Prevalence of giardiasis among primary school children

Summary This cross-sectional study was conducted to investigate the prevalence of intestinal parasites among primary school children in Northern Jordan. Stool specimens were collected from 1100 children of both sexes from urban and rural schools. A questionnaire covering relevant informations was completed for each child. Wet mount preparation, formaline-ether concentration technique, and trichrome stain were prepared for the recovery and identification of parasites. Giardia lamblia was observed in 396 (36%) of the stool specimens examined. The infection rates were higher in the younger age group where several of them had diarrhoea and reported variable symptoms. The infection rates declined with age and children were asymptomatic. Rates were higher in children from the rural areas, from low income families, and it was higher in boys than girls.
Contaminated drinking water is suspected to be the major potential source of infection. The importance of the asymptomatic cases and the epidemiological factors contributing to the transmission in these areas are discussed.     

Enzyme-linked immunosorbent assay for Giardia-specific IgA in mouse intestinal secretions

We describe an ELISA for trophozoite-specific IgA in the intestinal secretions of mice infected with Giardia muris. Using this method, trophozoite-specific IgA was demonstrated in intestinal secretions of Giardia-infected immunocompetent BALB/c mice. Such antibody was undetectable in the intestinal secretions of Giardia-infected athymic (nude) mice. Immunocompetent BALB/c mice are able to clear G. muris infection whereas nude mice are not. The study provides evidence that the chronicity of G. muris infection in nude mice results from lack of intestinal trophozoite-specific IgA in these animals. By means of the ELISA, trophozoite-specific IgA was demonstrated in intestinal secretions from immunocompetent mice in the absence of protease inhibitors.     

Giardia muris infection in mice with concurrent graft-versus-host reaction

The effects of concurrent graft-versus-host reaction (GvHR) on the course of Giardia infection in CBA x BALB/c F1 mice have been examined, to test the hypothesis that T-cell-mediated immunity, in the form of a local DTH reaction, alters the host-parasite relationship in favour of the host by changing the physical environment of the parasite. GvHR did not enhance immunity, indeed mice infected with Giardia at a late stage of GvHR had significantly higher faecal cyst excretion and prolongation of the plateau phase of infection, indicating a degree of immunodeficiency.     

肠道贾第虫病42例的临床分析

目的 :观察贾第虫病的临床表现及甲硝唑对贾第虫病的治疗作用。方法 :用甲硝唑治疗 42例贾第虫病患者 ,剂量为 0 .4g,日 3次 ,连服 7～ 10 d为一疗程 ,其中服 1个疗程的有 3 5例 ,服 2个疗程的有 5例 ,服 3个疗程的有 2例。结果 :经治疗后 ,全部患者的症状如腹泻及 (或 )腹痛等胃肠道症状均消失 ,粪检结果恢复正常。患者服药期间的不良反应轻 ,仅有轻微的胃肠道反应 ,如恶心、厌食等。结论 :甲硝唑治疗贾第虫病具有疗效好、耐受性好的优点     

用PCR扩增tim基因检测蓝氏贾第鞭毛虫

采用聚合酶链反应 (PCR)对蓝氏贾第鞭毛虫 (Giardialamblia)的磷酸丙糖异构酶 (triosephosphateisomerase ,缩写为tim)基因进行特异性扩增 ,结果扩增出 1条 6 83bp的DNA片段。此方法的特异性可高达10 0 % ,而其它DNA样本 ,如日本血吸虫 (Schistosomajaponicum)、刚地弓形虫 (Toxoplasmagondii)、微小隐孢子虫 (Cryptosporidiumparvum)、溶组织内阿米巴 (Entamoebahistolytica)、旋毛虫 (Trichinellaspiralis)和阴道毛滴虫 (Trichomonasvaginalis) ,以及人体血细胞等均未出现扩增反应。本法的敏感性也很高 ,可检测到0 4pg贾第虫包囊的DNA。 13株来自不同地理位置和 或宿主的贾第虫DNA样本在PCR中均各产生 1条长为 6 83bp的目的片段。上述结果表明本实验建立的检测贾第虫的PCR方法有效     

High-density proteoglycan induces specific suppression of adjuvant-induced arthritis in rats.

We compared the levels of serum antibodies in male and female C57Bl/6 mice during the primary and after challenge infection with Giardia muris. Male mice began passing cysts in their faeces earlier than females, and were shedding cysts for over 60 days, while females stopped shedding cysts by day 20 after infection. In both males and females there were significant increases in parasite-specific IgM 10 and 20 days after infection. No differences in parasite-specific serum IgA were observed until 40 days after infection. Parasite-specific IgG (whole) levels were elevated on days 20 and 40 in females, while males showed no significant increases. In addition, females had a much stronger IgG2b and IgG3 response than males. After challenge with either cysts or soluble parasite protein only the females had significant increases in specific anti-parasite IgG2b. Our data show differential ability of males and females to control the infection with G. muris is paralleled by a difference in the anti-parasite serum IgG response of the mice.     

Estimate of Burden and Direct Healthcare Cost of Infectious Waterborne Disease in the United States

Provision of safe drinking water in the United States is a great public health achievement. However, new waterborne disease challenges have emerged (e.g., aging infrastructure, chlorine-tolerant and biofilm-related pathogens, increased recreational water use). Comprehensive estimates of the health burden for all water exposure routes (ingestion, contact, inhalation) and sources (drinking, recreational, environmental) are needed. We estimated total illnesses, emergency department (ED) visits, hospitalizations, deaths, and direct healthcare costs for 17 waterborne infectious diseases. About 7.15 million waterborne illnesses occur annually (95% credible interval [CrI] 3.88 million–12.0 million), results in 601,000 ED visits (95% CrI 364,000–866,000), 118,000 hospitalizations (95% CrI 86,800–150,000), and 6,630 deaths (95% CrI 4,520–8,870) and incurring US $3.33 billion (95% CrI 1.37 billion–8.77 billion) in direct healthcare costs. Otitis externa and norovirus infection were the most common illnesses. Most hospitalizations and deaths were caused by biofilm-associated pathogens (nontuberculous mycobacteria, Pseudomonas, Legionella), costing US $2.39 billion annually.     

蓝氏贾第鞭毛虫承德株分子生物学研究

目的：探讨蓝氏贾第鞭毛虫大、小型包囊存在的原因。方法：用分子生物学技术对３株贾第虫（ＣＨ２、ＣＨ３、ＣＨ４）进行ｔｉｍ基因扩增和序列测定。结果：经与ＧｅｎＢａｎｋ登记虫株比较和用ＤＮＡｓｔａｒ软件处理的结果表明,此３株贾第虫的基因型属２型（ＪＨ型）。结论：大、小型包裹在形态学上经过统计学处理显示有显著差异,但与基因型无关。     

Refractory giardiasis: A molecular appraisal from a tertiary care centre in India

Purpose: The intestinal flagellate Giardia lamblia includes many genetically distinct assemblages, of which assemblage A and B, predominantly infect humans. Nitroimidazoles derivatives (metronidazole and tinidazole) and nitazoxanide are some of the therapeutic agents for treatment of giardiasis. Nevertheless, some individuals with giardiasis are non-responsive to standard therapy. The present study highlights cases of refractory giardiasis and attempts to elucidate if genetic heterogeneity in the parasite is associated with treatment failure. Materials and Methods: Three stool samples were obtained on three consecutive days from 4000 patients with diarrhoea and were microscopically examined for the detection of trophozoites, and/or cysts, using both normal saline and Lugol’s iodine. A hemi-nested polymerase chain reaction (PCR) assay using triose phosphate isomerase (tpi) as the target gene was performed to determine the assemblages. Sequencing of the PCR products of the patients showing failure to treatment of giardiasis was also performed. Results: Two per cent (82/4000) of the total patients were microscopically positive for Giardia lamblia in the stool samples. All these patients were treated with metronidazole/tinidazole as per the standard regimens. However, eight patients showed treatment failure to giardiasis as stool examinations were repeatedly positive even after treatment with multiple courses of anti-giardial therapy. Genetic characterisation of all eight Giardia isolates showed that they belonged to Assemblage B and had homogeneous sequences. These patients were either treated with extended regimens or with combination therapy of anti-giardials. Conclusion: In our experience, combination of two or more drugs for a longer duration is the treatment modality to treat refractory giardiasis.     

Treatment of Giardiasis after Nonresponse to Nitroimidazole

During January 2008–October 2013, a total of 12 cases of giardiasis at the Chaim Sheba and Shaare Zedek Medical Centers, Israel, did not respond to nitroimidazole; 83.3% were associated with travel and 33% with immunoglobulin deficiency. Among 110 published cases, the most effective treatment was quinacrine (efficacy 90%–100%), but its availability is limited.