| 作成者 |
高岡, 宏行
多田, 功
橋口, 義久
馬場, 稔
是永, 正敬
OCHOA, A. J. Onofre
CONVIT, Jacinto
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内容記述 |
The larval development of the north Venezuelan Onchocerca volvulus in the 3 Guatemalan simuliid species, i.e. Simulium callidum, S. ochraceum and S. haematopotum was experimentally studied, as compared with that in S. metallicum, the natural vector in the northern Venezuela. All these 3 species ingested as many microfilariae as did the Venezuelan S. metallicum, while feeding on the infected volunteer. However, most microfilarine ingested by S. ochraceum and S. haematopotum were found damaged probably due to the buccopharyngeal armature. The subsequent migration of the microfilariae occurred in 20% S. callidum but very rarely in the other 2 species, while it took place in 76% S. metallicum. At 22℃, third-stage larvae were found in 8% S. callidum and 3% S. haematopotum, but not in all the 51 S. ochraceum examined 9-14 days postfeeding. In contrast, they were found in 16 or 29% of S. metallicum from Venezuela. Overall, it was indicated that beside S. metallicum, the 2 other Guatemalan blackfly species, S. callidum and S. haematopotum, can, despite the low rates, support larval development of the north Venezuelan O. volvulus to the third stage. Our data do not seem to support the assumption that there is mutual incompatibility of O. volvulus to tee vectors between Guatemala and ncrth Venezuela. 西半球のオンコセルカ症各流行地間のOnchocerca volvulus株の相異を調べる目的で, ベネズエラ北部流行地のO. volvulus保有者をクァテマラのブユ3種(Simulium callidum, S. haematopotum, S. ochraceum)に吸血させ, 仔虫のとりこみ, 胸筋への移行, 感染幼虫への発育等を検討した。仔虫のとりこみは, 3種すべてにみられたが, S. haematopotumとS. ochraceumでは, 咽頭部の歯状突起で傷害をうけほとんどが死亡していた。その結果, これら2種では仔虫の胸筋への移行もきわめて少なかった。第3期幼虫への発育はS. ochraceumではみられなかったが, S. callidumとS. haematopotumではおのおの, 8%と3%のブユに認められた。これらの結果から, ベネズエラ北部のO. volvulusは, 先に報告したS. metallicumと合わせて, グァテマラ産の少なくとも3種のブユ体内で発育することが明らかとなった。また, 同じく先に報告したように, グァテマラのO. volvulusもベネズエラのS. metallicumで第3期幼虫へ発育する。したがって, 従来の考え方に反してグァテマラとベネズエラ両国間では, 本症の臨床像に差が認められるものの, 両国のO. volvulusはブユへの感染能に関してはほとんど差がないものと思われる。 |
eiseid_37_4_319-323.pdf
