Correlation between meteorological data observed at Gokwe and intensity of malaria outbreak or the number of clinical malaria cases occurring at malaria season in whole Zimbabwe was studied. Meteorological year (Met Year) in this country starts in July at the coldest month and ends in the next June, and malaria peak season lasts from January to May. The correlation of the number of clinical malaria cases at peak season in thousand (Mp) and meteorological factors was calculated from the data in 8 years from Met Year 1990/1991 to 1997/1998.
Among single factors, correlation was highest with a total rainfall (mm) in a year (Rt) followed by that in January (R1), in February (R2) and average temperature in August (Av8), showing the coefficients of 0.873, 0.870, 0.862 and 0.739, respectively. The adjusted R² of the above factors were 0.722, 0.717, 0.700 and 0.470, respectively, where Av8 was non significant statistically. In two meteorological factors, the correlations higher than a single factor were a combination of R1+R2 with an adjusted R² of 0.792. Malaria at peak season will be increased by more rainfall in January, February and total in a year, and may be high average temperature in August. Formulae of regression lines are as follow, and by these, intensity of malaria outbreak at malaria season will be indicated.
1. Mp = 361.30 × Av8-6, 182.96 (approximation)
2. Mp = 3.12 × R1+43.37 (good fit)
3. Mp = 1.82 × R1+2.47 × R2-15.02 (best fit)
4. Mp = 1.463 × Rt-323.21 (good fit for retrograde study)

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A field study was conducted to evaluate the effects of indoor residual house spraying of Bifenthrin and Deltamethrin on malaria vector population of Anopheles minimus s.l., from April 1999 to April 2001 at rural villages in Mae Hong Son province, northern Thailand. Nine villages in Mae Hong Son province were selected for the present study (three villages for control and three villages each for insecticide spray). The residual spray of Bifenthrin (25 mg/m²) showed greater adulticiding effects on An. minimus s.l. population than Deltamethrin (20 mg/m²). In Bifenthrin treated villages, a clear decrease in biting density of An. minimus s. l. was found in human bait collection as well as animal bait collection after the insecticide spray. In all of the three villages, the average density after insecticide spray was significantly lower than that observed before the spray. The effects of Deltamethrin on An. minimus s. l. density was found only in one village out of the three treated villages. A significant decrease in parous rate after insecticide spray was found in all the villages sprayed with Bifenthrin, whereas no significant changes were observed in control villages. The average parous rate in the villages treated with Deltamethrin became significantly higher after the insecticide spray. These results clearly suggested that the residual spray of Bifenthrin (25 mg/m²) was more effective than Deltamethrin (20 mg/m²).

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Tropical subjects regulate core temperature with less amount of sweat against heat compared to temperate subjects through long-term heat-acclimatization. The purpose of the study is to determine whether acclimatization in tropical subjects decay during a stay in temperate area. Local sweating response activated by acetylcholine (ACh) applied iontophoretically among Malaysians (n=26) with varying duration of stay in Japan and Japanese residents subjects (J-R n=30). Based on their length of stay, Malaysian subjects were divided into three groups, group M-S (n=9) with a duration of stay oflto 12 months, M-M (n=7) with 13 to 36 months and M-L (n=10) with 37 to 72 months. ACh, the primary transmitter for sudomotor innervation, was iontophoretically administered on the forearm. Sweating response elicited directly (DIR) and indirectly via axon reflex (AXR) were evaluated by quantitative sudomotor axon reflex test. The onset-time of AXR was shortened with the longer duration of stay among Malaysian subjects (P <0.01). DIR, sweat volume directly (ACh muscarinic receptors) induced by ACh for 6-11 min, was 0.68±0.35 mg/cm², 1.02±0.64 mg/cm², 1.45±0.71 mg/cm² and 2.39±0.47 mg/cm² in M-S, M-M, M-L and J-R, respectively. These were statistically different (P <0.01). From these results, suppressed neuroglandular response to ACh was confirmed in Malaysians. It is suggested that long-term heat-acclimatization acquired in tropical subjects may decay after immigration to temperate area.

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Human Heterophyes nocens infection was confirmed in 2 areas of Mikkabi-cho, Shizuoka Prefecture where high prevalence of Metagonimus yokogawai infection had been reported. The total prevalence showed 9.6% by stool examination. Among the patients, the older age's males predominated, and the infection within the same family was often observed. Adult worms were collected from stool samples of the patients after treatment with praziquantel. The worms were identified as H. nocens with morphological characteristics. The average size of eggs (27.8×16.1 μm) appeared in stools of the patients was slightly larger than that reported earlier, and rather equivalent to eggs of M. yokogawai. Questionnaire study revealed a correlation of a habit of eating raw fish, mullet in particular, and the trematode infection in Hamana Lake.

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We conducted a survey of the prevalence of Toxoplasma gondii infection in children living in Jaboatão dos Guararapes, Pernambuco, Brazil from 1998 to 1999. This city is situated adjacent to Recife, capital of the state of Pernambuco. We determined the prevalence of specific anti-T. gondii IgG antibodies in 196 individuals from 2 to 16 years of age. Individuals who were IgG antibody negative also underwent specific anti-T. gondii IgM testing to detect recent infection with the parasite. Seroprevalence was 79.1%, and high titers of IgG antibody were observed in 49% of positive subjects. The prevalens of antibodies to T. gondii increased with age, with a multiple correlation coefficient (R) of 0.709; however, there was no significant difference in antibody status by sex. Out of 47 children who did not have specific anti-T. gondii IgG antibody, 4 were determined by specific anti-T. gondii IgM antibody analysis to have been recently infected. Stool was examined for soil-transmitted helminth eggs to assess the frequency of soil contact in the entire study population. Stool examination in the population revealed that soil-transmitted helminthiases was highly endemic, with an infection rate of 85.2%in this area. These results suggest that the primary mode of T. gondii transmission to humans is through contact with soil.

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A new black-fly species, Simulium nemuroense sp. nov., is described from pharate female, pharate male, pupal and larval specimens collected from Hokkaido, Japan. This new species is assigned to the slossonae species-group within the subgenus Simulium (Simulium) , by having the following characters : in both sexes of adults, no hairs on the basal portion of radial vein; in the female, the claw with a large basal tooth and the genital fork with two projections on each arm, one directed anteriorly and the other posteromedially; in the male, the ventral plate lamellate with a median wide projection, the style longer than the coxite and with a prominent basal protuberance; and in the larva, the postgenal cleft very deep and the presence of the ventral papillae. S. nemuroense sp. nov. is easily distinguished from all the three known species by several characters including the male genitalia with a wide ventral plate and a hairy basal protuberance of the style, and the cocoon with an anterodorsal projection. This is the first record of the slossonae species-group in Japan.

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