Sowunmi A, Fateye B A
Department of Pharmacology and Therapeutics and Institute for Advanced Medical Research and Training, University of Ibadan, Ibadan, Nigeria.
Ann Trop Med Parasitol. 2003 Jul;97(5):469-79. doi: 10.1179/000349803235002452.
The clinical features of their primary Plasmodium falciparum infections and of the recrudescent infections that emerged after chloroquine (CQ) treatment were evaluated in 48 children. Compared with the primary infections, the recrudescent infections were accompanied by significantly fewer symptoms and lower densities of parasitaemia but a much higher gametocytaemia:parasitaemia ratio (0.051 v. 0.00097; P = 0.0000000). There was a negative correlation between the recrudescent parasitaemia and the time elapsing between its detection and the subsequent onset of symptoms (r = -0.44; P = 0.006). The recrudescent parasitaemia was significantly lower [with geometric means and (ranges) of 117 (40-9756) v. 1112 (30-25,592) asexual forms/microl; P = 0.009] and the recrudescent gametocytaemia:parasitaemia ratio significantly higher (0.59 v. 0.024; P = 0.0000002) in those who were asymptomatic for at least 5 days after detection of the recrudescent parasitaemia than in those who were symptomatic at recrudescence. The disposition kinetics of the gametocytaemias in 18 primary infections--from nine children who failed CQ treatment and nine other children, matched for age and gender with the failures, who were CQ-treatment successes--were analysed. The results showed that the maximum gametocytaemia, time taken to reach the maximum gametocytaemia, the half-life of the gametocytaemia and the area inscribed by the plot of gametocytaemia against time were significantly higher, and the clearance of gametocytaemia significantly slower, in the children with primary infections that recrudesced. It therefore appears that continuing the use of CQ in areas where some parasites are resistant to the drug may confer survival and propagation advantages on the resistant parasites.
对48名儿童的原发性恶性疟原虫感染以及氯喹（CQ）治疗后出现的复发感染的临床特征进行了评估。与原发性感染相比，复发感染伴随的症状明显较少，寄生虫血症密度较低，但配子体血症与寄生虫血症的比率要高得多（0.051对0.00097；P = 0.0000000）。复发寄生虫血症与其检测到之后症状随后发作之间所经过的时间呈负相关（r = -0.44；P = 0.006）。在检测到复发寄生虫血症后至少5天无症状的儿童中，复发寄生虫血症明显较低[无性体的几何平均数及（范围）为117（40 - 9756）对1112（30 - 25,592）/微升；P = 0.009]，且复发配子体血症与寄生虫血症的比率明显较高（0.59对0.024；P = 0.0000002），高于复发时有症状的儿童。分析了18例原发性感染中配子体血症的处置动力学，这18例感染来自9名CQ治疗失败的儿童以及另外9名年龄和性别与治疗失败儿童相匹配的CQ治疗成功儿童。结果显示，在复发的原发性感染儿童中，最大配子体血症、达到最大配子体血症所需时间、配子体血症的半衰期以及配子体血症随时间变化曲线所围成的面积明显更高，且配子体血症的清除明显更慢。因此，在一些寄生虫对该药物具有抗性的地区继续使用CQ似乎可能会赋予抗性寄生虫生存和繁殖优势。
