Angélica Terashima

Update on hepatobiliary flukes: fascioliasis, opisthorchiasis and clonorchiasis

Purpose of review Hepatobiliary flukes – Fasciola, Opisthorchis, Clonorchis– are a major public health problem in east Asia, east Europe, Africa and Latin America. The present review focuses on current knowledge of clinical, diagnostic and treatment aspects caused by hepatobiliary flukes that can be applied to current protocols in endemic areas. Recent findings Specific risk factors and geographic areas for these flukes have been heavily reported recently, with millions of people infected worldwide. Human cases in nonendemic areas, related to immigration and the international food trade (i.e. raw vegetables and fish), have also been reported. Diagnostic imaging changes include track-like lesions that are a characteristic feature of acute fascioliasis on computed tomography scanning of the liver. Newly available diagnostic serological tests may detect early infection and, therefore, help reduce severe clinical complications such as recurrent cholangitis, cholecystitis, hepatic tumours, cysts, calcification, cholelithiasis, pancreatitis, most importantly, cholangiocarcinoma related to Opisthorchis viverrini and possibly Clonorchis sinensis, and liver fibrosis associated with Fasciola hepatica infections. Highly effective antiparasitic treatment is available for all flukes. Summary There is a better understanding of risk factors, clinical manifestations and complications, novel diagnosis tests and effective treatment, which together should help reduce the morbidity and mortality of these infections.

Regulatory T Cell Expansion in HTLV-1 and Strongyloidiasis Co-infection Is Associated with Reduced IL-5 Responses to Strongyloides stercoralis Antigen

Background Human strongyloidiasis varies from a chronic but limited infection in normal hosts to hyperinfection in patients treated with corticosteroids or with HTLV-1 co-infection. Regulatory T cells dampen immune responses to infections. How human strongyloidiasis is controlled and how HTLV-1 infection affects this control are not clear. We hypothesize that HTLV-1 leads to dissemination of Strongyloides stercoralis infection by augmenting regulatory T cell numbers, which in turn down regulate the immune response to the parasite. Objective To measure peripheral blood T regulatory cells and Strongyloides stercoralis larval antigen-specific cytokine responses in strongyloidiasis patients with or without HTLV-1 co-infection. Methods Peripheral blood mononuclear cells (PBMCs) were isolated from newly diagnosed strongyloidiasis patients with or without HTLV-1 co-infection. Regulatory T cells were characterized by flow cytometry using intracellular staining for CD4, CD25 and FoxP3. PBMCs were also cultured with and without Strongyloides larval antigens. Supernatants were analyzed for IL-5 production. Results Patients with HTLV-1 and Strongyloides co-infection had higher parasite burdens. Eosinophil counts were decreased in the HTLV-1 and Strongyloides co-infected subjects compared to strongyloidiasis-only patients (70.0 vs. 502.5 cells/mm3, p = 0.09, Mann-Whitney test). The proportion of regulatory T cells was increased in HTLV-1 positive subjects co-infected with strongyloidiasis compared to patients with only strongyloidiasis or asymptomatic HTLV-1 carriers (median = 17.9% vs. 4.3% vs. 5.9 p<0.05, One-way ANOVA). Strongyloides antigen-specific IL-5 responses were reduced in strongyloidiasis/HTLV-1 co-infected patients (5.0 vs. 187.5 pg/ml, p = 0.03, Mann-Whitney test). Reduced IL-5 responses and eosinophil counts were inversely correlated to the number of CD4+CD25+FoxP3+ cells. Conclusions Regulatory T cell counts are increased in patients with HTLV-1 and Strongyloides stercoralis co-infection and correlate with both low circulating eosinophil counts and reduced antigen-driven IL-5 production. These findings suggest a role for regulatory T cells in susceptibility to Strongyloides hyperinfection.

Cryptosporidium muris, a Rodent Pathogen, Recovered from a Human in Perú

Cryptosporidium muris, predominantly a rodent species of Cryptosporidium, is not normally considered a human pathogen. Recently, isolated human infections have been reported from Indonesia, Thailand, France, and Kenya. We report the first case of C. muris in a human in the Western Hemisphere. This species may be an emerging zoonotic pathogen capable of infecting humans.

Hepatic fibrosis and Fasciola hepatica infection in cattle.

This study focuses on the development of fibrosis of the liver of cattle with Fasciola hepatica infection, correlating with the intensity of infection. Animals with an established diagnosis of chronic F. hepatica infection were identified in a slaughterhouse in Lima, Peru. The study included 24 fresh cattle livers from infected animals and two uninfected controls. Tissues were stored at 4 degrees C for approximately 8 h after which they were brought to a necropsy room and examined. Between 9 and 12 biopsies were randomly obtained from each liver. Histological staining of formalin-fixed liver sections with haematoxylin and eosin (H & E) and Massons trichrome were performed. Liver samples were examined using a pathology protocol that included 30 items. Histopathologically, 16 out of 30 liver specimens (67.6%) showed diffuse fibrotic lesions (cirrhosis) with a mean number of Fasciola of 116 +/- 30 (range 4-435). Pathological data were matched to number of adult parasites and presence of cirrhosis after being reviewed by two independent pathologists. There was concordance between the two pathologists (K = 0.72). The group with cirrhosis showed an average of 116 +/- 30 adult parasites whereas the group not showing cirrhosis contained 56 +/- 28 flukes (P = 0.2). To measure how number of flukes and diagnosis of cirrhosis are related we used Kendalls tau-b coefficient; the correlation was +0.296 (P = 0.04). Receiver Operating Characteristic (ROC) curve results showed that the best point was 38 parasite adults, which had 93.8% sensitivity and 75% specificity. We conclude that as the number of F. hepatica adult forms increases, the likelihood of developing liver fibrosis will also increase in cattle.

Fasciolosis humana y animal en el Perú: impacto en la economía de las zonas endémicas

Fasciola hepatica is the causative agent of fasciolosis in Peru; the disease is an important public health problem by the high prevalence of the human infection affecting mainly children and a major veterinary problem by the high rates of infected livestock. The human disease is endemic in the Sierra and the Coast but sporadic in the Amazonia, and reported in 18 Departments, while the animal infection in 21 of 24 Departments of Peru. Transmission occurs in Andean rural populations engaged in agriculture, but recently an increasing number of people became infected in the cities. The epidemiological situation in Peru includes i) Departments with non-autochtonous cases, where infection occurs by consumption of contaminated vegetables brought from endemic areas or infection is acquired by visit to endemic areas; ii) Departments with hypoendemic and mesoendemic villages, where transmission occurs by ingest of contaminated vegetables and prevalence ≤10%; and iii) Departments with hyper-endemic villages with human prevalence >10 %, with an intense transmission by consumption of contaminated vegetables. The disease affects bovine, sheep, goat, swine, equine, South American camelids, rabbits and guinea pigs. The negative impact of fasciolosis in the livestock economy is not lesser than US

Parasitosis intestinal en poblaciones urbana y rural en Sandia, Departamento de Puno, Perú

50 million per year, estimation based on the prevalence and the number of condemned livers in the abattoirs. It is difficult to estimate the economic impact of this infection in the human health due to its status of neglected disease, but fasciolosis is hyper-endemic in the poorest Andean areas of Peru where the situation has to be recognized as a public health emergency.

Treatment failure in intestinal strongyloidiasis: an indicator of HTLV-I infection

* Instituto de Medicina Tropical Alexander von Humboldt (IMTAvH). Av. Honorio Delgado 430, Urb. Ingieneria,San Marin de Porres. A.P. 4314 - Lima 100, Peru. E-mail: egh@upch.edu.pe** Laboratorio de Parasitologia. Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru.LUIS MARCOS*, VICENTE MACO*, ANGELICA TERASHIMA*, FRINE SAMALVIDES**,ELBA MIRANDA** y EDUARDO GOTUZZO*.

Fascioliasis in relatives of patients with Fasciola hepatica infection in Peru

BACKGROUND The association of severe strongyloides with HTLV-I is well known; however, the seroprevalence of HTLV-I in other groups with strongyloidiasis is still unknown. We conducted a prospective study in patients with intestinal strongyloidiasis without known immunodepression who failed to respond to standard therapy with ivermectin or thiabendazole (failure was defined as one positive stool examination at the post-therapy follow up). All these patients were tested for HTLV-I by ELISA and Western Blot. RESULTS Forty seven patients were evaluated: 74.5% (35 out of 47) were HTLV-I positive, without significant difference between males (76%) and females (72.7%). CONCLUSIONS We recommend that all patients with uncomplicated intestinal strongyloidiasis, who fail standard therapy, be studied for HTLV-I infection.

Field Evaluation of a Coproantigen Detection Test for Fascioliasis Diagnosis and Surveillance in Human Hyperendemic Areas of Andean Countries

High prevalence rates of human fascioliasis have been described in several regions of Peru. We surveyed 20 families in an endemic area of Peru in order to determine the proportion of infection with F. hepatica in relatives of diagnosed subjects and in order to identify associated risk factors. The study included feces and blood samples of 93 subjects. Ages ranged from one to 53 (mean = 18.6; SD = 14.2). The overall prevalence of fascioliasis by fecal examinations was 33.3% (n = 83) and by serology, 51.9% (n = 86). The prevalence in age group I (< or = 19 years old) by coprological and serological tests was 61.4% and 75.9%, respectively; in group II (> 19 years old) 15.4% and 37.5%. The main associated risk factor with fascioliasis was eating salads (OR = 3.29, CI = 1.2 - 9.0, p = 0.02). In conclusion, human fascioliasis is highly prevalent in the relatives of index cases and the most significant risk factor of acquiring fascioliasis in the family is eating salads in endemic areas.

Frequent HTLV-1 infection in the offspring of Peruvian women with HTLV-1-associated myelopathy/tropical spastic paraparesis or strongyloidiasis

Background Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in a few countries. Two hyperendemic areas were chosen: Huacullani, Northern Altiplano, Bolivia, representing the Altiplanic transmission pattern with high prevalences and intensities; Cajamarca valley, Peru, representing the valley pattern with high prevalences but low intensities. Coprological sample collection, transport and study procedures were analyzed to improve individual diagnosis and subsequent treatments and surveillance activities. Therefore, a coproantigen-detection technique (MM3-COPRO ELISA) was evaluated, using classical techniques for egg detection for comparison. Methodology and Findings A total of 436 and 362 stool samples from schoolchildren of Huacullani and Cajamarca, respectively, were used. Positive samples from Huacullani were 24.77% using the MM3-COPRO technique, and 21.56% using Kato-Katz. Positive samples from Cajamarca were 11.05% using MM3-COPRO, and 5.24% using rapid sedimentation and Kato-Katz. In Huacullani, using Kato-Katz as gold standard, sensitivity and specificity were 94.68% and 98.48%, respectively, and using Kato-Katz and COPRO-ELISA test together, they were 95.68% and 100%. In Cajamarca, using rapid sedimentation and Kato-Katz together, results were 94.73% and 93.58%, and using rapid sedimentation, Kato-Katz and copro-ELISA together, they were 97.56% and 100%, respectively. There was no correlation between coproantigen detection by optical density (OD) and infection intensity by eggs per gram of feces (epg) in Cajamarca low burden cases (<400 epg), nor in Huacullani high burden cases (≥400 epg), although there was in Huacullani low burden cases (<400 epg). Six cases of egg emission appeared negative by MM3-COPRO, including one with a high egg count (1248 epg). Conclusions The coproantigen-detection test allows for high sensitivity and specificity, fast large mass screening capacity, detection in the chronic phase, early detection of treatment failure or reinfection in post-treated subjects, and usefulness in surveillance programs. However, this technique falls short when evaluating the fluke burden on its own.