Abstract: Objective　To investigate the effects of nitroquine on the development of different stages of Plasmodium yoelii in Anopheles stephensi. Methods　An. stephensi mosquitoes were fed with conventional sucrose water or sucrose water containing 100 μmol/L nitroquine one day prior to P. yoelii infection. Following starvation for 24 hours, mosquitoes were fed with the blood of Kunming mice infected with P. yoelii, and the number of oocysts was observed in the stomach of An. stephensi. After 6 days and 14 days of infection, the mosquitoes were starved for 24 hours, and then fed with conventional sucrose water or nitroquine treated sucrose water. The An. stephensi mosquitoes were starved for 24 hours 6 and 14 days post⁃infection with P. yoelii, and then fed with conventional sucrose water or nitroquine⁃containing sucrose water, the numbers of P. yoelii sporozoites were examined in the hemolymph and salivary glands of An. stephensi. Results　Following exposure to nitroquine⁃containing sucrose water one day prior to P. yoelii infections, the number of P. yoelii oocysts was significantly lower in the An. stephensi stomach on day 7 (119.2 ± 16.1 vs. 207.3 ± 21.8; t = 3.207, P < 0.05). After conventional sucrose water was ceased for 24 hours on day 6, and An. stephensi was fed with nitroquine⁃containing sucrose water, the number of P. yoelii sporozoites peaked in the hemolymph on day 14 in the nitroquine treatment group (952.3 ± 22.7) and on day 12 in the sucrose water treatment group (1 287.0 ± 39.0), and there was a significant difference in the number of sporozoites in the salivary glands between the nitroquine treatment group and the sucrose water treatment group (9 467.0 ± 1 304.0 vs. 10 533.0 ± 758.7; t = 0.707, P = 0.506) on day 17. After conventional sucrose water was ceased for 24 hours on day 14, and An. stephensi was fed with nitroquine⁃containing sucrose water, the number of sporozoites in the salivary glands was significantly greater in the nitroquine treatment group than in the sucrose water treatment group (21 900.0 ± 2 613.0 vs. 10 533.0 ± 732.3; t = 4.188, P < 0.05). Conclusions　Nitroquine treatment exhibits diverse effects the development of different stages of P. yoelii, and nitroquine treatment may reduce the transmission of P. yoelii in uninfected An. stephensi.

Key words: Anopheles stephensi, Plasmodium yoelii, Nitroquine, Transmission interruption

摘要： 目的　观察硝喹对斯氏按蚊体内不同时期约氏疟原虫发育的影响。方法　在感染约氏疟原虫1 d前给予常规蔗糖水或硝喹蔗糖水（含100 μmol/L硝喹）供斯氏按蚊吸食，停糖水24 h后用感染约氏疟原虫的昆明鼠血餐，观察硝喹处理后约氏疟原虫在蚊胃内的卵囊数量变化。感染6、14 d后停常规蔗糖水24 h，随后给予常规蔗糖水或硝喹蔗糖水供斯氏按蚊吸食，观察斯氏按蚊血淋巴及唾液腺中的约氏疟原虫子孢子数量变化。结果　感染前1 d将斯氏按蚊暴露于硝喹蔗糖水后，感染第7天蚊胃中约氏疟原虫卵囊数量[（119.2 ± 16.1）只]较常规蔗糖水组[（207.3 ± 21.8）只]显著降低（t = 3.207，P < 0.05）。感染第6天停常规蔗糖水24 h，将斯氏按蚊暴露于硝喹蔗糖水后，按蚊血淋巴中约氏疟原虫子孢子数量峰值[（952.3 ± 22.7）只]在感染第14天出现，常规蔗糖水组按蚊血淋巴中子孢子数量峰值[（1 287.0 ± 39.0）只]在感染第12天出现；感染第17天，硝喹蔗糖水和常规蔗糖水组按蚊唾液腺中子孢子数量分别为（9 467.0 ± 1 304.0）只和（10 533.0 ± 758.7）只，差异无统计学意义（t = 0.707，P = 0.506）。感染第14天停常规蔗糖水24 h，将斯氏按蚊暴露于硝喹蔗糖水后，按蚊唾液腺中约氏疟原虫子孢子数量[（21 900.0 ± 2 613.0）只]较常规蔗糖水处理组[（10 533.0 ± 732.3）只]显著增加（t = 4.188，P < 0.05）。结论　在斯氏按蚊感染疟原虫不同时期给予硝喹处理对其体内约氏疟原虫发育影响不一，未感染斯氏按蚊经硝喹处理后可减少疟原虫传播。

关键词: 斯氏按蚊, 约氏疟原虫, 硝喹, 传播阻断