Intestinal parasitic infections and associated factors in children of three rural schools in Colombia. A cross-sectional study

Prevalence of intestinal parasites and Helicobacter pylori coinfection, and contributing factors among patients with gastrointestinal manifestations at Addis Zemen primary hospital, Northwest Ethiopia

BACKGROUND

The urease-producing Helicobacter pylori increase the likelihood that pathogenic intestinal protozoa will use the stomach's increased hydrogen potential to propagate the disease. Coinfections exacerbate the onset and severity of gastrointestinal symptoms. This study aimed to assess the prevalence of intestinal parasites/Helicobacter pylori coinfection and contributing factors in patients with gastrointestinal symptoms at Addis Zemen Primary Hospital, Northwest Ethiopia.

METHODS

From April to July 2023, patients with gastrointestinal problems participated in a cross-sectional study carried out in a hospital. To collect the clinical and sociodemographic data, a questionnaire was employed. Intestinal parasites and Helicobacter pylori were detected using the saline stool wet mount and Helicobacter pylori stool antigen tests, respectively. SPSS version 20 was used to analyze the data and variables with p-values < 0.05 were considered statistically significant.

RESULT

The study included 384 participants in total, of which 47.3% (182/384) were farmers and 50.3% (193/384) were women. Of the study subjects, 69/384 or approximately 18%, had intestinal parasitic infections. In 12% of cases (46/384), Helicobacter pylori were detected. A coinfection of Helicobacter pylori and intestinal parasites was found in 5.5% (21/384) of the subjects. Multiple logistic regression revealed increased risk of coinfection of Helicobacter pylori and intestinal parasites in patients who drink surface water (AOR: 10.7, p = 0.03) family history of Helicobacter pylori (AOR: 3.3, p = 0.024) and those with untrimmed fingers (AOR: 4.9, p = 0.031).

CONCLUSIONS

Giardia lamblia and Entamoeba histolytica/dispar/ moshkovskii/ bangladeshi complex are the most common protozoans that cause coinfection with Helicobacter pylori. Drinking surface water, family history of Helicobacter pylori and untrimmed fingers are the contributing factors to intestinal parasites/Helicobacter pylori coinfection.

Co-infection of Helicobacter pylori and intestinal parasites in children of selected low-income communities in Lagos State, Nigeria

Helicobacter pylori and intestinal parasites cause gastrointestinal diseases with a high prevalence in children in resource limited developing countries. There is paucity of information in Nigeria on co-infection of H. pylori and intestinal parasites. The study was conducted to determine the prevalence of H. pylori and parasite co-infection in children from selected low-income communities in Lagos, Nigeria. Fecal samples were collected from 151 healthy children aged ≤11 years across six low-income communities in Lagos. H. pylori was detected using stool antigen test and conventional PCR assay, intestinal parasites were detected using formol-ether concentration and nested PCR assay. Structured questionnaires were administered to parents and legal guardians of the children by an interviewer to collect relevant data on demographic and lifestyle factors. The prevalence of H. pylori was 31.79% (48), with a higher prevalence in children aged 2-3 years. The prevalence of intestinal parasites was 21.19% (32) with the lowest frequency found in children aged 8-9 years. The parasites detected include: A. lumbricoides (10.6%), G. intestinalis (7.3%), hookworm (1.99%), E. histolytica (0.66%), S. mansoni (0.66%). There was co-infection prevalence of 10.6% (16) which was associated with the parasites: G. intestinalis (7.3%) and A. lumbricoides (3.97%). Polyparasitism with G. intestinalis and A. lumbricoides was reported in 2 children infected with H. pylori. This study which is the first reported in Lagos established a low prevalence of H. pylori and intestinal parasite co-infection in children and provides better understanding of the epidemiology of H. pylori infection associated with intestinal parasites in Nigeria.

Waterborne Cryptosporidium species and Giardia duodenalis in resources of MENA: A systematic review and meta-analysis

This review explores our understanding of Cryptosporidium species and Giardia duodenalis distribution in Middle East and North African (MENA) water resources. Results emphasize that Cryptosporidium species (sp.) and G. duodenalis (oo)cysts are present in distinct categories of water in ten MENA countries. Cryptosporidium sp. proportional prevalence in the MENA region was 24.5% (95% CI 16.3-33.8), while G. duodenalis prevalence was 37.7% (95% CI 21.9-55.1). Raw wastewater and surface water were the water categories most significantly impacted. Both parasites were reported in the various types of MENA drinking waters. The most frequent species/genotypes reported were C. hominis, C. parvum, and G. duodenalis assemblage A. Despite the high prevalence of (oo)cysts reported, we should consider the absence of waterborne outbreaks. This indicates significant underestimation and underreporting of both parasites in MENA. Stakeholders should apply water contamination legislation to eradicate Cryptosporidium sp. and G. duodenalis (oo)cysts from water resources/categories.

Molecular detection and characterization of Giardia spp., Cryptosporidium spp., and Blastocystis in captive wild animals rescued from central Colombia

Cryptosporidium, Giardia, and Blastocystis are significant causes of diarrhea worldwide. However, studies on their prevalence in wild animals are limited, compared to humans and domestic animals. In this study, we collected 23 stool samples from captive wild rescued animals in Boyacá, Colombia. Using conventional PCR, we detected Cryptosporidium spp., Giardia spp., and Blastocystis in over half of the samples (69.6%). Cryptosporidium spp. (43.5%) were the most commonly found, followed by Giardia spp. (39.1%) and Blastocystis (13.0%). Co-infections involving these parasites were also observed. Subsequent genotyping revealed Cryptosporidium canis and Cryptosporidium ryanae as the predominant species. These findings contribute valuable information about the ecoepidemiology of intestinal parasites in Colombian wild animals.

Differential gut microbiome in spondyloarthritis patients associated to Blastocystis colonization

The role of Blastocystis in intestinal health is an open controversy, and little is known about the potential effect of this microorganism in autoinflammatory diseases such as spondyloarthritis (SpA). Here, we analyzed the gut microbiome of 36 SpA patients and 13 control individuals and demonstrated that the richness, diversity, and taxonomic composition between these two groups are different. We also showed that colonization by Blastocystis in control individuals increases the richness and diversity of the intestinal microbiome, whereas in SpA patients, it does not seem to have any impact. This may reflect a potential role of Blastocystis in sculpting the gut microbiome architecture in control individuals, whereas in subjects with SpA, the modulation of the microbiome may be governed by disease-dependent factors that cannot be overcome by Blastocystis. Regarding taxonomic characterization, SpA patients colonized by Blastocystis showed significant increases in the phylum Pseudomonadota, class Gammaproteobacteria, family Succinivibrionaceae, and genus Succinivibrio. Simultaneously, there were significant increases in the class Bacilli, order Lactobacillales, families Lactobacillaceae and Clostridiaceae, and genera Lactobacillus and Clostridium in non-colonized SpA patients. On the other hand, PICRUSt analysis in Blastocystis-positive SpA patients showed elevations in pathways that may enhance antioxidant capacities and alleviate intestinal inflammation, while Blastocystis-negative SpA patients showed significant changes in pathways that promote cell division/proliferation and can lead to larger changes in the gut microbiome. Our analyses lead us to believe that these changes in the gut microbiome of SpA patients may trigger protective mechanisms as an initial response to inflammation in an attempt to restore balance in the intestinal environment.

Exploring Blastocystis genetic diversity in rural schoolchildren from Colombia using next-generation amplicon sequencing reveals significant associations between contact with animals and infection risk

Blastocystis is a common intestinal protist with a global distribution in humans and many other animals. Yet, the status of Blastocystis as a pathogen, the risk factors associated with its transmission, and its zoonotic potential remain ill-defined. Here, we explored subtype (ST) diversity and potential risk factors for Blastocystis infection in 98 children from Apulo, Colombia. Samples were screened for Blastocystis via PCR, and ST identification was performed through next-generation amplicon sequencing (NGS). Associations between the presence of Blastocystis and individual STs and sociodemographic variables were assessed via logistic regression analyses. Seventy-one samples (72.4%) were Blastocystis-positive, and NGS revealed the presence of five STs (ST1-ST5). ST1, ST2, and ST3 were common and observed in nearly equal proportions (~ 40%), while samples with ST4 (1.4%) and ST5 (5.6%) were comparatively rare. The presence of mixed STs in the same sample was also common (28.2%). Comparisons among children within the same household identified that shared ST profiles were common, but diversity within family units was also observed. Logistic regression analyses returned significant associations between the presence of Blastocystis, individual subtypes, or mixed subtypes for several variables. Intriguingly, the presence of animals was one of the most common significant associations. Taken together, these data represent an important step forward in understanding both the potential routes and risk factors that may influence Blastocystis transmission and will be useful in shaping future studies which seek to clarify the relationships between STs, pathogenicity, and zoonotic transmission.

Burden and Epidemiology of Human Intestinal Giardia duodenalis Infection in Colombia: A Systematic Review

The genus Giardia is a unicellular protozoan able to parasitize both humans and animals. Cysts of Giardia can be found in soil samples, aquatic environments, food, and any surface that gets in contact with the feces of parasitized animals. The aim of this systematic review was to analyze the burden and epidemiology of Giardia infection in Colombia summarizing recent scientific reports and existing knowledge and to identify knowledge gaps that may be addressed in future investigations. This work follows the guidelines established by "Preferred Reporting Items for Systematic Reviews and Meta-Analyzes" (PRISMA). Published scientific literature from 1 January 2010 to 18 September 2022 was searched in six electronic scientific databases using the search terms: "Giardia" OR "Giardiasis" AND "Colombia". Twenty-three scientific articles were performed in 22 departments of Colombia at rural, urban, and a combination of rural and urban contexts. The prevalence of Giardia in the Colombian population was between 0.9 and 48.1% when the samples were analyzed with classical microscopy; the range of Giardia prevalence was even bigger (4.2-100%) when qPCR and nested PCR were used. The dominant Giardia assemblages found in Colombia were A and B, and most frequent subassemblages were AII, BIII, and BIV.

Updates on the worldwide burden of amoebiasis: A case series and literature review

BACKGROUND

Amoebiasis is an intestinal and tissue parasitic infection caused by the protozoan Entamoeba histolytica. Despite significant medical importance and worldwide dispersion, little is known about the epidemiology and distinct geographical distribution of various clinical forms of amoebiasis in the world. In this study, we present an amoebiasis case series referred to Avicenne Hospital (Bobigny, France) from 2010 to 2022 followed by an overview of the released literature to explore diverse clinico-pathology of amoebiasis and to update the actual epidemiological situation of this parasitosis worldwide.

METHODS

The referred patients underwent a combination of clinical and parasitological examinations and imaging. The study was followed by an overview of released literature performed based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline.

RESULTS

A total of 15 patients with amoebiasis were diagnosed with an average age of 48.5 years old at the occurrence time of infection. Men (78%) were the most affected patients. Most of the cases were reported following a trip to endemic regions, such as Mali, India, Nepal, Algeria, Cameroon or Congo. All of the processed patients exhibited a hepatic amoebiasis. Amoebic abscess was observed in all cases with an average size of 6.3 cm. Of these patients, seven cases (46.7%) benefited from drainage following a risk of rupture or superinfection of the abscess. A compilation of findings extracted from 390 scientific publications via seven major medical databases, allowed us to update the main epidemiological and clinical events that has led to the current worldwide expansion of amoebiasis. We presented a clinical and epidemiological overview of the amoebiasis accompanied with a worldwide illustrative map displaying the current distribution of known amoebiasis foci in each geographical ecozone of Asia, Europe, Africa, Americas, and Australia.

CONCLUSIONS

Although Metropolitan France is not known as an endemic region of amoebiasis, amoebic liver abscess was the most frequent clinical form observed among our 15 patients processed. Most of infected patients had a history of travel to or lived-in endemic areas before arriving in France.

Decreased fecal calprotectin levels in Spondyloarthritis patients colonized by Blastocystis spp

Spondyloarthritis (SpA) is a group of chronic inflammatory systemic diseases mainly characterized by inflammation in the spine and/or peripheral joints. Although a link between SpA-pathogenesis, intestinal inflammation and gut dysbiosis has been proposed, studies have been focused on bacteria-host interactions and very little has been reported regarding intestinal parasites. Here, intestinal parasitic infection of 51 SpA-patients were evaluated and compared to healthy control individuals. No significant differences in the frequency of any parasite between SpA-patients and control individuals were found. Significantly higher levels of fecal calprotectin (FCP) were found in the SpA-patients compared to the control individuals. However, FCP levels were the same when comparing SpA-patients and control individuals, both colonized by Blastocystis spp. On the other hand, when comparing Blastocystis spp. colonized and Blastocystis spp. free SpA-patients, FCP levels were significantly higher in those Blastocystis spp. free. Without ignoring the small sample size as a study limitation, the results showed that in the SpA-patients colonized by Blastocystis spp., the FCP levels were significantly lower than those in the Blastocystis spp. free group and comparable to those in the control group. These findings seem to suggest a relationship between Blastocystis spp. and intestinal inflammation in SpA-patients, but studies intended to explore that interaction specifically should be designed.

Detangling the Crosstalk Between Ascaris, Trichuris and Gut Microbiota: What´s Next?

Helminth infections remain a global public health issue, particularly in low- and middle-income countries, where roundworms from theTrichuris and Ascaris genera are most prevalent. These geohelminths not only impact human health but most importantly also affect animal well-being, in particular the swine industry. Host-helminth parasite interactions are complex and at the same time essential to understand the biology, dynamics and pathophysiology of these infections. Within these interactions, the immunomodulatory capacity of these helminths in the host has been extensively studied. Moreover, in recent years a growing interest on how helminths interact with the intestinal microbiota of the host has sparked, highlighting how this relationship plays an essential role in the establishment of initial infection, survival and persistence of the parasite, as well as in the development of chronic infections. Identifying the changes generated by these helminths on the composition and structure of the host intestinal microbiota constitutes a field of great scientific interest, since this can provide essential and actionable information for designing effective control and therapeutic strategies. Helminths like Trichuris and Ascaris are a focus of special importance due to their high prevalence, higher reinfection rates, resistance to anthelmintic therapy and unavailability of vaccines. Therefore, characterizing interactions between these helminths and the host intestinal microbiota represents an important approach to better understand the nature of this dynamic interface and explore novel therapeutic alternatives based on management of host microbiota. Given the extraordinary impact this may have from a biological, clinical, and epidemiological public health standpoint, this review aims to provide a comprehensive overview of current knowledge and future perspectives examining the parasite-microbiota interplay and its impact on host immunity.

The controversies surrounding Giardia intestinalis assemblages A and B

Giardia intestinalis continues to be one of the most encountered parasitic diseases around the world. Although more frequently detected in developing countries, Giardia infections nonetheless pose significant public health problems in developed countries as well. Molecular characterisation of Giardia isolates from humans and animals reveals that there are two genetically different assemblages (known as assemblage A and B) that cause human infections. However, the current molecular assays used to genotype G. intestinalis isolates are quite controversial. This is in part due to a complex phenomenon where assemblages are incorrectly typed and underreported depending on which targeted locus is sequenced. In this review, we outline current knowledge based on molecular epidemiological studies and raise questions as to the reliability of current genotyping assays and a lack of a globally accepted method. Additionally, we discuss the clinical symptoms caused by G. intestinalis infection and how these symptoms vary depending on the assemblage infecting an individual. We also introduce the host-parasite factors that play a role in the subsequent clinical presentation of an infected person, and explore which assemblages are most seen globally.

Frequency and distribution of Blastocystis sp. subtypes in patients with spondyloarthritis in Bogotá, Colombia

Although Blastocystis sp. is one of the most prevalent intestinal parasites worldwide, its role as a pathogen remains unclear. The use of molecular techniques to assess the genetic heterogeneity of Blastocystis sp. has become important to understand its function in some intestinal pathologies and if it is a key component of intestinal microbiota. Spondyloarthritis is a group of immune-mediated autoinflammatory diseases in which microbial dysbiosis in the gut (including parasites, bacteria and fungi) and intestinal inflammation are common features apparently associated with the pathophysiology of these disorders. This study included 74 patients diagnosed with spondyloarthritis and 57 systemically healthy individuals (included as controls), who were screened for intestinal parasites. Blastocystis sp. was detected in 68% and 73% of the patients with spondyloarthritis and controls, respectively. In faecal samples positive for Blastocystis sp., an 18S rRNA gene fragment of Blastocystis sp. was amplified and sequenced to identify their genetic sub-types. Patients with spondyloarthritis showed similar frequencies of ST1, ST2 and ST3 subtypes of Blastocystis sp. (30% each). The same subtypes were observed in controls, wherein almost 60% of the samples showed ST3. In addition, ST6 was found only in one sample from each group. ST1 subtype showed the greatest genetic variability. Although the same subtypes were detected in both patients with spondyloarthritis and controls, subtype prevalence studies conducted in Colombia indicate an association between ST3 and individuals with irritable bowel syndrome. This opens an interesting research avenue to further study of the epidemiology of Blastocystis sp. and its possible relationship with intestinal conditions in immunocompromised patients.

Epidemiological and Molecular Characterization of Blastocystis Infection in Children Attending Daycare Centers in Medellín, Colombia

Simple Summary

Blastocystis infection affects more than 1000 million people globally. Its frequency varies depending on sociodemographic conditions, hygienic habits, provision of public services, and predisposing factors for contracting the infection, considering the child population as the most affected in developing countries. The lack of studies on this protozoan prevents the understanding of its transmission dynamics and its implications for the population’s health. For this protozoan, the diagnosis is based on microscopic reporting by conventional techniques; and subtype identification, which vary depending on the epidemiological distribution, host, and symptoms. In our study, we describe its epidemiological and molecular characterization in a child population. Additionally, we compare the diagnosis methods of Blastocystis; our research identified a better sensitivity with molecular methods and a great diversity of alleles and subtypes in this population.

Abstract

Background: The present study aims to perform an epidemiological and molecular characterization of Blastocystis infection in a child population attending daycare centers of Medellín, Colombia. Methods: A total of 265 children aged 0–5 years were enrolled in five children’s centers in urban sectors of Medellín, northwestern Colombia. Stool samples were taken to identify intestinal parasites by direct examination, Ritchie–Frick concentration, and molecular identification of Blastocystis by conventional PCR and subtype (ST) identification by PCR barcoding with subsequent phylogenetic reconstruction. Kappa index was calculated to evaluate the agreement between microscopy and PCR for the diagnosis of Blastocystis. Results: The prevalence of intestinal protozoa was 36.6% (97/265), with Blastocystis as the most frequent parasitic protozoan at 15.8% (42/265), followed by Giardia intestinalis at 15.5% (41/265) and Endolimax nana at 15.1% (40/265). The prevalence of Blastocystis by PCR was 53.2% (141/265), the subtypes identified were ST3 at 30.5% (18/59), ST2 at 23.7% (14/59), ST1 at 20.3% (12/59), and with less frequency, ST4 at 5.1% (3/59), ST6 at 1.7% (1/59) and ST16 at 15.3% (9/59) allele 162. Conclusion: This study provides the first genetic characterization of Blastocystis subtypes circulating in a population of Medellín, Colombia, and also updates the epidemiology of Blastocystis subtypes in the world with the first identification of ST16 in humans.

Assessment of Parasitic Contamination of Lettuce and Cabbages Sold in Selected Markets in Maputo City, Mozambique

Background

In Mozambique, vegetables are the main source of nutrients and they are consumed raw or cooked. Their consumption, especially in their raw form, might be a source of contamination, which may take place during production and/or transportation as well as in the markets. In this study we aimed to assess the profile and frequency of parasites in lettuces and cabbages sold in some selected markets in Maputo city, the capital of Mozambique.

Methods

A cross sectional study was conducted between February and March 2018, in 10 selected markets from Maputo City. A total of 100 combined samples of lettuces and cabbages were analyzed using a spontaneous sedimentation method. Data such as gender and age of the vendors and about handling of vegetables at the point of sale were also collected.

Results

Out of the samples, 84 (84%) were contaminated with parasites (86% of lettuces and 82% of cabbages). The analyses performed revealed the presence of E. coli (66%), S. stercoralis (40%), E. histolytica (20%), A. duodenalis (6%), S. haematobium (4%), A. lumbricoides (2%), S. mansoni (2%) and T. trichiura (1%). Two markets, Janete and Fajardo showed contamination in all samples. A Chi square analysis revealed a significant association between the contaminated cabbages and the market where they were obtained. The majority of vendors (57%) do not wash their hands before handling vegetables. Most of the vendors had tables to place vegetables (72%) and those tables are cleaned before display (86%). None of the differences observed in each risk factor studied were statistically significant.

Conclusion

The present study highlights that contamination of raw vegetables with pathogenic parasites in markets might represent a vector for transmission of intestinal and water- borne parasites to consumers. Future studies should investigate the extent of vegetable contamination at each stage of the supply chain from the farm to consumers, as well as its relationship to human parasitic infection and its consequences. Good hygienic practices of farmers, vendors and consumers should be enforced to break the contamination chain. Whenever possible, hydroponic cultivation should be encouraged to avoid the influence of highly contaminated soils.

Water, sanitation, and hygiene conditions and prevalence of intestinal parasitosis among primary school children in Dessie City, Ethiopia

BACKGROUND

Intestinal parasitosis is a major public health problem that affects the health of primary school children in low- and middle-income countries where water, sanitation, and hygiene (WASH) conditions are deficient. Since there is a paucity of information on the prevalence and associated factors of this problem among primary school children in Dessie City in Ethiopia, this study was designed to address these gaps.

METHODS

A school-based cross-sectional study was conducted among 407 stratified-sampled primary school children in five primary schools at Dessie City from April to June 2018. Data were collected using a pretested structured questionnaire, an observation checklist and laboratory analysis of stool samples. Stool specimen from each study participant was collected using clean, properly labeled and leak-proof stool cup. A portion of stool from each study participant collected sample was processed using saline wet mount technique and examined by microscope. The remaining specimens were preserved with 10% formalin and transported to Dessie Comprehensive Specialized Hospital laboratory to be processed by using formol-ether concentration technique. Then, slide smears were prepared from each processed stool specimen and finally, it was microscopically examined with 10x as well as 40x objectives for the presence or absence of intestinal parasites. Factors significantly associated with intestinal parasitosis were determined using binary logistic regression model at 95% CI (confidence interval). Thus, bivariate (COR [crude odds ratio]) and multivariable (AOR [adjusted odds ratio]) logistic regression analyses were carried out. From the multivariable analysis, variables having a p-value of less than 0.05 were declared as factors significantly associated with intestinal parasitosis among primary school children.

MAIN FINDINGS

The overall prevalence of intestinal parasitosis was found to be 16.0% (95% CI: 12.5-19.4%), of these, 50.8% were positive for protozoa, 32.2% for helminth infections and 16.9% for double co-infections. Entamoeba histolytica was the most prevalent parasite (29.2%), followed by Giardia lamblia (21.5%), Ascaris lumbricoides (18.5%), Hymenolepis nana (9.2%) and Enterobius vermicularis (4.6%). Prevalence rates were similar among government (16.3%) and private (15.7%) school children. Water consumption was less than 5 liters per capita per day in 4 of the 5 schools. Thirty-eight (9.3%) of primary school students reported that they practiced open defecation. About two-thirds (285, 70.0%) said they always washed their hands after defecation. Mother's education (illiterate) (AOR = 3.3; 95% CI: 1.20-9.37), father's education (illiterate) (AOR = 3.9; 95% CI: 1.40-10.82), fathers who could read and write (AOR = 3.3; 95% CI: 1.25-7.86), handwashing before meal (sometimes) (AOR = 2.2; 95% CI: 1.11-4.17) and poor knowledge of WASH (AOR = 9.3; 95% CI: 2.17-16.70) were statistically associated with presence of intestinal parasitic infections.

CONCLUSION

We concluded that the prevalence of intestinal parasitosis in the study area among Grades 4-8 primary school children had public health significance. Factors significantly associated with intestinal parasitosis among primary school children's were illiterate mothers and fathers, irregular handwashing of children before meals, and poor knowledge of WASH. Health education to improve students' WASH knowledge and mass deworming for parasites are recommended as preventive measures; and improvements to the quality of WASH facilities in primary schools are strongly recommended to support these measures.

Molecular epidemiology of Giardia spp. in northern Vietnam: Potential transmission between animals and humans

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village.

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Giardia spp. assemblage A and E have been detected in buffalo, cattle and pigs, as well as in humans, while assemblage B appeared only in humans.

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This was the first report of assemblage E in humans in Vietnam.

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Zoonotic transmission of assemblage AII and E could not be excluded in our study site.

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In addition to the ‘animal-to-human’ route, there potentially might be transmission routes from ‘humans-to-humans’ and/or ‘humans-to-animals’ in this study site.

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The novel genotype belonging to assemblage AIII has been isolated only in buffalo.

Multilocus genotyping of Giardia intestinalis in pet dogs of Medellín Colombia

According to a few parasitological and epidemiological studies, Giardia is the most prevalent parasitic infection among pet dogs in the city of Medellín, the second-largest city in Colombia. This study determined the assemblages of Giardia in the fecal samples of dogs obtained from 18 veterinary centers of Medellín. One hundred fecal samples of dogs diagnosed with Giardia using microscopy were analyzed via nested polymerase chain reaction (PCR) using three genes (gdh, bg, and tpi). The PCR products were purified and sequenced, and phylogenetic analyses were conducted using the maximum likelihood algorithm of the three loci. From the 100 samples analyzed, 47 were Giardia-positive via PCR. Genotypes C and D were detected in six samples, neither of which were associated with human infection. However, the zoonotic potential of Giardia cannot be ruled out because of the small number of samples that could be sequenced for assemblage assignation.

Microbiota characterization in Blastocystis-colonized and Blastocystis-free school-age children from Colombia

BACKGROUND

Blastocystis is a protist that lives in the intestinal tract of a variety of hosts, including humans. It is still unclear how Blastocystis causes disease, which presents an ongoing challenge for researchers. Despite the controversial findings on the association between Blastocystis and clinical digestive manifestations, there is currently no consensus as to whether this protozoan actually behaves as a pathogen in humans. Furthermore, the relationship between Blastocystis and the intestinal microbiota composition is not yet clear. For that reason, the aim of this study was to identify if colonization by Blastocystis is related to changes in the diversity and relative abundance of bacterial communities, compared with those of Blastocystis-free individuals in a group of Colombian children.

METHODS

We took stool samples from 57 school-aged children attending a daycare institution in Popayán (Southwest Colombia). Whole DNA was extracted and examined by 16S-rRNA amplicon-based sequencing. Blastocystis was detected by real time PCR and other intestinal parasites were detected by microscopy. We evaluated if Blastocystis was associated with host variables and the diversity and abundance of microbial communities.

RESULTS

The composition of the intestinal bacterial community was not significantly different between Blastocystis-free and Blastocystis-colonized children. Despite this, we observed a higher microbial richness in the intestines of children colonized by Blastocystis, which could, therefore, be considered a benefit to intestinal health. The phylum Firmicutes was the predominant taxonomic unit in both groups analyzed. In Blastocystis-free individuals, there was a higher proportion of Bacteroidetes; similarly, in children colonized by Blastocystis, there was a higher relative abundance of the phylum Proteobacteria; however, no statistically significant differences were found between the comparison groups.

CONCLUSIONS

The presence of Blastocystis showed a decrease in Bacteroides, and an increase in the relative abundance of the genus Faecalibacterium. It was also evident that the presence of Blastocystis was unrelated to dysbiosis at the intestinal level; on the contrary, its presence did not show statistically differences in the intestinal microbiota composition. Nevertheless, we believe that Blastocystis plays a role in the ecology of the intestinal microbiota through its interaction with other microbial components.

Prevalence and associated risk factors of Intestinal parasites in rural high-mountain communities of the Valle del Cauca-Colombia

The aim of this study was to measure the prevalence of gastrointestinal parasites (GI) in domestic animals and children in high mountain populations in the districts of Combia and Toche, Valle del Cauca-Colombia. These communities have been affected by the armed conflict in Colombia and are susceptible to health risk factors related to the Colombian post-conflict. Prevalence and risk factors were measured using Bayesian methods on 45 structured interviews applied to 29 families in Combia and 16 in Toche. This inquire aimed to analyze the socio-economic and demographic factors associated with the presence of parasites. This interview was conducted with 50 children: 40 (80%) from Rita Sabogal school district of Toche, and 10 (20%) from Tablones-Atanasio Girardot schools. 23 faecal samples from asymtomatic children from these schools were collected. Subsequently, 308 animals were characterized through the analysis of 64 faecal samples from asymptomatic individuals (20,8%); 18/41 from dogs (43,9%), 18/175 from poultry (10,3%), 7/13 from cats 56,84%, 6/20 from equines (30%) and from 15/59 cattle (25,43%). The prevalence of intestinal parasites among children under six years was 60% [95% PI = 41%-78%]; Endolimax nana, 24% [95% PI = 9,8%-42%]; Iodamoeba buetschlii, 16% [95% PI = 4,7%-32%]; Entamoeba coli, 35% [95% PI = 18%-55%]; Giardia lamblia, 12% [95% PI = 2,7%-27%]. In Equids the presence of Strongylus spp was 37% [95% PI = 10%-71%]; Parascaris equorum, 37% [95% PI = 10%-71%]; in dogs, Dipylidium caninum was 20% [95% PI = 6%-39%]; Trichuris trichiura, 9% [95% PI = 1,3%-26%]; Toxocara canis, 25% [95% PI = 9%-46%]; in cats, Toxocara cati had a prevalence of 44% [95% PI = 16%-75%]; cyst of Eimeria spp, 15% [95% PI = 3,4%-33%]; in poultry and Eimeria zuernii in cattle, 50% [95% PI = 23%-77%]. There was no association with exposure of humans to animal parasites. However, we conclude that female and children under 6 years of age are more likely OR (6,72-2,3) to get parasites.

Molecular Epidemiology and Risk Factors of Blastocystis sp. Infections Among General Populations in Yunnan Province, Southwestern China

BACKGROUND

Blastocystis is a common enteric parasite of controversial pathogenic roles in human diseases. Although the prevalence of Blastocystis infections has been investigated in a diverse range of populations, there is little knowledge on the molecular epidemiology and risk factors of Blastocystis infections among general populations in southeastern China.

MATERIALS AND METHODS

A total of 507 individuals were randomly selected in Yunnan province, China from July 2016 to March 2017. Stool specimens were sampled for detection of Blastocystis sp. using PCR assay, and the risk factors of Blastocystis infections were identified. Blastocystis isolates were subtyped, and the associations of Blastocystis infections and subtypes with clinical manifestations were examined.

RESULTS

The overall detection rate of Blastocystis sp. was 9.47% (95% CI: 7.13-12.44%). Toilet type (OR = 3.248, 95% CI: 1.245-8.473), anemia (OR = 2.601, 95% CI: 1.245-8.473) and type of daily drinking water (OR = 3.11, 95% CI: 1.557-6.213) were identified as risk factors of Blastocystis infections; however, Blastocystis infections showed no associations with clinical symptoms. Four subtypes (ST1 to ST4) were characterized in Blastocystis isolates, in which ST3 was predominant (4.73%, 95% CI: 3.2-6.94%), followed by ST1 (3.16%, 95% CI: 1.95-5.07%), ST4 (1.38%, 95% CI: 0.07-2.82%) and ST2 (0.2%, 95% CI: 0-1.11%). In addition, ST1 subtype infection was found to correlate with anemia (OR = 4.66, 95% CI: 1.631-14.314).

CONCLUSIONS

There is a high prevalence of Blastocystis infections among general populations in Yunnan province, southwestern China, and toilet type, anemia and type of daily drinking water are risk factors of Blastocystis infections. ST3 is the dominant subtype of Blastocystis sp. characterized, and ST1 correlates with anemia. Improving hygiene conditions, developing healthy lifestyles and intensifying health education programs are strongly recommended to reduce the prevalence and transmission potential of Blastocystis infections.

Concurrent infection of intestinal parasites and Helicobacter pylori among school-age children in Central Ethiopia

Background

Coinfection of multiple intestinal microbial pathogens plays an important role in individuals harboring these organisms. However, data on magnitude and risk factors are scarce from resource limited settings.

Objective

We examined the prevalence and associated risk factors of intestinal parasites and Helicobacter pylori co-infection among young Ethiopian school children.

Method

Data from a total of 434 Ethiopian school children from the Ziway region were analyzed in the study. Stool antigen and blood serum antibody tests were used to detect H. pylori, while the presence of any intestinal parasites was detected using direct wet mount microscopy and formol-ether concentration techniques. A structured questionnaire was delivered to mothers and legal guardians of the children by an interviewer to collect data relevant demographic and lifestyle factors. Multivariate logistic regression analysis was performed to assess the association of these sociodemographic characteristics with the coinfection of H. pylori and intestinal parasites.

Results

The prevalence of coinfection with any intestinal parasites and Helicobacter pylori was 23.0% (n = 92/400). Univariate analysis showed an increased risk for co-infection among children whose mothers had non-formal education (COR: 1.917, p < 0.01) and those who had no history of child vaccination (COR: 3.455, p = 0.084). Children aged 10–14 and those who lived in a house that had a flush or ventilated latrine were found at lower odds of coinfection between intestinal parasites and Helicobacter pylori (COR: 0.670, p = 0.382; COR: 0.189, p = 0.108). Multivariate regression analysis showed increased odds of co-infection among children whose mothers had non-formal education (AOR: 1.978, p < 0.01). Maternal education was also associated with a two-fold increase in odds for H. pylori and any protozoa co-infection (AOR: 2.047, p < 0.01).

Conclusion

Our study shows a moderate prevalence of H. pylori and intestinal parasite co-infection and identified maternal education as a significant risk factor among school children.

High Prevalence of Intestinal Pathogens in Indigenous in Colombia

Background: Intestinal infections remain a major public health burden in developing countries. Due to social, ecological, environmental, and cultural conditions, Indigenous peoples in Colombia are at particularly high risk. Materials: 137 stool samples were analyzed by microscopy and real-time-Polymerase Chain Reaction (RT-PCR), targeting protozoan parasites (Giardia intestinalis, Entamoeba histolytica, Cryptosporidium spp., and Cyclospora cayetanensis), bacteria (Campylobacter jejuni, Salmonella spp., Shigella ssp./enteroinvasive E. coli (EIEC), Yersinia spp., enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), enterotoxin-producing E. coli (ETEC), enteroaggregative E. coli (EAEC), and Tropheryma whipplei), and helminths (Necator americanus, Strongyloides stercoralis, Ascaris lumbricoides, Ancylostoma spp., Trichuris. trichiura, Taenia spp., Hymenolepis nana, Enterobius vermicularis, and Schistosoma spp.). Microscopy found additional cases of helminth infections. Results: At least one pathogen was detected in 93% of the samples. The overall results revealed protozoa in 79%, helminths in 69%, and bacteria in 41%. G. intestinalis (48%), Necator/hookworm (27%), and EAEC (68%) were the most common in each group. Noteworthy, T. whipplei was positive in 7% and T. trichirua in 23% of the samples. A significant association of one infection promoting the other was determined for G. intestinalis and C. jejuni, helminth infections, and EIEC. Conclusions: The results illustrate the high burden of gastrointestinal pathogens among Indigenous peoples compared to other developing countries. Countermeasures are urgently required.

Molecular detection and genotyping of intestinal protozoa from different biogeographical regions of Colombia

Background

Intestinal parasitic protozoa represent a serious problem of public health particularly in developing countries. Protozoa such as Blastocystis, Giardia intestinalis, Entamoeba histolytica and Cryptosporidium spp. are associated with diarrheal symptoms. In Colombia, there is little region-specific data on the frequency and circulating genotypes/species of these microorganisms. Therefore, the main objective of our study was to employ molecular detection and genotyping of G. intestinalis and Blastocystis, Cryptosporidium and Entamoeba spp. in samples from different biogeographical regions of Colombia.

Methods

We collected 649 human fecal samples from five biogeographical regions of Colombia: the Amazon, Andean, Caribbean, Orinoco and Pacific regions. Blastocystis, G. intestinalis, Cryptosporidium spp. and Entamoeba complex were detected by microscopy and conventional PCR. Molecular genotyping was conducted to identify Blastocystis subtypes (STs) (18s), G. intestinalis assemblages (triose phosphate isomerase and glutamate dehydrogenase) and Cryptosporidium species (18s). Genetic diversity indices were determined using dnasp.5.

Results

We detected G. intestinalis in 45.4% (n = 280) of samples, Blastocystis in 54.5% (n = 336) of samples, Cryptosporidium spp. in 7.3% (n = 45) of samples, Entamoeba dispar in 1.5% (n = 9) of samples, and Entamoeba moshkovskii in 0.32% (n = 2) of samples. Blastocystis STs 1–4, 8 and 9 and G. intestinalis assemblages AII, BIII, BIV, D and G were identified. The following Cryptosporidium species were identified: C. hominis, C. parvum, C. bovis, C. andersoni, C. muris, C. ubiquitum and C. felis. The Caribbean region had the highest frequency for each of the microorganisms evaluated (91.9% for G. duodenalis, 97.3% for Blastocystis, 10.8% for Cryptosporidium spp., 13.5% for E. dispar and 2.7% for E. moshkovskii). The Orinoco region had a high frequency of Blastocystis (97.2%) and the Andean region had a high frequency of G. intestinalis (69.4%). High and active transmission was apparent in several regions of the country, implying that mechanisms for prevention and control of intestinal parasitosis in different parts of the country must be improved.