Variation in exposure to Anopheles gambiae salivary gland peptide (gSG6-P1) across different malaria transmission settings in the western Kenya highlands
Variation in exposure to Anopheles gambiae salivary gland peptide (gSG6-P1) across different malaria transmission settings in the western Kenya highlands
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DOI：
10.1186/1475-2875-11-318
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发表时间：
2012-09-10
期刊：
影响因子：
3
通讯作者：
Yan, Guiyun
中科院分区：
文献类型：
--
作者：
Badu, Kingsley;Siangla, Joram;Yan, Guiyun
背景：现有的疟疾传播指标在低传播强度下的敏感性有限。需要强有力的监测系统作为干预措施，以监测减少传播和防止迅速重新感染。基于对寄生虫和媒介抗原的抗体反应的血清学工具是传播测量的潜在工具。本研究旨在评估冈比亚按蚊唾液腺多肽(gSG6-P1)在不同传播环境和季节对人类暴露于按蚊叮咬的生物标志物的抗体反应。抗MSP-1(19)免疫应答者和无应答者之间的比较允许探索gSG6-P1肽作为疟疾传播减少地区监测工具的稳健性。方法：在年龄分层的队列中(=15岁)，对来自肯尼亚西部三个地区[Kisii(低流行)、Kakamega(中流行)和Kombewa(高流行)]的1366名参与者进行了gSG6-P1的总免疫球蛋白水平的测定，其中包括在疟疾低传播季和高传播期额外检测MSP-1(19)特异性反应的607份血清。比较不同传播强度地区间的抗体水平和流行率。结果：上山人群gSG6-P1抗体阳性率为36%，谷底人群为50%(x(2)=13.2df=1，p<；0.001)。谷底的gSG6-P1抗体水平中位数是上山人群的两倍[4.5比2.05，p<；0.001]，并且具有季节性变化。GSG6-P1血清阳性者出现MSP-1(19)抗体的几率几乎是阴性者的3倍(OR=2.87，95%CI[1.977，4.176])。Kisii、Kakamega和Kombewa的寄生虫感染率分别为4%、19.7%和44.6%，而相当于gSG6-P1的血清阳性率分别为28%、34%和54%。结论：gSG6-P1的血清阳性率在区分低、中、高传播环境和季节性波动方面敏感而可靠。
Background: The existing metrics of malaria transmission are limited in sensitivity under low transmission intensity. Robust surveillance systems are needed as interventions to monitor reduced transmission and prevention of rapid reintroduction. Serological tools based on antibody responses to parasite and vector antigens are potential tools for transmission measurements. The current study sought to evaluate antibody responses to Anopheles gambiae salivary gland peptide (gSG6-P1), as a biomarker of human exposure to Anopheles bites, in different transmission settings and seasons. The comparison between anti-MSP-1(19) IgG immune responders and non-responders allowed exploring the robustness of the gSG6-P1 peptide as a surveillance tool in an area of decreasing malaria transmission.Methods: Total IgG levels to gSG6-P1 were measured in an age-stratified cohort (= 15 years) in a total of 1,366 participants from three localities in western Kenya [Kisii (hypoendemic), Kakamega (mesoendemic), and Kombewa (hyperendemic)] including 607 sera that were additionally tested for MSP-1(19) specific responses during a low and a high malaria transmission seasons. Antibody prevalence and levels were compared between localities with different transmission intensities. Regression analysis was performed to examine the association between gSG6-P1 and MSP-1(19) seroprevalence and parasite prevalence.Result: Seroprevalence of gSG6-P1 in the uphill population was 36% while it was 50% valley bottom (chi(2) = 13.2, df = 1, p < 0.001). Median gSG6-P1 antibody levels in the Valley bottom were twice as high as that observed in the uphill population [4.50 vs. 2.05, p < 0.001] and showed seasonal variation. The odds of gSG6-P1 seropositives having MSP-1(19) antibodies were almost three times higher than the odds of seronegatives (OR = 2.87, 95% CI [1.977, 4.176]). The observed parasite prevalence for Kisii, Kakamega and Kombewa were 4%, 19.7% and 44.6% whilst the equivalent gSG6-P1 seroprevalence were 28%, 34% and 54%, respectively.Conclusion: The seroprevalence of IgG to gSG6-P1 was sensitive and robust in distinguishing between hypo, meso and hyper transmission settings and seasonal fluctuations.