first intermediate host

基本解釋

Objective Investigation of the species ofParagonimus, its first and second intermediate host (snail and crab) and the infection rate ofParagonimus in Songxi county, Fujian province.
目的調(diào)查福建省松谿縣肺吸蟲蟲種，第一、二中間宿主及其感染率。
Two species of snails, namely, Tricula fujiansis and Semisulcospira libertina were found, but only the former was the first intermediate host. The infection rate of snails was 0.7%(4/569).
全縣發(fā)現(xiàn)福建擬釘螺和放逸短溝踡兩種螺螄，衹有前者爲(wèi)斯氏貍殖吸蟲和泡囊貍殖吸蟲的第一中間宿主，其感染率爲(wèi)0 7% （4/ 5 6 9）。