High-fat diet increases the severity of Giardia infection in association with low-grade inflammation and gut microbiota dysbiosis.

Exogenous factors that may influence the pathophysiology of Giardia infection remain incompletely understood. We have investigated the role of dietary fat in the pathogenesis of Giardia infection. Male 3 to 4-week-old C57BL/6 mice were fed either a low fat (LF) or a high fat (HF) diet for 12 days and challenged with G. duodenalis. In infected animals, the trophozoite burden was higher in HF + Giardia mice compared to the LF + Giardia group at day 7 post infection. Fatty acids exerted direct pro-growth effects on Giardia trophozoites. Analysis of disease parameters showed that HF + Giardia mice exhibited more mucosal infiltration by inflammatory cells, decreased villus/crypt ratios, goblet cell hyperplasia, mucus disruption, increased gut motility, and elevated fecal water content compared with LF + Giardia. HF diet-dependent exacerbation of Giardia-induced goblet cell hyperplasia was associated with elevated Atoh1 and Muc2 gene expression. Gut microbiota analysis revealed that the HF diet alone induces a taxonomic shift. HF + Giardia mice exhibited microbiota dysbiosis characterized by an increase of Firmicutes and a decrease of Bacteroidetes and significant changes in α- and ß-diversity metrics. Taken together, the findings suggest that a HF diet exacerbates the outcome of Giardia infection. The data demonstrate that elevated dietary fat represents an important exogenous factor promoting the pathophysiology of giardiasis.

The Distribution of Intestinal Parasites in Patients Presenting to a University Hospital in Istanbul: A Seven-year Retrospective Analysis

Objective: The purpose of this study was to determine the intestinal parasite distributions in patients who applied to the Parasitology Laboratory of Istanbul University-Cerrahpasa, Cerrahpasa Medical Faculty, by evaluating the parasites retrospectively. Methods: Normal saline and stool lugol were applied for direct examination of stool samples that were sent for parasite examination; cellophane band samples were evaluated microscopically. The samples suspected to have protozoa were evaluated using modified acid fast and trichrome staining methods. We evaluated the parasitological examination results of patients who applied to our laboratory between January 2012 and December 2018. Results: A total of 2.96% of the 20,948 patients who applied had parasites in their faeces. Blastocystis spp. was detected at the highest rate (63.23%), followed by Giardia intestinalis (17.26%), Enterobius vermicularis (12.58%), Taenia saginata (2.42%), Cryptosporidium spp. (1.94%) and Entamoeba histolytica/dispar (1.45%). Conclusion: Although the prevalence of intestinal parasitic infections has decreased when compared to previous years, it still remains important. For this reason, solving infrastructure problems, providing information on personal hygiene and sanitation rules are among the most important tasks needed to reduce the prevalence of intestinal parasites.

Intestinal parasites including Cryptosporidium, Cyclospora, Giardia, and Microsporidia, Entamoeba histolytica, Strongyloides, Schistosomiasis, and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre- and post-transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid-organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post-transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor-derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid-organ transplant recipients are unmet needs.

Prevalence, Characteristics, Risk Factors, and Impact of Intestinal Parasitic Infections on School Children in Jeddah, Western Saudi Arabia.

Intestinal Parasitic Infections (IPIs) are a major public health problem worldwide, especially among children with a need for periodical evaluation of prevalence and risk factors to adopt an appropriate prevention strategy. This cross-sectional prospective study was conducted to identify prevalence, risk factors, characteristics, and impact of IPIs on school children in different regions of Jeddah, Saudi Arabia. Children were recruited from randomly selected schools. Questionnaires were distributed to students and filled by their parents to collect relevant information about sociodemographic, environmental, and hygienic living conditions. Stool samples and anthropometric measurements as indicators of nutritional status were collected from students who agreed to participate in the study. Fecal samples were examined by direct smear and formol-ether concentration method. Out of 581 collected stool samples, only 31 (5.3%) samples were positive for IPIs especially Blastocystis hominis (10 samples) and Giardia lamblia (six samples). The only two significant risk factors associated with IPIs were drinking water from tanks [odds ratio (OR): 3.35, 95% confidence interval (CI): 1.60-6.99, p = 0.001] and washing hands with only water (OR: 2.63, 95% CI: 1.17-5.93, p = 0.03). There was no significant impact of IPIs on growth parameters or level of children's academic performance.

RORγt+ Treg to Th17 ratios correlate with susceptibility to Giardia infection.

Infections with Giardia are among the most common causes of food and water-borne diarrheal disease worldwide. Here, we investigated Th17, Treg and IgA responses, and alterations in gut microbiota in two mouse lines with varying susceptibility to Giardia muris infection. Infected BALB/c mice shed significantly more cysts compared with C57BL/6 mice. Impaired control of infection in BALB/c mice was associated with lower Th17 activity and lower IgA levels compared with C57BL/6 mice. The limited metabolic activity, proliferation and cytokine production of Th17 cells in BALB/c mice was associated with higher proportions of intestinal Foxp3+RORγt+ regulatory T cells and BALB/c mice developed increased RORγt+ Treg:Th17 ratios in response to G. muris infection. Furthermore, G. muris colonization led to a significantly reduced evenness in the gut microbial communities of BALB/c mice. Our data indicate that differential susceptibility to Giardia infections may be related to RORγt+ Treg controlling Th17 activity and that changes in the microbiota composition upon Giardia infection partially depend on the host background.

A spatial analysis of giardiasis and cryptosporidiosis in relation to public water supply distribution in North West England.

Giardia and Cryptosporidium are both waterborne parasites and leading causes of gastroenteritis. Although specimens from diarrhoeic patients are routinely examined for Cryptosporidium, they are often not examined for Giardia so many cases go undiagnosed. Since 2002, all faecal specimens in Central Lancashire have been tested for infection with Giardia and Cryptosporidium. The aim of this paper is to gain insight into the factors contributing to giardiasis and cryptosporidiosis, including evidence of transmission via drinking water. Our analysis found a higher risk of both conditions for young children and a second peak in risk of giardiasis in adults. There was a significantly higher risk of giardiasis for males and a higher risk of cryptosporidiosis for females. The geographical location was significant, with an increased risk in the north. Residence in an area with increased supply from one water treatment works was a significant predictor for cryptosporidiosis.

A Bayesian spatio-temporal framework to identify outbreaks and examine environmental and social risk factors for infectious diseases monitored by routine surveillance.

Spatio-temporal disease patterns can provide clues to etiological pathways, but can be complex to model. Using a flexible Bayesian hierarchical framework, we identify previously undetected space-time clusters and environmental and socio-demographic risk factors for reported giardiasis and cryptosporidiosis at the New Zealand small area level. For giardiasis, there was no seasonal pattern in outbreak probability and an inverse association with density of dairy cattle (ß^1 = -0.09, Incidence Risk Ratio (IRR) 0.90 (95% CI 0.84, 0.97) per 1 log increase in cattle/km2). In dairy farming areas, cryptosporidiosis outbreaks were observed in spring. Reported cryptosporidiosis was positively associated with dairy cattle density: ß^1 = 0.12, IRR 1.13 (95% CI 1.05, 1.21) per 1 log increase in cattle/km2 and inversely associated with weekly average temperature: ß^1 = -0.07, IRR 0.92 (95% CI 0.87, 0.98) per 4 °C increase. This framework can be generalized to determine the potential drivers of sporadic cases and latent outbreaks of infectious diseases of public health importance.

Risk factors for sporadic Giardia infection in the USA: a case-control study in Colorado and Minnesota.

Giardia duodenalis is the most common intestinal parasite of humans in the USA, but the risk factors for sporadic (non-outbreak) giardiasis are not well described. The Centers for Disease Control and Prevention and the Colorado and Minnesota public health departments conducted a case-control study to assess risk factors for sporadic giardiasis in the USA. Cases (N = 199) were patients with non-outbreak-associated laboratory-confirmed Giardia infection in Colorado and Minnesota, and controls (N = 381) were matched by age and site. Identified risk factors included international travel (aOR = 13.9; 95% CI 4.9-39.8), drinking water from a river, lake, stream, or spring (aOR = 6.5; 95% CI 2.0-20.6), swimming in a natural body of water (aOR = 3.3; 95% CI 1.5-7.0), male-male sexual behaviour (aOR = 45.7; 95% CI 5.8-362.0), having contact with children in diapers (aOR = 1.6; 95% CI 1.01-2.6), taking antibiotics (aOR = 2.5; 95% CI 1.2-5.0) and having a chronic gastrointestinal condition (aOR = 1.8; 95% CI 1.1-3.0). Eating raw produce was inversely associated with infection (aOR = 0.2; 95% CI 0.1-0.7). Our results highlight the diversity of risk factors for sporadic giardiasis and the importance of non-international-travel-associated risk factors, particularly those involving person-to-person transmission. Prevention measures should focus on reducing risks associated with diaper handling, sexual contact, swimming in untreated water, and drinking untreated water.

Characterization of the Giardia intestinalis secretome during interaction with human intestinal epithelial cells: The impact on host cells.

BACKGROUND: Giardia intestinalis is a non-invasive protozoan parasite that causes giardiasis in humans, the most common form of parasite-induced diarrhea. Disease mechanisms are not completely defined and very few virulence factors are known. METHODOLOGY: To identify putative virulence factors and elucidate mechanistic pathways leading to disease, we have used proteomics to identify the major excretory-secretory products (ESPs) when Giardia trophozoites of WB and GS isolates (assemblages A and B, respectively) interact with intestinal epithelial cells (IECs) in vitro. FINDINGS: The main parts of the IEC and parasite secretomes are constitutively released proteins, the majority of which are associated with metabolism but several proteins are released in response to their interaction (87 and 41 WB and GS proteins, respectively, 76 and 45 human proteins in response to the respective isolates). In parasitized IECs, the secretome profile indicated effects on the cell actin cytoskeleton and the induction of immune responses whereas that of Giardia showed anti-oxidation, proteolysis (protease-associated) and induction of encystation responses. The Giardia secretome also contained immunodominant and glycosylated proteins as well as new candidate virulence factors and assemblage-specific differences were identified. A minor part of Giardia ESPs had signal peptides (29% for both isolates) and extracellular vesicles were detected in the ESPs fractions, suggesting alternative secretory pathways. Microscopic analyses showed ESPs binding to IECs and partial internalization. Parasite ESPs reduced ERK1/2 and P38 phosphorylation and NF-κB nuclear translocation. Giardia ESPs altered gene expression in IECs, with a transcriptional profile indicating recruitment of immune cells via chemokines, disturbances in glucose homeostasis, cholesterol and lipid metabolism, cell cycle and induction of apoptosis. CONCLUSIONS: This is the first study identifying Giardia ESPs and evaluating their effects on IECs. It highlights the importance of host and parasite ESPs during interactions and reveals the intricate cellular responses that can explain disease mechanisms and attenuated inflammatory responses during giardiasis.

Determinants and Impact of Giardia Infection in the First 2 Years of Life in the MAL-ED Birth Cohort.

BACKGROUND.: Giardia are among the most common enteropathogens detected in children in low-resource settings. We describe here the epidemiology of infection with Giardia in the first 2 years of life in the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project (MAL-ED), a multisite birth-cohort study. METHODS.: From 2089 children, 34916 stool samples collected during monthly surveillance and episodes of diarrhea were tested for Giardia using an enzyme immunoassay. We quantified the risk of Giardia detection, identified risk factors, and assessed the associations with micronutrients, markers of gut inflammation and permeability, diarrhea, and growth using multivariable linear regression. RESULTS.: The incidence of at least 1 Giardia detection varied according to site (range, 37.7%-96.4%) and was higher in the second year of life. Exclusive breastfeeding (HR for first Giardia detection in a monthly surveillance stool sample, 0.46 [95% confidence interval (CI), 0.28-0.75]), higher socioeconomic status (HR, 0.74 [95% CI, 0.56-0.97]), and recent metronidazole treatment (risk ratio for any surveillance stool detection, 0.69 [95% CI, 0.56-0.84]) were protective. Persistence of Giardia (consecutive detections) in the first 6 months of life was associated with reduced subsequent diarrheal rates in Naushahro Feroze, Pakistan but not at any other site. Giardia detection was also associated with an increased lactulose/mannitol ratio. Persistence of Giardia before 6 months of age was associated with a -0.29 (95% CI, -0.53 to -0.05) deficit in weight-for-age z score and -0.29 (95% CI, -0.64 to 0.07) deficit in length-for-age z score at 2 years. CONCLUSIONS.: Infection with Giardia occurred across epidemiological contexts, and repeated detections in 40% of the children suggest that persistent infections were common. Early persistent infection with Giardia, independent of diarrhea, might contribute to intestinal permeability and stunted growth.

Multiple Simultaneous Gastrointestinal Parasitic Infections in a Patient with Human Immunodeficiency Virus.

Patients with the human immunodeficiency virus (HIV) infection are at high risk for gastrointestinal infections causing diarrhea, particularly when those infections are parasitic in nature. This propensity is more pronounced in AIDS, where opportunistic parasitic infections may cause severe diarrhea, marked absorptive dysfunction, and significant risk of mortality. There are scant data regarding parasitic infections among HIV patients in the developed world; most studies and research come from povertystricken areas of South Africa, India, Iran, and the South Pacific. Although multiple infections with the same or different parasites have been reported, simultaneous infections are rare. We present the case of a 35-year-old man who developed a co-infection with Giardia, Cryptosporidium, and Strongyloides, simultaneously, the diagnosis being made after the judicious evaluation of a stool sample. Given the associated morbidity, prompt diagnosis and treatment are needed to avoid further complications in patients with HIV. To our knowledge this is the first reported case of triple parasitic infection in a patient with HIV.

Giardia lamblia infection after pancreas-kidney transplantation.

Infection is a common complication of solid organ transplantation. It is associated with an increased risk of acute cellular rejection and loss of graft function. The most common infections are due to bacteria and viruses, including transmission of cytomegalovirus from donor to recipient. In the past years, an increasing number of parasitic infections have been documented in transplant recipients. We describe the first reported case of intestinal Giardia lamblia transmission following simultaneous pancreas and kidney transplantation.

A large community outbreak of gastroenteritis associated with consumption of drinking water contaminated by river water, Belgium, 2010.

SUMMARY On 6 December 2010 a fire in Hemiksem, Belgium, was extinguished by the fire brigade with both river water and tap water. Local physicians were asked to report all cases of gastroenteritis. We conducted a retrospective cohort study among 1000 randomly selected households. We performed a statistical and geospatial analysis. Human stool samples, tap water and river water were tested for pathogens. Of the 1185 persons living in the 528 responding households, 222 (18·7%) reported symptoms of gastroenteritis during the time period 6-13 December. Drinking tap water was significantly associated with an increased risk for gastroenteritis (relative risk 3·67, 95% confidence interval 2·86-4·70) as was place of residence. Campylobacter sp. (2/56), norovirus GI and GII (11/56), rotavirus (1/56) and Giardia lamblia (3/56) were detected in stool samples. Tap water samples tested positive for faecal indicator bacteria and protozoa. The results support the hypothesis that a point-source contamination of the tap water with river water was the cause of the multi-pathogen waterborne outbreak.

Forest fragmentation and risk of giardiasis in New York State.

In the United States, giardiasis is endemic in northern and northeastern states, but its ecology and epidemiology remain elusive. The underlying physical landscape may play a role in shaping points of contact between humans, animals, and Giardia cysts. This study examined 11 years of surveillance data in New York State to measure the relationship between forest fragmentation and the incidence of giardiasis. Adjusted Poisson models showed that increasing points of contact between forested land and developed land, as measured by their shared edges [incident rate ratio (IRR) = 1.003; P < 0.001] and by the perimeter length of forested patches (IRR = 1.31; P = 0.01), were associated with higher incidence of giardiasis cases, whereas increasing forest density was associated with a lower incidence (IRR = 0.97; P < 0.001). These associations were independent of both temperature and surface water area. While these results are only suggestive due to the county-level aggregated data, the findings do identify a potentially important signal in the landscape epidemiology of giardiasis and highlight the need for better, more targeted, field studies on individual water sources for household consumption, inter-species contact in ecotones, surface water contamination, and human giardiasis cases.

[Common variable immunodeficiency: digestive involvement of a systemic disease]. / Inmunodeficiencia variable común: afectación digestiva de un trastorno sistémico.

Common variable immunodeficiency is characterized by a primary deficiency in antibody production that is clinically manifested by respiratory recurrent infections and gastrointestinal diseases (infectious, inflammatory and neoplastic). Above 50% of the patients have diarrhea and 10% develop idiopathic malabsorption and weight loss. We present the case of a 34-year-old woman submitted to our service for chronic diarrhea, abdominal pain and bloating and history of recurrent respiratory infections since childhood. The laboratory assessment showed severe hypoproteinemia and confirmed low IgG, IgA and IgM levels. Upper gastrointestinal endoscopy and videocapsule endoscopy showed a nodular duodenum with multiple polypoid-like formations all through the small bowel. Histology confirmed chronic duodenitis and Giardia lamblia infection. With the diagnosis of common variable immunodeficiency, monthly intravenous gammaglobulin infusion was initiated and metronidazole was indicated for Giardia lamblia infection achieving excellent clinical and laboratory response.

Inmunodeficiencia variable común: afectación digestiva de un trastorno sistémico / [Common variable immunodeficiency: digestive involvement of a systemic disease].

Common variable immunodeficiency is characterized by a primary deficiency in antibody production that is clinically manifested by respiratory recurrent infections and gastrointestinal diseases (infectious, inflammatory and neoplastic). Above 50

of the patients have diarrhea and 10

develop idiopathic malabsorption and weight loss. We present the case of a 34-year-old woman submitted to our service for chronic diarrhea, abdominal pain and bloating and history of recurrent respiratory infections since childhood. The laboratory assessment showed severe hypoproteinemia and confirmed low IgG, IgA and IgM levels. Upper gastrointestinal endoscopy and videocapsule endoscopy showed a nodular duodenum with multiple polypoid-like formations all through the small bowel. Histology confirmed chronic duodenitis and Giardia lamblia infection. With the diagnosis of common variable immunodeficiency, monthly intravenous gammaglobulin infusion was initiated and metronidazole was indicated for Giardia lamblia infection achieving excellent clinical and laboratory response.

Inmunodeficiencia variable común: afectación digestiva de un trastorno sistémico. / [Common variable immunodeficiency: digestive involvement of a systemic disease].

Common variable immunodeficiency is characterized by a primary deficiency in antibody production that is clinically manifested by respiratory recurrent infections and gastrointestinal diseases (infectious, inflammatory and neoplastic). Above 50

of the patients have diarrhea and 10

develop idiopathic malabsorption and weight loss. We present the case of a 34-year-old woman submitted to our service for chronic diarrhea, abdominal pain and bloating and history of recurrent respiratory infections since childhood. The laboratory assessment showed severe hypoproteinemia and confirmed low IgG, IgA and IgM levels. Upper gastrointestinal endoscopy and videocapsule endoscopy showed a nodular duodenum with multiple polypoid-like formations all through the small bowel. Histology confirmed chronic duodenitis and Giardia lamblia infection. With the diagnosis of common variable immunodeficiency, monthly intravenous gammaglobulin infusion was initiated and metronidazole was indicated for Giardia lamblia infection achieving excellent clinical and laboratory response.

[Cryptosporidium spp. and Giardia spp. prevalence and risk factors in dairy calves of the north-western zone of the Bogota Savanna]. / Prevalencia y factores de riesgo de Cryptosporidium spp. y Giardia spp. en terneros de ganado lechero de la zona noroccidental de la Sabana de Bogotá

OBJECTIVE: The present study was aimed to establishing Cryptosporidium spp. and Giardia spp. prevalence in 0 to 2 months old dairy calves of the north-western zone of the Bogota Savanna. In addition, associated factors related to a failure in Good Practices of Livestock could incur in human and animal infection. METHODS: This was a cross-sectional study; calves' fecal samples were used. Farms' Good Practices of Livestock were observed by means of an observation blank. Giardia spp. and Cryptosporidium spp. prevalence was determinate by means of laboratory results (Ritchie for Giardia spp. and modified Ziehl-Neelsen for Cryptosporidium spp.). Odds Ratios (OR) were calculated in association between this two genera of protozoa and Good Practices of Livestock. RESULTS: Thirty three dairy farms were evaluated, where fecal samples of 308 calves were taken. Giardia spp. prevalence was 37.7 %, 115 infected animals; Cryptosporidium spp. prevalence was 4.9 %, 15 infected animals. CONCLUSION: There is an important Giardia spp. and Cryptosporidium foci in the north-western zone of the Bogota Savanna, without a previous knowledge. Giardia spp. prevalence for this zone is in the highest rank reported for South-America and Cryptosporidium spp. prevalence is in en the lowest one. Associated risk factors of Giardia spp. and Cryptosporidium spp. in dairy farms of the north-western zone of the Bogota Savanna depend of a Good Practices of Livestock performance.