海南山区当前疟疾流行特征研究

STUDIES ON CURRENT CHARACTERISTICS OF MALARlA ENDEMlC IN MOUNTAINOUS AREAS OF HAINAN PROVINCE

１９８９年以来对海南山区的疟疾现状和流行特征的深入调查研究表明，海南山区的疟疾已由原来的稳定性超高度流行变为当前非稳定性中低度地方性流行，疟疾年带虫发病率约为３％～５％，恶性疟约占１／３，多数居民点疟疾传播已明显降低，仅少数近山麓村庄为高发点，高发村庄的疟原虫率约为５％。上山住宿是疟疾感染，特别是恶性疟感染的主要来源，部分上山作业和住宿的居民是疟疾感染的高危人群，多数疟疾病例治疗不彻底是疟疾持续传播的重要原因。少数民族农民蚊帐使用、求医行为和医疗卫生条件已有所改善，但社会经济与人的行为因素对疟疾的流行与控制仍有重要影响；恶性疟对氯喹的抗性有所下降，但对哌喹的抗性增加；随着土地和森林的大规模开垦及热带经济作物的发展导致生态环境的改变，主要媒介大劣按蚊的分布及危害已大为缩小；微小按蚊已广泛复现，由残存状态上升为次要媒介，其生态习性已有所改变，在当地居民点其传疟作用较低，但在临时的或新的居民点可引起疟疾暴发。上述流行特征将为今后制定防治对策提供重要依据。

The investigations of current malaria situation and haracteristics of endemic were conducted in the mountainous areas of Hainan Province in recent years. It indicates that local malaria has been changed from stable hyperendemicity to unstable hypo mesoendemicity, the annual parasite incidence of malaria was about 3%～5% with a proportion of 1/3 for falciparum malaria; the malaria transmission in most villages decreased markedly except a few villages located at mountain foot with higher risk of infection and with a parasite rate about 5%; overnight staying in forest mountain was the main source of malaria infection especially of falciparum malaria infection; people who stay overnight in mountain was a high risk population; unradical cure in most malaria cases was an important factor causing persistent transmission of malaria; the behaviour of using bednet and seeking medicine and the conditions of medicine and health care of peasants of national minorities have been improved but the factors of socio economic status and human behaviour have still an important impact on malaria endemic and its control. The resistance of falciparum malaria to chloroquine has decreaced but has increased to peperaquine. The geographical distribution and its endangerment to human of the main vector, Anopheles dirus , have been obviously reduced following the change of natural ecological environment due to the large scale reclaim of wasteland and forest and development of tropical economic crops; An. minimus has reappeared widely and became a secondary vector from a residual status previously, and its behaviour has changed and its role of transmiting malaria was lower in local residential spots but was higher in new or temporary residential spots. The results of the study will provide an important basis for making a malaria control strategy in the future.