CHAPTER V. Sanitary Work At Havana

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.

It was evident, therefore, that a number of mosquitoes might have bitten him before he was discovered and cared for. As it would be twelve or fourteen days before these mosquitoes would become infectious, we had plenty of time to attend to them. From the known habits of the stegomyia mosquito we did not think they would leave the house in which they had become infected, though in an individual case this might occur, and a mosquito wander into a contiguous house.

To meet this condition of affairs, as soon as the case was concluded, the house in which the patient had been sick and all the contiguous houses were fumigated with such material as would kill the mosquitoes. In order that the fumigation might be effective the house had to be carefully gone over and all cracks and crevices stopped, so as to make the building as nearly air-tight as in the nature of things it could be made. This was a very laborious process and required care and expert supervision. Most of the stopping of crevices was done with paper and paste. Sulphur is probably the most effective substance in killing the mosquito. The rolled sulphur was used at the rate of about a pound to the thousand cubic feet of space to be fumigated. We generally used the Dutch oven placed in a box of sand or vessel of water, so that in case of a leak, or in case of the oven’s getting too hot, the floor would not catch on fire. With a large force of ignorant men engaged in this work constant watchfulness has to be used to see that fires do not occur. The proper amount of sulphur is placed in the Dutch oven, a little alcohol poured over the sulphur, and a match applied. The sulphur will burn for three or four hours, and will produce very dense fumes which will fill the building and kill all the mosquitoes. The fumes of sulphur in a building which has been well prepared will kill not only all mosquitoes, but all insect and animal life, and is by far the best material to use for this purpose. It is generally somewhat difficult to start the sulphur burning with alcohol alone, and I have noticed that the men got in the habit of using an ounce or two of pyrethrum placed on top of the sulphur for the purpose of starting the fire. The pyrethrum was moistened with the alcohol and would burn for a considerable time after the alcohol was consumed, in almost every instance starting the sulphur burning.

The fumes of sulphur will tarnish gilt metals of all kinds, and injure most light-colored fabrics. This occurs particularly where the air is heavily charged with moisture. In cases in which sulphur was likely to do damage, we used pyrethrum powder. This powder does not tarnish or injure fabrics of any kind. The building must be prepared in the same way as for sulphur, and the vessel in which the pyrethrum is burned must be arranged as above described for sulphur. The fumes of pyrethrum do not generally kill the mosquito, but simply intoxicate her. In the course of time she revives and eventually entirely recovers. For this reason the building should be opened up within a couple of hours after the burning of the pyrethrum, and all mosquitoes carefully gathered and burned.

In almost all dwellings of the better class of tenants there are fixtures and fabrics which will be injured by the fumes of sulphur. Therefore, in this class of buildings we generally used pyrethrum. For fumigating in this same class of buildings where pyrethrum was used we found a mixture of camphor and carbolic acid, one part of camphor to three of carbolic acid, very useful. This should be placed in a tin dish and vaporized with a spirit lamp. The same procedure should be observed as a precaution against fire as is taken with sulphur. The mixture when vaporized gives off dense white fumes which kill the mosquito. Generally, where care has to be taken for fear of injuring fixtures and fabrics, this mixture is preferable to pyrethrum. Pyrethrum should be used at the rate of one pound to the thousand cubic feet, and the camphor mixture at the rate of an ounce for the same space.

In Havana we had to deal with cigar manufactories and tobacco storehouses on a large scale. Here we could use neither sulphur, pyrethrum, nor the camphor mixture, as they all affected the delicate flavor of the tobacco. At first we used to move all tobacco out of a building to be fumigated. This was very laborious and added largely to the cost of fumigation and also tended to drive out from the building the infected mosquitoes before they had been reached by fumigation. Mr. Joseph Le Prince, who was in charge of this work, after much experimenting found that the fumes from tobacco stems did not hurt the flavor of tobacco, and were almost as deadly to the mosquito as was sulphur. We could therefore fumigate with this material buildings where tobacco was stored without injury to the tobacco. The stems were a waste product in cigar manufacturing, and could be obtained in large quantities at little cost. They should be used at the rate of two pounds to the thousand cubic feet, and with the same precautions against fire as are taken in other cases.

Formalin we found useless. It has apparently little effect upon insect life.

From our general knowledge of the life history of all species of mosquitoes, we knew they had to spend eight or nine days in a larval stage, and that while in this larval stage they lived in water. Therefore, collections of water were necessary for the development of the mosquito. The stegomyia mosquito we knew preferred clear, clean water, such as is supplied by the various collections of rain water needed for domestic purposes. The city of Havana had pipe water over only a small portion of its area. By far the larger portion of the population obtained its water supply from rain water stored in cisterns, tanks and receptacles of all kinds. We resolved to stop mosquito-breeding in all such places.

The city was divided into twenty inspection districts, each district under the charge of a sanitary inspector. This inspector was required to get around to each house in his district once a month and make a careful inspection with regard to mosquito-breeding, and report to the central office on a printed blank the conditions found. If this report indicated that the condition of the premises amounted to a sanitary nuisance, the householder was proceeded against. An order had been promulgated making it a sanitary nuisance for any householder to have mosquito larvæ on his premises. The health officer was given authority to impose a fine for such nuisance; the fine was collected by the Cuban courts, and the proceeds of the fine deposited in the Cuban treasury. The health officer had authority to remit the fine at any stage of the proceedings. In practice, it came about that the whole matter was settled in the Sanitary Department. We employed a lawyer to whom cases of fines were referred. When a householder was reported by the sanitary inspector as having larvæ on his premises, he was notified that under the sanitary ordinance he was fined five dollars for having this nuisance on his premises, but that if the nuisance were abated, the fine would be remitted. This usually brought the man promptly to the office with the statement that the nuisance had been abated. An inspector was sent around, and if the householder’s statement was found to be correct, the fine was remitted.

In a certain number of cases this notice caused no action on the part of the householder. In these cases the fine was sent to the judge of the district for collection by him. In the few cases in which the first notice had not brought the householder to terms, this action by the court did. If he reported that he had abated the nuisance and the inspector when sent to investigate found this to be the case, the fine was withdrawn. In this way we did very little fining. Out of about twenty-five hundred fines levied in the last nine months of 1901, only fifty were finally imposed and deposited in the treasury.

The Sanitary Department was said to be decidedly the most popular of the American departments with the Cubans, and it was this very power of assessing and remitting fines that was the principal cause of our popularity. The Cuban had been accustomed to looking upon laws and ordinances as devices for filling the pockets of the officials, and fines as the legitimate perquisites of those officials. When a fine was remitted, he looked upon it as a personal present from the pocket of the chief sanitary officer to himself, and was grateful accordingly. Why the chief sanitary officer should take so great an interest in mosquito larvæ he could not comprehend. But that officer evidently did take a most decided interest in the matter, and had he not demonstrated his friendship by taking five dollars, which was as good as in his pocket, and giving it to him, the offender? His loyalty was appealed to and generally he remained ever afterwards the friend of the Department.

Cisterns, barrels and receptacles for containing and storing rain water for drinking and domestic purposes were absolutely necessary in the case of the larger part of the population. It was necessary that we prepare these receptacles so that they could not breed mosquitoes. If it were arranged so that mosquitoes could not lay their eggs on the surface of the water, this object would be accomplished. It was therefore provided that all receptacles should be covered in such a manner that mosquitoes could not have access to them. The tops were covered, a small hole being left in the top by means of which water could enter. This hole was covered with wire netting, and a spigot was placed in the bottom whereby the water could be drawn off. This was done at public expense. At the central office squads of carpenters with material loaded in wagons were always on hand to go out for this work. If the sanitary inspector reported that such work was necessary, it was immediately attended to by one of these squads.

For carrying into execution the orders pertaining to mosquito work the city was divided into eight districts, each district in charge of a mosquito inspector. A great deal of stegomyia breeding went on in the interior of the dwellings. Every family had an earthen vessel in which drinking-water was kept for daily use. This always had larvæ in it. It was the inspector’s duty to empty this vessel, point out the larvæ to the housekeeper, and explain that if the vessel were emptied once a day and the larvæ washed out, mosquito development could not occur. All sorts of vessels in a house which might contain water had to be considered as possible breeding-places for mosquitoes. Every housekeeper in Havana, when we started work there, had a number of breeding-places for mosquitoes in her domestic establishment. Among these may be mentioned flower-pots in which a little too much water had been used; cans filled with water, in which the legs of tables had been placed as a protection against ants, etc.

Each mosquito inspector had with him five men, and one of these men carried a sufficient amount of oil to pour upon any pools or puddles about the premises that might need oiling. They picked up old bottles and cans which might contain water and become breeding-places, and generally looked after the yards. The district inspector, at the same time, made a general report on the premises in writing, and on this report the owner was called to account if unsanitary conditions were found existing.

Next to cisterns and water barrels, roof gutters were found to be the most general breeding-places for the stegomyia mosquitoes. Leaves and trash fall upon the roofs, are washed into the gutters, and these make little dams behind which water collects and remains after the rain has ceased. At other times the gutter sags and thus forms a collection of water. In the tropics you can always count upon roof gutters as being places for mosquito-breeding, and being inaccessible and difficult to inspect, such breeding-places are seldom disturbed.

During its larval stage the mosquito lives entirely in water, but has to come to the surface frequently for the purpose of getting air. This necessity is seized upon by man for the purpose of destroying the larvæ. If kerosene oil is poured upon the water, it spreads in a very thin film over the surface. Now when the larvæ rise to breathe, the oil gets into their breathing-tubes when they attempt to force them through the thin film of oil spread over the surface of the water. This suffocates and kills the insect and is very effective.

It is very surprising and impressive to see how rapidly such a system will free a city of mosquitoes, and how after a few months of such work you cease to be annoyed by them. In yellow-fever work this system of destroying mosquito larvæ is the essential; everything else is secondary to it. In the built-up portions of a city such as Havana, caring for the cisterns, water barrels and containers is the essential work, but as you approach the suburbs, pools and puddles become more frequent, and this character of mosquito breeding-places becomes more important than containers. Wherever possible these breeding-places should be drained, though oiling in this class of work has a very useful field. In the suburbs, in these pools and puddles, the anopheles, the malarial mosquito, becomes common and this disease has to be looked after. We had fifty men engaged in this work, under a different set of inspectors from those doing the stegomyia work. This was made necessary, as the men doing the anopheles work were occupied almost entirely in the suburbs of the city. The details I will describe in another place.