Hogh B, Gamage-Mendis A, Butcher G A, Thompson R, Begtrup K, Mendis C, Enosse S M, Dgedge M, Barreto J, Eling W, Sinden R E
Department of Epidemiology Research, Danish Epidemiology Science Centre, Statens Serum Institut, Copenhagen.
Am J Trop Med Hyg. 1998 Feb;58(2):176-82. doi: 10.4269/ajtmh.1998.58.176.
Using serum or infected blood from Danish volunteers and Plasmodium falciparum-infected Mozambican patients, respectively, the impact of curative doses of chloroquine and pyrimethamine/sulfadoxine upon infectivity of P. falciparum to Anopheles arabiensis and An. gambiae or of P. berghei to An. stephensi was studied. Both treatments cleared circulating P. falciparum gametocytes within 28 days. Before this clearance, chloroquine enhanced infectivity to An. arabiensis, whereas pyrimethamine/sulfadoxine decreased infectivity. Patients harboring chloroquine-resistant parasites as opposed to -sensitive ones were 4.4 times more likely to have gametocytes following treatment. In contrast, pyrimethamine/sulfadoxine-resistant parasites were 1.9 times less likely to produce gametocytes. In laboratory infections using replicated P. berghei or P. falciparum preparations, serum from chloroquine-treated, uninfected, nonimmune volunteers enhanced gametocyte infectivity with increasing efficiency for 21 days following treatment, whereas pyrimethamine/sulfadoxine significantly suppressed infectivity. The observed enhancement in infectivity induced by the use of chloroquine combined with increased gametocytemias in chloroquine-resistant strains may in part explain the rapid spread of chloroquine resistance in endemic populations.
分别使用丹麦志愿者的血清或感染血液以及感染恶性疟原虫的莫桑比克患者的血液，研究了治疗剂量的氯喹和乙胺嘧啶/磺胺多辛对恶性疟原虫对阿拉伯按蚊和冈比亚按蚊的感染性，或伯氏疟原虫对斯氏按蚊的感染性的影响。两种治疗方法均在28天内清除了循环中的恶性疟原虫配子体。在清除之前，氯喹增强了对阿拉伯按蚊的感染性，而乙胺嘧啶/磺胺多辛则降低了感染性。携带氯喹抗性寄生虫而非敏感寄生虫的患者在治疗后出现配子体的可能性高4.4倍。相比之下，乙胺嘧啶/磺胺多辛抗性寄生虫产生配子体的可能性低1.9倍。在使用复制的伯氏疟原虫或恶性疟原虫制剂进行的实验室感染中，来自接受氯喹治疗、未感染、无免疫力的志愿者的血清在治疗后21天内以递增的效率增强了配子体感染性，而乙胺嘧啶/磺胺多辛则显著抑制了感染性。观察到使用氯喹诱导的感染性增强以及氯喹抗性菌株中配子体血症增加，这可能部分解释了氯喹抗性在流行人群中的快速传播。
