Centre de Recherche Biomédicale Espoir Pour La Santé, 269 Route de la corniche, Sor, BP: 226, Saint-Louis, Sénégal.
Malar J. 2013 Aug 30;12:301. doi: 10.1186/1475-2875-12-301.
The Northern part of Senegal is characterized by a low and seasonal transmission of malaria. However, some Plasmodium falciparum infections and malaria clinical cases are reported during the dry season. This study aims to assess the relationship between IgG antibody (Ab) responses to gSG6-P1 mosquito salivary peptide and the prevalence of P. falciparum infection in children during the dry season in the Senegal River Valley. The positive association of the Ab response to gSG6-P1, as biomarker of human exposure to Anopheles vector bite, and P. falciparum infectious status (uninfected, infected-asymptomatic or infected-symptomatic) will allow considering this biomarker as a potential indicator of P. falciparum infection risk during the dry season.
Microscopic examination of thick blood smears was performed in 371 and 310 children at the start (January) and at the end (June) of the dry season, respectively, in order to assess the prevalence of P. falciparum infection. Collected sera were used to evaluate IgG response to gSG6-P1 by ELISA. Association between parasitological and clinical data (infected-asymptomatic or infected-symptomatic) and the anti-gSG6-P1 IgG levels were evaluated during this period.
The prevalence of P. falciparum infection was very low to moderate according to the studied period and was higher in January (23.5%) compared to June (3.5%). Specific IgG response was also different between uninfected children and asymptomatic carriers of the parasite. Children with P. falciparum infection in the dry season showed higher IgG Ab levels to gSG6-P1 than uninfected children.
The results strengthen the hypothesis that malaria transmission is maintained during the dry season in an area of low and seasonal transmission. The measurement of IgG responses to gSG6-P1 salivary peptide could be a pertinent indicator of human malaria reservoir or infection risk in this particular epidemiological context. This promising immunological marker could be useful for the evaluation of the risk of P. falciparum exposure observed during dry season and, by consequences, could be used for the survey of potential pre-elimination situation.
塞内加尔北部的疟疾传播水平较低且具有季节性。然而，在旱季仍有报道称出现了一些恶性疟原虫感染和疟疾临床病例。本研究旨在评估在塞内加尔河河谷地区，旱季期间 IgG 抗体（Ab）对 gSG6-P1 疟蚊唾液肽的反应与恶性疟原虫感染的流行率之间的关系。Ab 对 gSG6-P1 的阳性反应作为人类接触疟蚊叮咬的生物标志物，与恶性疟原虫感染的状态（未感染、无症状感染或有症状感染）呈正相关，这将使 gSG6-P1 成为评估旱季期间恶性疟原虫感染风险的潜在指标。
分别在旱季开始（1 月）和结束（6 月）时对 371 名和 310 名儿童进行厚血涂片镜检，以评估恶性疟原虫感染的流行率。收集血清，通过 ELISA 评估 gSG6-P1 的 IgG 反应。在此期间，评估了寄生虫学和临床数据（无症状感染或有症状感染）与抗 gSG6-P1 IgG 水平之间的关系。
根据研究期间，恶性疟原虫感染的流行率从低到中不等，1 月（23.5%）高于 6 月（3.5%）。在感染的无症状携带者和未感染者之间，gSG6-P1 的特异性 IgG 反应也不同。在旱季感染恶性疟原虫的儿童的 IgG Ab 水平高于未感染者。
结果加强了旱季在低季节性传播地区维持疟疾传播的假说。gSG6-P1 唾液肽的 IgG 反应测量可能是评估特定流行病学背景下人类疟疾储存库或感染风险的一个有希望的免疫标志物。这种有前途的免疫标志物可能有助于评估旱季观察到的恶性疟原虫暴露风险，因此可用于调查潜在的消除前情况。
