THE SANITARY BOARD OF HAVANA
At this time, February, 1901, I was health officer of the city of
Havana. The efforts of the Department had been concentrated for more
than two years previous upon controlling yellow fever in that city.
Not only had we met with no success, but yellow fever was actually
worse than when we commenced work. Ample funds and power had been
given us by General Wood, the military governor, and we had by far
the best and most efficient sanitary organization of whose existence,
either before or since that time, I have any knowledge.
When the work of the Reed Board began to point to the mosquito as the
conveyor of yellow fever, the Sanitary Department of Havana was at
its wits’ end and was glad to receive this discovery as a means of
possible help. I, as health officer of Havana, had nothing to do with
the work of the Reed Board in any way whatever, except that I was a
very interested spectator and kept in close touch with the work as
it developed. We assisted the Board in every way that we could. All
the hospitals in the city were under our control, so that we were
enabled to furnish them ample clinical material.
Neither the Reed Board nor any of its members had anything to do
with the practical working out of the methods whereby their theory
was demonstrated, and by means of which yellow fever was finally
eliminated from Havana. These methods were first originated and
worked out by the Sanitary Department of Havana during the year 1901.
They have since been copied and successfully applied in many parts of
the world where yellow fever formerly prevailed.
Dr. Finlay, in a reprint from the _Journal of the American Medical
Association_, April 19, 1902, says:
The final confirmation of the rôle which appertains to the culex
mosquito deso (now included in the genus stegomyia of Theobald) in
the transmission of yellow fever, has now been sanctioned by the
experiments of Drs. Reed, Carroll, Agramonte and the lamented Dr.
Lazear, at Quemados de Marianao, during the winter of 1900, and
afterwards by those of Dr. Guiteras at the Experimental Station
of Las Animas, last summer, and finally by the splendid practical
results obtained by the Chief Sanitary Officer of Havana, Major W.
C. Gorgas, during the epidemic year which has just been completed.
With those facts and the ones which I had gathered in former years,
it is now possible to determine with some degree of precision the
conditions which are necessary in order that yellow fever may
develop in an epidemic form in a given locality, not too highly
situated above the sea level and where temperatures between 25° and
35° C. (77° and 95° F.) either temporarily or habitually prevail.
Dr. Reed and I discussed on several occasions the possibility of
making practical application of his discoveries. It did not seem to
us possible to destroy the adult mosquito in sufficient numbers to
be of any practical use. And we were not sufficiently familiar at
that time with the life history of the mosquito to think of any other
way in which the subject could be approached with a fair prospect of
success.
We, of the Sanitary Department, after a great deal of discussion
and thought given to the matter, decided that we should adopt all
measures that seemed likely to be useful, being guided in our plans
principally by the life history of the mosquito.
After the first two cases—in all some twenty-six—all the Board’s
cases had been very light. We concluded, therefore, that our
strongest measure would be vaccination; that is, to have an infected
mosquito bite a non-immune and give him a light case. If this proved
as successful as had vaccination in smallpox, we could see that this
measure alone would entirely protect against yellow fever, just as
had vaccination against smallpox. We consulted the military governor,
General Wood, on the subject, and he agreed to let us try it as one
of the several preventive measures which we were putting into effect
against yellow fever.
We announced that we were ready at Las Animas Hospital to immunize
against this disease anyone who wished to be treated in this way.
There was no lack of applicants. This was in February, 1901. Most
of the work of the Army Board had been done during the preceding
fall, and at this time we had only one infected mosquito left, which
had been given us by Dr. Reed. This old lady was a veteran in every
sense. She had given several people yellow fever, but her greatest
claim to celebrity was the fact that it had been fifty-seven days
between the first case of fever and the last one which she had given.
The weather is cool in Havana during January, February and March, so
that the stegomyia under ordinary conditions become quite sluggish
in their movements and a great many die. Mosquitoes decrease so
much during these months that yellow fever becomes more or less
rare, and it was very difficult for us to infect our mosquitoes.
While for one hundred and forty years there had never been a single
month in which there had not been some reported case of yellow fever
in Havana, still only a very small proportion of these cases was
recognized during the first three days, and it must be remembered
that a mosquito has to bite within that period of the disease in man
to become infected. We were, therefore, keeping our only infected
mosquito with a great deal of care and tenderness, knowing that we
had to depend upon her to start our vaccination work.
In all Havana there is probably not a single fireplace or other means
of artificial heat, so we sent to the United States and imported an
oil-stove wherewith to keep her ladyship’s room always at summer
temperature. Her home was a large glass jar on a table in the center
of a sunshiny room. In this jar was hung a lump of white sugar on
which she fed when hungry, and to this was added now and then a small
piece of banana. A small vessel containing water was also kept in
the jar. In order that she might have a plentiful supply of fresh
air, the glass top was not placed upon the jar, but a sleeve of
mosquito-netting was tied over its top.
Within the last fifteen years a great deal of study has been given
to mosquito life. It is now known that there are some seven hundred
different species of mosquitoes; that in all species of mosquitoes
the natural food is the various vegetable juices. In all species the
female has to have a feed of blood before she can lay eggs. Blood
does not seem to be necessary for life, but merely stimulates the
function of ovulation. In order that the female may get this blood,
she is furnished with biting apparatus not possessed by the male.
The male never bites, not being physically able to do so. The female
stegomyia, therefore, is alone concerned in the transmission of
yellow fever.
Las Animas Hospital being the yellow-fever hospital for the city of
Havana was a center of attraction for most of the doctors of the
Health Department. Dr. John W. Ross, Dr. John Guiteras and myself
were at this hospital almost every day. Dr. Guiteras had charge of
the vaccination work and of the laboratory where the mosquitoes for
this work were being bred. Our lady mosquito was therefore directly
under his charge. She had given so many people yellow fever and was
therefore so valuable for our prospective work that we all when at
the hospital would drop in to see how she was coming along and to pay
our respects.
One morning about daylight I got a message stating that her ladyship
was in a most critical and desperate plight, as some time during
the night she had gotten her wing caught in a mesh of the mosquito
netting, and had struggled to free herself for so long a time that
when she was discovered by the attendant in the morning, she was
almost dead. I rapidly dressed and hurried to the hospital. Similar
messages had been sent to Dr. Ross and Dr. Guiteras. We found her
condition even worse than had been represented. Two or three of the
doctors on the staff of the hospital had been promptly called in,
and the services of several of our trained nurses had been likewise
obtained. Her wing had been gently liberated from the mesh of the
netting, and her ladyship laid upon a soft bed of cotton batting. The
oil-stove was started up, and the room brought to a very hot summer
temperature, but it was all of no avail. She finally ceased to kick
about nine o’clock in the morning, and died with a larger attendance
of doctors and nurses around her table than had ever been present
around the deathbed of any mere human in the city of Havana.
This account may sound somewhat exaggerated, but the scene still
comes back to my mind’s eye very vividly, how earnest and serious we
all were. A half-dozen of the leading practitioners of Havana were
sitting around the deathbed of this mosquito, looking and feeling
exceedingly mournful and depressed. And it was a very heavy blow to
the Health Department of Havana. It was well on into the summer,
the month of July, before we succeeded in getting another infected
mosquito, and in proceeding with our vaccination work. Finally,
we succeeded in infecting several mosquitoes, and bit with these
mosquitoes sixteen persons, of whom eight developed the disease.
Much to our alarm, several of these cases developed very violent
symptoms, much more so than had occurred in any of the cases of
the Army Board, with the exception of Lazear and Carroll. Three of
these eight positive cases vaccinated by Dr. Guiteras died; one of
those who died was a Miss Maas, a trained nurse from the United
States, who requested to be allowed to get immunity in this way. Why
our cases should have been so severe, and all of the cases of the
Board so mild, no one has attempted to explain. It is a fact that
during the hot summer weather the extrinsic period of incubation in
the mosquito, that is, the time after which the mosquito bites the
man sick with yellow fever until she herself is able to convey the
disease, is considerably shorter than the same period during the cool
winter months, this period in the summer months being from twelve to
fourteen days, and in the winter months, from fifteen to twenty days.
I am inclined to think that there is probably the same difference in
the virulence of the infection developed by the mosquito in the hot
summer months, and in the cool winter months.
This experience demonstrated to us most forcibly that vaccination
could not take any prominent part in our preventive measures against
yellow fever. While Dr. Guiteras was going on with his preparatory
work at Las Animas and getting ready for his vaccinations, he invited
to the hospital some fifteen or twenty members of the International
Sanitary Congress who had expressed themselves as being particularly
skeptical with regard to the mosquito theory of the transmission of
yellow fever. This Congress assembled in Havana during the month of
February, 1902. The laboratory at Las Animas was the room I have just
described as being the home of the mosquito known as “Her Ladyship.”
It was carefully screened with wire netting at all the windows, and
the single door was protected by a vestibule which itself had double
doors. This vestibule was built upon a platform some four feet above
the ground and just outside the door of the laboratory. The visitors
pretty well filled the small room. Dr. Guiteras started at one end
of his laboratory, explaining that in this jar he had the eggs of
the stegomyia mosquito, and invited his visitors to examine them;
in the next jar, the larvæ; in the next, the pupæ; in the next, the
young mosquito just born, and in the last jar, the mosquitoes which
had passed their period of extrinsic incubation and were now ready to
convey yellow fever.
While handling this jar, the sleeve of mosquito-netting accidentally
slipped off, and a dozen or more mosquitoes soared toward the
ceiling of the room. Our visitors stood for a moment dumfounded,
open-mouthed and wide-eyed. Then each one of the twenty, at the
same moment, made a rush for the door. The vestibule was small and
would hold only about four persons, so that the pressure from behind
toppled it over onto the ground four feet below, and in a moment,
there were some twenty gentlemen in a pile on the ground struggling
to get as far as possible from these deadly lady mosquitoes.
Dr. Guiteras afterwards assured us that his mosquitoes had
never bitten a sick man and were not infected; that he was only
demonstrating the processes of mosquito-breeding and infection that
would have to be carried out in the vaccination process. Our visitors
laughingly acknowledged that, at any rate, their subconscious selves
had been convinced of the correctness of the theory of the mosquito
transmission of yellow fever.