Olukosi Yetunde A, Oyebola Muyiwa K, Ajibaye Olusola, Orok Bassey A, Aina Olugbenga O, Agomo Chimere O, Iwalokun Bamidele A, Akindele Samuel K, Enya Veronica N V, Okoh Hilary I
Malaria Research Laboratory, Nigerian Institute of Medical Research, 6 Edmond Crescent, P.M.B. 2013, Yaba, Lagos, Nigeria.
Parasitology and Bioinformatics Unit, Faculty of Science, University of Lagos, Lagos, Nigeria.
Malariaworld J. 2014 Feb 26;5:3. doi: 10.5281/zenodo.10878545. eCollection 2014.
A recovery in chloroquine efficacy following a period of cessation has raised the possibility of its reintroduction for malaria chemotherapy. We investigated the prevalence of the major markers of chloroquine resistance years after the withdrawal of the drug in Nigeria.
Finger prick blood samples were collected from participants presenting with symptoms of malaria in two selected health centres each representing Lekki and Ijede communities of Lagos, Nigeria. Thick and thin blood smears were prepared for microscopy and dry blood spots made from malaria-positive participants for parasite DNA extraction. The detection of mutations in the chloroquine resistance transporter ( and multidrug resistance ( genes was performed by nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).
Of the 1527 blood samples that were confirmed by PCR to be positive, 412 and 344 were typed for the molecular detection of and gene mutations, respectively. The mutant alleles of were present among 290 (70%) parasite carriers while the mutant allele was found in 117 (34%) of the total population. There were higher distributions of the mutant alleles for the two loci in Ijede than in Lekki. The observed frequencies of mutant alleles in the two parasite populations were in agreement with the expected frequencies predicted by Hardy-Weinberg. In comparing data with studies conducted between 2000 and 2002 in Ijede, we observed an increase in the prevalence of mutant type against a marginal decline in the mutant type.
The high frequencies of mutation are suggestive of a persistent drug pressure and continuing inefficacy of chloroquine as an antimalarial drug.
氯喹停药一段时间后疗效恢复，这增加了其重新用于疟疾化疗的可能性。我们调查了尼日利亚停用该药物数年之后氯喹耐药主要标志物的流行情况。
从两个选定的健康中心有疟疾症状的参与者中采集手指针刺血样，这两个健康中心分别代表尼日利亚拉各斯的莱基和伊杰德社区。制备厚血涂片和薄血涂片用于显微镜检查，并从疟疾阳性参与者的血样中制备干血斑用于提取寄生虫DNA。通过巢式聚合酶链反应（PCR）和限制性片段长度多态性（RFLP）检测氯喹耐药转运蛋白（ ）和多药耐药（ ）基因中的突变。
在经PCR确认 呈阳性的1527份血样中，分别对412份和344份进行了 和 基因突变的分子检测分型。 在290名（70%）寄生虫携带者中存在突变等位基因，而在总人群中有117名（34%）发现了 突变等位基因。伊杰德两个位点的突变等位基因分布高于莱基。在两个寄生虫群体中观察到的 突变等位基因频率与哈迪 - 温伯格预测的预期频率一致。将数据与2000年至2002年在伊杰德进行的研究进行比较时，我们观察到 突变型的流行率增加，而 突变型略有下降。
突变的高频率表明持续存在药物压力以及氯喹作为抗疟药物持续无效。
