Surveillance for sulfadoxine-pyrimethamine resistant malaria parasites in the Lake and Southern Zones, Tanzania, using pooling and next-generation sequencing.
Surveillance for sulfadoxine-pyrimethamine resistant malaria parasites in the Lake and Southern Zones, Tanzania, using pooling and next-generation sequencing.
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DOI：
10.1186/s12936-017-1886-9
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发表时间：
2017-06-05
期刊：
影响因子：
3
通讯作者：
Gutman J
中科院分区：
文献类型：
--
作者：
Ngondi JM;Ishengoma DS;Doctor SM;Thwai KL;Keeler C;Mkude S;Munishi OM;Willilo RA;Lalji S;Kaspar N;Kitojo C;Paxton LA;Hathaway NJ;Bailey JA;Juliano JJ;Meshnick SR;Gutman J
在疟疾高发地区，妊娠期疟疾仍然是一个重大的公共卫生挑战。建议使用磺胺嘧啶-乙胺嘧啶（SP）进行妊娠期间歇性预防性治疗（IPTp），以预防MiP的不良后果。在发现dhps581突变（高水平SP耐药的关键标志物）的地区，SP对IPTp的有效性可能会降低;以前曾报道这种突变在坦桑尼亚北方的坦加地区很常见，但其他地区的数据有限。作为正在进行的努力，以产生全国范围内的SP耐药性数据的一部分，在7个地区，包括坦桑尼亚大陆的湖泊和南部地区的卫生中心（HC）发热患者的疟疾寄生虫的SP耐药性的分子标志物的频率进行了调查。2015年4月至6月，在7个地区的14个卫生机构的门诊部进行了横断面调查。从同意接受疟疾快速诊断试验且近期（过去2个月内）未暴露于SP或相关药物的患者中采集1750份干血斑（DBS）样本（每个机构117至160份）。从DBS中提取DNA，由HC合并，并进行合并的靶向扩增子深度测序，以估计每个目标基因座处的突变寄生虫等位基因频率。dhps540突变在所有14个位点中很常见，范围为55%至98.4%的序列。dhps581突变的频率范围为0 - 2.4%，但Kayanga HC（卡盖拉地区，湖区）除外，其中24.9%的序列发生突变。仅在Kanyanga HC（0.06%）检测到dhfr164突变。通过合并DNA提取物，可以在单次深度测序运行中直接确定14个位点中突变的等位基因频率。dhps540突变体在所有地点都很常见。令人惊讶的是，dhps581在一个健康中心很常见，但在所有其他中心都很罕见，这表明突变分布存在地理上的微观异质性，准确的监测需要包括多个位点。需要更好地理解dhps581突变体对IPTP-SP功效的影响。
Malaria in pregnancy (MiP) remains a major public health challenge in areas of high malaria transmission. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is recommended to prevent the adverse consequences of MiP. The effectiveness of SP for IPTp may be reduced in areas where the dhps581 mutation (a key marker of high level SP resistance) is found; this mutation was previously reported to be common in the Tanga Region of northern Tanzania, but there are limited data from other areas. The frequency of molecular markers of SP resistance was investigated in malaria parasites from febrile patients at health centres (HC) in seven regions comprising the Lake and Southern Zones of mainland Tanzania as part of the ongoing efforts to generate national-wide data of SP resistance. A cross-sectional survey was conducted in the outpatient departments of 14 HCs in seven regions from April to June, 2015. 1750 dried blood spot (DBS) samples were collected (117 to 160 per facility) from consenting patients with positive rapid diagnostic tests for malaria, and no recent (within past 2 months) exposure to SP or related drugs. DNA was extracted from the DBS, pooled by HC, and underwent pooled targeted amplicon deep sequencing to yield estimates of mutated parasite allele frequency at each locus of interest. The dhps540 mutation was common across all 14 sites, ranging from 55 to 98.4% of sequences obtained. Frequency of the dhps581 mutation ranged from 0 to 2.4%, except at Kayanga HC (Kagera Region, Lake Zone) where 24.9% of sequences obtained were mutated. The dhfr164 mutation was detected only at Kanyanga HC (0.06%). By pooling DNA extracts, the allele frequency of mutations in 14 sites could be directly determined on a single deep-sequencing run. The dhps540 mutant was very common at all locations. Surprisingly, the dhps581 was common at one health center, but rare in all the others, suggesting that there is geographic micro-heterogeneity in mutant distribution and that accurate surveillance requires inclusion of multiple sites. A better understanding of the effect of the dhps581 mutant on the efficacy of IPTp-SP is needed.