MALARIA CONTROL STRATEGY AND BIODIVERSITIES OF HUMAN, PARASITES, MOSQUITOES AND ENVIRONMENT IN MELANESIA

我们将美拉尼西亚岛孤立地区的疟疾研究与撒哈拉以南非洲进行比较，以调查人类、寄生虫、蚊子和环境多样性之间的相互作用，以了解传播、免疫和疾病之间的关系。我们对瓦努阿图恶性疟原虫卵裂子表面蛋白-1等位基因的研究表明，岛屿上的遗传多样性一般有限而稳定，岛屿之间高度隔离，这意味着疟疾疫苗在基因库有限的地方更有效，如在孤立的种群中。我们的调查显示，在肯尼亚西部的高地边缘地区，贫血在5岁以下儿童中最为常见（34%），其次是低地村庄的育龄妇女（16%）。在5岁以下儿童中，贫血（海拔1440米为57% ~海拔2040米为11%）和恶性疟原虫（海拔31% ~ 0%）患病率均与海拔高度显著相关，提示疟疾也是高原边缘地区贫血的主要原因。减少疟疾流行的措施将因此减少贫血和与艾滋病毒传播风险相关的输血需求。在低至中度传播的Aneityum岛上，我们很可能通过将丙二醛与浸渍蚊帐结合使用而阻断了传播，并取得了持续和显著的成果（Kaneko 2000）。初步的血清流行病学结果表明，在没有抗原刺激的情况下，以前反复接触疟疾的成年人的免疫记忆仍将保留多年。

We do the studies of malaria in isolated areas on Island Melanesia in comparison with Sub-Saharan Africa to investigate the interactions among diversities of humans, parasites, mosquitoes and environment to understand relations among transmission, immunity and disease.1.Our studies on merozoite surface protein-1 alleles of P.falciparum in Vanuatu suggested generally limited and stable genetic diversity on islands and a high degree of isolation between the islands, implying that malaria vaccines will be more effective where there is a limited gene pool, as in isolated populations.2.In the highland fringe of Western Kenya our survey showed that anemia was most common in children 【less than or equal】5 years of age (34%) followed by women of childbearing age (16%) in the lowland villages. In children 【less than or equal】5 years, both anemia (ranged from 57% at 1440m to 11% at 2040m) and P.falciparum (from 31% to 0%) prevalence significantly correlated with altitude, suggesting malaria is also the main cause of anemia in the highland fringe areas. Measures that reduce the prevalence of malaria will consequently reduce anemia and the need for blood transfusions associated with the risk of HIV transmission.3.On Aneityum island with low-to-moderate transmission, we have most probably interrupted transmission by combining MDA with impregnated bed nets and achieved sustained and significant gains (Kaneko 2000). The preliminary seroepidemiological results suggest that without antigenic stimulation immunologic memory will still remain for many years in adults previously repeatedly exposed to malaria.