Breeding ecology of visceral leishmaniasis vector sandfly in Bihar state of India

Soil samples weighing 255.3 kg, collected from 50 villages of 5 visceral leishmaniasis (VL) endemic districts of Bihar state were examined for sandfly breeding, using the soil incubation method. Breeding of sandflies was detected in 46% of the villages and 7.3% of the soil samples examined. Intra-domestic soil was found to be infested with 2 species of sandflies, Phlebotomus argentipes Annandale and Brunetti and Phlebotomus papatasi (Scopoli). In comparison with human houses, P. argentipes was found to show greater propensity to breed in cattle sheds; breeding prevalences in villages and soil samples, for the species, were significantly higher in cattle sheds than in human houses. The preference for breeding sites by the sandflies appeared to be associated with the pH of the soil. P. argentipes thus preferred to breed in the alkaline soil of cattle shed, and P. papatasi in the soil with neutral pH, of human houses. The emergence of adult P. argentipes from soil samples was mainly observed from April to October.     

江苏省黑热病流行病学和免疫学的动态观察

自1958年来，江苏省对黑热病继续采取积极的防治措施，至1985年，全省共发生11例黑热病病人。为全面考核黑热病在江苏省的流行趋势．于1991和1996年两次对原黑热病流行区11个县市区56个村庄近万人进行了黑热病流行病学和免疫学观察。在1991年的调查中：未发现现患病人，未查见中华白蛉，人群LDT阳性率在0～9岁组最低，未有IFAT阳性者。在1996年的调查中：也未发现病人，0～9岁组没有LDT阳性者．未有IFAT阳性者。两次调查结果发现，各个年龄组LDT阳性情况与黑热病基本消灭地区（如山东）一致。可以认为，江苏省目前已无现患黑热病病人，中华白蛉密度极低，人群免疫状况与黑热病基本消灭地区相同。所以．江苏省黑热病防治效果巩固。     

四川省九寨沟县中华白蛉调查

对四川省九寨沟县中华白蛉生物学的观察,表明中华白蛉是当地的优势蛉种,是黑热病的重要传播媒介。当地白蛉季节较长,密度高,高峰季节峰幅宽,导致传播黑热病的强度增加。野外洞穴药物滞留喷洒对控制白蛉密度有着重要的作用。     

克拉玛依地区的利什曼病Ⅻ.利什曼原虫单克隆抗体对大沙鼠及白蛉体内利什曼原虫的检测

本文报道建立的抗杜氏利什曼L.donovani,抗硕大利什曼L.major,抗热带利什曼L.tropica及抗新疆克拉玛依大沙鼠体内的利什曼原虫的4种单克隆抗体(McAb),以免疫荧光法的交叉反应显示出有较强的特异性,应用McAb的dot-ELISA试验,对新疆大沙鼠体内分离的利什曼原虫及白蛉自然感染的利什曼原虫前鞭毛体进行检测,证实新疆克拉玛依鼠体、蛉体的利什曼原虫仅与当地大沙鼠体内利什曼原虫制备的McAb呈阳性反应。     

新疆北部大沙鼠的生存环境以及鼠间的利什曼原虫和媒介的调查

在新疆天山北部的荒漠内，很多大沙鼠Ｒｈｏｍｂｏｍｙｓ ｏｐｉｍｕｓ的耳皮下组织内有利什曼原虫的感染。有的地方，鼠的感染率可达１００％（ＮＮＮ基培养法），已鉴定的原虫有都兰利什曼Ｌｅｉｓｈｍａ－ｎｉａ ｔｕｒａｎｉｃａ和沙鼠利什曼Ｌ．ｇｅｒｂｉｌｌｉ两种。大沙鼠洞是多种白蛉的栖息和吸血的场所，洞内的优势蛉种为蒙古白蛉Ｐｈｌｅｂｏｔｏｍｕｓ ｍｏｎｇｏｌｅｎｓｉｓ和安氏白蛉Ｐｈ．ａｎｄｒｅｊｅｕｉ。调     

白蛉人工光诱法与油纸法比较

目的 比较人工光诱法和油纸法两种白蛉监测方法的适用范围以及各自的优劣,为科学评价其监测结果提供依据.方法 分别比较了人房、畜圈、农田、果园和荒地等处油纸法捕获率的差异,在人房和野外以及不同人员人工光诱法捕获率的差异,着重观察了有无光照对油纸法的影响.结果 人工光诱法捕获率较高,平均每小时捕获数为42 ～405只；熟练培训的捕蛉人在人房和野外捕获白蛉数量差异有统计学意义.油纸法容易受灯光的影响.无光照时,捕获率较低,平均每张油纸捕获数仅为0～4只；有光照时,晚间白蛉集中在距离光源1m范围内活动,1m外则受光照影响甚微.结论 人工光诱法捕获率高,适合多种环境监测；油纸法捕获率低,更适宜在有光照下作为白蛉监测方法.     

Incubation Period for Neuroinvasive Toscana Virus Infections

Toscana virus (TOSV) is an emerging pathogen in the Mediterranean area and is neuroinvasive in its most severe form. Basic knowledge on TOSV biology is limited. We conducted a systematic review on travel-related infections to estimate the TOSV incubation period. We estimated the incubation period at 12.1 days.     

Insect-specific flaviviruses,a worldwide widespread group of viruses only detected in insects

Several flaviviruses are important pathogens for humans and animals (Dengue viruses, Japanese encephalitis virus, Yellow-fever virus, Tick-borne encephalitis virus, West Nile virus). In recent years, numerous novel and related flaviviruses without known pathogenic capacity have been isolated worldwide in the natural mosquito population. However, phylogenetic studies have shown that genomic sequences of these viruses diverge from other flaviviruses. Moreover, these viruses seem to be exclusive of insects (they do not seem to grow on vertebrate cell lines), and were already defined as mosquito-only flaviviruses or insect-specific flaviviruses. At least eleven of these viruses were isolated worldwide, and sequences ascribable to other eleven putative viruses were detected in several mosquito species. A large part of the cycle of these viruses is not well known, and their persistence in the environment is poorly understood. These viruses are detected in a wide variety of distinct mosquito species and also in sandflies and chironomids worldwide; a single virus, or the genetic material ascribable to a virus, was detected in several mosquito species in different countries, often in different continents. Furthermore, some of these viruses are carried by invasive mosquitoes, and do not seem to have a depressive action on their fitness.The global distribution and the continuous detection of new viruses in this group point out the likely underestimation of their number, and raise interesting issues about their possible interactions with the pathogenic flaviviruses, and their influence on the bionomics of arthropod hosts. Some enigmatic features, as their integration in the mosquito genome, the recognition of their genetic material in DNA forms in field-collected mosquitoes, or the detection of the same virus in both mosquitoes and sandflies, indicate that the cycle of these viruses has unknown characteristics that could be of use to reach a deeper understanding of the cycle of related pathogenic flaviviruses.     

Epidemiological and entomological survey in a focus of visceral leishmaniasis in Pap district (Fergana Valley) of Namangan region, Uzbekistan

An active focus of human visceral leishmaniasis (VL) is present in Uzbekistan, Namangan region, Pap district, situated along the Fergana Valley at an altitude of 900–1300 m a.s.l. An overall total of 19 VL cases, all recorded in children less than 14 years of age, have been reported during the period of 1987–99 in three villages, namely Oltinkon (9 cases), Chodak (7 cases) and Guliston (3 cases). Clinical and epidemiological features suggest that the disease is zoonotic in nature and that it is possibly caused by Leishmania infantum, though no characterization of the causative agent was performed due to the failure in isolating the parasite. Currently, diagnosis is made exclusively on the basis of clinical manifestations followed by demonstration of parasites in bone marrow aspirates. Standardized monthly sandfly collections (July–September 1999) were made with sticky traps and hand captures from houses and peri-domestic areas. Twenty houses were monitored over two consecutive days every month in five villages scattered along the valley, three of which were the VL foci (Oltinkon, Chodak, Guliston) and the other two, Kandigan and Khonabad, were located at the top (>1300 m a.s.l.) and at the bottom of the valley (740 m a.s.l.), respectively. Among the sandfly species identified, Phlebotomus sergenti (46.0%) was the most prevalent species through the entire period, followed by P. papatasi (18.8%), P. longiductus (15.5%), P. alexandri (10.3%), P. angustus (6.6%), S. sumbarica (2.2%), P. keshishiani (0.6%) and S. grekovi (0.1%). The role of the suspected vector, P. longiductus in the transmission of VL cases in the Fergana focus is discussed in relation to its abundance and distribution in the valley.     

克拉玛依地区的利什曼病XIV．硕大白蛉吴氏亚种自然感染前鞭毛体的鉴定

硕大白蛉吴氏亚种是新疆克拉玛依地区的主要蛉种之一，具有强的亲人性，在野外和居民点内常能查见该蛉有前鞭毛体的自然感染。本文结果表明，白蛉自然感染的前鞭毛体能使仓鼠及ＢＡＬＢ／ｃ小鼠发生内脏利什曼病；在感染仓鼠内脏涂片上的无鞭毛体，由蛉体而来的明显较由大沙鼠而来的都兰利什曼原虫为小；白蛉自然感染的前鞭毛体在ＮＮＮ培养基内生长不良；用￣（３２）Ｐ标记的ｇｐ￣（６３）基因为探针，与婴儿利什曼原虫、都兰利什曼原虫及白蛉自然感染的前鞭毛体的ＤＮＡ进行杂交，证实蚌体自然感染的原虫与婴儿利什曼原虫同源。克拉玛依无内脏利什曼病人，但人群中有皮肤利什曼病流行。关于硕大白蛉吴氏亚种自然感染的来源以及当地的皮肤利什曼病究竟是由都兰利什曼原虫抑或婴儿利什曼原虫所致，尚待阐明。