Mueller Ivo, Kaiok Japalis, Reeder John C, Cortés Alfred
PNG Institute of Medical Research, Goroka, Papua New Guinea.
Am J Trop Med Hyg. 2002 Nov;67(5):459-64. doi: 10.4269/ajtmh.2002.67.459.
Although most of the Papua New Guinea highlands are too high for stable malaria transmission, local epidemics are a regular feature of the region. Few detailed descriptions of such epidemics are available, however. We describe the investigation of a malaria epidemic in the Obura Valley, Eastern Highlands Province, Papua New Guinea. Of the 244 samples examined by microscopy, 6.6% were positive for Plasmodium falciparum only, 9.4% were positive for Plasmodium vivax only, and 1.2% were mixed infections. MSP2 and MSP3alpha genotyping and AMA1 sequencing were used to determine the genetic variation present in a sample of P. falciparum and P. vivax infections. The P. vivax infections were found to be genetically highly diverse. In contrast, all P. falciparum samples were of a single genotype. This striking difference in genetic diversity suggests endemic, low-level local transmission for P. vivax but an outside introduction of P. falciparum as the most likely source of the epidemic.
虽然巴布亚新几内亚的大部分高地海拔过高，不利于疟疾的稳定传播，但局部流行却是该地区的常见特征。然而，关于此类疫情的详细描述却很少。我们描述了对巴布亚新几内亚东部高地省奥布拉山谷疟疾疫情的调查。在通过显微镜检查的244个样本中，仅恶性疟原虫呈阳性的占6.6%，仅间日疟原虫呈阳性的占9.4%，混合感染的占1.2%。采用MSP2和MSP3α基因分型以及AMA1测序来确定恶性疟原虫和间日疟原虫感染样本中的基因变异情况。结果发现，间日疟原虫感染在基因上具有高度多样性。相比之下，所有恶性疟原虫样本均为单一基因型。这种基因多样性的显著差异表明，间日疟原虫存在地方性、低水平的局部传播，但恶性疟原虫最有可能是从外部传入导致此次疫情。
