【摘要】 本文报告陇南川北山区中华白蛉若干生物学观察的结果及其与人、犬内脏利什曼病的关系。中华白蛉为本区的优势种,具有野栖习性,发生季节自5月至10月,7月为高峰期,峰幅宽和持续时间长为其特点。我们对中华白蛉全季节的性营养周期变动作了观察和分析,指出它是阐明蛉口动力学、预报和预防疾病发生的重要指征。饲血测试表明中华白蛉吸犬血率为61.5%(198/322),当地犬感染内脏利什曼病是与当地中华白蛉吸犬血的习性密切相关。不同垂直高度中华白蛉的发育史比较观察,证明其发育期长短是受自然因素的严格制约。提高温度和增加光照并不能使滞育幼虫提前解除滞育;相反,在自然室温和自然光下饲养的滞育幼虫是实验室饲养越冬幼虫的理想方法。中华白蛉人工感染试验和自然感染调查数据表明,本区中华白蛉是传播人、犬内脏利什曼病的唯一媒介。同时证明本区存在黑热病的自然疫源地。调查说明了媒介生态习性与其传病有直接的关系,并可表达在相互间传播,它们是怎样起着不同的传播作用,因此,研究媒介的生物学及其传病的各种因素有重要的意义。更多还原

【Abstract】 Four species of sandflies were found in the mountainous regions and identified as phlebotomus chinensis, Sergentotnvia koloshanensis, S. squamirostris and S. suni. Among them, Ph. chinensis, as observed by its in-frequent biting indoors, It was the sole sandfly which contacted and sucked human and domestic dog blood c. Its activity season extended from the later part of May to the meddle part of October, with the high peak at July and the longest soason about 4.5-6 months. During the sandfly season of 1990, the vertical distribution survey indicated that Ph. chinensis was present in the mountainous regions from 980—2730m above sea level. The gonotrophic cycle of the female Ph. chinensis was observed and analysed in.the fly season of 1990. A comparative observation on the development of Ph. chinensis in the different vertical altitudes was car-ried out in June, 1988. The reults showed that the whole life cycle without diapouse of the sandfly from alti-tudes 2000m or more was 48—58d (average 56d),while those from 1400—1500m was 43—56d (average50.8d) ,t=3.18,P<0.01, showing significant different between them. A repeated survey was done in Nan-ping, Sichuan during July, 1989, and the results demonstrated that the developmental cycle of Ph. chinensis was regulated by the natural factors just as the other species of sandflies. The laboratory breeding of larvae in diapause at higher temperature (27±1C) and illumination could not result in recovery of development, on the contrary that would cause gradual increase of larval mortality. Therefore, the proper way for breeding larvae in diapause was to keep them at the room temperature and matural illumination。 Ph. chinensis artificially infected with visceral leishmaniasis by biting infected Cricetulus barabensis indi-cated that 280 of 431 (65.0%) sandflies became infected. The promastigotes ont only developed in the midgut, but also invaded the esophagus ,pharynx and proboscis(53.6%in esophagus, 27.1% in pharynx and 3.4%in proboscis). 531 females of Ph. chinensis were collected from the wild mountainous regions 2000m above sea level, and one of them (0.19%) was found to be infected with the promastigotes of L. donovani. Besides, about 2616 females of Ph. chinensis collected from the mountainous area below 1600m sea level, 0. 31% of them were naturally infected, and the promastigotes from one of the infected sandfly were also i dentified as L. donovani by Dot ELISA. The distribution of the promastigotes in the infected flies were simi-lar to that of the artificial infection. Epidemiological investigations showed that all visceral leishmaniasis patients and clogs were ppresent in the area below 1600m sea level, and the area above 2000m sea level where neither man nor dog had been ex-isted. Evidently, the source of the natural infection of sandflies were come from the wild animals. According to the data from present studies, we deem it adequate to conclude that in the mountainous regions above 2000m sea level, Ph. chinensis is a favourahle vector for transmitting visceral leichmaniasis in the wild ani-mals,and a natural euzoonotic focus must be existed. While in the mountainous area below 1600mm sea level, Ph. chinensis is the opptimum vector in the transmission of human and dog visceral leishmaniasis.更多还原