1907 in the bodies of hajis
who had died of other causes. It
appeared to cause only a mild variety of diarrhea, not real cholera.
In 1937, El Tor showed up in the Celebes where, although the
infection rate was low, it had a mortality rate of over 50%. Still, the disease did not take on epidemic characteristics until
1961, for reasons that can only be guessed at. Then it spread from East Asia to the Subcontinent and on to the
Middle East, Southern Europe, and East and West Africa, where it seems
likely to remain.
As the pandemic spread, Phillips and his team developed an
efficient procedure for responding to cholera epidemics in the
Philippines, South Korea, South Vietnam, East Pakistan, Malaysia and
Sarawak. The Navy offered
their services as soon as news of an epidemic was received, and a team
of three or four scientists and eight to ten technicians was dispatched
by military aircraft as soon as an invitation arrived. They first indoctrinated local physicians and nurses in the Navy
method of treatment, then requested permission to conduct research.
The Navy treatment, with a mortality rate consistently under one
percent, had evolved in Cairo and Bangkok. The specific gravity of the patient’s blood was measured to
determine the volume of fluid needed to restore the plasma to normal
levels. Fluid balance was
rapidly restored intravenously and maintained thereafter by matching
inflow with outflow. The
fluids used contained minerals to match those lost in diarrhea, and
sodium bicarbonate to counteract acidosis. The cholera cured itself, as Phillips said, like the common cold.
This method of treatment was a definite advance over
previously-used therapies, and Phillips received the Albert Lasker
Clinical Research Award in 1967 in recognition of that fact. It had, however, practical limitations in dealing with
large-scale epidemics in developing countries. The fluids had to be made from sterile, distilled water to avoid
fevers, and they needed to be administered under medically controlled
conditions. Patients would
often require infusions of more than their own weight in liquids,
placing a huge burden on logistical services.
The NAMRU group was well aware of the shortcomings of their
method. Much of the
research they carried out after introducing their treatment to an
epidemic area was devoted to the search for a means of oral rehydration.
The principal problems were that fluids taken orally generally
induced nausea and vomiting, and that even if they could be kept down,
the body seemed unable to absorb needed sodium and chloride from them.
In July 1962, in Manila, Phillips found, literally, the solution.
Adding glucose to the swallowed fluid allowed sodium, chloride,
and greater amounts of water to be absorbed by the body. Fluid balance was restored
immediately. An editorial in the prestigious medical journal Lancet in 1978
valued the finding thus: “The
discovery that sodium transport and glucose transport are coupled in the
small intestine, so that glucose accelerates absorption of solute and
water, was potentially the most important medical advance this
century.”
Credit for this momentous discovery may rightly be shared by
physiologists at Oxford, Harvard and Yale, and by the clinician N.S.
Chatterjee, who in 1953 experimented with cholera patients; but in the
history of science vs. cholera, the accolade is assigned by Van
Heyningen and Seal to Phillips. He
was, for a long time, not himself convinced of the utility of his
findings.
Encouraged by the initial observation, a small NAMRU team treated
40 patients with the glucose solution, after initial intravenous
rehydration, in September. Five
died, drowned, technically, by water drawn to the lungs from their cells
by an excessively salty solution. This
failure soured Phillips on the oral rehydration notion, to the point
that when he received the Lasker prize in 1967 he referred to the
glucose solution as a hope that did not materialize. He also, as head of the PSCRL after 1965, actively restrained
experimentation on oral rehydration, as we shall see later.
In 1962, as Phillips was experimenting with oral rehydration,
NAMRU was perfecting its epidemic response procedure, and the PSCRL was
at last becoming operational in Dacca, another American medical research
team set up shop in Calcutta. Under
an NIH grant program that we will examine in more depth, Johns Hopkins
University set up a Center for Medical Research and Training (JHCMRT) in
Calcutta. They started a
cholera research program because the disease was important to the site,
not because the grant required work on cholera nor because Johns Hopkins
was experienced in the disease.
The Hopkins group found pre-NAMRU procedures in effect for
dealing with cholera. Patients
admitted for treatment at the Infectious Diseases Hospital in Calcutta,
to which they were attached, had a mortality rate of 30%. Phillips’ work in Cairo in 1948 had gone unnoticed, perhaps
because it was published in an obscure journal or because, as often
happens in the Third World, the Hospital couldn’t afford the
periodical in which it appeared. The
major NAMRU advances during the Bangkok outbreak were more recent, and
hadn’t been demonstrated in the Subcontinent. The Hopkins group arranged a controlled comparison of the methods
used by the Indian physicians with those recommended by NAMRU. The dramatic differences in results led the Indians to abandon
traditional therapy.
The Hopkins group exchanged information and visits with the NIH
scientists at the PSCRL regularly. Craig Wallace, who was with Phillips at NAMRU-2 and headed the
Hopkins group from 1964-66, says that both Hopkins and PSCRL made
important observations, but each would in time have done what the other
accomplished. Their working
conditions differed substantially. Hopkins was primarily a research group, admitting only a few
patients per day for observation but caring for as many as several
hundred a day. The PSCRL on
the other hand was a front-line treatment center. During one period of Moslem-Hindu tension in East Pakistan,
cholera broke out among a group of Hindus taking shelter in several
cotton and jute mills. Patients
were transported by the truckload to the Mitford Hospital, the hospital
in Narayanganj, and the PSCRL, each receiving about a third of the
victims. Within 48 hours
all but two of the PSCRL patients had been discharged, with zero deaths,
while 27% had died at Mitford and 47% at Narayanganj. Thereafter, the PSCRL was charged with treatment of all diarrheal
cases in Dacca.
The Hopkins team had advantageous conditions for conducting
intensive clinical studies. They were attached to a large hospital where it was possible
to develop excellent laboratory facilities. Their Indian colleagues, including S.N. De, who had already
succeeded in identifying the cholera toxin, had vast experience with
cholera. Links to the Johns
Hopkins School of Medicine were also important, even though some of the
field staff did not come directly from the parent institution.
Among the achievements of the Calcutta group was the appreciation
of the value of antibiotics in the treatment of cholera. It was known, from previous experiments by Chaudhuri in Calcutta
and Phillips in NAMRU, that antibiotics would not alone reduce the death
rate from cholera. Once the disease had damaged the lining of the gut, the
damage was done. It takes a
week for the damaged cells to grow back, by which time the cholera
vibrios have gone away of their own accord, so Phillips saw no sense in
using antibiotics for treatment. At
Calcutta, the Hopkins group showed that using tetracycline, only half
the volume of replacement fluids and half the hospitalization time were
required for recovery.
The Calcutta team also made important advances in identifying
causes of severe diarrhea other than cholera. Early in their stay they noted that cholera vibrios could be
identified in only about half of the patients in their care. In 1964, an unusual epidemic of non-cholera diarrhea broke out at
the time of year cholera could be expected to appear. Of 145 patients studied, 86% did not have cholera, although they
were just as sick as if they did. In
1968, Hopkins workers identified the causative agent as Escherichia coli,
an organism that had been known to exist harmlessly in the large bowel,
but was now found to act much like cholera in the small bowel. E. coli is not the only non-cholera diarrhea-producing organism
by far, but it is one of the most dangerous world-wide for children
under two years of age.
The Hopkins advantage in having facilities for intensive clinical
work was balanced in Dacca by the opportunity for field surveillance and
epidemiological studies. One of the important missions of the PSCRL was to test the
efficacy of cholera vaccines. This
task required access to an area with a high incidence of cholera, in
which comparisons could be made of cholera attack rates in people given
a vaccine and control groups given placebos. PSCRL needed a cholera ward in which to treat those who
contracted the disease, and ready access to a sizable population at risk.
With the assistance
of local authorities, a group of 23 villages in the Matlab thana, one of
the most densely populated areas of East Pakistan, was selected. The thana was a subdivision of Comilla District, about 40 miles
from Dacca. The villages were most easily reached by boat through rivers
and canals.
The Matlab thana surveillance area, and another developed shortly
thereafter at Teknaf, remains a major resource for epidemiological
research and experimental interventions, in such fields as nutrition and
family planning as well as diarrheal diseases. Experiments there demonstrated conclusively that it is far
cheaper and more effective for a poor country to devote its resources to
providing therapy centers and gradually upgrading sanitation than to
administering large-scale vaccination programs. The vaccines then and until now available are effective at
most for three or four months and need to be administered a month before
exposure to the disease. Therapy,
particularly after an oral rehydration method became available, is
relatively inexpensive.
The Dacca and Calcutta units differed from the NAMRU approach in
various ways. As a
laboratory man, Phillips favored tests of blood specific gravity in
order to determine the volume of replacement fluid needed. The more clinically oriented physicians at JHCHRT and PSCRL soon
came to prefer quicker assessments made by judging the degree of
dehydration by the fullness of the skin, assessing blood pressure by
pulse, and other observations.
In 1965 the stage was set for a grand finale to our story:
Phillips was appointed to direct the PSCRL. Phillips was at heart a laboratory
scientist. He had little background or interest in epidemiology. His first concern was to understand the disease process, but he
had relatively little interest in or appreciation of patient care. He was a physiologist, not a
clinician. His attitudes were not shared by many of his Dacca colleagues,
several of whom came from the Center for Disease Control, an
organization dedicated to results in large populations.
The second area where Phillips was swimming against the tide was
oral rehydration. The 1962 setback in Manila apparently inhibited both Phillips
and his colleague Wallace; both were extremely cautious in permitting
clinical experimentation with oral rehydration in the units they ran
during the next five years, Phillips in Dacca and Wallace in Calcutta. Yet the idea was far from forgotten, and Wallace continued to
believe that it would work under proper conditions.
Research on the glucose transporter continued at both PSCRL and
JHGMRT in the field, and at Johns Hopkins and other laboratories in the
United States. Results were
encouraging, and the natural interest of the field staff in Dacca to try
the oral technique were reinforced, in the winter of 1966-7, by the
outbreak of the biggest cholera epidemic the PSCRL had yet witnessed,
giving rise to the fear that they might run short of intravenous fluids.
The first experiment, in Chittagong in 1967, was not a success,
although not catastrophic as in Manila. The second attempt was more
encouraging. Despite official opposition, from Phillips and NIH in Washington,
a controlled field trial was conducted in 1969 in Matlab thana, in the
midst of an epidemic in which a shortage of intravenous fluids actually
did occur. The result was a powerful affirmation of the value of oral
rehydration. The need for
intravenous fluids was reduced by 80% and in mild cases it was not
needed at all. Even
Phillips became convinced again of the promise of the technique.
In Calcutta, the Hopkins group were working along similar lines. They demonstrated in 1968 that oral rehydration could be used
successfully to maintain balance after initial intravenous rehydration
had been used, but they preferred to await further study before
experimenting further. Their
hands were forced by an outbreak of disease among a concentration of
350,000 refugees from the civil war in East Pakistan in May 1971. The death toll was huge; a fatality rate of 30% prevailed among
patients in the refugee camps. There
was no hope of producing the amounts of intravenous fluid needed for
such numbers, nor of training the personnel to administer it. The Hopkins group consequently prepared packets of dry
ingredients in their library in Calcutta and sent them to the camps,
where an Indian team from the JHCMRT dissolved the packets in clean
drinking water and dispensed the liquid to patients. Packets for 50,000 liters of solution were
prepared. In all, 3,700 patients were treated, only the most seriously ill
intravenously, with a mortality rate of 1% among those in the JHCMRT
tent, and 3.6% for others using the solution.
Indian resentment over American involvement in Vietnam, and over
American policies on the Subcontinent in the early l970s, made the
Hopkins situation in Calcutta increasingly uncomfortable. Had the program been designed to assist Indian research and
treatment efforts, and in particular, had it been meant to train Indian
scientists, it might have had more local support, but the NIH grants of
the time were designed purposely and rather narrowly to support American
research and training, not to build the competencies of their Third
World colleagues. As it
was, when cholera broke out among the Bengali refugees, no Americans
were permitted to participate in their treatment. The next year, relations became so strained that Hopkins staff
had problems obtaining visas to visit the unit and it was decided to
abandon the Calcutta location. They
moved the unit to Dacca and affiliated with the CRL.
Civil turmoil also brought research to an end at the PSCRL at
this time, as the Bengalis struggled for independence. The laboratory remained open for the treatment of patients --
indeed the conflict brought them the greatest number of cholera patients
of their history -- but throughout 1971 most of the expatriate staff
were kept elsewhere for security reasons.
Fortuitously, another mechanism for advancing cholera research
appeared on the scene in 1965. President
Johnson received Prime Minister Sato of Japan in Washington to discuss,
primarily, balance of payments problems between the two countries. The meeting produced few positive results on that score, and the
President reportedly asked Colin MacLeod, a member of the ubiquitous
Inner Circle who was then Deputy Science Advisor, to come up with a
suitable topic for constructive cooperation in order to avoid too
discouraging a final communique. MacLeod,
after working all night, came up with an idea that became the U.S.-Japan
Cooperative Medical Science Program. The purpose of the program was to
expand cooperation between the two countries on human health problems
“of great concern to all the peoples of Asia.”
Malaria, cholera, schistosomiasis, tuberculosis and stomach
cancer were singled out for early attention.
As a face-saving device, the US-Japan program served its purpose
in the 24 hours in which such communiques are on anyone’s mind, but
the program continues to be both popular and important to work on
cholera. No money crosses
borders under this program, and no collaborative research is supported. Each side funds its own research, and panels on each of the major
diseases meet annually, alternating hosts, to report accomplishments.
Initially, US participation in the program was guided and funded
out of the Office of International Research at NIH, but later it came
under NIAID. In the first
ten years of the program, 58 grants and contracts were made in the
cholera field in the US, and a similar number in Japan. The program was an important source of funds for researchers, but
whether it still is, is questionable. NIH no longer carries the US-Japan program as a line item in its
budget, although in 1983 roughly $11 million in grants were made under
its aegis. All such grants
are funded from regular NIH appropriations and it is not clear if the
abolition of the program would have any effect at all on the awards made.
It can be argued that the loss of the program would have a
profound effect on the awards because of the authorizations question. The US-Japan program operates under the only active delegation of
presidential authority to conduct research for international health
purposes. This power is given to the President in the International
Health Research Act of 1960. It
has been delegated only three times, including the US-Japan case. Its broader use has consistently been opposed by the Department
of State, to that Department’s lasting discredit.
Now we are ready to return to strife-torn Dacca, endemic home of
cholera and other diarrheal diseases, to see what happened to the PSCRL
when Bangladesh gained independence.
F. PSCRL TO
CRL TO ICDDR/B
1971 was a difficult year for the SEATO center, and for Dacca
generally. Strikes and
riots disrupted research in February, and work came to a standstill in
March when West Pakistani troops attacked the Bengalis. Months of fighting
followed. The laboratory was untouched, but much of the surrounding area
was bombed between March and December. The local staff, led by Deputy Director Mujibur Rahman, kept the
laboratory open, working without regular salary and treating as many as
1500 patients a month. Research
was of course impossible, but refrigerators and deep freezers were kept
going to protect biological and chemical specimens until they could
again be studied. Most of
the American staff was evacuated in April and the remainder in December
as intensive fighting took place.
The People’s Republic of Bangladesh emerged from the conflict
on December 16, 1971. The immediate consequence of independence for the laboratory
was the loss of its SEATO affiliation and the loss of eligibility for
PL-480 funds. The latter
was the more critical. In
early 1972 the laboratory was on the verge of bankruptcy and its future
was much in doubt.
Within a week of independence, a group of Americans who had
worked at the laboratory formed themselves into a Committee for the
Continuation of the Cholera Research Laboratory. The CCCRL was led by William B. Greenough III, a physician who
had been among the first to serve in the SEATO lab and who was to later
become director of the ICDDR/B. The
Committee kept interest in the laboratory alive at AID and NIH,
stimulating an interim AID grant of $500,00O to maintain the institution
while its future was being negotiated.
At NIH, the Director asked the Cholera Advisory Committee to
determine the scientific justification for maintaining access to a
population in which cholera was endemic. He was advised that the
anticipated expenditure of $1,500,000 per year was justified. Although
access to a cholera endemic population was not necessary for
physiological or pharmacological research, it was necessary to carry out
field trials on vaccines. Additional
valuable studies could also be conducted in the field in search of a
single method for rehydrating children and on other diarrheal diseases
such as E. coli.
Negotiations dragged on until mid-1974. The new government wanted NIH participation, but wanted the
institution to be a Bengali laboratory in direction and operation,
responsible to the Ministry of Health. This was unacceptable to NIH. Eventually a compromise was reached under which the laboratory
would continue for three years as an autonomous body with a Directing
Council of three Bengalis, two Americans, and one representative each
from participating nations or international organizations. NIH organized the Scientific Review and Technical Advisory
Committee to advise the Directing Council, and selected the director of
the Cholera Research Laboratory (CRL).
This was not meant to be a permanent arrangement. AID was no more eager to assume a continuing recurring cost
burden than was ICA in 1959. AID’s
motivation in seeking to internationalize the laboratory, however, went
beyond a simple desire to share the financial burden. Diarrheal diseases are leading killers of children worldwide, and
AID saw the value of developing the potential of this highly successful
institution, attracting high-quality international staff, and lending
permanence to the work.
Between April 1976 and February 1978, no less than five reports
were issued recommending expanding international participation in the
CRL and broadening the scope of its activities. The two most influential of these reports came from W.F. Verwey,
Director of CRL from 1974 to 1977, and W.H. Mosley, Chairman of the
Department of Population Dynamics at Johns Hopkins and successor to
Verwey as Director of CRL. Mosley
knew the CRL well, having been the epidemiologist who set up the Matlab
surveillance area in 1965.
As recommended by Verwey and Mosley, AID opted for the
internationalization of the CRL along the lines pioneered in the
agricultural field, in the institutions supported by the Consultative
Group for International Agricultural Research (CGIAR). That model involved funding from many private, international
and national sources, an international board of trustees, a technical
committee, and an international mandate that transcended Bangladesh
concerns.
Mosley, as Director, struggled to internationalize the
institution. He received
strong support from the Resident Representative of the UNDP, who in
turn was backed by the UNDP in New York. The Ford Foundation, which along with the Rockefeller Foundation
was a founder of the original international agricultural research
centers, played a key role in backing the internationalization idea with
funds to cover contingency expenses.
There was, however, opposition. WHO, aware of the rather marginal role FAO had played in the
international agricultural research picture and more interested in
primary health care, was distinctly opposed. AID and the UNDP made every effort to keep WHO informed and out
of open opposition. Within
Bangladesh there were some who opposed internationalization as a drain
on their country’s resources; others saw the chance to take over a
well-equipped institution if the broader effort failed.
Planning and negotiation went on for two years, with the scope of
the laboratory, its name and its mission constantly under debate. In early 1978 a review meeting at the CRL, attended by 20
international and six Bangladesh scientists and the senior staff of the
CRL, examined the current scientific program at the laboratory,
considered the arguments for internationalization and recommended a
course of action. The
consensus of the meeting favored a concentration on diarrheal diseases
at the proposed center, with biological and demographic population
studies relevant to these diseases, and nutritional studies with a focus
on maternal and fetal malnutrition, breast-feeding, and weaning.
Finally, a draft ordinance to establish the International Center
for Diarrheal Disease Research, Bangladesh (ICDDR/B) was prepared, by an
international committee consisting of representatives of WHO, Australia,
Bangladesh, the Ford Foundation, the International Development Research
Center of Canada, the United Nations Fund for Population Activities,
UNICEF, the United Kingdom and the United States, under the chairmanship
of the resident representative of the UNDP. The Bangladesh Government promulgated the ordinance on 6 December
1978. In February 1979 the
UNDP sponsored an organizational meeting at WHO Headquarters in Geneva,
and over 20 donor participants signed a memorandum of understanding. This memorandum and the Bangladesh ordinance constitute the ICDDR/B
charter. President Ziaur Rahman formally inaugurated the ICDDR/B on 26
June 1979.
We will return to the ICDDR/B in the next section. Here it
remains to summarize the accomplishment of the SEATO laboratory and its
bilateral successor before we review the main points of the cholera
story for the purposes of this paper.
The Cholera Research Laboratory’s major scientific value lay in
its ability to conduct clinical research and field investigations of
high standard in endemic areas. Studies
at CRL revealed many of the abnormalities in intestinal functions
associated with diarrhea, whether caused by cholera or not. They clarified the abnormal dehydration and fluid loss that must
be corrected in treatment in order to lower the mortality rate from
around 30% to less than 1%. Simplified
treatment procedures were developed at CRL So that low mortality rates
could be achieved in relatively primitive situations with minimal
equipment and training.
Field trials conducted by the CRL showed that cholera vaccine may
be protective in an epidemic situation, but for only a limited duration.
These results led the Public Health Service of the United States
to abandon the cholera vaccination requirement for travelers to the
United States from cholera-infected areas. WHO also no longer recommends cholera vaccination for travel to
or from cholera-infected areas.
The CRL proved to be a useful facility for testing and refining
work begun elsewhere. Subsequent
work at CRL, for example, confirmed the Hopkins findings that
tetracycline was most effective against the cholera vibrio, and that
oral administration of the antibiotic effectively shortened the duration
of the disease. Oral
rehydration therapy, initiated at NAMRU-2, was greatly refined and
developed at CRL, leading to the development of a formula for the use of
local materials in the preparation of soluble packets for administration
by mothers or little-trained health workers. UNICEF and WHO made extensive use of this formula in their work
around the world.
CRL also pioneered research at the village level on the pros and
cons of combining nutrition, family planning and oral rehydration
therapy in local interventions. The CRL work on cholera thus extended all the way from
physiological research to public health campaigns for countering the
disease. This broad range
of activity is extremely rare in medical institutions.
One of the greatest benefits of the PSCRL and the CRL for the
United States was the field experience it afforded a generation of young
researchers who then made a lasting commitment to tropical disease
problems. Many of them now
occupy senior faculty positions at Johns Hopkins, Harvard and Case
Western Reserve universities.
G.
THE BEARING OF THE CHOLERA STORY ON OUR THEME
The cholera story illustrates many of the points we will wish to
make concerning the models of international collaboration examined below.
Our purpose is to
highlight the kind of contributions American scientists and institutions
can make to combating tropical diseases.
The cholera problem is not identical to all others, but the
example is useful for several reasons. First, the connection between basic science and the development
of an inexpensive cure for the disease is fairly straightforward, more
so perhaps than for most diseases. An understanding of the glucose transporter system in the gut,
and an awareness that it continues to function during diarrheal
diseases, led to the development of a cure of such simplicity that in
the 19th century it would surely have been called miraculous.
Secondly, the disease was ignored by modern science for nearly a
century at a cost of untold thousands of lives. A time lag of 75 years between Koch’s postulation of a toxin
and its discovery by De, and of nearly 100 years between Latta’s
experiments with rehydration and perfection of the technique by NAMRU,
would have been scandalous for a disease of greater concern to us.
A third striking feature is the speed with which progress was
made when modern scientists did finally get into the fray. Some reasons why this was so include:
·
Cholera
researchers benefited from research technologies developed in other,
better funded, fields.
·
The
Inner Circle monitored progress, set priorities, devised strategies, and
shifted resources to combat cholera.
·
The
value of scientific infrastructure is revealed by the knowledge
explosion set off by the distribution of purified toxin to the
scientific community. Informal communications, seminars and workshops,
and publications also played important parts in advancing the frontier
of understanding cholera.
A fourth point is the variety of justifications that underlay
official action. Phillips’
work in the NAMRUs was of course fueled by military considerations. Diplomatic factors led to the American response to the Bangkok
outbreak in 1959 and to establishment of the SEATO laboratory. Political face-saving was initially behind the US-Japan
program. The ICMRT program supporting the Johns Hopkins team in Calcutta
was an effort to protect the health of Americans. Development and humanitarian factors led to the
ICDDR/B. Scientific/medical concerns led to the distribution of the
purified toxin and, of course, to many of the individual actions
justified so variously above. All
of these motivations are legitimate wellsprings of action, but the
picture that emerges from this history is not one of a prudent,
thoughtful blueprint for the conquest of disease. Indeed, it seems unlikely that we would have as coherent and a
successful story to tell as we do were it not for the fortuitous
interest in cholera taken by that remarkable group of old boys from the
Rockefeller Institute.
Fifth, the cholera experience illustrates the many types of
research and experimentation required to learn to deal with a tropical
disease, and the variety of social and economic factors that affect
interventions at the village level. The process of science extends from the laboratory worker in
an American university working on purified toxins, who may never have
encountered a person with cholera, to the social scientist in Matlab
thana concerned with sanitary and nutritional practices of village
mothers.
A final point is that medical science was advanced immeasurably
by work on the disease; indeed it changed our approach to study of the
gastro-intestinal tract.
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