云南省19个县(市)印度囊棒恙螨的分布调查

目的 探讨云南省印度囊棒恙螨在不同宿主、不同地域及其不同生境的分布情况.方法 选择云南省19个县(市)进行现场调查,用鼠笼加食饵诱捕小兽,收集其双侧耳廓和外耳道的恙螨幼虫,用Hoyer's液封片后在显微镜下逐一分类鉴定到种.统计不同恙螨种类、构成比及其在对应寄生宿主的染螨率和螨指数,分析其在不同宿主体表和不同地域、生境的分布情况.结果 调查19个县(市)共采集到印度囊棒恙螨1267只,占采集到所有恙螨的1.36％;相对于云南省其它主要恙螨种,印度囊棒恙螨宿主特异性高,仅在7种3224只小兽体表有分布,且94.40％寄生在黄胸鼠体表.从地域分布来看,19个县(市)中6个县(市)有印度囊棒恙螨分布,主要集中在云南省南部和中西部.从生境来看,印度囊棒恙螨喜活动于坝区的房屋周围生境.结论 印度囊棒恙螨分布于云南省南部和中西部的坝区房屋周围生境,且集中寄生于黄胸鼠(恙虫病主要宿主动物)体表.     

云南北部金沙江流域小兽体表恙螨种类及空间分布格局研究

[目的]了解云南北部金沙江流域恙螨的种类组成、优势种及其种群空间分布格局等。[方法]选择云南北部金沙江流域的巧家、绥江两县的农舍、农田、灌木丛和森林4种生态环境诱捕小兽,选择小兽耳窝和臀部位作为恙螨固定采集部位,用镊子取耳窝和臀部的全部恙螨,70%乙醇固定,Hoyer液封片后于显微镜下鉴定种类。用扩散系数、丛生指数、Cassie指数及聚块指数等指标评价种群空间分布格局。[结果]共捕获小兽302只,经分类鉴定地隶属7目13属16种。共采集恙螨4550只,经分类鉴定隶属3亚种12属63种。大多数小兽体表恙螨种类较丰富,最高的达42种。优势种为攸氏无前恙螨、微板无前恙螨、小板纤恙螨、中华纤恙螨和乡野纤恙螨等,它们占恙螨总数的75.68%。所有优势种在其对应主要宿主体表的4个种群空间分布格局参数都大于相应的界限值0或1,均为聚集型分布。[结论]云南北部金沙江流域恙螨数量丰富,种类复杂。恙螨在小兽体表呈群居寄生。     

云南省北部金沙江流域小兽体表恙螨群落的研究

目的研究云南省北部金沙江流域小兽体表恙螨的群落结构。方法选择云南省北部金沙江流域的巧家、绥江两县的农舍、农田、灌木丛和森林4种生态环境诱捕小兽,选择小兽耳窝和臀部作为恙螨固定采集部位,用镊子采集全部恙螨,70%乙醇固定,Hoyer液封片后于显微镜下鉴定虫种。用群落生态学方法计算群落结构、多样性和相似性指数。结果共捕获小兽302只,经分类鉴定隶属3目7科13属16种。共采集恙螨4550只,经分类鉴定隶属3亚科12属63种,优势种为攸氏无前恙螨、微板无前恙螨、小板纤恙螨、中华纤恙螨、西盟合轮恙螨和乡野纤恙螨,占恙螨总数的78.40%。在6种主要小兽中,有4种小兽体表恙螨群落的物种丰富度超过10,最高达32;有4种小兽体表恙螨群落的多样性指数超过1,最高达2.5732。不同生境同一种小兽体表寄生恙螨群落相似性指数都>0.9。结论云南省北部金沙江流域小兽体表恙螨群落结构比较复杂,种类多,生物多样性较高。     

云南省大理洱海周边地带小兽体表恙螨群落结构

目的了解大理洱海周边地带小兽体表恙螨寄生状况、恙螨物种多样性及群落结构特点.方法选择云南省大理洱海周边的不同地理方位作为野外抽样调查地点,用鼠笼（夹）加食饵诱捕小兽.以小兽耳窝作为固定采集部位,用手术刀片刮取耳窝的全部恙螨,70%酒精保存,Hoyer＇s液封片后于显微镜下鉴定螨种.群落结构用丰富度（S）、Shannon-Wiener多样性指数（H＇）、均匀度（J＇）及优势度指数（C＇）描述.结果捕获小兽3 313只,经鉴定隶属7科14属21种.从3 313只小兽双侧耳窝共采获恙螨56 150只,经鉴定隶属3亚科13属109种.8种优势螨种占全部恙螨的74.42%.多数小兽体表恙螨种类丰富（8种以上）,最多达58种.多数恙螨种类可同时寄生于不同宿主（5种以上）,最多可寄生15种小兽.优势螨种在相应宿主寄生其染螨率（2.06%～59.02%）和螨指数（0.462 7～68.560 6）差异很大.在17种主要小兽中,有13种小兽体表恙螨群落的物种丰富度超过10,最高可达58;有15种小兽体表恙螨群落的多样性指数超过1,最高达2.583 4.结论大理洱海周边地带小兽体表恙螨寄生普遍,恙螨物种多样性高、群落结构比较复杂.多数恙螨的宿主范围广泛,宿主特异性较低.     

热带珊瑚岛地里纤恙螨的生态分布

目的：查清热带珊瑚岛地里纤恙螨的生态分布，制定防制措施。方法：用漂浮法采集具有代表性生境土壤里的地里纤恙螨成虫；笼日法捕小兽，收集地里纤恙螨幼虫。结果：土壤里地里纤恙螨阳性率为42.2%，恙螨平均数2.8;小兽带螨率和带螨指数分别为70.0%,82.2；以黄胸鼠最高，分别为98.0%和146.8；生境以房舍周围的小兽带螨指数和土壤中恙螨数最高，分别为99.8和4.8。结论：综合防制应抓住重点。     

云南省大理洱海周边地带小兽体表恙螨种群空间分布型研究

目的 研究云南省大理洱海周边地带小兽宿主体表恙螨种群空间分布类型。方法 应用扩散系数（C）、丛生指数（I）、Cassie指数（CA）及聚块指数（m^＊／m）进行分析。结果 捕获小兽3313只，经鉴定隶属7科14属21种。从3313只小兽双侧耳壳、耳窝共采获恙螨56150只，经鉴定隶属3亚科13属109种。在分类统计的基础上选定8种恙螨为种群空间分布型测定对象，6种小兽为宿主样方单位。4种分布型指数的测定结果表明，8种优势恙螨在其对应宿主体表的空间分布均表现为聚集分布，各数值明显大于界限值0或1。结论 云南省大理洱海周边地带小兽宿主体表恙螨种群空间分布类型既不是随机的，也不是均匀的，而呈聚集型分布，恙螨在小兽体表呈群居寄生。     

高湖纤恙螨叮人和传病能力的研究

为研究高湖纤恙螨(Leptotrombidium(L.)kaohuense)能否叮人以至传病,我们于1984年进行了实验观察。     

云南省部分地区地里纤恙螨分布调查

目的 探讨云南省地里纤恙螨在宿主选择及在不同地域的分布情况.方法 选择云南省部分县(市)进行现场调查,用鼠笼加食饵诱捕小兽,收集其双侧耳廓和外耳道的恙螨幼虫,用Hoyer's液封片后在显微镜下逐一分类鉴定到种.统计不同恙螨种类、构成比及其在对应寄生宿主的感染率(染螨率)和感染度(螨指数),分析其在不同宿主体表和不同地域的分布情况.结果 在调查的19个县(市)共捕获小兽10 222只,在其体表采集到92 990只恙螨,经分类鉴定隶属于3亚科22属225种.其中采集到地里纤恙螨共1544只,仅占所有恙螨的1.659%;且宿主特异性低,仅在调查点的6个县(市)的19种8518只小兽体表采集到.结论 历史上认为地里纤恙螨是云南省恙虫病流行区优势螨种和主要媒介可能只是某些局部地区的情况,不同地域生境的恙螨构成和优势螨种可能存在差别.

Abstract：

Objective To investigate the distribution of Leptotrombidium deliense among different small mammal hosts in some areas of Yunnan province. Methods A field survey was carried out in some counties of Yunnan province and the small mammal hosts were captured, using mouse cages and traps with baits. Chigger mites on the surface of two auricles were scraped off by a bistoury, and then preserved in 70% ethanol. Every specimen of the chigger mites on the slides was finally identified into species under a microscope. Some conventional statistical methods were adopted to calculate all the collected chigger mite species and the constituent ratios of Leptotrombidium deliense in different areas and on different hosts, together with its prevalence and mean abundance on different hosts. Results A total of 10 222 small mammal hosts were captured from 19 counties and identified as 11 families, 34 genera and 62 species in 5 orders, and 92 990 individuals of chigger mites were collected from the body surface of these small mammal hosts. All the collected chigger mites were identified as 3 subfamilies, 22 genera, and 225 species. Meanwhile, Leptotrombidium deliensee only accounted for 1.659% of the total. The host specificity of Leptotrombidium deliense was very low and 1544 individuals of Leptotrombidium deliense collected from 8518 small mammal hosts belonged to 6 families, 13 genera and 19 species in 3 orders. Our results showed that Leptotrombidium delienses were mainly collected from Insectivora and Rodentia. Leptotrombidium deliense had long been considered as the dominant species of chigger mites and the main vector of tsutsugamushi disease in Yunnan province of China, but our results seemed not thoroughly supporting this point of view. Conclusion Traditionally, Leptotrombidium deliense was the dominant species and the main vectors of scrub typhus in Yunnan province. However, based on our results, the above view might be true in some local places and the composition of chigger mites and the main vector of tautsugamushi disease might be different in regions and habitats in Yunnan province.     

闽西地区恙虫病疫源地调查

「目的」查明闽西地区恙虫病自然疫源地分布及宿主动物种群、宿主动物和健康人群恙虫病立克次体感染情况。「方法」诱捕野栖、家栖鼠类，分类鉴定；收集宿主动物体表寄生恙螨分类鉴定；采集宿主动物、健康人群血清监测恙虫病抗体；采集宿主动物脾脏检测恙虫病立克次体。「结果」我区鼠类有３科７属１８种，以黄毛鼠、针毛鼠、褐家鼠为优势种群，恙螨有２科９属２０种，以中华无前恙螨、地理纤恙螨、似太平洋无前恙螨为优势种群，对恙     

深圳市南山区恙虫病宿主动物分布及感染状况

目的了解深圳市南山区恙虫病宿主动物分布及感染状况,及恙虫病传播媒介种类。方法采用笼补法捕鼠,计算鼠密度;采集鼠血,以荧光定量PCR法检测恙虫病东方体核酸;收集鼠耳恙螨,计算带螨指数。结果 2013—2015年,共布放鼠笼3 600笼次,捕获活鼠193只,鼠密度5.4%;其中褐家鼠150只(占77.7%),黄胸鼠39只(占20.2%),小家鼠4只(占2.1%)。带螨鼠9只,带螨率为4.7%,带螨指数为0.15;共检获恙螨29只,均为地里纤恙螨。收集鼠血标本130份,其中1份褐家鼠恙虫病东方体核酸阳性,阳性率0.77%。结论南山区鼠密度、带螨指数和鼠恙虫病感染率均较低,主要媒介为地里纤恙螨;应继续加强恙虫病的监测和防控工作。     

Clinical and laboratory evidence of the importance of the tick D. marginatus as a vector of B. burgdorferi in some areas of sporadic Lyme disease in Bulgaria

56 adult ticks D. marginatus and 38 adult ticks H. punctata were sampled by the flagging method, transferred to the laboratory, dissected and tested for infection with Lyme disease spirochetes. 3 (7.9%) of the adult H. punctata and 2 (3.57%) of the adult D. marginatus were infected with B. burgdorferi (Bb). This report also presents the case of a patient, who developed Lyme disease symptoms after he had been bitten by a D. marginatus tick. The clinical diagnosis was confirmed by serological testing and by a biopsy, taken from the patient's skin lesion. The skin biopsy was examined under an electron microscope and Bb was found in the sections of the deeper strata of the dermis in two structural forms: (a) cylindrical bodies (protoplasm cylinder) with circular ends covered with a three-layered membrane; (b) granules, situated among the collagenous fibres either closely adhered to them or covered with a membrane. The result of the study demonstrates that in single cases in some ecosystems, ticks D. marginatus might be implicated in Bb transmission to humans as secondary vectors.     

Screening of the municipal water system of La Plata, Argentina, for human intestinal parasites

The La Plata River, though severely contaminated by intestinal parasites through the discharge of tons of crude fecal material from a main sewage channel, nevertheless provides drinking water to two-thirds of La Plata, Argentina, after conventional purification at a processing plant. With intestinal parasitosis being endemic here, we investigated the importance of this water in transmitting such pathogens to the city's populace by means of standard methodology for sample acquisition and processing involving filter-concentration of waterborne particulates. Of 14 tap-water samples collected from the distribution network, 12 pertained to four zones (A-D) within the city center; while the remaining 2 were obtained near the processing plant, 15 kilometers outside the city. Although parasites were found within the samples derived from the four urban zones, none were detected in the specimens obtained near the plant. The four downtown areas differed from each other as to the quantity and nature of the parasites present in their water: whereas zones A and B registered similar lower levels of contaminants, C and D exhibited higher values significantly different from the former two and from each other. Given an average parasite count/l citywide of 0.38 and a probability of encountering a parasite within 11 of water of 0.32, the municipal network is seen to contribute to the transmission of intestinal parasites. A routine system of water-quality control is therefore needed throughout the city along with the establishment of infrastructures for locating and eliminating peripheral sources of contamination.     

Seroepidemiology of rickettsial infections in Morocco

The prevalence of antibodies reactive withRickettsia conorii, Rickettsia typhi, Coxiella burnetii andEhrlichia chaffeensis was investigated using indirect immunofluorescence (IFA) test on human sera obtained from 300 blood donors in Casablanca and 126 sera obtained from clinical laboratories in Fez. In sera from Casablanca, antibodies reactive at titers >=1: 32 were found againstR. conorii (7%), andR. typhi (1.7%), but not againstE. chaffeensis. In the sera from Fez, antibodies were also detected againstR. conorii (5.6%),R. typhi (4%), but not againstE. chaffeensis. By Western immunoblotting, seroprevalence forR. conorii was in Casablanca and 4.8% in Fez. Antibodies reactive at titers >=1:50 againstC. burnetii (phase II) were present in sera from Casablanca (1%) and Fez (18.3%).Abbreviations IFA Immunofluorescence assay - MSF Mediterranean spotted fever - PBS Phosphate-buffered saline     

Absorption,metabolism and elimination of N,N-dimethylformamide in humans

Summary Excretion of N,N-dimethylformamide (DMF) and DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethyl-formamide (F) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) has been monitored in the urine of volunteers during and after their 8-h exposure to DMF vapour at a concentration of 10, 30 and 60 mg · m^–3. The pulmonary ventilation in these experiments was typically about 101 · min^–1 and the retention in the respiratory tract was 90%. After exposure to 30 mg DMF · m^–3, the yield of compound determined in the urine represented 0.3% (DMF), 22.3% (MF), 13.2% (F) and 13.4% (AMCC) of the dose absorbed via the respiratory tract. The excretion curves of the particular compounds attained their maximum 6–8h (DMF), 6–8h (MF), 8–14h (F) and 24–34h (AMCC) after the start of the exposure. The half-times of excretion were approximately 2, 4, 7 and 23 h respectively. In contrast to slow elimination of AMCC after exposure to DMF, AMCC was eliminated rapidly after AMCC intake. This discrepancy could be explained by rate-limiting reversible protein binding of a reactive metabolic intermediate of DMF, possibly methylisocyanate.     

Percutaneous absorption of N,N-dimethylformamide in humans

Summary Skin penetration fo N,N-dimethylformamide (DMF) liquid or vapour was studied in volunteers. Exposure to liquid DMF was performed in two ways: in a dipping experiment, one hand was dipped up to the wrist in DMF for 2–20 min, while in a patch experiment, 2 mmol DMF was applied to the skin and allowed to be absorbed completely. The period of exposure to DMF vapour (50 mg · m^–3) was 4 h. The DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethylformamide (F), and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) were monitored in the urine. Liquid DMF was absorbed through the skin at a rate of 9.4 mg · cm^–2 · h^–1. Percutaneous absorption of DMF vapour depended strongly on ambient temperature and humidity and accounted for 13%–36% of totally excreted MF. The results suggest that skin absorption of liquid DMF is likely to contribute to occupational exposure substantially more than penetration of DMF vapour. The yield of metabolites after transdermal DMF absorption was only half of that seen after pulmonary absorption. Elimination of MF and F but not that of AMCC was delayed, which supports the contention that AMCC should be used instead of MF as the most suitable biomarker of DMF in cases where percutaneous intake can occur.     

A vulnerable population in a time of crisis: Drug users and the attacks on the World Trade Center

In this article, we present preliminary findings from a qualitative study focused on the impact of the World Trade Center attacks on New York City residents who are current or former users of heroin, crack, and other forms of cocaine. In it, we present data describing their responses to and feelings about the attacks, changes in drug use after the attacks, and factors affecting changes in use. Our analysis is based on 57 open-ended interviews conducted between October 2001 and February 2002. The majority of study participants reported that the attacks had a significant emotional impact on them, causing anxiety, sadness, and anger. Several described practical impacts as well, including significant reductions in income. On September 11th and the weeks and months that followed, several participants who had been actively using did increase their use of heroin, crack, and/or other forms of cocaine. Reductions in use were, however, as common over time as were increases. There was some relapse among former users, but this was limited to those who had stopped using drugs within the 6 months immediately preceding the attacks. A diverse set of factors interacted to control use. For some participants, these factors were internal, relating to their individual motivations and drug use experiences. Other participants were essentially forced to limit use by marked reductions in income. For others, access to health and social service professionals, as well as drug treatment, proved to be key. Department of Family Medicine and Community Health at Montefiore Medical Center     

The impact of needle-exchange programs on the spread of HIV among injection drug users: A simulation study

Objective. To determine the impact of the implementation of a needle-exchange program (NEP) on the spread of human immunodeficiency virus (HIV) in an injection drug user (IDU) community. We conducted a Monte Carlo simulation study of a theoretical population of 10,000 IDUs. The population was followed monthly from 1984 to 2000. HIV was assumed to be transmitted only by needle sharing. The NEP was introduced in 1989 and evaluated over a period of 11 years. The impacts of the proportion of the population attending the NEP, the risk level of IDUs attending the NEP, the reduction in needle-sharing frequency, and the number of new needle-sharing partners acquired at the NEP on prevalence and incidence of HIV were determined. Increasing the proportion of the population who always attend the NEP and eliminating needle-sharing incidents among IDUs who always attended the NEP were the most effective ways of reducing the spread of HIV. Attracting high-risk users instead of lower risk users to the NEP also reduced the spread of HIV, but to a lesser extent. NEPs are effective at reducing the spread of HIV; even under the worst case scenario of low risk users more likely to attend the NEP, one additional partner per month as a result of attending the NEP, and poor NEP attendance, the estimated prevalence was still less than that from the scenario without an NEP. Under our model, NEPs were shown to reduce the spread of HIV significantly. Efforts should be focused on getting as many IDUs as possible to become regular NEP attenders and stop sharing needles rather than partially reducing the frequency of sharing by a larger number of IDUs.     

Re-assessment of the influence of polymorphisms of phase-II metabolic enzymes on renal cell cancer risk of trichloroethylene-exposed workers

Problem Individual differences in susceptibility to trichloroethylene-induced nephrocarcinogenicity may be conferred by genetic polymorphisms of glutathione S-transferases (GST), because enzymes of this group are pivotal for the metabolic activation of trichloroethylene. Because of a potential involvement of N-acetylation in the detoxication of reactive trichloroethylene metabolite(s) to N-acetyl-cysteine derivatives, polymorphisms of the NAT2 gene may also be relevant. Methods The primary collective used for a re-investigation of these questions was that of a hospital-based case-control study by Brüning et al. (Am J Ind Med 43:274–285, 2003) of 134 renal cell cancer cases (20 cases exposed to trichloroethylene) and 401 matched controls. Genetic polymorphisms of GSTT1, GSTM1, GSTP1 and NAT2 were studied. Additional control collectives of non-diseased persons were used for comparison of allele frequencies. Results No genetic influences on the development of renal cancer due to trichloroethylene were apparent, related to the deletion polymorphisms of GSTT1 and GSTM1, as well as to the NAT2 rapid/slow acetylator states. However, renal cell cancer cases displayed a somewhat higher proportion of the homozygous GSTP1 313A wild type (GSTP1*A), although this was not statistically significant (χ² test: P = 0.1071, when using only the original controls of Brüning et al. (2003); P = 0.0781 with inclusion of the additional controls). Conclusion The re-investigation does not confirm the working hypothesis of an influence of the deletion polymorphisms of the glutathione S-transferases GSTT1 and GSTM1 on renal cell cancer development due to high occupational exposures to trichloroethylene.     

Selenium content of Portuguese unifloral honeys

The selenium contents of a total of 62 unifloral honeys from Erica spp., Castanea sativa, Eucalyptus spp., Lavandula stoechas, Citrus spp. and Echium plantagineum honeys collected in Portugal were determined by fluorometry after reaction with 2,3-diaminonaphthalene. The selenium levels of the honey samples studied were low, ranging from <1.0 to 2.91 μg/100 g fresh weight. The honeys from Erica spp., C. sativa and E. plantagineum presented the highest selenium values from all the honeys studied (median values 1.69, 1.51 and 1.51 μg/100 g fresh weight), and the honeys from Eucalyptus spp., L. stoechas and Citrus spp. presented the lowest values (median values 1.33, 1.28 and 1.20 μg/100 g fresh weight). The selenium content of Erica spp., was significantly higher than that observed for the Eucalyptus spp., L. stoechas and Citrus spp. and the selenium level of the Eucalyptus spp., was also significantly lower than that observed C. sativa and E. plantagineum honeys. From these results it can be concluded that honey is a marginal source of Se for the Portuguese population.     

Brucella phagotypes : Their relation to the spread of infection in Italy

The spread of Brucella infection in man in Italy during the last three years is briefly reviewed with reference to the Brucella strains collected and typed.The strains were tested by H₂S production, dye-inhibition, agglutination by monospecific sera, and sensitivity to a phage set. From 108 tested strains, 91 have been identified by means of the traditional tests as Br. melitensis, sometimes with some irregularities, 10 as Br. abortus, while 7 were not typable.It was possible to recommend some phage sensitivity patterns of Br. melitensis for epidemiological purposes: one phagotype is much more frequent in the north, another in the south of Italy.However, the currently recommended phagotypes must be considered provisional and will be modified in the light of more extensive studies.Corresponding author.