High Prevalence of Intestinal Capillariasis in Chronic Diarrhea Patients in Thailand: Serological Screening Using a Rapid Lateral-Flow Immunochromatographic Assay.

Intestinal capillariasis is an emerging fish-borne helminthic disease caused by the round worm Capillaria philippinensis. Chronic infection may lead to death if the disease is misdiagnosed and inappropriate treatment is given. We used a rapid lateral-flow immunochromatographic test for screening of intestinal capillariasis in patients with chronic diarrhea. We screened 292 chronic diarrhea patients who had visited hospitals in Thailand. Sixty-six (22.6%) cases were positive according to the kit. All positive patients received mebendazole at 200 mg twice per day for 30 consecutive days or albendazole at 200 mg twice per day for 10 consecutive days. Later, stool concentration techniques, used to examine stool samples from all serologically positive individuals on three consecutive days, revealed C. philippinensis eggs, larvae, and/or adults. The kit is useful for screening and rapid diagnosis of intestinal capillariasis in chronic diarrhea patients in an endemic area for prevention of serious disease and facilitates treatment.

A Hospital-Based Study of Intestinal Capillariasis in Thailand: Clinical Features, Potential Clues for Diagnosis, and Epidemiological Characteristics of 85 Patients.

Intestinal capillariasis caused by Capillaria philippinensis, a fish-borne nematode, is an important, emerging zoonotic helminthiasis. Cases may be fatal if suitable treatment is not administered in time. We reported a hospital-based study of 85 cases in Thailand, most of which were in the northeast. All patients had a history of eating raw or insufficiently cooked fresh water fish or prawns. The clinical manifestations are characterized by chronic diarrhea, borborygmi, abdominal pain, marked weight loss, muscle weakness, fatigue, dizziness, anorexia, and edema, as well as protein and electrolyte loss. Fecal examination revealed C. philippinensis in all patients. Although 16 of the total of 85 (18.8%) cases were initially found to be negative for C. philippinensis using fecal examination, further examination using an immunoblotting technique found them to be positive for the IgG antibody against Trichinella spiralis larval antigen. One day after administration of 400 mg of albendazole, eggs and/or larvae and/or adult C. philippinensis were found in 16 fecal samples. After treatment with mebendazole (200 mg twice a day for 30 days) or albendazole (200 mg twice a day for 10 days), all 85 patients recovered. The potential clues for diagnosis are clinical manifestations, history of eating raw contaminated food, and positive serological test, and fecal examinations under professional. Administration of anthelminthic drugs stimulates the excretion of larvae, eggs, and/or adult worms and can be used as a supportive method for the diagnosis of intestinal capillariasis in areas where serological test is not available.

An eleven-year retrospective hospital-based study of epidemiological data regarding human strongyloidiasis in northeast Thailand.

BACKGROUND: Human strongyloidiasis is a chronic and persistent gastrointestinal disease caused by infection with soil-transmitted helminths of the genus Strongyloides. The aim of this research was to obtain diagnostic prevalence regarding strongyloidiasis in northeast Thailand through a hospital-based study. METHODS: Patients' demographic data and the results of stool examinations conducted using the formalin ethyl acetate concentration technique were collected from the parasitology laboratory records at Srinagarind Hospital in Khon Kaen, Thailand. The relevant information from years 2004 to 2014 was collected and descriptively analyzed. RESULTS: Of a total of 22,338 patients, 3889 (17.4%) had stool samples that tested positive for Strongyloides larvae. The highest prevalence was 22.8% (95% CI = 19.6-26.2%) in the year 2004. This percentage progressively decreased, reaching 11.2% (95% CI = 10.2-12.4%) in 2013 and remaining stable at 12.9% (95% CI = 11.8-14.1%) in 2014. Males (2741 cases) had double the positivity rate of females (1148 cases). The prevalence of infection was highest (25.9%; 95% CI = 24.5-27.3%) among patients that were 51-60 years of age. CONCLUSIONS: Areas endemic for strongyloidiasis should be emphasized under the national helminth control program and health education campaigns. Nationwide assessments should also be performed regarding Strongyloides infection, including risk factors, treatment, and prevention. The diagnostic laboratory data presented here identify the geographical focus of disease to be the northeastern region of the country. Further targeted surveillance using more sensitive methods will almost certainly reveal a higher individual disease burden than found in this report.

HUMAN TRICHOSTRONGYLIASIS: A HOSPITAL CASE SERIES.

Trichostrongylus is a common nematode found to infect livestock throughout the tropics and can cause accidental zoonosis in humans. In the Lao PDR and Thailand, cases of human trichostrongyliasis have been reported sporadically but clinical data are limited. We retrospectively reviewed 41 cases of trichostrongyliasis who presented to Srinagarind Hospital, Thailand from 2005 to 2012. The diagnosis of trichostrongyliasis was made by finding their eggs in the stool of patients. Of the 41 cases reviewed, 30 were Thais and 11 from the Lao PDR; their age range was 26-86 years. Fifty-eight point five percent of the cases were male, 56.1% had a primary school or a lower education level, 56.1% were farmers or laborers, 63.4% lived in a rural area and 95.1% had underlying disease. Twenty-one patients were co-infected with Opisthorchis viverrini (14/21; 66.7%) and Strongyloides stercoralis (10/21; 47.6%) while the remaining (n = 20) had a single infection with Trichostrongylus only. All the trichostrongyliasis only patients who had underlying disease not related to the gastrointestinal (GI) tract had normal bowel habits and normal grossly appearing stool. GI symptoms, such as abdominal pain, flatulence, bloating, nausea, vomiting, anorexia, diarrhea and constipation, were not found in these patients suggesting they had a light infection. This study is the first report of the clinical features of a trichostrongyliasis case series from tertiary care hospital in Thailand.

Hypoalbuminemia as a predictor of diarrhea caused by blastocystis hominis.

Blastocystis hominis is an intestinal protozoan found worldwide, particularly in developing countries, that may cause gastrointestinal symptoms, including diarrhea. We conducted a hospital-based study to identify clinical factors predictive of diarrhea caused by B. hominis. We studied patients with positive stool samples for B. hominis by formalin ethyl acetate concentration technique at Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand between 2003 and 2010. Patients were divided into diarrhea and non-diarrhea groups. Diarrhea patients were categorized if the diarrhea was associated with B. hominis only. In total, 81 patients with isolated B. hominis infection were studied. Of those, 17 patients (21%) had diarrhea associated with B. hominis infection. Eight variables were included in the final model predicting diarrhea caused by B. hominis on multiple logistic regression analysis. Only serum albumin level was significantly associated with diarrhea cases in this study with an adjusted OR of 0.162 and a 95% CI of 0.027- 0.957. Hypoalbuminemia is associated with diarrhea associated with blastocystosis.

Rapid detection of Brugia malayi in mosquito vectors using a real-time fluorescence resonance energy transfer PCR and melting curve analysis.

We developed real-time fluorescence resonance energy transfer (FRET) polymerase chain reaction (PCR) combined with melting curve analysis for detection of Brugia malayi DNA in blood-fed mosquitoes. Real-time FRET PCR is based on a fluorescence melting curve analysis of hybrid formed between amplicons generated from a family of repeated DNA element, 153-bp HhaI repeated sequence, specific to genus Brugia and specific fluorophore-labeled probes. The B. malayi-infected mosquitoes were differentiated from Wuchereria bancrofti-infected and uninfected mosquitoes and from genomic DNA of Dirofilaria immitis--and Plasmodium falciparum--infected human red blood cells and human leukocytes by their melting temperature. Sensitivity and specificity were both 100%. Melting curve analysis produces a rapid, accurate, and sensitive alternative for specific detection of B. malayi in mosquitoes, allows high throughput, and can be performed on small samples. This method has the potential for endemic area mapping or monitoring effect of brugian filariasis mass treatment programs.

A modified filter paper culture technique for screening of Strongyloides stercoralis ivermectin sensitivity in clinical specimens.

An in vitro test for the detection of ivermectin sensitivity of Strongyloides stercoralis in human clinical specimens was developed. The test has a simple procedure that combines parasite culture with a drug assay. It is based on the principle of the drug effect on larval development test, combined with a modified coproculture using the filter paper culture technique. This does not require parasite isolation, and drug sensitivity can be shown in relationship to the dose. This test can be applied in field surveys for anthelmintic sensitivity and for appropriate drug rotation strategies when drug resistance occurs.

Detection of Paragonimus heterotremus eggs in experimentally infected cats by a polymerase chain reaction-based method.

A polymerase chain reaction (PCR) procedure for the detection of Paragonimus heterotremus eggs in stool samples was developed and compared with Stoll's egg count method. The primers were designed on the basis of a previously constructed pPH-13-specific DNA probe, which produced an approximate 0.5-kb amplified product. This PCR method could detect as few as 5 eggs in 0.6 g of artificially inoculated feces of a healthy control cat or as little as 1 x 10(-4) ng of P. heterotremus genomic DNA. The assay had 100% sensitivity in all infected cats. The method did not yield an approximate 0.5-kb product with DNA from other parasites such as Gnathostoma spinigerum, Trichinella spiralis, Fasciola gigantica, Echinostoma malayanum, Opisthorchis viverrini, Dirofilaria immitis, and Taenia saginata; exceptions were Paragonimus siamensis and Paragonimus westermani. In addition, no genomic DNA from Escherichia coli, Burkholderia pseudomallei, Acinetobacter anitratus, Mycobacterium tuberculosis, Staphylococcus aureus, beta-Streptococcus grA, and Proteus mirabilis or from the vertebrate and invertebrate hosts of P. heterotremus was amplified in the PCR assay. This assay has great potential for application in clinical epidemiological studies.