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.
CHAPTER V
SANITARY WORK AT HAVANA
The Army Board had demonstrated that the mosquito, to become infected, had always to bite some patient with yellow fever within the first three days of his disease. It was evident, therefore, that if we could prevent this being done in every case of yellow fever in Havana, the disease would disappear. This measure alone would be sufficient for eliminating yellow fever.
To accomplish this we required all cases of yellow fever in the city to be reported to the central office of the Health Department. They were at once seen by the official diagnosis commission, and if pronounced yellow fever, were at once moved to Las Animas Hospital in a carefully screened ambulance and placed in screened wards. The routine at Las Animas Hospital precluded the possibility of any mosquitoes biting the patient. Most of the Americans, and in fact patients of all classes, preferred to go to Las Animas. Under Dr. Ross’s care the hospital soon obtained the reputation of saving more yellow-fever patients than could be done at the other hospitals, or at their homes. This reputation was justly acquired. The statistics of this hospital amply bore out the reputation which public opinion gave it. If the patient elected, he could stay in his own home, the room or rooms to be screened were agreed upon, a skilled force of carpenters were sent by the central sanitary office, who thoroughly and carefully screened the designated apartments. Only one point of exit and entrance was left, and this was protected by a vestibule and double door. A number of squads of carpenters, each furnished with its own wagon loaded with the necessary wire netting, lumber, and other material, were always on duty, so that usually within an hour after notice came to the central office night or day, the patient was either removed to the hospital or was being screened at his own home.
To see that sanitary regulations were carried out and that only authorized persons were admitted within the screened quarters of the patient, an officer of the Sanitary Department was always on duty. He sat in the vestibule and required that one door should be closed always before the second was opened. He was changed every eight hours, that is, he was on duty only eight hours in each twenty-four. We soon found that this method could not be carried out in its entirety; that it was the exception that we could get hold of a patient during his initial chill. Generally the patient had been sick one or two days before he came under our observation.