The American Journal of Tropical Medicine and Hygiene - Volume s1-27, Issue 4, July 1947

The five known endemic areas of schistosomiasis in Japan were surveyed by the Commission on Schistosomiasis with the view of ascertaining the extent of these areas and gathering information which would be pertinent to the prevention of this disease in military personnel. The methods employed in the surveys included the compiling of all available information from national, prefectural, and local health authorities, the collection and examination for schistosome eggs of stool samples from children in certain representative schools in each area, and the collection and examination of Oncomelania nosophora, the snail intermediate host of Schistosoma japonicum, in an effort to determine its distribution within the area and the rate of infection with cercariae of the parasite.

The endemic areas surveyed were as follows:

• (1)  The Tone River area in Chiba and Ibaraki Prefectures.
• (2)  The Kofu area in Yamanashi Prefecture.
• (3)  The Numazu area in Shizuoka Prefecture.
• (4)  The Fukuyama area in Hiroshima and Okayama Prefectures.
• (5)  The Kurume area in Saga and Fukuoka Prefectures, island of Kyushu.

Individuals found infected with S. japonicum on stool examination have been reported from other areas including Tochigi, Aomori, and Fukui Prefectures. National health authorities were of the opinion that such cases do not represent infection acquired in these Prefectures but rather imported infections. A relatively large number of such cases has been reported from Fukui Prefecture (1) but it was the view of Japanese health officials and parasitologists that these reports are either in error or represent cases of infection acquired elsewhere. In reply to a specific inquiry, the Health Officer of Fukui Prefecture stated that there were no cases of the disease in that Prefecture. Schistosomiasis was formerly endemic in certain parts of Tokyo Prefecture, but it is said that all these foci of infection have now been eradicated.

The Tone River area, which lies partly in Chiba Prefecture and partly in Ibaraki Prefecture, apparently has the lowest infection rate of any area in Japan. While the disease is still endemic in certain parts of this river valley, it is at a very low ebb. An examination by the commission of 390 school children in six localities revealed only 3 cases of the disease. The commission was unable to find specimens of O. nosophora in any place in which a search was made, although the snail undoubtedly still occurs in certain sections. However, the entire river valley east of the junction of the Kinu River should be regarded as a possible endemic area.

From the standpoint of incidence of infection and morbidity rate, the Kofu area, Yamanashi Prefecture, is the most important one in Japan. Of 458 children from four schools in which examinations were conducted by the commission, 245, or 53.5 per cent, were found infected. In spite of the fact that a control campaign has been aggressively carried on in this area since 1942, it is apparent that little has actually been accomplished in the reduction of the incidence of infection or the number of clinical cases.

The Numazu area in Shizuoka Prefecture covers only about 10 square miles and is the smallest focus of the disease in Japan. Only 9 per cent of 155 children from a school in the center of the area were found infected. Authorities stated that there has been a marked decrease in the number of clinical cases of schistosomiasis in this area since the drainage of a large swamp in the heart of the area in 1942.

The Fukuyama area in Hiroshima and Okayama Prefectures ranks third in importance of the endemic areas in Japan. Examination of 357 school children in the area indicated an infection rate of 9.5 per cent. Through the organized control work which has been carried on in this area over the past 30 years, the disease has been gradually reduced and the distribution of the snail intermediate host considerably restricted. At the time of the present surveys, the infection seemed to be confined principally to the townships of Kannabe and Miyuki in Fukayasu County of Hiroshima Prefecture, with the center of the focus near the village of Katayama where the disease was first discovered.

The Kurume area in Saga and Fukuoka Prefectures, island of Kyushu, is approximately of the same size as is the endemic focus at Kofu, Yamanashi Prefecture. However, the infection is more spotty than in the Kofu area, some sections showing a high incidence of the infection while in other sections the disease is at a much lower ebb. Examination of 328 children in three schools within the area revealed an infection rate of 25.9 per cent. The distribution of the snail intermediate host within the area varies considerably, the snails being found in abundance in the high incidence zones and few in number or absent in certain other sections where the incidence was found to be lower. This situation is apparently due to the operation of natural factors since practically no control work has been carried out in this area.

A total of 1,688 school children between the ages of 8 and 15 years was examined by the commission in the five endemic areas. Of these, 381, or 22.6, were infected with S. japonicum. Due to a confusion in records, the sex of 14 individuals was not recorded; one of these individuals was positive. Of the remainder, 802 were males, of whom 234, or 29.2 per cent were infected, while 872 were females, of whom 146, or 16.7 per cent, were found positive. This considerable difference between the infection rates in males and females confirms the impression of Japanese health authorities and physicians that males more frequently suffer from the disease due probably to their greater opportunities for acquiring infection.

• 1.  All structures of 299 premises in a block of over 38 square miles in Wheeler Reservoir, North Alabama, were sprayed in June with approximately 200 mgm. of DDT per sq. ft., and a similar block was maintained as a control. Inspections of more than one-fourth of all premises in the two areas were made three times each month during July, August, and September and densities of A. quadrimaculatus recorded. The single application of spray markedly reduced the number of mosquitoes for a period in excess of three months. It appears from our observation that residual spraying of premises provides a more effective barrier to the transmission of malaria than does house spraying alone.
• 2.  The study did not elicit any significant decline in mosquito density in the treated area as indicated by larval density, counts from keg shelters or the untreated surfaces of barns.
• 3.  The added cost in this study of spraying all structures on premises was not in excess of one-third the cost of spraying the houses alone—$3.92 compared to $3.00.
• 4.  The importance of treatment of large blocks of premises is emphasized.
• 5.  On the basis of previous information on human blood feeding of A. quadrimaculatus and the present observation of almost complete elimination of this species within the premise by DDT residual spraying of all structures, it appears that complete DDT residual spraying offers more protection against malaria transmission than mosquito-proofing with its practical limitations.
• 6.  Many beneficial side effects as regards a public health program result from the residual spray application including the control of other disease transmitting and pest insects.

• 1.  Methods for collecting, feeding, storing, and manipulating the mite, Dermanyssus gallinae, have been discussed.
• 2.  The life cycle is reviewed with the aid of photomicrographs.
• 3.  Experimental data on the ability of a variety of animals to serve as hosts for the chicken mite is presented.
• 4.  The question of these mites attacking man is discussed.

A strain of jungle yellow fever virus was maintained by alternate passage through marmosets and Haemagogus equinus for seven cycles, after which passages were voluntarily discontinued.

A comparison was made between the efficacy of H. equinus and A. aegypti as vectors of the virus, by submitting the two species to the same experimental conditions and by testing the mosquitoes individually through allowing them to feed upon baby mice at varying periods following the infective meal.

It was found that under the imposed experimental conditions 72 of 164 A. aegpti and 38 of 163 H. equinus transmitted the virus, thus giving a transmission of 43.9 and 23.3 per cent respectively, or an index of 0.53 for H. equinus as compared with an assumed index of 1 for A. aegypti.

Psychic disturbances following the treatment of malaria with quinacrine have been reported by a number of authors.1–4 In such instances it has usually been impossible to exclude as the cause of the mental disturbance the malarial fever itself or some hypothetical toxic substance resulting from the rapid destruction of a large number of parasites by quinacrine. In the present report malaria could be positively excluded as a factor in a number of individuals who developed severe toxic mental reactions following the ingestion of large doses of quinacrine.

PROCEDURE

Thirty-one medical, dental and medical administrative corps officers of a United States Army General Hospital volunteered to take quinacrine at first in suppressive and then in therapeutic dosage. None of these officers gave a history of having had malaria, and all of them had been stationed both before and throughout the observation period in a non-endemic area.The dosage schedule was as follows: Quinacrine hydrochloride 0.1 gram daily for 1–2 weeks,0.1 gram twice daily for one week, and concluded by 0.4 gram three times the next day, 0.3 gram threetimesthe following day, and 0.1 gram thrice daily for the remaining four days.

The lymph node is such a prominent feature, and is of such diagnostic potentiality in so many tropical diseases that a review and correlation of its reactions may be of some value. This review does not include the minutiae of the pathologic pictures possible in the lymph node in the various tropical diseases, nor is it concerned with the discussion of the diseases themselves. The detailed pathology of tropical diseases, including those in which lymph nodes are prominently involved such as filariasis, have been covered by recent publications. The purpose of this paper is simply to emphasize the significant features in the lymph nodes from those diseases in which that structure is conspicuously involved.

It is possible to group these diseases in several ways. One would include those in which the defense mechanism is phagocytosis by the reticuloendothelial system: Oroya fever, histoplasmosis, visceral leishmaniasis and malaria.Another group could include those in which the dominant clinical and pathologic feature is centered in the lymph nodes.

Field trials in British Guiana in 1946 showed that metachloridine at doses of 1 to 2 grams weekly, divided into 2, 3 or 5 parts, completely suppressed natural infections of P. malariae and partially suppressed parasitemia with P. falciparum. Limited data indicate good suppression of P. vivax. No toxicity was seen during the treatment period of 6 months. Lower doses should be tried to determine the minimum effective dose for the suppression of P. malariae and higher doses should be tried for the same purpose in infections with P. falciparum. The ability of metachloridine to suppress clinical symptoms of infections with P. falciparum should be determined.

In studies of the cholera epidemic in Chungking in 1945 (1), cultures of vibrios derived from several patients were classified as of the Ogawa type in one laboratory. The same strains were sent to Dr. William Burrows of the University of Chicago, who reports different results (2). He has recently proposed the classification of Vibrio comma on a serologic basis, but substituting the eponymic or place-name classification with a preferable one of capital letters to indicate the antigenic structure (3). According to his studies, three strains were classified as type AB or of the Ogawa type; two were type AC or the Inaba type; two were type ABC corresponding to the Hikojima type, and two contained antigen B but lacked A. The last mentioned, according to Burrows' scheme of classification, would not belong to 0 subgroup 1 and presumably are not cholera vibrios.Strains of the various types, as classified, showed no orderly pattern of resistance to streptomycin.

Hookworm infection has rightly been considered the foremost parasitic problem in Florida. These parasites, introduced into the State from Africa, encountered the three requisites necessary for their propagation; equitable temperature throughout the year, ample rainfall, and sandy, well drained soil. These factors in an area where a large part of the rural population lived under poor economic conditions provided ideal opportunity for establishing a high incidence and intensity of infection.

Historical Background. Hookworm infection was recognized as an important medical problem in Florida as early as 1903 (3). From January of that year until 1909, an active anti-hookworm campaign was carried to the physicians and teachers of the State by the Board of Health. Accurate diagnosis by microscopic examination of fecal material was begun in 1909. The first survey was made in 1910, just prior to the one conducted in the other southeastern states by the Rockefeller Sanitary Commission (15), later known as the International Health Board of the Rockefeller Foundation.

The establishment of a tropical disease research center in Liberia, open to all medical students and scientists without restriction as to nationality, race or creed, has been announced by Dr. Thomas T. Mackie, president of the American Foundation for Tropical Medicine.

“Over 50 per cent of the world's population lives in tropical areas, subject to many little understood diseases, yet at the time of Pearl Harbor, we found there were only 24 civilian doctors in the entire United States with background training in tropical medicine,” Dr. Mackie said, pointing out the immediate need for extensive research in this field.

Liberia, the African Republic founded just 100 years ago by freed American slaves, offers ideal conditions to study the three factors which at present keep the peoples of the tropics in virtual bondage, Dr. Mackie continued. These factors are 1) ineffective agriculture with poor crop yield, 2) prevalence of highly endemic diseases of domestic animals, which together make for almost universal malnutrition.

The decision that the Fourth International Congress on Tropical Medicine and the Fourth International Congress on Malaria should meet jointly in the United States of America in the spring of 1948 was reached after consultation with officers of the two organizations. The advantages in a combined congress of these international bodies were demonstrated when they met together in Amsterdam in 1938. The Fourth International Congresses on Tropical Medicine and Malaria, as the joint meeting has been designated, will meet in Washington from May 10 to 18, 1948. The Congresses will be under the sponsorship of the Department of State of the United States Government, which is issuing invitations to other Governments to send representatives. The Department of State as sponsor will have the cooperation of the following agencies and scientific societies interested in tropical medicine:

Bureau of Medicine and Surgery, U. S. Navy

Department of Agriculture

National Research Council

Note: Books received for editorial consideration will be intermittently listed. This acknowledgement must be regarded as an adequate expression of appreciation for the courtesy of the author or publisher. Selections will be made for review in the interest of our readers.

Pablo Cova-García. Notas sobre los Anofelinos de Venezuela y su Identificacion. pp. 208. 42 numbered and 25 unnumbered full page figures. XII Conferencia Sanitaria Panamericana. Cuadernos amarillos No. 1. Publicaciones de la Comision Organisadora. Editorial Grafalit, Caracas, Venezuela, 1946.

Acta Tropica. Review of Tropical Science and Tropical Medicine issued in collaboration with eminent Swiss and foreign specialists by R. Geigy, A. Gigon, F. Speiser, R. Tschudi, Professors in the University of Basel. Vol. 2, 1945. pp. 1–384. Price Swiss francs 30.00. Verlag für Recht und Gesellschaft, A. G., Basel.

Herman Mooser. Die Beziehungen des murinen Fleckfiebers zum Klassischen Fleckfieber. Supplementum 4. Acta Tropica pp. 1–87. Verlag fur Recht und Gesellschaft, A. G. Basel.

This comprehensive volume is divided into three parts, the first of which contains brief chapters on the students of Western American fleas, the medical importance of fleas, field and laboratory technique, and the anatomy of the flea in relation to its taxonomy.

Part II, Systematic Classification, occupies more than half of the volume, and in it are listed 246 species and sub-species of fleas occurring in the area west of the 100th meridian. These are divided among 66 genera and five families. The comparative richness of the flea fauna of this area is indicated by the fact that only 33 genera and some 55 species are known from east of the 100th meridian. For each species are given a short taxonomic description, the known range, full host records, and some notes on biology, abundance, and medical importance. Original drawings of the important anatomical characters for nearly all species are a valuable feature.