Molecular detection of intestinal parasites in a rural community of Colombia: A one health approach to explore potential environmental-zoonotic transmission.

AIMS: Protozoan and helminth parasitic infections pose significant public health challenges, especially in developing countries with rural populations marked by suboptimal hygiene practices and socio-economic constraints. The parasites are the etiological agents of these infections and have a notably elevated global prevalence. Therefore, this study focuses on estimating the frequency and transmission dynamics of several parasitic species, including Blastocystis, Giardia, Cryptosporidium spp., Entamoeba histolytica, Ascaris lumbricoides, Trichuris trichiura, Taenia spp. and hookworms, within a rural community in southwest Colombia with a particular emphasis on the One Health framework, considering environmental and zoonotic transmission potentials. METHODS AND RESULTS: This study involved the analysis of 125 samples, encompassing human participants (n = 99), their domestic pets (dogs) (n = 24) and water sources (n = 2). Parasite detection was carried out utilizing a combination of microscopy and molecular techniques. Furthermore, the characterization of Blastocystis subtypes (STs) was achieved through Oxford Nanopore sequencing of the rRNA-18S gene. The investigation also entailed the examination of potential associations between intestinal parasitism and various sociodemographic factors. Results revealed a high frequency of parasitic infections when employing molecular methods, with Blastocystis (n = 109/87%), Giardia (n = 20/16%), Ancylostoma duodenale (n = 28/22%), Ancylostoma ceylanicum (n = 7/5.6%), E. histolytica (n = 6/4.8%), Cryptosporidium spp. (n = 12/9.6%) and even Taenia (n = 1/0.8%) detected. Cryptosporidium spp. was also identified in water samples. Coinfections were prevalent, with 57% (n = 70) of samples exhibiting single-parasite infections and 43% (n = 53) showing various degrees of polyparasitism, emphasizing the complexity of transmission dynamics. Blastocystis subtyping, conducted via Oxford Nanopore sequencing, revealed a diversity of subtypes and coexistence patterns, with ST2 being the most prevalent. CONCLUSIONS: This research underscores the importance of using molecular techniques for frequency estimation, particularly emphasizing the relevance of zoonotic transmission in parasitic infections. It highlights the significance of the One Health approach in comprehending the circulation of parasites among animals, humans and environmental sources, thereby directly impacting public health and epidemiological surveillance.

Microbiome Alterations Driven by Trypanosoma cruzi Infection in Two Disjunctive Murine Models.

Alterations caused by Trypanosoma cruzi in the composition of gut microbiome may play a vital role in the host-parasite interactions that shapes physiology and immune responses against infection. Thus, a better understanding of this parasite-host-microbiome interaction may yield relevant information in the comprehension of the pathophysiology of the disease and the development of new prophylactic and therapeutic alternatives. Therefore, we implemented a murine model with two mice strains (BALB/c and C57BL/6) to evaluate the impact of Trypanosoma cruzi (Tulahuen strain) infection on the gut microbiome utilizing cytokine profiling and shotgun metagenomics. Higher parasite burdens were observed in cardiac and intestinal tissues, including changes in anti-inflammatory (interleukin-4 [IL-4] and IL-10) and proinflammatory (gamma interferon, tumor necrosis factor alpha, and IL-6) cytokines. Bacterial species such as Bacteroides thetaiotaomicron, Faecalibaculum rodentium, and Lactobacillus johnsonii showed a decrease in relative abundance, while Akkermansia muciniphila and Staphylococcus xylosus increased. Likewise, as infection progressed, there was a decrease in gene abundances related to metabolic processes such as lipid synthesis (including short-chain fatty acids) and amino acid synthesis (including branched-chain amino acids). High-quality metagenomic assembled genomes of L. johnsonii and A. muciniphila among other species were reconstructed, confirming, functional changes associated with metabolic pathways that are directly affected by the loss of abundance of specific bacterial taxa. IMPORTANCE Chagas disease (CD) is caused by the protozoan Trypanosoma cruzi, presenting acute and chronic phases where cardiomyopathy, megaesophagus, and/or megacolon stand out. During the course of its life cycle, the parasite has an important gastrointestinal tract transit that leads to severe forms of CD. The intestinal microbiome plays an essential role in the immunological, physiological, and metabolic homeostasis of the host. Therefore, parasite-host-intestinal microbiome interactions may provide information on certain biological and pathophysiological aspects related to CD. The present study proposes a comprehensive evaluation of the potential effects of this interaction based on metagenomic and immunological data from two mice models with different genetic, immunological, and microbiome backgrounds. Our findings suggest that there are alterations in the immune and microbiome profiles that affect several metabolic pathways that can potentially promote the infection's establishment, progression, and persistence. In addition, this information may prove essential in the research of new prophylactic and therapeutic alternatives for CD.

Case Report: Molecular Diagnosis of Cystoisospora belli in a Severely Immunocompromised Patient with HIV and Kaposi Sarcoma.

Diarrhea in an immunocompromised patient has a broad infectious differential. Diagnosis is difficult despite advances in diagnostic modalities. We report a case of a 45-year-old Nigerian woman who immigrated to the United States 2 years ago. She presented to the hospital with gastrointestinal bleeding, newly diagnosed HIV, and disseminated Kaposi sarcoma. During hospitalization, the patient had an onset of watery diarrhea and high eosinophilia. Subsequent stool analysis using multi-parallel real-time quantitative polymerase chain reaction for 13 parasites was positive for Cystoisospora belli. The patient was treated with trimethoprim-sulfamethoxazole, but had relapsed disease when her antibiotics were stopped prematurely. After restarting trimethoprim-sulfamethoxazole, her diarrhea and eosinophilia improved, and she had undetectable Cystoisospora belli DNA on repeat stool quantitative polymerase chain reaction. This case highlights the importance of a thorough workup for diarrhea, including parasites, especially for immunocompromised patients. Antibiotic prophylaxis is recommended in patients with Cystoisospora belli and HIV/AIDS.

Molecular Detection of Soil-Transmitted Helminths and Enteric Protozoa Infection in Children and Its Association with Household Water and Sanitation in Manhiça District, Southern Mozambique.

Intestinal parasite infections can have detrimental health consequences in children. In Mozambique, soil-transmitted helminth (STH) infections are controlled through mass drug administration since 2011, but no specific control program exists for enteric protozoa. This study evaluates STH and protozoan infections in children attending healthcare in Manhiça district, Southern Mozambique, and its association with water and sanitation conditions. We conducted a cross-sectional study in children between 2 and 10 years old in two health centers (n = 405). A stool sample and metadata were collected from each child. Samples were analyzed by multi-parallel real-time quantitative PCR (qPCR). We fitted logistic regression-adjusted models to assess the association between STH or protozoan infection with household water and sanitation use. Nineteen percent were infected with at least one STH and 77.5% with at least one enteric protozoon. qPCR detected 18.8% of participants with intestinal polyparasitism. Protected or unprotected water well use showed a higher risk for at least one protozoan infection in children (OR: 2.59, CI: 1.01-6.65, p-value = 0.010; OR: 5.21, CI: 1.56-17.46, p-value = 0.010, respectively) compared to household piped water. A high proportion of children had enteric protozoan infections. Well consumable water displayed high risk for that.

Elevated Pediatric Chagas Disease Burden Complicated by Concomitant Intestinal Parasites and Malnutrition in El Salvador.

The eradication of the vector Rhodnius prolixus from Central America was heralded as a victory for controlling transmission of Trypanosoma cruzi, the parasite that causes Chagas disease. While public health officials believed this milestone achievement would effectively eliminate Chagas disease, case reports of acute vector transmission began amassing within a few years. This investigation employed a cross-sectional serosurvey of children either presenting with fever for clinical care or children living in homes with known triatomine presence in the state of Sonsonate, El Salvador. Over the 2018 calendar year, a 2.3% Chagas disease seroprevalence among children with hotspot clustering in Nahuizalco was identified. Positive serology was significantly associated with dogs in the home, older participant age, and a higher number of children in the home by multivariate regression. Concomitant intestinal parasitic infection was noted in a subset of studied children; 60% having at least one intestinal parasite and 15% having two or more concomitant infections. Concomitant parasitic infection was statistically associated with an overall higher parasitic load detected in stool by qPCR. Lastly, a four-fold higher burden of stunting was identified in the cohort compared to the national average, with four-fifths of mothers reporting severe food insecurity. This study highlights that polyparasitism is common, and a systems-based approach is warranted when treating Chagas disease seropositive children.

Urban versus Rural Prevalence of Intestinal Parasites Using Multi-Parallel qPCR in Colombia.

Stool samples from 122 children living in an urban slum (n = 72) and rural (n = 50) areas were analyzed using multi-parallel real-time quantitative PCR to determine intestinal prevalence parasites from two communities in Colombia. Findings indicated a prevalence of 86.1% Blastocystis spp., 62.5% Giardia intestinalis, 19.4% Cryptosporidium spp., 19.4% Ascaris lumbricoides, and 5.6% Trichuris trichiura in an urban slum; and 76% Blastocystis spp., 68% G. intestinalis, 20% Entamoeba histolytica, 50% A. lumbricoides, 46% T. trichiura, and 2% Strongyloides stercoralis in rural areas. Polyparasitism was higher in rural (58%) than urban (25%) areas (P = 0.001). Trichuris trichiura burden was higher in the rural area (P = 0.002). Over 40% of helminthic infections in rural areas had a heavy parasite burden by WHO classification. Over half of urban and rural children were infected with G. intestinalis and Blastocystis spp. Our data provide accurate epidemiologic surveillance for public health interventions.

Parasitic infections represent a significant health threat among recent immigrants in Chicago.

Parasitic infections are likely under-recognized among immigrant populations in the USA. We conducted a cross-sectional study to evaluate if such infections have health impacts among recent immigrants in Chicago and to identify predictive factors for parasitic infections. A total of 133 recent immigrants were enrolled, filling out a standardized medical questionnaire and providing blood and stool samples. Appriximately 12% of subjects (15/125) who provided a blood or stool sample for testing were found to have evidence of current or prior infection with a pathogenic parasite, of which Toxocara spp. (8 subjects, 6.4%) and Strongyloides stercoralis (5 subjects, 4%) were most commonly identified. Parasitic infection was more likely among subjects who had immigrated within the previous 2 years and those with a self-reported history of worms in the stool. The most useful surrogate markers identified for parasitic infections were an elevated immunoglobulin E level (seen in 46.7% (7/15) of subjects with parasitic infections and 20% (22/110) of uninfected individuals, p = 0.04) and the presence of Blastocystis hominis cysts on Ova & Parasite exam (detected in 38.5% (5/13) of subjects with parasitic infections who provided a stool sample and 5.1% (5/98) of uninfected subjects, p = 0.002). Our study found that parasitic infections may be common in recent US immigrants, which highlights an important health disparity among a vulnerable population that merits further study. Additionally, clinical risk factors, symptoms, and laboratory findings traditionally thought to be associated with parasites were commonly found but not predictive of infection in this study population.

Comparison of Cytokine Responses in Ecuadorian Children Infected with Giardia, Ascaris, or Both Parasites.

AbstractMore than 2 billion people are infected with parasites globally, and the majority have coinfections. Intestinal protozoa and helminths induce polarizing CD4+ T-helper cell 1 (Th1) mediated cytokine responses within the host. Such immune polarization may inhibit the ability of the host to mount an adequate immune response for pathogen clearance to concurrent pathogens. The current study evaluated the plasma cytokine profile in Ascaris and Giardia coinfected children compared with Giardia- and Ascaris-only infected children. Fecal samples and blood samples were collected from asymptomatic 3-year-old children living in the district of Quininde, Ecuador. Stool samples that tested positive for Giardia lamblia-only, Ascaris lumbricoides-only, or G. lamblia and A. lumbricoides coinfections were confirmed by quantitative real-time polymerase chain reaction. Plasma samples from the study subjects were used to quantitate cytokines. A total of 39 patients were evaluated. Children with coinfection had a significant decrease in Th1 cytokine production, interleukin 2 (IL-2) (P < 0.05), IL-12 (P < 0.05), and tumor necrosis factor alpha (P < 0.05) compared with Giardia-only infected children. Coinfected children had an increase in IL-10/interferon gamma (IFN-γ) ratio compared with uninfected (P < 0.05) and Ascaris alone (P < 0.05). The increased IL-10/IFN-γ ratio in the setting of decreased Th1 cytokine response indicates Th2 polarization in the coinfected group. Reduced Th1 cytokines in children coinfected with Ascaris and Giardia may impair the host's ability to eradicate Giardia infection leading to chronic giardiasis.

The hookworm Ancylostoma ceylanicum intestinal transcriptome provides a platform for selecting drug and vaccine candidates.

BACKGROUND: The intestine of hookworms contains enzymes and proteins involved in the blood-feeding process of the parasite and is therefore a promising source of possible vaccine antigens. One such antigen, the hemoglobin-digesting intestinal aspartic protease known as Na-APR-1 from the human hookworm Necator americanus, is currently a lead candidate antigen in clinical trials, as is Na-GST-1 a heme-detoxifying glutathione S-transferase. METHODS: In order to discover additional hookworm vaccine antigens, messenger RNA was obtained from the intestine of male hookworms, Ancylostoma ceylanicum, maintained in hamsters. RNA-seq was performed using Illumina high-throughput sequencing technology. The genes expressed in the hookworm intestine were compared with those expressed in the whole worm and those genes overexpressed in the parasite intestine transcriptome were further analyzed. RESULTS: Among the lead transcripts identified were genes encoding for proteolytic enzymes including an A. ceylanicum APR-1, but the most common proteases were cysteine-, serine-, and metallo-proteases. Also in abundance were specific transporters of key breakdown metabolites, including amino acids, glucose, lipids, ions and water; detoxifying and heme-binding glutathione S-transferases; a family of cysteine-rich/antigen 5/pathogenesis-related 1 proteins (CAP) previously found in high abundance in parasitic nematodes; C-type lectins; and heat shock proteins. These candidates will be ranked for downstream antigen target selection based on key criteria including abundance, uniqueness in the parasite versus the vertebrate host, as well as solubility and yield of expression. CONCLUSION: The intestinal transcriptome of A. ceylanicum provides useful information for the identification of proteins involved in the blood-feeding process, representing a first step towards a reverse vaccinology approach to a human hookworm vaccine.

Identification of human intestinal parasites affecting an asymptomatic peri-urban Argentinian population using multi-parallel quantitative real-time polymerase chain reaction.

BACKGROUND: In resource-limited countries, stool microscopy is the diagnostic test of choice for intestinal parasites (soil-transmitted helminths and/or intestinal protozoa). However, sensitivity and specificity is low. Improved diagnosis of intestinal parasites is especially important for accurate measurements of prevalence and intensity of infections in endemic areas. METHODS: The study was carried out in Orán, Argentina. A total of 99 stool samples from a local surveillance campaign were analyzed by concentration microscopy and McMaster egg counting technique compared to the analysis by multi-parallel quantitative real-time polymerase chain reaction (qPCR). This study compared the performance of qPCR assay and stool microscopy for 8 common intestinal parasites that infect humans including the helminths Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, and the protozoa Giardia lamblia, Cryptosporidium parvum/hominis, and Entamoeba histolytica, and investigated the prevalence of polyparasitism in an endemic area. RESULTS: qPCR showed higher detection rates for all parasites as compared to stool microscopy except T. trichiura. Species-specific primers and probes were able to distinguish between A. duodenale (19.1%) and N. americanus (36.4%) infections. There were 48.6% of subjects co-infected with both hookworms, and a significant increase in hookworm DNA for A. duodenale versus N. americanus (119.6 fg/µL: 0.63 fg/µL, P < 0.001) respectively. qPCR outperformed microscopy by the largest margin in G. lamblia infections (63.6% versus 8.1%, P < 0.05). Polyparasitism was detected more often by qPCR compared to microscopy (64.7% versus 24.2%, P < 0.05). CONCLUSIONS: Multi-parallel qPCR is a quantitative molecular diagnostic method for common intestinal parasites in an endemic area that has improved diagnostic accuracy compared to stool microscopy. This first time use of multi-parallel qPCR in Argentina has demonstrated the high prevalence of intestinal parasites in a peri-urban area. These results will contribute to more accurate epidemiological survey, refined treatment strategies on a public scale, and better health outcomes in endemic settings.

Intraventricular Taenia solium cysts presenting with Bruns syndrome and indications for emergent neurosurgery.

Bruns syndrome is an unusual phenomenon, characterized by attacks of sudden and severe headache, vomiting, and vertigo, triggered by abrupt movement of the head. The presumptive cause of Bruns syndrome is a mobile deformable intraventricular mass leading to an episodic obstructive hydrocephalus. Intraventricular tumors have been associated with Bruns syndrome; however, few cases of intraventricular neurocysticercosis have been reported to present with Bruns syndrome. We report the first series of fourth ventricular neurocysticercosis presenting with Bruns syndrome in the United States and review the other published cases where surgery was indicated.

Corticosteroid withdrawal precipitates perilesional edema around calcified Taenia solium cysts.

Calcified Taenia solium granulomas are the focus of repeated episodes of perilesional edema and seizures in 50% of persons with calcifications, history of seizures, and a positive serology for cysticercosis. The pathophysiology is unclear but recent studies suggest the edema is caused by inflammation. We report two new cases and four other published cases where cessation of corticosteroids appeared to result in recurrence or new appearance of perilesional edema around calcifications. This suggests that perilesional edema is an immune-mediated phenomenon.

Prevalence of Strongyloides stercoralis in an urban US AIDS cohort.

OBJECTIVES: We examined the prevalence of Strongyloides stercoralis (Ss) infection in a cohort of AIDS patients from a US urban centre. We monitored our cohort for possible cases of dissemination or immune reconstitution inflammatory syndrome after antiretroviral therapy (ART) initiation. METHODS: One hundred and three HIV-infected participants were prospectively sampled from a cohort observational study of ART-naive HIV-1-infected patients with CD4 ≤100 T cells/µl. Clinical symptoms, corticosteroid therapy, eosinophilia, CD4 count, and plasma HIV-RNA were reviewed. Sera were tested by an enzyme-linked immunosorbent assay (CrAg-ELISA) to crude Ss extract or to an Ss-specific recombinant protein (NIE) and by luciferase immunoprecipitation system assay (LIPS) for Ss-specific antibodies. RESULTS: Twenty-five per cent of study participants were Strongyloides seropositive by CrAg-ELISA and 62% had emigrated from Strongyloides-endemic areas. The remaining 38% of the seropositives were US born and tested negative by NIE and LIPS. CrAg-ELISA-positive participants had a median CD4 count of 22 T cells/µl and a median HIV-RNA of 4·87 log(10) copies/ml. They presented with diarrhea (27%), abdominal pain (23%), and skin manifestations (35%) that did not differ from seronegative patients. Peripheral blood eosinophilia was common among seropositive patients (prevalence of 62% compared to 29% in seronegatives, P = 0·004). Seropositive patients were treated with ivermectin. There were no cases of hyperinfection syndrome. DISCUSSION: Strongyloidiasis may be prevalent in AIDS patients in the USA who emigrated from Ss-endemic countries, but serology can be inconclusive, suggesting that empiric ivermectin therapy is a reasonable approach in AIDS patients originating from Strongyloides endemic areas.

Peripheral blood stem cell transplant-related Plasmodium falciparum infection in a patient with sickle cell disease.

BACKGROUND: Although transmission of Plasmodium falciparum (Pf) infection during red blood cell (RBC) transfusion from an infected donor has been well documented, malaria parasites are not known to infect hematopoietic stem cells. We report a case of Pf infection in a patient 11 days after peripheral blood stem cell transplant for sickle cell disease. STUDY DESIGN AND METHODS: Malaria parasites were detected in thick blood smears by Giemsa staining. Pf HRP2 antigen was measured by enzyme-linked immunosorbent assay on whole blood and plasma. Pf DNA was detected in whole blood and stem cell retention samples by real-time polymerase chain reaction using Pf species-specific primers and probes. Genotyping of eight Pf microsatellites was performed on genomic DNA extracted from whole blood. RESULTS: Pf was not detected by molecular, serologic, or parasitologic means in samples from the recipient until Day 11 posttransplant, coincident with the onset of symptoms. In contrast, Pf antigen was retrospectively detected in stored plasma collected 3 months before transplant from the asymptomatic donor. Pf DNA was detected in whole blood from both the donor and the recipient after transplant, and genotyping confirmed shared markers between donor and recipient Pf strains. Lookback analysis of RBC donors was negative for Pf infection. CONCLUSIONS: These findings are consistent with transmission by the stem cell product and have profound implications with respect to the screening of potential stem cell donors and recipients from malaria-endemic regions.

Evaluation and differential diagnosis of marked, persistent eosinophilia.

High-grade eosinophilia can be a diagnostic dilemma, as the etiologies are extensive and varied. Hypereosinophilic syndromes (HES) are a group of heterogeneous disorders, many of which remain poorly defined. By definition, HES must be distinguished from other disorders with persistently elevated eosinophilia with a defined cause. Although marked eosinophilia worldwide is most commonly caused by helminth (worm) infections, non-infectious causes must be considered, and include drug reactions, malignancies, and immunologic, inflammatory and allergic diseases.