Che-ju strain of B. malayi was successfully transmitted to three domestic cats by subcutaneous injection of infective-stage larvae obtained from naturally-infected Ae. togoi. The second generation of the strain of B. malayi was established in nine cats which had been inoculated subcutaneously with the infective larvae developed in laboratorybred Nagasaki strain of Ae. togoi. The third generation was built up by subcutaneous inoculation in two cats through Ae. togoi and four cats through Liverpool strain of Ae. aegypti. The prepatent periods were 91-131 days. The microfilaria counts in the peripheral blood gradually increased in one third to two thirds of successfully transmitted cats. The microfilariae of Che-ju strain exhibited a subperiodic tendency in the cat. The average infection rate of laboratorybred Nagasaki strain of Ae. togoi was 69.3% with infective larvae of B. malayi. The mean number of larvae per mosquito was 5.8 with the infective larvae. Nagasaki strain of Ar. subalbatus was not susceptible to B. malayi infection. B. pahangi developed to the infective form in both Ae. togoi and Ar. subalbatus.

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Acute schistosomiasis japonica has become a rare disease in the past fifteen years in Kofu basin because of the marked decrease of Oncomelania nosophora, however, our attention is drawn to the chronic type of disease which has many clinical problems.
The purpose of this study is to clarify epidemiological status of schistosomiasis at present by means of rectal biopsy, the threshold value of the skin test and COP test.
In the period from 1967 to 1973, the 217 patients of Koma-Kyoritsu Hospital were examined by rectal biopsy, the skin test with Melcher's antigen and COP test under the suspicion of chronic schis-tosomiasis. For determining the threshold value of the skin test, twofold dilution series of the antigen solution were prepared, and microscopic examination was made on the raw specimen obtained by rectal biopsy to see whether the eggs were fresh or old.
The results were as follows :
1) The egg positivity of rectal biopsy specimen was significantly higher than that of stool specimen tested with MIFC method.
2) The COP positivity increased in parallel to the increase of the threshold value of the skin test indiluting grade. Among the patients of rectal biopsy, the COP positivity seemed to be higher in the case with 100 or more eggs. It was also significantly higher in the case being detected fresh eggs in the mucosal specimen.
3) The area irrigated by the River Kamanashi was divided into three districts, I, II and III, according to the collected numbers of the snails, which increased in number in order of I < II < III.
a. The incidence of cases with low dilution threshold value of the skin test decreased in order of I = II > III, while cases with high dilution threshold value increased in order of I< II< III.
b. The incidence of the egg-positive cases by rectal biopsy increased in order of I< II< III.
c. The incidence of the patients with eggs over 100 by rectal biopsy increased in order of I < II <III.
d. The incidence of the patients with only old eggs by rectal biopsy decreased in order of I > II > III, while that of the patients being detected fresh eggs increased in order of I< II < III. Thus, results of rectal biopsy and the threshold value of the skin test corresponded with the distribution of the snails both quantitatively and qualitatively.
As mentioned above, the rectal biopsy and the threshold value of the skin test are the important diagnostic parameters, and they are also important for epidemiological analysis of chronic schistosomiasis in such a situation of infection in Japan, where the eggs in feces used to be discovered with difficulty.

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A new improved method to demonstrate plasmodia in tissue section is presented and discussed. Sections are treated with 0.25% potassium permanganate, 2% oxalic acid and 2% iron alum before the application of Giemsa solution buffered at pH 7.2. Differentiation is carried out in 0.5% acetic acid and then in methanol and isopropanol. From our experience this method provides advantages over other methods such as Sano's Giemsa stain, Sano's Pappenheim double stain, Thomas' method, Mallory's PMB method, Price's method, Wolbach's method, Bayley's method and Drury's method, since plasmodia in the tissue can more clearly be demonstrated and more constant results can be obtained.
Ten-percent buffered formalin and Zenker's formalin solution are better fixatives than Bouin's, Carnoy's and ethanol for this purpose.
A new method for the removal of malarial pigment using pyridine is also presented.

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A 21-year-old nurse was admitted to Tenri Hospital on June 25, 1973 in comatous state. She had neither been to the malarial endemic area nor been transfused. However, three weeks before admission she had taken care of a patient with falciparum malaria as a nurse for two days. Six days before admission she had suffered from fever and headache. And three days before admission she had lapsed into coma.
The thin blood films revealed Plasmodium, falciparum parasites. The parasite count was 4, 230/cmm, erythrocyte count was 423 × 10⁴/cmm, and leucocyte count was 14, 300/cmm.
She was administered 600 mg of chloroquine, 1, 000 mg of sulformethoxine and 50 mg of pyri-methamine through a stomach tube, but she died 4 hours after her admission.
Necropsy findings were as follows : (a) Macroscopic findings; the brain was violet in color and splenomegaly, 330 g, was seen. Several small bleeding foci were seen in the gastrointestinal tracts and respiratory organs. (b) Microscopic findings; malarial parasites were revealed in the red blood cells of many organs, especially of the brain, spinal cord, spleen, liver, lungs and lymph nodes. Malarial pigments were demonstrated in the spleen, liver, lymph nodes, heart, lungs, kidneys, ovaries, uterus and bone marrow.
Possible infectious course of this case was discussed. It was presumable that the source of the infection was an imported falciparum malaria case and that she was accidentaly, artificially and directly infected through nursing.

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[in Japanese]

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