Kato-Katz and Lumbreras rapid sedimentation test to evaluate helminth prevalence in the setting of a school-based deworming program

Demographic Characteristics and Low Iron Status Markers Are Associated with Hemoglobin Levels and Anemia among Children Living at High Elevation in Cusco, Peru

Anemia is a complex condition associated with diet, chronic infections, and blood loss. Children living at high altitudes have higher absolute hemoglobin levels due to hypoxemia. However, they are exposed to repeated infections and dietary limitations. We conducted a cross-sectional study to identify factors affecting the hemoglobin concentration in children living in high-altitude rural communities in the Anta province of Peru. All children 3-16 years of age attending public schools were invited to participate. We enrolled children 3-16 years old in schools and visited their homes to collect demographic, socioeconomic, medical history, and anthropometric data. Children provided blood and stool samples for complete blood counts, iron status markers, and helminth infection testing. Among the 2,000 children enrolled, the mean age was 9.9 (±3.4) years, 1,004 (50.2%) were female, and the median residence altitude was 3,398 (interquartile range 3,35-3,497) meters. The mean hemoglobin level was 15 (±1.15) mg/dL; 320 (16%) had anemia as defined by WHO. Children with anemia were more likely to have lower serum iron levels (odds ratio [OR] 2.8 [95% CI 2.2-3.6], P <0.001) and serum transferrin saturation (OR 2.8 [95% CI 2-3.9], P <0.001). Younger age (OR 0.85 [95% CI 0.82-0.89], P <0.001), stunting (OR 0.68 [95% CI 0.59-0.79], P <0.001), education of the mother (OR 0.94 [95% CI 0.91-0.98], P <0.005), and low eosinophils (OR 0.49 [95% CI 0.26-0.9], P = 0.022) were associated with anemia. Helminth infections were not associated with anemia. Anemia among children at high altitude is multifactorial, but iron deficiency is a contributing factor. Further studies are needed to evaluate iron status and anemia in children living at high altitudes.

Clinical characteristics of human fascioliasis in Egypt

There is a lack of epidemiological data on fascioliasis in Egypt regarding disease characteristics and treatment outcomes across different governorates. We aimed to identify the demographic, epidemiologic, clinical, laboratory, and radiological characteristics and treatment outcomes of patients diagnosed with fascioliasis in Egypt. Data on human fascioliasis were collected retrospectively from patients' medical records in the period between January 2018 and January 2020. The study included 261 patients. More than 40% of enrolled patients were in the age group of 21-40 years old. Geographically, 247 (94.6%) were from Assiut Governorate with 69.3% were from rural areas. The most frequent symptoms were right upper quadrant pain (96.9%), and fever (80.1%). Eosinophilia was found in 250 cases (95.8%). Hepatic focal lesions were detected in 131 (50.2%); out of them 64/131 (48.9%) had a single lesion. All patients received a single dose of 10 mg/kg of triclabendazole, 79.7% responded well to a single dose, while in 20.3% a second ± a third dose of treatment was requested. After therapy, there was a reduction in leucocytes, Fasciola antibodies titer, eosinophilic count, bilirubin, and liver enzymes with an increase in hemoglobin level. According to our findings, a high index of suspicion should be raised in cases with fever, right upper abdominal pain, and peripheral eosinophilia, and further imaging workup is mandated to detect hepatic focal lesions. Prompt treatment by triclabendazole can serve as a standard-of-care regimen even for suspected cases.

What about the Cytoskeletal and Related Proteins of Tapeworms in the Host's Immune Response? An Integrative Overview

Recent advances have increased our understanding of the molecular machinery in the cytoskeleton of mammalian cells, in contrast to the case of tapeworm parasites, where cytoskeleton remains poorly characterized. The pertinence of a better knowledge of the tapeworm cytoskeleton is linked to the medical importance of these parasitic diseases in humans and animal stock. Moreover, its study could offer new possibilities for the development of more effective anti-parasitic drugs, as well as better strategies for their surveillance, prevention, and control. In the present review, we compile the results of recent experiments on the cytoskeleton of these parasites and analyze how these novel findings might trigger the development of new drugs or the redesign of those currently used in addition to supporting their use as biomarkers in cutting-edge diagnostic tests.

The diagnosis of human and companion animal Strongyloides stercoralis infection: Challenges and solutions. A scoping review

Strongyloidiasis is the infection caused by soil-transmitted nematodes of Strongyloides species, infecting humans and some animals. Strongyloides stercoralis is the species with most clinical and epidemiological relevance in humans and dogs, due to its high prevalence and its capacity of inducing a life-threatening hyperinfection. Diagnosis of strongyloidiasis is challenging, due to the absence of a single reference standard test with high sensitivity and specificity, which also hampers the estimation of the accuracy of other diagnostic tests. In this chapter, we review the deployment and performance of the parasitological, immunological, molecular tests for the diagnosis of strongyloidiasis in humans and in dogs. Further, we comment the available evidence from genotyping studies that have addressed the zoonotic potential of S. stercoralis. Finally, we discuss the use of different diagnostic methods in relation to the purpose (i.e., screening, individual diagnosis, inclusion in a clinical trial) and the setting (endemic/non-endemic areas) and report the accuracy figures reported by systematic reviews on either parasitological, serological or molecular techniques published in literature.

Geospatial analysis of the associations between environmental contamination with livestock feces and children with chronic fascioliasis in the Anta province of Cusco, Peru

Fasciola hepatica is a neglected parasitic infection with significant human health and livestock industry impact. The Andean Altiplano harbors an estimated 50% of the Fasciola’s world infection burden. There is scarce data regarding the spatial associations between different Fasciola hosts. In this project, we aimed to determine the geospatial relationships between Fasciola eggs passed in feces of different livestock species and the risk of infection among each household as a unit. We used data from a cross-sectional study evaluating children and livestock feces for Fasciola infection around households in three districts of Anta province, in the Cusco region of Peru. Each sample was geographically tagged and evaluated for fascioliasis using microscopy methods. A total of 2070 households were included, the median age was 9.1 years (6.7–11.8), 49.5% were female, and 7.2% of the households had at least one infected child. A total of 2420 livestock feces samples were evaluated. The infection rate in livestock samples was 30.9%. The highest infection rate was found in sheep with 40.8%, followed by cattle (33.8%), and swine (26.4%). The median distance between a household with an infected child to a positive animal sample was 44.6 meters (IQR 14.7–112.8) and the distance between a household with no infected children to a positive animal sample was 62.2 meters (IQR 18.3–158.6) (p = 0.025). The multivariable logistic regression adjusted by presence of poor sanitation, unsafe water consumption, altitude, and presence of multiple infected children per household demonstrated an association between household infection and any cattle feces at a 50 meters radius (Uninfected: OR 1.42 (95%CI 1.07–1.89), p = 0.017. Infected: OR 1.89 (95%CI 1.31–2.73), p = 0.001), positive cattle feces at a 100 meters radius (OR 1.35 (95% CI 1.08–1.69), p = 0.008), and negative cattle feces at a 200 meters radius (OR 1.08 (95% CI 1.01–1.15), p = 0.022). We identified potential hot and cold spots for fascioliasis in the Anta province. An association between environmental contamination with feces from different livestock species and infected children in rural households was found in our study. Local health authorities may apply this strategy to estimate the risk of infection in human populations and apply targeted interventions.

Fasciola hepatica is the parasite that causes fascioliasis in the Andes region. The factors associated with transmission of the disease among humans have not been well described in the area studied. In this study, we evaluate the spatial relationships between infected households and the environmental burden of Fasciola eggs passed by different livestock in the Cusco region of Peru. We geographically marked and tested for fascioliasis feces provided by children and livestock. Infected and uninfected cattle as well as sheep feces were more likely to be in proximity to human households with infected children than to households without infected children. We were able to identify and map the areas of higher and lower infections rates. This information and strategy may be used in the control of the disease.

Triclabendazole Treatment Failure for Fasciola hepatica Infection among Preschool and School-Age Children, Cusco, Peru1

We conducted a retrospective cohort study of children who had chronic fascioliasis in the highlands of Peru to determine triclabendazole treatment efficacy. Children passing Fasciola eggs in stool were offered directly observed triclabendazole treatment (>1 doses of 10 mg/kg). Parasitologic cure was evaluated by using microscopy of stool 1–4 months after each treatment. A total of 146 children who had chronic fascioliasis participated in the study; 53% were female, and the mean ± SD age was 10.4 ± 3.1 years. After the first treatment, 55% of the children achieved parasitologic cure. Cure rates decreased after the second (38%), third (30%), and fourth (23%) treatments; 17 children (11.6%) did not achieve cure after 4 treatments. Higher baseline egg counts and lower socioeconomic status were associated with triclabendazole treatment failure. Decreased triclabendazole efficacy in disease-endemic communities threatens control efforts. Further research on triclabendazole resistance and new drugs to overcome it are urgently needed.

Stunting in pre-school and school-age children in the Peruvian highlands and its association with Fasciola infection and demographic factors

Fascioliasis is a zoonotic trematode infection that is endemic in the highlands of Peru. Chronic fascioliasis can be asymptomatic and remain undiagnosed for years. Chronic malnutrition in children, as manifested by stunting, leads to delayed cognitive development and lost productivity. We hypothesized that fascioliasis is among the factors associated with stunting in children from endemic areas. We conducted a cross-sectional study among children attending pre-school and school in 26 communities in the Anta province in the Cusco region of Peru. We conducted interviews to collect information on demographic, socioeconomic, and medical history. Blood was collected and tested for complete cell count and FAS2 ELISA for Fasciola antibodies. Three stool samples per participant were tested for parasites by Kato-Katz and Lumbreras rapid sedimentation methods. Chronic fascioliasis was determined by the presence of ova in stool. Children's height, weight, and age were recorded and used to calculate height for age Z scores (HAZ). Three thousand children participated in the study. Nine percent (264) of children had at least one positive test for Fasciola infection, 6% (164) had chronic fascioliasis, and 3% (102) had only positive antibody tests. The median HAZ was -1.41 (IQR: -2.03 to -0.81) and was similar in males and females. Twenty six percent (776) of children had stunting with HAZ < -2. Children with chronic fascioliasis had a lower median HAZ than children without Fasciola (-1.54 vs. -1.4, p = 0.014). History of treatment for malnutrition, history of treatment for anemia, having other helminths in stool, lower socioeconomic score, living at a higher elevation, and fewer years of schooling of both parents were associated with a lower HAZ score. In a multiple regression analysis, older age and a lower socioeconomic score were associated with a lower HAZ score. While fascioliasis and other helminths were associated with lower HAZ, they were not independent of the socioeconomic score.

Human Fascioliasis: Current Epidemiological Status and Strategies for Diagnosis, Treatment, and Control

Purpose of the Review

This review aims to critically assess current knowledge about the epidemiology, diagnosis, and management of Fasciola infection in humans.

Recent Findings

Fascioliasis is an emerging neglected zoonotic infection affecting the health and wellbeing of human populations. The burden of infection is unclear, and studies have shown the geographic expansion of fascioliasis in human and livestock likely related to climate change. The infection can be asymptomatic or present in acute or chronic forms. Regardless of the presentation, fascioliasis can be associated with long-term complications such as anemia and malnutrition. Early in the infection, antibody testing is the only tool available for diagnosis confirmation. In the chronic forms serology and stool microscopy are helpful. Other tests such as antigen detection and PCR-based methods including isothermal tests have shown promising results. Triclabendazole is the only drug available to treat Fasciola infection. However, reports of resistant infections in livestock and human threaten the clinical care and control of the infection in endemic areas.

Summary

Fascioliasis is an emerging infection around the world with an uncertain burden. Lack of standardization of diagnostic testing and treatment alternatives hinder treatment and control of the infection.

Intestinal cestodes

PURPOSE OF REVIEW

Cestodes infections in humans are among the most prevalent parasitosis worldwide. Although tapeworm infection is often asymptomatic, they can be associated with a range of symptoms. The landscape of cestode infections is changing with rapid diagnosis techniques and advanced molecular diagnosis aiding in identification of species specific epidemiology.

RECENT FINDINGS

Traditional descriptions of species by location have been challenged with molecular diagnostic techniques, which show variation in distribution of species, thought to be because of globalization and importation of disease.

MAIN THEMES IN LITERATURE

Epidemiology, molecular diagnostic techniques.

SUMMARY

Infection by tapeworms is often asymptomatic or accompanied by mild symptoms though can occasionally cause severe disease and contribute to anemia and malnutrition. Tapeworm infection is most prevalent in resource-poor countries but the distribution is worldwide. Epidemiology of infection is changing because of molecular diagnostics, which allow more accurate tracking of species.