ケニア諸地域住民の腸管寄生原虫感染状況

1980年5月から11月の間にケニアのNaivasha，Kitui，M achakos，Taveta及びNandi Hillsの住民2,114人から採取した糞便についてホルマリン・エーテル法により腸管寄生原虫のシストの検査を行い感染状況を調査した。その結果，赤痢アメーパは31.8%， 大腸アメーパは52.3%と極めて高率を示し，その他は小形アメーパ4.8%，ヨードアメーパ8.7%，ランブル鞭毛虫8.3%，メニール鞭毛虫10.4%であった。腸トリコモナス及びEntamoeba hartmanniも少数例検出されたが，大腸パランチジウムやイソスポーラなどは検出されなかった。総陽性率(陽性総数/検査総数)は75.1%にも及び，飲料水，食物など生活環境が糞便によって高度に汚染されていることが示唆された。陽性率に男女聞の有意差は認められなかった。年齢別にみると，4歳以下の乳幼児でもすでにかなり高率に感染がみられるが，ランプノレ鞭毛虫を除き，特に30歳代から40歳代で最高値を示した。ランプル鞭毛虫は若年齢層ほど高い陽性率を示し4歳以下が最高であった。本調査は日本国際協力事業団(JICA)の医療協力「ケニア伝染病研究対策プロジェクト」の一環として行われたものであり，その撲滅対策を，戦後日本で実施され成果をあげた寄生虫予防対策事業との関連において考察した。During the period from May to November in 1980, a total of 2,114 stool specimens were collected from individuals living in Naivasha, Kitui, Machakos, Taveta and Nandi Hills areas in Kenya, and they were examined for intestinal protozoa by formol-ether concentration method followed by idoine-staining. Out of 2,114 specimens 673 (31.8%) were positive for Entamoeba histolytica, 1,105 (52.3%) for Entamoeba coli, 102 (4.8%) for Endolimax nana, 184 (8.7%) for Iodamoeba butschlii, 176 (8.3%) for Giardia lamblia, and 220 (10.4%) for Chilomastix mesnili. The total positive rate, which means the percentage of positive persons for any kinds of intestinal protozoa, was 75.1 per cent

東アフリカ・ケニア，タベタ地区におけるヒト住血吸虫症の浸淫状況

1974年にタベタ地区の3村落の住民に皮内反応と検使，検尿による住血吸虫卵の検出を試み，963名の結果について集計を行った。皮内反応の抗原としてはVBS adult S.japonicum antigen (1:10,000 dilution)を用い，糞便と尿の検体は集卵法l乙て検査した。虫卵陽性率はJipe 62.2%，Eldoro 68.0%, Kivalwa 69.6 %であった。Jipeでは主にS.mansoni，KivalwaではS.haematobium，Eldoroでは両種の浸淫が認められた。Eldoroでは男性より女性に虫卵陽性率が高かったが，JipeとKivalwaでは推計学的に虫卵陽性率の有意な性差は認められなかった。虫卵陽性率は小児では年齢と共に上昇し，5歳と14歳の間で最高値に達し，以後次第に減少した。皮内反応の陽性率は全体で76.4%で，虫卵陽性率より高い。小児では虫卵陽性者の多数で，皮内反応は弱いか或は全く反応を呈さなかった。皮内反応陽性率は年齢と共に増加し，40歳以上の住民では95%に達した。Jipeでは女性より男性に皮反内応陽性率が高かったが， EldoroとKivalwaでは性差は認められなかった。虫卵陽性の者ではS.mansoni感染者とS.haematobium感染者の聞に皮内反応の差は認められなかった。1975年にJipe，Kivalwa，Kuwahoma，Chalaの村落住民に検便と検尿を行った。KuwahomaではS.haematobiumの浸淫が認められた。Chalaでは住血吸虫の感染は稀であった。この限られた地域にそれぞれS.mansoni，S. haematobiumの感染が流行する村落，両種の感染の流行する村落が存在することが確認された。これら両種の住血吸虫症の流行する地域の疫学的調査に於て，皮内反応にVBS adult S. japonicum antigenを，検便，検尿に集卵法を用い得ることが明らかにされた。A total of 963 individuals in three villages were examined for schistosomiasis by both skin test and schistosome ova detection in stool and urine in 1974. The antigen used for skin test was VBS adult S. japonicum antigen (1: 10,000 dilution). Stool and urine samples were examined through the concentration methods. Egg-positive rate was 62.2 per cent in Jipe, 68.0 per cent in Eldoro, 69.6 per cent in Kivalwa. Jipe was infested mostly by S. mansoni, Kivalwa by S. haematobium and Eldoro by both two schistosomes. The egg-positive rate was higher in females than in males in Eldoro. In Jipe and Kivalwa, however, the differences in the rate between males and females were not statistically significant. The rate increased with age in children, reached a peak between the ages of 5 and 14 years and then decreased gradually. The positive rate of skin test was 76.4 per cent in total, higher than that of stool and urine examinations. The skin reaction was weak or absent among many egg-positive children. The skin-test positive rate increased as the age advanced and reached 95 per cent in inhabitants from 40 years up. The positive rate of skin test was higher among males than females in Jipe. No significant difference in the rate between males and females was found in Eldoro and Kivalwa. Among the egg-positive subjects there was no significant difference in skin reaction between S. mansoni infection and S. haematobium infection. In 1975 stool and urine samples from Jipe, Kivalwa, Kuwahoma and Chala were examined. Kuwahoma proved to be infested by S. haematobium. In Chala schistosome infection was rare. There exist villages infested by S. mansoni and/or S. haematobium in the small area. It seems that VBS adult S. japonicum antigen for skin test and the concentration methods for stool and urine examinations are of use in the epidemiological survey in the areas where S. mansoni and/or S. haematobium infections are prevailing

Egg excretion in the initial phase of experimental murine schistosomiasis mansoni: stability and association with worm burden Esquistossomose mansoni experimental murina: estabilidade da eliminação dos ovos nas fezes e sua associação com a carga parasitária na fase inicial da infecção

Stability of faecal egg excretion and correlation with results related to worm burden at the initial phase of schistosomiasis mansoni were observed in two groups of mice infected with different Schistosoma mansoni cercarial burdens, by means of analysis of quantitative parasitological studies and schistosome counts after perfusion. Thus, it may be stated that few quantitative parasitological stool examinations could be sufficient to express the infection intensity at the initial phase, on the same grounds that it was already demonstrated at the chronic phase. Furthermore, it is confirmed that the use of the number of eggs passed in the faeces as a tool to estimate the worm burden at the initial phase of schistosome infection is adequate.<br>Através da análise de exames parasitológicos quantitativos seriados e da contagem de esquistossomos após perfusão em dois grupos de camundongos infectados com diferentes cargas de cercárias de Schistosoma mansoni, verificou-se a existência da estabilidade da eliminação de ovos e sua correlação com a carga parasitária na fase inicial da esquistossomose mansoni. Deste modo, pode-se afirmar que poucos exames parasitológicos de fezes quantitativos podem ser suficientes para traduzir a intensidade da infecção também na fase inicial , à semelhança do já demonstrado para a crônica. Além disto, comprova-se a adequação do uso do número de ovos eliminados nas fezes como expressão da carga parasitária na fase inicial da infecção esquistossomótica