HEALTH PROTECTION IN A SHRINKING WORLD*

            DAVID J. SENCER
Director, National Communicable Disease Center, Athta, Georgia 30333

Not long ago, I received a telephone call from
n physician in Cleveland, Ohio, who had been
referred to NCDC by his local health department,
lie thought he had a patient who had South
,\frican tick typhus fever. I replied that I would
not know the difference between South African
tick typhus fever and tsutsugamushi fever. He
promptly told me that they were very similar."'
The physician had been in the Navy in the South
Pacific during World War II and had had oppor-
tunity to observe and manage tsutsugamushi
fever. His patient had returned 10 days pre-
viously from a safari in Kenya and had developed
lymphadenopathy, eschar, and fever.

If the Presidential Address of last year did not
indicate to this group the shrinking nature of this
lvorld, certainly this story should.`*' With today's
transportation, with today's dispersion of peo-
ple-military, Peace Corps. technicians, trav-
elers-the "fortress mentality" that perpetuates
stringent quarantine activities can no longer exist.
The Public Health Service was established in
li9S to prevent the importation of pestilential
disease from abroad. The Service still has that
responsibility, but today this responsibility can-
not be met by 1798 methods.

There is no single method which can protect
this nation, or any nation, against the importation
of disease. It must be a mix-a mix determined
by the nature of the disease and the technologies
available to control the disease. This includes
surveillance at the border, surveillance in the
interior, and global surveillance. It must also
include programs that control and ultimately
eradicate those diseases which are a threat to
this and other countries. These activities must
be carried out by the country seeking to protect
itself and by the countries in which diseases are

*Thirty-third Annual Charles Franklin Craig Lec-
ture, presented before the Seventeenth Annual Meet-
ing of The American Society of Tropical Medicine
and Hygiene, Atlanta, Georgia, 30 October 1968.
The views expressed are those of the author and
do not necessarily represent those of the U. S. De-
partment of Health, Education, and Welfare.

occurring. The endeavor must have the involve-
ment of international organizations and must be
conducted on the basis of science rather than
tradition.

The past 2% years have seen a drastic over-
haul of the quarantine procedures as practiced by
this country, turning from traditional to scien-
tific methods. Hopefully, at the next World
Health Assembly in Boston in July 1969, the
other nations of the world will join with the
United States in modernizing concepts of quaran-
tine by ratifying a major revision of the Inter-
national Sanitary Regulations."'

The changes in the United States' practice of
quarantine have been both programmatic and
procedural.
. The fact that Mexico has been free of smallpox
since 1951 has finally been recognized by the
United States of America. Therefore. the require-
ment that travelers from Mexico have a valid
smallpox vaccination certificate has been re-
moved. (Recently, Canada has adopted a similar
position, and a person can now travel from the
Yucatan to the Yukon without presenting his
vaccination certificate.)

For countless years, travelers entering this
country with an invalid vaccination certificate
have been vaccinated at the port of entry regard-
less of where they have been. Quarantine inspec-
tors are now following the first principle of good
tropical medicine and asking passengers, "Where
have you been?" If they have been in areas
where there has been no smallpox, and have an
invalid vaccination certificate. they are urged to
see their private physician or their health depart-
ment for vaccination. Only if the traveler has
been in an area which is reporting smallpox within
the past 14 days is he now vaccinated at port of
entry.

TO be alert to changing trends of disease oc-
currence across the globe, the statistics of the
Weekly Epidemiologic Record of the World
Health Organization have been computerized."'
This is not an accurate morbidity report, but
does reflect changing trends and, hopefully, as

341


342                      DAVID J.

countries see the benefits of this type of data
sharing, reporting in itself will be improved.

As part of a professional-awareness program,
an international counterpart of the Morbidity
and Mortality Weekly Report has been insti-
tuted."' Hopefully, this should help combat the
tragic lag-time in recognition of imported dis-
ease-witness the soldier with plague undiagnosed
for 11 days in a Dallas hospital"`-witness the
airman that died of malaria in a California
hospital."'

And, finally, the antiquated block inspection
characterized by an embarrassed quarantine in-
spector walking down the aisles of a dimly lit
airplane, assuring himself that none of the dis-
gruntled, tired passengers is incubating a loath-
some disease, is no more.

The changes in the International Sanitary
Regulations that are proposed are as much ones
of attitude as they are of substance. There are
substantive changes-typhus and louse-borne re-
lapsing fever would no longer be diseases subject
to quarantine. But, also, one of the recommenda-
tions of the Committee on International Quaran-
tine was that its name be changed to that of
the Committee on International Health Protec-
tion/Communicable Diseases. This is a signifi-
cant change and is reflected in many other
recommendations of the Committee."'

Member states are encouraged to call upon
the Organization for assistance in investigating
outbreaks of disease.

Surveillance is promoted as the best protec-
tion a country can have.

The Director-General is asked to take a more
assertive position toward those countries which
practice harsh and unnecessary measures of
quarantine.

Part of a system of health protection is the
eradication of disease that threatens a country.
Currently, there is a most successful venture in
international co-operation in disease prevention
being conducted by 18 West African nations with
the co-operation of the United States (USAID
and NCDC) and the World Health Organiza-
tion.`*' The goal of this co-operative effort is
the eradication of smallpox from West Africa,
one of the four principal foci of smallpox in the
world. To date, with less than 2 years into the
program, 60 million people have been vacci-
nated-over half the target population.`8910' They

SENCER

are being vacci&ed despite the logistic and tech-
nical problems that defy the imagination of a
person who has not experienced it.

But this is not just another mass vaccination
program. This is a program that includes assess-
ment, evaluation, and the development of a sur-
veillance system, with a prompt, effective, reac-
tion mechanism to suppress new occurrence of
disease.

The press is full of the many so-called failures
of foreign-aid programs, of the staggering cut-
backs in appropriations, but here is a program
of which this country can be justly proud, not
only of its technical excellence, but from its
many by-products.

In January of this year, a ceremony was held
in Ghana commemorating the 2.5 millionth vac-
cination. The speakers in the football field in
the village of Mampong were the Minister of
Health of Ghana, the Surgeon General of the
United States, the Minister of Health of Niger
(a French-speaking country), the Secretaries-
General of the French Organizations of West
African States, and a representative of the
World Health Organization. This coming to-
gether of the anglophone and francophone coun-
tries in itself is a triumph. But, then to hear
representatives of these countries, one after an-
other, in the World Health Assembly, stand up
and make a plea for better communications on
health matters between neighboring countries
(when to send a cable from Lagos to Cotonou-
a scant 2-hour drive-the route of the cable is
from Lagos to London to Paris to Cotonou.J--
these events give rise to the hope that through
a disease-eradication program, peripheral benefits
of improved methods of living together can be
achieved.

The bright, eager, intelligent, compassionate
young physicians and operations personnel that
have gone to work in Africa make an impression,
There is one country in West Africa where the
Chinese have made strong inroads. The reprc-
sentative from that country made a special point
in open session of the World Health Assembly in
May to praise the United States of America. The
praise was not just for financial assistance to the
Smallpox Eradication Program, but more sPe-
cifically for the high caliber of the young c.`-
technicians who are working with his peoPk
toward a common goal.


CHARLES FRANKLIN CRAIG LECTURE                 343

The benefits do not just accrue to the nations
that are being assisted. Not only is the United
States helping to protect itself by helping in
the eradication of smallpox, but it is also indi-
cating to these developing nations that the United
States is a country that cares.

The preceding are events that have transpired.
What follows is suggested for the future, but
for the very near future.

At the present time, yellow-fever control ac-
tivity in the Western Hemisphere is primarily
Aedes aegypti eradication-in Africa, emergency
control of epidemics-in South Asia, quarantine
of individuals who do not have valid vaccination
certificates and come from yellow-fever areas.
The latter two approaches are acceptable for the
technologies available and the conditions existent
in Africa and Asia. However, has the time come
for a review of the dependence on yellow-fever
control through A. aegy$ti in the Western
Hemisphere?

A. aegypti eradication was demonstrated at a
time when there were urban epidemics of yellow
fever with concurrent public concern.(u)
A. aegyfiti eradication was demonstrated at a
time and in an area where the widespread use of
artificial containers, such as the beer can, had
not come about.

A. aegypti eradication was demonstrated at a
time when vaccines had not been developed to
the efficacy and safety they have today.""
A. uegyfiti eradication was demonstrated at a
time when the jet injector for rapid immunization
was unknown.`13)

A. uegypti eradication was demonstrated before
the advent of chlorinated hydrocarbons and or-
ganic-phosphorus insecticides.`"'
A. aegypti eradication was developed before
methods of rapid application of insecticides had
been developed.""

Finally, it has been demonstrated that there
are other mosquitoes that can transmit yellow
fever.(18. 17)

There has not been a challenge of the biological
efficacy of A. aegyfiti eradication. Has there
been documented sufficient import of viremic
persons into an urban area where A. aegyfti
eradication has occurred to test whether other
vectors cannot take the place of A. aegyfiti in
the urban transmission cycle?
Can the concept of hemispheric eradication be

supported in the absence of global eradication?
Did not Anopheles gumbiae become established in
Brazil in days when transportation was much
slower and much less frequent? From whence
came gambiue?"*' That same coast of Africa that
led to the introduction of A. gumbiue into Brazil
is heavily infested with A. aegypti and the scene
of the most recent epidemic of yellow fever.`18'
Therefore, to be consistent with the concept of
A. uegypti eradication as a primary means of
controlling yellow fever, global eradication is
necessary. But global eradication is not some-
thing that can be staged in one country and then
another. It must be a simultaneous, total under-
taking. Without simultaneous totality, reinfesta-
tions will be the rule rather than the exception.
However, in 1968, can it be proposed to the
developing countries of the world that they place
a high priority on A. uegypti eradication in the
absence of the immediate threat of disease? This
would lead to major diversions of funds from
other health programs and a drain of scarce
managerial and scientific manpower. A country
struggling to provide even the barest of basic
health services cannot be expected to indulge in
the luxury of A. uegypti eradication for the pro-
tection of other nations.

The technical discussions at the 21st World
Health Assembly this past May in Geneva cen-
tered around the concept of surveillance. More
attention must be paid to surveillance of yellow
fever, its vectors, and its virus, particularly in
the jungle phase. In other diseases for which
there are not eradication methods, it is recog-
nized that there will be an occasional case, but
surveillance should be such that the initial case,
or at least the first generation of cases, arising
from an importation is recognized and the second
prevented. The technology to accomplish this in
the case of yellow fever is available with rapid,
mass vaccination and vector control. If the
punitive aspects of quarantine are dispelled, as
the current revision of the International Sanitary
Regulations hopes to do, countries should be
willing to admit to the occurrence of the disease
and take prompt action, soliciting assistance if
they cannot cope with the situation themselves.

In a redirection of the methods to control
yellow fever on a global basis, not only the
practice of surveillance and prompt epidemic
assistance must be strengthened, but both basic


344                       DAVID J.

SENCER

and operational research need to be expanded.
There are still many unanswered questions.

What is the density of A. uegypti necessary in
an urban situation to support the transmission of
the virus?

Can source reduction programs, as part of a
generalized community sanitation program, so
reduce the density of A. uegy$ti in the urban
situation that additional efforts would be un-
necessary?

Are there methods to control jungle yellow
fever?

What are the potentials of biological and
genetic control?

Global species eradication through mechan-
ical and chemical means alone is doubtful. The
development of insecticide resistance among A.
uegypfi has been documented, and there has
been speculation about changing habits of the
mosquito.`20'  Man has not been too successful
in eradicating other species. Those species which
have been eradicated, such as the passenger
pigeon, had a marginal ability to survive. The
A. aegypti, on the other hand. shows an uncanny
ability to adapt to new and changing environ-
ments.

This is not to deprecate the effort that has
been expended to eradicate the mosquito from
many parts of the world. Undoubtedly, this effort
has prevented disease and, quite likely, epidemics.
But change must not be resisted. The malaria-
eradication effort has taken advantage of the
introduction of new methods: From draining and
larviciding to residual spraying, to mass drug
therapy, and to multiple combinations thereof.
And yet, today, the World Health Organization
is willing to call for a reassessment of the strategy
of malaria eradication.`n' Now is the time for
a reassessment of the strategy of yellow-fever
control.

South African tick typhus fever will never
become a major problem to the health of the
United States, but malaria was a major problem
to the airman who died? undiagnosed, in a hos-
pital in California. You are but a small handful
of people who serve the tropical medicine needs
of this whole nation and, unfortunately, you
don't look any younger than you did 2 years
ago. There are organized governmental activities,
such as those described, that can aid in protecting
the nation against major exotic disease, but it is

upon the shoulders of you who teach to inculcate
upon all students of medicine that in this shrink-
ing world, one of the first questions that should
be asked in the medical history is, "Where have
you been?"

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CHARLES FRANKLIN CRAIG LECTURE                345

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