Maïga-Ascofaré Oumou, Rakotozandrindrainy Raphael, Girmann Mirko, Hahn Andreas, Randriamampionona Njary, Poppert Sven, May Jürgen, Schwarz Norbert G
Bernhard-Nocht Institute for Tropical Medicine, Hamburg, Germany.
University of Antananarivo, Antananarivo, Madagascar.
Malar J. 2015 May 3;14:188. doi: 10.1186/s12936-015-0704-5.
Malaria epidemiology in Madagascar is classified into four different areas, ranging from unstable seasonal transmission in the highlands to hyperendemic perennial transmission areas in the costal level. Most malaria studies in Madagascar are focused on symptomatic children. However, because of the low transmission in some areas with correspondingly low level of semi-immunity, adults are also at risk, in particular pregnant women. The objective of this study was to gain information on the genetic epidemiology of malarial infections in pregnant women in order to provide information for malaria control and elimination programmes in Madagascar.
Between May and August 2010, we carried out cross-sectional surveys targeting healthy pregnant women in six locations, three in the coastal area and three in the highlands at 850-1300 m. 1244 blood samples were screened for anti-Plasmodium falciparum antibodies by immunofluorescence test and for malarial infection by realtime-PCR. The prevalence of chloroquine and sulphadoxine-pyrimethamine resistance markers was also determined in all Plasmodium falciparum samples by PCR-RFLP as well as the multiplicity of infection through genotyping six neutral microsatellites.
In the highlands, 67.4% of the women presented antibodies against Plasmodium falciparum and 9.2% were carrying parasites, at the coast 95.6% and 14.8%, respectively. In the mean, 1.2 clones were detected in infected pregnant woman in the highlands and 1.5 at the coast. A higher level of monoclonal infections was found in the highlands (85.4%) compared to the coast (61.8%). Resistance markers for sulphadoxine-pyrimethamine were present only in two sites.
Immunity is triggered in Malagasy highland populations when they are infected with malaria parasites, but these populations could also serve as a reservoir for epidemics.
马达加斯加的疟疾流行病学分为四个不同区域，从高地不稳定的季节性传播到沿海地区的高度地方性常年传播区域。马达加斯加的大多数疟疾研究都集中在有症状的儿童身上。然而，由于一些地区传播率低，相应地半免疫水平也低，成年人也有风险，尤其是孕妇。本研究的目的是获取有关孕妇疟疾感染基因流行病学的信息，以便为马达加斯加的疟疾控制和消除计划提供信息。
2010年5月至8月期间，我们在六个地点对健康孕妇进行了横断面调查，其中三个在沿海地区，三个在海拔850 - 1300米的高地。通过免疫荧光试验筛选1244份血样中的抗恶性疟原虫抗体，并通过实时聚合酶链反应检测疟疾感染情况。还通过聚合酶链反应-限制性片段长度多态性在所有恶性疟原虫样本中测定氯喹和磺胺多辛-乙胺嘧啶耐药标志物的流行情况，并通过对六个中性微卫星进行基因分型确定感染复数。
在高地，67.4%的女性呈现抗恶性疟原虫抗体，9.2%携带寄生虫；在沿海地区，这两个比例分别为95.6%和14.8%。平均而言，在高地感染的孕妇中检测到1.2个克隆，在沿海地区为1.5个。与沿海地区（61.8%）相比，高地发现更高水平的单克隆感染（85.4%）。磺胺多辛-乙胺嘧啶的耐药标志物仅在两个地点存在。
马达加斯加高地人群感染疟原虫时会引发免疫，但这些人群也可能成为疫情的传染源。
