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pose of this paper to present certain evidence of the value of spleen. palpation, obtained during the course of investigations in child hygiene made by the United States Public Health Service.

During December, 1921, Maxcy and Coogle, of the malaria field forces, United States Public Health Service, made a malaria survey of a large group of boys of school age in Dunklin County, Mo. (1). It was the privilege of the writer to go over essentially the same ground during the months from August, 1922, to March, 1923. The data collected by Maxcy and Coogle and some of the data collected by the writer are combined in this report as evidence of the value of the enlarged spleen method in demonstrating the malaria prevalence of a community. It is a yardstick, applicable at once in the field rather than at some later date in the laboratory.

METHODS EMPLOYED.

Blood smears. As a routine procedure, blood smears were taken of all the children examined in a given school. The semithick method was used. Each slide received at least 10 minutes of examination in the hands of a trained technician, unless found positive sooner. Spleen. Similarly, palpation of the spleen was routine for all the grammar-school children, irrespective of sex. The examination was made with the child in the standing position and leaning forward until the body made approximately a right angle. In this position most children relax their abdominal walls sufficiently to allow deep palpation during a deep inspiration and expiration. Simultaneously with the inward pressure of the examining fingers, forward pressure is made with the palm of the other hand placed dorsally over the region of the spleen. Boys and girls were examined separately and away from the remainder of the class. Maxey and Coogle used essentially the same technique.

The method is believed to give consistent results. One school of 114 children with a high percentage of positives was reexamined with the greatest care, and there was no important difference in the total number of palpable spleens found. Examination with the relaxation of the abdomen is fully as good as 'that made with the patient lying down with the knees flexed.

DATA ON BLOOD SMEAR AND SPLEEN METHODS.

A comparison between the blood smear findings and the palpable spleens is shown in Table I.

TABLE I.-Relative value of blood smear and spleen methods as a malaria index, as shown by the examination of 880 school children (both sexes) in Dunklin County, Mo.

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The same group of 880 children was examined for palpable spleens and blood parasites. Forty-six, or 5.2 per cent, were found to have parasites in their blood, whereas 45, or 5.1 per cent, had palpable spleens a difference of only 0.1 per hundred in the two methods.

TABLE II.-Number of children with both positive blood and spleen; also the number with only one index positive.

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That the groups of children having positive bloods and palpable spleens, respectively, were not the same children, is shown in Table II. In this group of 880 children, only 21 had both positive blood and spleen, 25 had positive blood and negative spleen, and 24 had positive spleen and negative blood. Accepting both indices as evidence of malaria infection, we find 70 infected children in this group. On the basis of blood parasites alone only 46 were found, and by the spleen method alone, 45. Thus, each method falls short of the two methods combined, but in each case the difference is essentially the same.

In the Beech Corner school the parasite rate ran 5.3 per hundred higher than the spleen rate. Believing that perhaps the first examination was inaccurate, these children were again examined in a most careful manner and the same number of positives were found.

There was also considerable variation between the two indices in the Cardwell school as found on two different examinations. The children who were examined in October, 1922, were those who lived in town and did not go out to pick cotton. The group examined in January, 1923, consisted of more rural children, the cotton pickers. The much greater opportunity for infection during the vacations and cotton picking is believed to explain this higher rate. Both indices increased, especially the spleen index.

TABLE III.—A comparison of certain methods for the determination of malaria prevalence as shown by two surveys in Dunklin County, Mo.

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In Table III there is given a summary of all the data collected by Maxcy and Coogle in December, 1921, and of that collected by the writer a year later. Maxey and Coogle examined only boys in schools selected because of their proximity to the swamps, using only volunteers for blood smears. The writer included both boys and girls; and in getting blood smears in a school every child was included. Some of the schools included in the last survey were not located in the swamp sections. Again, the mosquitoes were less prevalent in the summer and fall of 1922 because of a longer dry season. It was to be expected, therefore, that the indices for the two surveys would not be the same. However, if independent workers are equaily proficient, the parasite-spleen ratio should be the same in the same community at the same time of the year, provided both methods are consistently reliable. Maxcy and Coogle report a parasite index

of 7.3 and a spleen index of 7.9. This is a, ratio of parasite to spleen index of 1 to 1.08. The writer found a parasite index for the county of 5.4 and a spleen index of 5.9, or a ratio of 1 to 1.09.

Barber and Coogle (2), working in Mitchell County, Ga., during January, February, and rch, 1921, report a spleen index of 2.0 per cent among the white boys of the county. This is low, but it followed a summer and fall of intensive quinine medication. In two schools they found a spleen rate of 4.9 among the boys and a parasite rate of 4.7 among the boys and girls combined. This is a ratio of 1 to 1.04. The number so examined was small and not entirely the same group; yet the figures are indicative of what might be expected.

TABLE IV.-Percentage of positive blood smears and of enlarged spleens in children of the present study, according to age distribution.

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Table IV shows the age distribution of the children in the present study with positive blood smears or palpable spleens. In this group age seems to have no effect on the frequency of either condition. This is not in agreement with the findings of Stephens and Christophers (3), who found that in children under 2 years of age the parasite rate is considerably above the spleen rate. With the increase in age, the ratio of the two indices gradually reverses until, after the age of 10, the spleen rate is much higher than the parasite rate. These figures are based on data obtained in India, where cinchonization is probably not very widespread. It may be said that the enlarged spleen of chronic malaria is to a certain extent the accumulative result of one or many infections. Its development and disappearance is gradual. In Dunklin County, Mo., we are dealing with a population which is partially cinchonized from time to time. This certainly has the effect of distorting the age distribution curve as compared with a population not so treated.

In estimating the amount of malaria in a community from either the parasite or the spleen index, it is important to know something of the antimalaria medication in the community, whether the medicine taken is "chill tonic" or quinine, and if the latter how near it comes to being standard treatment.

TABLE V-Prevalence of antimalaria medication among children with positive malaria histories.

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Of 313 children having a positive malaria history within two years who were questioned regarding the taking of medicine, 296, or 94.6 per cent, stated that they took either quinine or "chill tonic" or both. About one-half of this group took quinine, but none in quantities even approaching standard treatment quantities. At the Beech Corner school over 85 per cent of the children gave a history of having taken quinine in some form during the previous year, regardless of any chills during that time. In other words, quinine medication in some form is nearly universal in the heavily infected sections of Dunklin County, Mo.

TABLE VI.-Hemoglobin readings (Tallquist) on 750 school children in Dunklin

Negative blood and pleen...
Prave blood or spleen...

County, Mo.

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The hemoglobin count (Table VI) is presented merely as offering more evidence of the destructive effect of malaria on the blood hemoglobin. The lowest percentage of hemoglobin found in the children examined was 35 per cent (Tallquist). Most of the positive cases gave a reading between 60 and 70 per cent. The possible presence of intestinal parasites was not ruled out by microscopic examination; be stated, however, that some of the most anemie children were given quinine, and their hemoglobin promptly increased.

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DISCUSSION.

It is not necessary here to go into all the causes of splenic enlargement or the frequency with which it occurs. Reference is made to the Public Health Reports (4), where will be found a good abstract

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