Hii J L, Smith T, Vounatsou P, Alexander N, Mai A, Ibam E, Alpers M P
Guinea Institute of Medical Research, P.O. Box 378, Madang, Papua New Guinea.
Trans R Soc Trop Med Hyg. 2001 Jan-Feb;95(1):7-13. doi: 10.1016/s0035-9203(01)90315-3.
Relationships between area coverage with insecticide-free bednets and prevalence of Plasmodium falciparum were investigated in 7 community-based surveys over a 33-month period in 1990-93 in 6 villages in the Wosera area of Papua New Guinea. Spatial patterns in circumsporozoite rates for P. falciparum, P. vivax isomorphs K210 and K247, and P. malariae, and the proportions of mosquito blood meals positive for specific human, goat, cat, dog and pig antigens were determined using ELISAs. P. falciparum prevalence in humans was better explained by bednet coverage in the immediate vicinity than by personal protection alone. Circumsporozoite rates for both P. falciparum and P. vivax were also inversely related to coverage with bednets. There was some increase in zoophagy in areas with high coverage, but relatively little effect on the human blood index or on overall mosquito densities. In this setting, protracted use of untreated bednets apparently reduces sporozoite rates, and the associated effects on prevalence are greater than can be accounted for by personal protection. Even at high bednet coverage most anophelines feed on human hosts, so the decreased sporozoite rates are likely to be largely due to reduction of mosquito survival. This finding highlights the importance of local vector ecology for outcomes of bednet programmes and suggests that area effects of untreated bednets should be reassessed in other settings.
1990 - 1993年期间，在巴布亚新几内亚沃塞拉地区的6个村庄进行了为期33个月的7次社区调查，研究了无杀虫剂蚊帐的覆盖面积与恶性疟原虫流行率之间的关系。使用酶联免疫吸附测定法（ELISA）确定了恶性疟原虫、间日疟原虫同形体K210和K247以及三日疟原虫的环子孢子率的空间模式，以及对特定人类、山羊、猫、狗和猪抗原呈阳性的蚊虫血餐比例。与仅靠个人防护相比，紧邻区域的蚊帐覆盖率能更好地解释人类中恶性疟原虫的流行率。恶性疟原虫和间日疟原虫的环子孢子率也与蚊帐覆盖率呈负相关。在高覆盖率地区，蚊虫对动物的摄食有所增加，但对人类血指数或总体蚊虫密度的影响相对较小。在这种情况下，长期使用未处理的蚊帐显然会降低子孢子率，而且对流行率的相关影响大于个人防护所能解释的范围。即使在蚊帐覆盖率很高的情况下，大多数按蚊仍以人类宿主为食，因此子孢子率降低很可能主要是由于蚊虫存活率降低。这一发现凸显了当地媒介生态对蚊帐项目效果的重要性，并表明应在其他环境中重新评估未处理蚊帐的区域效应。
