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mosquitos. Not because we are worse off in this respect than other states, which we are decidedly not, but because we need to keep in the lead and maintain the reputation which this state justly deserves. The economic importance of the problem has already been referred to by Dr. Ebright. The above sum could be made to bring about maximum returns by meeting each proposed mosquito control district half way in the estimated cost of the work. 'Thus if $15,000 is needed to carry on the work, it is proposed that the state bear $7,500 of the expense. I believe the maximum amount of efficiency could be insured in this manner with expert supervision through the State Board of Health.
In the absence of such assistance local campaigns have been financed in various ways,-. g. by cash contributions, subscriptions, tag days (one of the tags used in Oroville, dated April 16, 1910, was here exhibited], business interests contributed liberally based on number of men employed, etc. In one community about $700 was contributed by a single fruit packing house. Each campaign thus financed was placed in charge of a trained worker who was held responsible for the results. Much good has been accomplished in this way, but a more permanent plan is now needed.
Mosquito Abatement by Law The next step has been the organization of mosquito abatement districts, under the new “mosquito abatenient districts” act, Assembly Bill No. 1565, Chapter 585, of the laws of 1915: “An act to provide for the formation, government operation, and dissolution of mosquito abatement districts in any part of the state to facilitate the extermination of mosquitos, flies and other insects.” Its provisions are sufficiently broad to cover all necessary work, not only in the control of malaria, but certain other evils. In referring to this act at a dinner given in Bakersfield in honor of the supervisors of Kern county the statement was made that this act is broad enough to cover anything which any community might undertake with reference to the control of mosquitos, flies and bugs in general, that the terni "bugs” is broad enough nowadays to cover almost any evil. That the viewpoint of "boosters” is rapidly changing is evidenced by the circumstance that facts are being faced squarely. "Mosquito abatement" as a toast at a banquet such as referred to above is a matter of no small import.
There have been already organized several such districts under the above act, among them one in San Mateo county and one in Marin county. Bakersfield and vicinity is organizing on a fifty-square-mile basis; Springville, in Tulare county, will organize a ten-square-mile district; Fairoaks, in Sacramento county, will probably organize a twentyfive-square-mile district, and one or more districts are proposed in Shasta county. Indeed, the interest is so great in this matter that the speaker has much to do in organizing this work under the auspices of the State Board of Health and the University of California. Several of the districts will avail themselves of the limit set by the provision of the act, namely ten cents on the $100 taxable property.
Oil as a Preventive Many of the more important practical aspects of malaria control have been pointed out by previous speakers, but a repetition or emphasis of these may be pardoned at this time. The importance of knowing everything possible about mosquitos is now evident; this also applies to the malaria parasite and the disease caused by it. Campaigns must be properly organized and financed and placed in supervision of competent experts, a saving in time and money and resulting in maximum efficiency. Time and again I see much waste and poor results, or no results, in misdirected mosquito campaigns. For example, my opinion was requested in the matter of mosquito control several years ago in Kern county. Oil had been recommended without proper qualifications. Heavy crude oil was applied to ponds, many of which were not breeding mosquitos. Other apparently insignificant pools were not oiled. Heavy crude oil with a paraffine base has the tendency to form blocks, and between these blocks, the mosquito wrigglers, if present, continue their development without harm. Many so-called mosquito campaigns have thus resulted in fiasco, and general skepticisin toward so-called scientific recommendations is engendered.
It may be pointed out that a very satisfactory oil for this purpose is a twenty-eight degree to thirty two degree Beaumé treated stove oil, which is cheap (I believe about 4 cents at Bakersfield), spreads well, and can be readily applied with a knapsack spray pump. As a substitute, one may use a mixture (equal parts mixed thoroughly) of ordinary crude oil and kerosene. I have not recommended the use of "larvicide" used in the Panama canal zone, because of the fact that it contains carbolic acid, the active poison, which would be dangerous for domesticated animals in almost any section of California. It is often difficult enough to persuade people to permit us to apply oil alone to mosquito breeding pools.
Draining the Breeding Pools The importance of drainage has already been sufficiently emphasized. As Dr. Wilbur has already pointed out, irrigation is one of the most important factors in the malaria problem. The relative absence of mosquitos (except in the Imperial valley and the salt marshes) and consequently the absence of malaria south of Tehachapi is due to the fact that the farmers there know how to handle their irrigation water to best advantage,-a matter of great econoinic importance in that section. An equal amount of care in the portions north of Tehachapi, where water is reiatively abundant and is largely wasted, would produce striking results.
With the development of rice culture in California we are confronted with a serious problem in mosquito control, and an added factor in the malaria question. Already letters of complaint and letters of inquiry are coming in, and the general tone of these letters is quite pessimistic. A study of the rice industry from the standpoint of mosquito control becomes imperative. I am glad to say that a graduate student has presented himself who has had some experience in this connection. Possibly we shall have to depend on certain natural enemies of the mosquito to overcome this difficulty.
Little has been done in our state to develop ordinances against mosquito breeding places. There is an ordinance in force in Tehama county known as an ordinance to exterminate mosquito larvae. The usual difficulty is met, that of enforcement. The Tehama county ordinance contains a defining sentence which is a new departure, and is very useful in determining whether or not the water is stagnant, i. e. actually in a state contrary to ordinance, namely, “The presence of mosquito larvae in said waters is proof that the water is stagnant."
Warnings on Quinine Treatment Before closing these preliminary remarks I wish to point out certain dangers in the continuous and heavy use of quinine. Entirely too much quinine is consumed per person in our great valleys, with the result that the malaria parasite becomes more or less resistant to the continuous large quantities of this chemical, and malaria persists even in the presence of the best known specific against it.
Quinine prophylaxis may be carried out to advantage in situations where mosquito control is impossible, or where you are inaugurating mosquito control work. Quinine prophylaxis involves sweeping individual treatment, and therefore almost unsurmountable difficulties arise where sentiments favoring personal liberty prevail.
Winter treatment of malaria carriers is most heartily favored by the speaker and it is believed that the State Board of Health will urge this matter upon the physicians of the state.
A wise combination of the methods above outlined, with our hope largely placed on persistent and widespread mosquito control, will most certainly result in driving the worst evil that we possess, namely malaria, out of the bounds of our beautiful state. (Applause.)
[Professor Herms' remarks were here illustrated by lantern slide pictures.]
THE PRESIDENT: The report of Professor Herms' work as well as his illustrations are certainly very interesting. We have two more papers tonight, but probably we have gone far enough in the subject to pause for a moment to see if anybody has any comments to make, or questions to ask of Dr. Herins. We could not go very far into the discussion, but I am sure Dr. Herms would be very glad to answer any questions.
MR. BIENENFELD: I think it would be very interesting to hear something more about the life history of that parasite, if it could be done shortly.
Remarks by William B. Herms PROFESSOR HERMS: The story of the life history of the malaria parasite is rather a long one, and could better have been taken up in greater detail at the time we had the slide. But I might repeat that there are two definite cycles, the human cycle which begins at the time the mosquito introduces the parasite into the body of the human being, the mosquito having picked up the parasite from some other human being having malaria, or having had the same and having beconie a carrier. There are many people who helieve that the mosquito picks up the malaria parasite in the swamps. This is, of course, a mistaken notion without foundation, except that the swamps and malaria are commonly associated. The mosquito picks up the parasite from the human being, and this undergoes a cycle of changes within the body of the insect. The parasite having undergone these changes and having multiplied it is then injected into the blood, -not only one but a great many with each bite of the insect. Each organism attacks a red cell enters it and eventually divides into a number of smaller bodies, eachi of these on liberation attacking other red corpuscles. Some of these parasites have the ability to develop into sexual forms, but the majority are asexual. These latter multiply every forty-eight hours (more or less, depending on the type of parasite) and after there are sufficient of these in the body of the human the well known malaria paroxysm shows itself. These paroxysms repeat themselves every other day or every fourth day depending on the kind of plasmodium, until quinine is taken or the strain runs out. Some persons remain infected literally for years even without reinoculation by the mosquito.
Some of these parasites, as already intimated, will develop into males and some into females. It is absolutely necessary that these should be present in the blood when the anopheles mosquito bites. There are certain factors which will explain why a person may be bitten and still not be infected with malaria, namely, the anopheles may not have been infected by not having bitten a malarial person at tlie right time, or the parasite may not have developed far enough in the body of the mosquito to be infective. Will this added information suffice? (Applause.)
THE PRESIDENT: Any further questions to ask Dr. Herms?
PROFESSOR HERMS: An oil at about twenty-eight degrees Beaumné or a product known as treated stove oil.
THE PRESIDENT: I think I will ask Mr. Burdick~he is our expert—if he takes issue with the speaker, that the Anopheles quadrimaculatus is the worst breed of mosquito?
MR. BURDICK: I wanted to ask that question be read and see if the stenographer got it.
THE PRESIDENT: We will pass to the next paper. Most of these papers treat of the same subject, but they have different titles. The next subject will be “The Source of Malaria in California and Its Control,” by Professor Karl F. Meyer, of the University of California, the assistant professor of tropical medicine in Berkeley.
Dr. Meyer was sent some years ago by the British Government to Central Africa to investigate the subject of tropical diseases there, and his experience is of great value to him in dealing with this question of malaria in California. We will ask Dr. Meyer to speak upon that subject of the control of malaria in California.