Yours of June 5th received. I inclose you a copy of Dr. Guiteras’ report for May.
We see still no success from our inoculations in twenty-two cases, but the great “but” comes in. I am not sure that any of the cases bitten were yellow fever. One of the last, from Tampico, I thought a pretty well marked case, though not dangerously ill, but his mosquitoes, on the 20th day, did not infect. I am disappointed beyond measure. I had hoped by this time to have Las Animas full to overflowing with inoculated cases, and be turning out immunes at the rate of some two hundred a month. But may be it is well as it is; in our enthusiasm we might have infected the city.
No case of yellow fever since May 7th, and still none on hand. The Board diagnosed one early in the month, but it turned out a well-marked case of typhoid fever. Of course I agree with you that nothing very definite can be deduced from our results this early in the season, though personally I am very much impressed by them. Our condition now is very much better than it was even in ’99, with regard to yellow fever, and of course our liability to it is very much better. ’98 and ’99, with regard to yellow fever, should be left out, as in these years there were no non-immunes in Havana, and they would not have had yellow fever no matter what the condition of infection would have been. I except of course, the latter part of ’99.
From the 1st of March to the 16th of June in ’99 (and mind you this has been far and away the best record Havana ever made), we had four deaths from yellow fever. In the same period this year, we have had one, which occurred March 16th. The deaths in ’99 occurred scattered over this period. It seems to me that the present condition of affairs indicates that we have been doing something that has had a great effect upon infection; and of course the only thing we have done this year that we did not do last year is the destruction of the mosquito. We commenced this work about the middle of February, just about the time that yellow fever practically disappears.
On the 12th of June, 1899, we had had for the month two cases of yellow fever, and in 1900, six. If you consider the amount of work there was to be done, to put oil in all the cesspools, all the water barrels and all the cisterns, once a month, and then keep the streams and pools in the suburbs drained, you will understand that seventy-five men is not at all a large force. I think I could use to advantage more. As you say, we could use less pyrethrum. We arrived at the rate of a pound per 1,000 cubic feet by experiments at Las Animas. We found that in this ratio we could kill mosquitoes in one and a half hours. It would probably be just as well to intoxicate them and sweep them up, and I shall probably cut down the quantity in a short time. We have to sweep them up anyway. But feeling that it may be possible that we have no infected mosquitoes in Havana I want to do everything I can think of, when a case occurs, to increase the chances of killing the infected mosquito in the neighborhood of where the patient got his infection.
We are using now from one hundred to two hundred pounds to the patient, killing the mosquitoes everywhere within half a dozen houses of the patient’s home. There is less objection raised to this than to the ordinary disinfection. It damages nothing, only keeps them out of their room for an hour or two, and kills the mosquitoes. I think there is much less opposition to us on this account than there was last year.
I feel confident that there is very little concealment of cases, and I do not feel much anxiety on this score. We cannot have many light cases without having a death now and then, and deaths would almost certainly be reported.
But what gives me the greatest confidence is that our non-immunes are made up entirely of Spaniards and Americans. The Americans promptly report themselves where there is anything suspicious, for the sake of the better care that they get at Las Animas. The Spaniards are all matriculated at one of the three “quintas,” and go there as soon as they are sick from any cause. These “quintas” are all very anxious to try and catch up to the record of Las Animas, and report every case that they think, by any possibility, will pass the Board. And then, too, I can control the “quintas” by frequent inspections. So it seems to me that there is very little probability of cases being concealed to any extent. Still, we can speak more definitely on this subject about the 1st of December than we can now.
All well. With kindest regards, I remain,
Very sincerely yours,
W. C. Gorgas,
To Maj. Walter Reed, Maj. & Surg., U. S. A.
Washington, D. C. Chief Sanitary Officer.