Cercarial dermatitis in the Netherlands caused by Trichobilharzia spp

Outbreaks of cercarial dermatitis which occurred in recreational lakes in the Netherlands were studied and a method for direct rapid detection of the parasite Trichobilharzia in water samples was developed. A standardized questionnaire with questions on health complaints and exposure was distributed to individuals who developed symptoms of cercarial dermatitis after visiting fresh water lakes. Snails from the suspected lakes were examined for the presence of Trichobilharzia by microscopy and PCR. Water samples were concentrated by filtration and examined by PCR. Water quality was tested according to European Bathing Water Directive 76/160/EEG. Trichobilharzia was detected in snails and water samples from lakes which met European bathing water standards. Despite a response of 25.5%, epidemiological data suggested that longer and more frequent exposure to the water resulted in increased reporting of symptoms of cercarial dermatitis and confirmed the importance of exposure as a risk factor. A novel method for direct detection of Trichobilharzia, which includes concentration of water samples by filtration and detection of the parasite by PCR proved to be a valuable and simple tool for confirmation of presumptive outbreaks, particularly when snails could not be found in the suspected water and public health protecting measures were necessary.     

Swimmer's itch: incidence and risk factors

Swimmer's itch (cercarial dermatitis) affects people engaged in open-water activities. We report incidence and risk factors for a US lake. Water exposures and swimmer's itch experience were reported daily for riparian household residents and guests at Douglas Lake, Michigan, in July 2000. Incidence of swimmer's itch was 6.8 episodes per 100 water exposure days. Positive risks were (1) exposures in shallow water and in areas with onshore winds and (2) more days of lake use in July. Further epidemiological studies will help public health agencies address this bothersome problem at recreational lakes.     

La dermatite cercarienne en Europe: un problème de santé publique nouveau?

Cercarial dermatitis is a parasitic impasse that has worldwide distribution. The condition manifests itself as a highly pruriginous skin rash and is due to penetration of the dermis by larval stages (furcocercariae) of avian trematodes. Many species may be responsible for this disease. In Europe the genus Trichobilharzia is widely represented, in particular by the species T. ocellata; the definitive host is the duck (Anas platyrhinchos); the intermediate hosts are snails of the genus Lymnea (L. ovata or L. stagnalis). In France, cases of cercarial dermatitis were reported in June and July 1994 to the health authorities of three départements in the Pays de la Loire Region (western France). The epidemiological situation, common to the three maintained ponds that were concerned, is as follows: high level of eutrophication of the sites, colonization of the ponds by L. ovata, and settlement by many duck colonies. The simultaneous occurrence of these three phenomena, combined with long hours of sunshine in the summer, is responsible for most of the foci of cercarial dermatitis recently described in Europe. Control of this condition is difficult, requiring strict maintenance of bodies of water and if necessary the use of molluscicides such as niclosamide. The use of praziquantel in baits for treating the definitive hosts appears to interrupt the natural cycle of the avian Schistosomatidae. In the light of the observations reported here and the analysis of recent publications, cercarial dermatitis may be regarded as an emerging disease. Its public health impact needs to be evaluated at the global level.     

Development of molecular approaches for the identification of transmission sites of schistosomiasis

Primers targeting the gene encoding the small subunit rRNA were designed to amplify DNA from Schistosoma mansoni with high specificity. Three PCR systems were developed: conventional PCR, two-step nested PCR (NPCR) and single-tube nested PCR (STNPCR). The limits of detection of parasite DNA for the conventional PCR, NPCR and STNPCR were 10 pg, 0.1 fg and 1 fg, respectively. The assays were highly specific for S. mansoni and did not recognise DNA from closely related non-schistosome trematodes. Using pools of Biomphalaria molluscs, PCR, NPCR and STNPCR were positive in 6/16 (37.5%), 15/16 (93.8%) and 13/16 (81.3%) of the tested samples, respectively, whereas the observation of cercariae shedding after exposure to light was able to detect S. mansoni infection in 6/16 (37.5%) of the pools. Thus, the molecular detection systems had a higher level of sensitivity than standard screening of intermediate hosts by cercarial shedding when DNA was purified from pools of snails collected from endemic areas. These PCR protocols have potential to be used as tools for monitoring of schistosome transmission.     

Investigation of an outbreak of cercarial dermatitis

We present the investigation of an outbreak of cercarial dermatitis that occurred in a recreational-tourist lake in the Quebec City region (Canada) in the summer of 1999. A case-reporting form was sent to 450 families likely to have activities that would bring them in contact with the lake's water. The snails were characterized and the prevalence of their infestation by schistosomes was investigated. In total, 63 episodes consistent with cercarial dermatitis were reported. Sixty-nine percent of the cases occurred from swimming at the same beach. This location was the one where the only population of snails in the lake was identified. Shoreline residents were informed that they should not feed waterfowl, and a clean-up of the snail population was done at the start of the following summer. There were no cases of cercarial dermatitis at this site the following summer.     

Cercarial dermatitis and lake eutrophication in south-central Chile

Cercarial dermatitis is caused by exposure to the cercariae of schistosome species which have birds or mammals as their definitive hosts. A public alarm was raised in the summer of 2004 when this parasitic disease was observed for the first time in south-central Chile at Laguna Chica de San Pedro (36 degrees 51' S, 73 degrees 05' W). Swimmers at this eutrophic lake were surveyed in order to estimate the amount of cercarial dermatitis in the area; participants were observed during the summers of 2004 and 2005 for clinical signs of cercarial dermatitis and 25 Chilina dombeyana snails were collected monthly from Laguna Chica de San Pedro during one year and then examined for animal schistosome cercariae. We found that 3% of the swimmers had pruritic maculopapular rashes on their legs, arms, necks, or other body parts and that between 9.1% (May 2006) and 52.4% (November 2004) of the snails examined were infected with the bird schistosome cercariae Trichobilharzia sp.     

Trichobilharzia anseri n. sp. (Schistosomatidae: Digenea), a new visceral species of avian schistosomes isolated from greylag goose (Anser anser L.) in Iceland and France

Parasitological investigations carried out on birds in Iceland and France highlight the presence of four species of avian schistosomes from greylag geese (Anser anser L.): the european nasal species Trichobilharzia regenti and three visceral species, among which an unknown species isolated from blood vessels of the large intestine and liver. Morphological and molecular analyzes of different parasite stages (eggs, adults) revealed new species of Trichobilharzia genus – Trichobilharzia anseri sp. nov. Studies on host–parasite relationship under natural conditions, showed that the life-cycle includes the snail Radix balthica (syn. R. peregra) as intermediate host. The cercariae, already isolated in Iceland from two ponds of the Reykjavik capital area – the Family park and Tjörnin Lake – are the same as those isolated in 1999 by Kolářová et al. during the first study on Icelandic parasitic agents of cercarial dermatitis.     

Aminothiophenedicarboxamides and dicyanothiopheneacetamides as effective synthetic molluscicides against Indoplanorbis exustus snail

New thiophenedicarboxamide 2a-c and dicyanothiopheneacetamide 3a-c derivatives were synthesized and their bioactivity against Indoplanorbis exustus snails was evaluated. The I. exustus snail is a serious host of parasite of genus Schistosoma which infects cattle. Thus reduces livestock productivity and also acts as a source of cercarial dermatitis in human beings. The results obtained show a significant (P < 0.05) molluscicidal activity with LC(50) = 0.6043 ppm for compound 2a and LC(50) = 0.6511 ppm for compound 3a.     

Species Identification of Birds Nasal Trichobilharzia in Sari,North of Iran

Background

Cercarial dermatitis is known as an endemic parasitic disease in North of Iran, a hypersensitive skin reaction to the penetration of nonhuman schistosome larvae into human skin. In recent studies in this region, final and intermediate hosts were recognized and Trichobilharzia was identified as the main causative agent of cercarial dermatitis in this region, but to date the parasite species haven''t been identified. Therefore this study was performed to species identification of nasal Trichobilharzia in infected birds for the first time.

Methods

A total of 45 Anas clypeata birds identified as final host, were collected from Sari in North of Iran and infected nasal tissues analyzed using molecular techniques. Genomic DNA was isolated by phenol/chloroform extraction method and ITS region of rDNA were amplified with specific primers its5Trem and its4Trem, then sequenced area were compared with existing records in GenBank.

Results

Twelve samples were infected with Trichobilharzia and results of PCR reaction indicated that all of them belonged to T. regenti. The sequence alignment of present work isolates and those deposited in GenBank showed differences in nucleotide sequences of repeat region in ITS1.

Conclusion

Trichobilharzia regenti is the most frequent parasite of Anatid birds in North of Iran. This corresponds to the distribution of this parasite along the flyway of migratory birds, which annually migrate from Siberia and northern countries of Caspian Sea to wintering areas in southern regions of it.     

Histopathologie pulmonaire d'un modèle mammifère et dermatite cercarienne humaine

Objective – People which have been repeatly exposed to agents of cercarial dermatitis, presented sometimes alteration of the general status with pulmonary disorders or anaphylactic shock symptoms, from which the mechanics remain unknown.Methods – In order to elucidate them, a mammalian model gerbil Meriones unguiculatus has been used for exposure to ocellate furcocercariae, emitted by naturally infected Lymnaea peregra, native from Leman Lake. A duck exposure, to the same cercariae, aimed to obtain identifiable adult worms. The duck Cairina moschata developed Schistosomatidae worms close to Ornihobilharzia. The gerbil experienced five exposures to the cercariae during seven days. It has been sacrified after the last exposure and submitted to histological analysis.Results – The gerbil skin displayed evidences of dermatitis, scratching changes associated with lymphocytic vasculitis, devoid of schistosomula. Grossly, the lungs showed whitish granulations alongside the lung arteries, their collaterals and the bronchial tree. These nodules corresponded to lesions of lymphocytic vasculitis developed beneath alive or faintly damaged worms. The peripheral lung parenchyma presented macrophagic alveolitis. The lung invasion by avian bilharziae of Austrobilharzia and Trichobilharzia has been reported in several mammalian models. In this study, the worms found in the gerbil were close to Ornithobilharzia. The identified pulmonary lesions could have the same nature than those responsibles for respiratory distress in asthmatic children and lung disorders in ricefield workers having superimposed cercarial dermatitis.Comment – Immature avian bilharziae could be dangerous for Humans repeatly exposed to their cercariae.     

A study on cercarial dermatitis in Khuzestan province, south western Iran

Background

Cercarial dermatitis' or swimmer's itch' is an itchy inflammatory response to the penetration of the skin by non-human schistosome parasites. In the hot season, (May to September) in Khuzestan province in the south west of Iran, swimming in canals and agriculture activities in swampy areas are common. This survey was made on people from villages north of Ahwaz city in south west Iran, to estimate cercarial dermatitis in this region.

Methods

2000 people were observed for clinical signs of cercarial dermatitis. Also 2000 Lymnaea gedrosiana snails were collected from agriculture canals and examined for animal schistosome cercariae during 1998–2000.

Results

From this survey 1.1% of people had pruritic maculopapular rash on their feet, hands or other parts of body. From the total of examined snails, 2.4% were found to be infected with bird schistosome cercariae including Trichobilharzia species.

Conclusion

Cercarial dermatitis could be a health problem in this area. This is the first report of cercarial dermatitis from this region of Iran.     

Public health importance and risk factors for cercarial dermatitis associated with swimming in Lake Leman at Geneva,Switzerland.

Fifteen cohorts of healthy bathers were recruited at four Lake Leman beaches between 3 July and 23 August 1996 to assess the public health importance of cercarial dermatitis in Geneva, Switzerland. Telephone follow-up interviews were carried out after 2-7 days. Overall, 153 bathers out of 555 reported probable cercarial dermatitis at follow-up. Median daily attack rate was 27.7% (2.2-57.7%). Of the cases, 11.1% noticed more than 30 skin lesions, 19.6% described severe itching, 50.3% used a drug treatment, 3.9% visited a doctor and 15% claimed they would reduce their bathing activities. History of cercarial dermatitis, time spent in the water, hour of the day, barometric pressure and maximum daily atmospheric temperature predicted disease occurrence in multivariate analysis. While a benign disease, cercarial dermatitis may have a negative impact on the local water recreation industry. The identification of risk factors for the disease may help produce better preventive recommendations for the bathers.     

广东新会环境水源军团菌分布类型研究

目的对广东新会公共环境水源中军团菌进行分离培养及种属鉴定，了解其分布状况，为军团菌病的预防控制提供依据。方法2007年8月在广东新会两个天然湖泊及6家宾馆的内湖和空调冷凝塔中共采集水样23份，作军团菌分离培养，用生化试验和PCR等方法进行初步鉴定，最后根据16srRNA和mip基因测序，最终确定菌种。结果23份水样中检出军团菌20份，检出率高达86．9％；检出军团菌30株，其中嗜肺军团菌21株，非嗜肺军团菌9株，包括戈尔曼军团菌5株，菲氏军团菌2株，长滩军团菌2株；同时发现同一水样中有多种军团菌共存现象。结论在广东矫会环境水源中军团菌普遍存在，且有多种军团菌共存状况，应引起相关部门的重视．以防军团病的暴发流行。     

Mutagenicity of drinking water obtained by different treatment procedures from two northern Italian lakes

Raw water and drinking water samples collected from four treatment plants supplied by two north Italian lakes were studied for their mutagenic activity. The samples were concentrated on XAD‐2 columns and the adsorbates were tested at increasing doses with the Ames test, using Salmonella typhimurium TA98 and TA100 strains, with and without metabolic activation. Raw water from both lakes was found to contain direct‐acting mutagens detectable with TA98 strain. The analysis of water from the four treatment systems showed that new mutagens detectable with strain TA100 (?S9) were produced when pre chlorination or post chlorination with NaCIO was performed, as previously found by other authors. When chlorine dioxide and/or ozone were used, TA98 mutagenicity was reduced and no new mutagens were produced. The results showed the applicability of the Ames test to evaluate drinking water treatment processes and to produce additional data useful in the detection of potential health hazards associated with drinking water production.     

Detection of Infection with Larval Stages of Ornithobilharzia turkestanicum using PCR in Field-Collected Snails of Lymnaea gedrosiana from Northwestern Iran

Background

Infection with Ornithobilharzia turkestanicum has been reported in a wide range of animals worldwide. This study was undertaken to assess the utility of polymerase chain reaction (PCR), for detecting the infection with O. turkestanicum larvae stages in Lymnaea gedrosiana.

Methods

A total of 6,759 Lymnaeidae snails were collected from six aquatic habitats in West Azarbaijan, northwest Iran. Of these, the snails of L. gedrosiana were identified. To detect infected L. gedrosiana with the larval stages of O. turkestanicum, they were subjected for cercarial shedding and molecular examinations. The genomic DNA was extracted and PCR was performed to specifically amplify a fragment of the nuclear 28SrRNA gene of O. turkestanicum.

Results

Of all collected snails, 5.4% (365/6,759) were the snails of L. gedrosiana. The cercarial shedding method revealed that 23.56% (86/365) of the snails were infected. The PCR patterns confirmed that 28.77% (105/365) snails of L. gedrosiana were infected with larval stages of O. turkestanicum. The infected snails were observed in five studied sites. The highest infection rate (66.66%, 20/30) was recorded in the snails of Ghargologh in the northern part. Only 35.24% (37/105) of the infected snails were from the plain areas, whereas the remaining existed in high altitudes.

Conclusion

It was concluded PCR method could be an efficient and fast method for uncovering the actual rate of infection with larval stages of O. turkestanicum in the snails of L. gedrosiana. This method can be also useful for the domestic animals and public health management programs in the country.     

泰州市116份公共场所集中空调冷却水嗜肺军团菌监测结果

目的 为了解泰州市公共场所集中空调冷却水中嗜肺军团菌污染状况,为军团病的防控提供数据。方法 于2013-2015年采集了泰州市公共场所集中空调冷却水116份,进行了嗜肺军团菌分离培养,同时进行嗜肺军团菌核酸检测。结果 116份冷却水样本中26份分离培养出嗜肺军团菌,检出率为22.4%,荧光PCR法嗜肺军团菌核酸检测结果31份核酸阳性,检出率为26.7%。宾馆(饭店)、商场(超市)冷却水样中分离培养检出率分别为19.7%、27.5%,荧光PCR法嗜肺军团菌核酸阳性检出率分别为22.3%、35.0%。结论 泰州公共场所的集中空调冷却水嗜肺军团菌污染情况严重,已对长期在此环境下工作人群健康构成潜在威胁。     

2008年-2010年南平市城乡饮用水卫生状况分析

目的:了解南平市城乡生活饮用水卫生状况,为提高饮用水卫生管理质量提供科学依据。方法:对2008年-2010年南平市城乡集中式供水和分散式供水的水质检测资料进行统计、分析和评价。结果:三年共检测样品689份,合格率为68.2%。其中集中式供水水样586份,合格率为80.9%;分散式供水水样103份,合格率为49.2%,集中式供水水样合格率与分散式供水水样合格率比较有显著性差异。水源水、山泉水和井水中合格率最低的是细菌总数和总大肠菌群。出厂水和末梢水各项目的合格率均在93.9%以上。结论:集中式供水水样合格率明显高于分散式供水水样的合格率;水源水、山泉水、井水是影响我市城乡饮用水合格率的主要因素;提高水质净化处理技术,加强水源地管理是保证饮水安全的关键。     

Industrial Pseudomonas folliculitis

INTRODUCTION: Complaints of poor water quality and skin rashes among workers at a US cardboard manufacturing facility were investigated to determine potential causes. METHODS: Employees were interviewed regarding work duties and health symptoms. Areas of dermatitis in affected employees were visually examined. Collected water samples were tested for potential chemical and microbial contaminants. RESULTS: A total of 27 employees were identified with complaints of recent skin rashes affecting primarily the upper and lower extremities. Dermatitis complaints were associated with water contact and work in areas with poor water quality. Water testing showed high levels of Pseudomonas aeruginosa. Other tested substances were not at levels of concern. CONCLUSIONS: Overgrowth of P. aeruginosa occurred in the water system shortly after the facility switched to a closed-loop water recycling system and was the most likely cause of the observed dermatitis. To our knowledge, this is the first reported outbreak of Pseudomonas folliculitis in an industrial setting.     

Environmental health outcomes and exposure risks among at-risk communities living in the Upper Olifants River Catchment,South Africa

Potential exposure to water and air pollution and associated health impacts of three low-income communities in the Upper Olifants River Catchment, South Africa, was investigated through a cross-sectional epidemiological study comprising a household survey. Water samples were collected and analysed for microbial indicators and pathogens. Ambient air-monitoring included some of the criteria pollutants, as well as mercury and manganese. Associations between environmental exposure and health outcomes were analysed by means of logistic regression. Despite poor water and air quality episodes, the communities’ self-perceived health was good with relatively low prevalence of reported health outcomes. Hygiene practices with respect to water collection and storage were often poor, and most likely contributed to the regularly contaminated water storage containers. Community proximity to the polluted stream was associated with increased prevalence in adverse health outcomes. This paper reports on preliminary results and additional multivariate analyses are necessary to further understand study results.     

Cryptosporidium spp. and Giardia duodenalis as pathogenic contaminants of water in Galicia,Spain: The need for safe drinking water

The objectives of this cross-sectional study were to detect the presence of Cryptosporidium spp. and Giardia duodenalis in drinking water treatments plants (DWTPs) in Galicia (NW Spain) and to identify which species and genotype of these pathogenic protozoans are present in the water. Samples of untreated water (surface or ground water sources) and of treated drinking water (in total, 254 samples) were collected from 127 DWTPs and analysed by an immunofluorescence antibody test (IFAT) and by PCR. Considering the untreated water samples, Cryptosporidium spp. were detected in 69 samples (54.3%) by IFAT, and DNA of this parasite was detected in 57 samples (44.8%) by PCR, whereas G. duodenalis was detected in 76 samples (59.8%) by IFAT and in 56 samples (44.0%) by PCR. Considering the treated drinking water samples, Cryptosporidium spp. was detected in 52 samples (40.9%) by IFAT, and the parasite DNA was detected in 51 samples (40.1%) by PCR, whereas G. duodenalis was detected in 58 samples (45.6%) by IFAT and in 43 samples (33.8%) by PCR. The percentage viability of the (oo)cysts ranged between 90.0% and 95.0% in all samples analysed. Cryptosporidium andersoni, C. hominis, C. parvum and assemblages A-I, A-II, E of G. duodenalis were identified. The results indicate that Cryptosporidium spp. and G. duodenalis are widespread in the environment and that DWTPs are largely ineffective in reducing/inactivating these pathogens in drinking water destined for human and animal consumption in Galicia. In conclusion, the findings suggest the need for better monitoring of water quality and identification of sources of contamination.