Sowunmi A, Fateye B A
Department of Pharmacology and Therapeutics and Institute for Medical Research and Training, University of Ibadan, Ibadan, Nigeria.
Ann Trop Med Parasitol. 2003 Oct;97(7):671-82. doi: 10.1179/000349803225002381.
The clinical features of the primary Plasmodium falciparum infections in 25 children, and of the recrudescent infections that emerged after pyrimethamine-sulfadoxine (PS) treatment of the children had failed, were evaluated. In addition, the gametocyte sex ratios in these children and in age- and gender-matched controls who had PS-sensitive (PS-S) infections were also examined. Compared with the primary infections, the recrudescent infections were accompanied by significantly fewer symptoms and lower levels of parasitaemia but significantly higher gametocytaemia:parasitaemia ratios. Although the mean gametocyte sex ratio was female-biased pre-treatment, in both the PS-resistant (PS-R) and PS-S infections it became male-biased on days 7 and 14 post-treatment. The times taken to attain a sex ratio of 1 were similar in both groups. The predominance of macrogametocytes seen 'early' post-treatment (on day 3) was later replaced by a predominance of microgametocytes (on days 7 and 14). Analysis of the disposition of gametocytaemia, from the time to attain a sex ratio of 1, showed that the area under the curve of the plot of the level of microgametocytaemia upsilon. time and the mean half-life of the microgametocytaemia were significantly greater and microgametocytaemia clearance was significantly slower than the corresponding values for macrogametocytaemia. Although sex ratios in Plasmodium may naturally become more male-biased as the infection progresses, it is possible that PS treatment may have contributed to the male-biased sex ratios observed post-treatment.
对25名儿童原发性恶性疟原虫感染以及在乙胺嘧啶-磺胺多辛（PS）治疗失败后出现的再燃感染的临床特征进行了评估。此外，还检查了这些儿童以及年龄和性别匹配的患有PS敏感（PS-S）感染的对照者的配子体性别比。与原发性感染相比，再燃感染的症状明显较少，寄生虫血症水平较低，但配子体血症与寄生虫血症的比率明显较高。虽然治疗前平均配子体性别比偏向雌性，但在PS耐药（PS-R）和PS-S感染中，治疗后第7天和第14天均变为偏向雄性。两组达到1:1性别比所需的时间相似。治疗后“早期”（第3天）可见的大配子体优势随后被小配子体优势（第7天和第14天）取代。从达到1:1性别比的时间分析配子体血症的分布情况，结果显示，小配子体血症水平与时间关系图的曲线下面积以及小配子体血症的平均半衰期明显更大，且小配子体血症清除明显慢于大配子体血症的相应值。虽然疟原虫的性别比可能会随着感染的进展自然地变得更偏向雄性，但PS治疗可能促成了治疗后观察到的偏向雄性的性别比。
