OOKINETE RATES IN AFROTROPICAL ANOPHELINE MOSQUITOS AS A MEASURE OF HUMAN MALARIA INFECTIOUSNESS
OOKINETE RATES IN AFROTROPICAL ANOPHELINE MOSQUITOS AS A MEASURE OF HUMAN MALARIA INFECTIOUSNESS
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DOI：
10.4269/ajtmh.1992.47.41
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发表时间：
1992-07-01
影响因子：
3.3
通讯作者：
VAUGHAN, JA
中科院分区：
文献类型：
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作者：
BEIER, JC;COPELAND, RS;VAUGHAN, JA
冈比亚按蚊；在肯尼亚西部的两个恶性疟原虫流行地点采集了兔的样型疟原虫样本。由于卵母体是一个持续时间较短的过渡阶段，发生在受精后和卵囊发育之前，因此只检查了半妊娠和妊娠期的雌性血消化。均质化的中肠制剂被标记在显微载玻片上，并在吉姆萨染色后进行显微镜检查。总体而言，在8个月的时间里，1079只按蚊中有4.4%检测到同源基因。鼠按蚊卵率高于安氏按蚊。gambiae s.l，半孕鼠的卵母细胞率高于妊娠鼠。在这两个地点，每个物种每只受感染雌性的卵母细胞几何平均数量少于5个，观察到的最大数量仅为12个。低频率和低数量的卵母细胞足以在媒介种群中产生4-18%的孢子子率。恶性疟原虫在这两个地点的强烈传播是由嗜人病媒维持的，其中每23次血液中只有1次引起通常少于5个原虫的感染。人类疟疾传染性与媒介传染性之间的关系取决于从卵母体到随后的卵囊和孢子体阶段的高效发育过渡。
Anopheles gambiae s.l. and An.funestus were sampled for Plasmodium spp. ookinetes in two P. falciparum-endemic sites in western Kenya. Since the ookinete is a transitional stage of short duration, occurring after fertilization and before oocyst development, only females in the half-gravid and gravid stages of blood digestion were examined. Preparations of homogenized midguts were spotted onto microslides and examined microscopically after staining with Giemsa. Overall, ookinetes were detected in 4.4% of 1,079 anophelines examined over an eight-month period. Anopheles funestus had higher ookinete rates than An. gambiae s.l., and ookinete rates were higher in half-gravid than in gravid An. gambiae s.l. Geometric mean numbers of ookinetes per infected female were less than five for each species at the two sites, and the maximum number observed was only 12. The low frequencies and numbers of ookinetes were sufficient to produce sporozoite rates of 4-18% in the vector populations. The intense transmission of P. falciparum in these two sites is maintained by anthropophilic vectors where only one in 23 blood meals initiates an infection of generally less than five ookinetes. Relationships between human malaria infectiousness and vector infectivity are dependent upon the high efficiency of the developmental transition from the ookinete to the subsequent oocyst and sporozoite stages.