Accuracy of Dengue, Chikungunya, and Zika diagnoses by primary healthcare physicians in Tegucigalpa, Honduras.

BACKGROUND: Dengue, Chikungunya, and Zika are co-endemic in Honduras and are often misdiagnosed due to similar clinical and epidemiological behavior. Most arboviral infections reported in primary care are based on clinical diagnoses without laboratory confirmation. Therefore, the accuracy of physicians' diagnoses and the factors that affect them needs to be evaluated. METHODS: A cross-sectional study with convenience sampling at primary healthcare centers was conducted from June to September 2016 and 2017. Clinical data and dried blood spots on Whatman 903 filter paper from 415 arboviral cases and 248 non-arboviral febrile cases were collected. Viral RNA was extracted from a 6-mm DBS paper disc and confirmed by RT-qPCR and sequencing. RESULTS: Only 30.84% of diagnostic accuracy was observed in physicians in primary care when comparing arboviral clinical diagnosis with RT-qPCR detection. Moreover, in Dengue and Zika clinical cases, only 8.23% and 27.08% were RT-qPCR confirmed, respectively. No Chikungunya cases were confirmed. In 2017, 20.96% of febrile cases were RT-qPCR confirmed arboviral infections. The symptoms of 45.5% of arboviral cases can fit more than one case definition for arboviruses. The "symptom compliance" and "patient with suspected close contact" were the criteria most utilized by physicians for arboviral diagnosis. The pattern of the epidemiological curves of the arboviral clinical cases didn't match the one of the RT-qPCR confirmed cases. CONCLUSIONS: Low diagnostic accuracy for overall and individual arboviral infections was observed in physicians. Unspecific symptomatology, overlapping case definitions, and reported close contact to an arboviral patient might contribute to misdiagnosis. Without laboratory confirmation, surveillance data may not reflect the real behavior of these diseases and could impact health interventions.

Cytomegalovirus viral interleukin-10 in patients with Aspergillus infection and effects on clinical outcome.

BACKGROUND: Human cytomegalovirus (CMV) is associated with aspergillosis, but the simultaneous presence of CMV viral interleukin-10 (cmvIL-10) and aspergillosis has never been investigated. CmvIL-10 is produced by CMV-infected cells and acts as an immune modulator during CMV infection. The aim of this study was to evaluate cmvIL-10 levels in peripheral blood and its influence on the clinical outcomes of Aspergillus infection. METHODS: Patients who visited or were admitted to the hospital with suspected Aspergillus infection, including invasive aspergillosis (IA) and chronic pulmonary aspergillosis (CPA), were prospectively enrolled. The cmvIL-10, human IL-10 (hIL-10), IL-1B, IL-6, IL-8, IFN-γ, and TNF-α levels in peripheral blood were measured. RESULTS: Patients with Aspergillus infection had a higher level of cmvIL-10 than the control group (158 ± 305 vs 27.9 ± 30.4 pg/ml, p < .05). The level of cmvIL-10 was not correlated with CMV viremia or end-organ disease. The cmvIL-10 but not hIL-10 level was positively correlated with the IFN-γ level (p < .05) and marginally negatively correlated with IL-1B and IL-8 levels (p < .1). In patients with CPA, a high level of cmvIL-10 (≥100 pg/ml) was a poor prognostic factor for long-term survival (p < .05). In contrast, CMV viremia or end-organ disease was associated with poor survival in patients with IA (p = .05). CONCLUSIONS: Aspergillus infection was associated with CMV coinfection with cmvIL-10 in blood. A cmvIL-10 concentration ≥100 pg/ml was a predictor for unfavourable outcome in CPA patients.

AIG1 affects in vitro and in vivo virulence in clinical isolates of Entamoeba histolytica.

The disease state of amebiasis, caused by Entamoeba histolytica, varies from asymptomatic to severe manifestations that include dysentery and extraintestinal abscesses. The virulence factors of the pathogen, and host defense mechanisms, contribute to the outcomes of infection; however, the underlying genetic factors, which affect clinical outcomes, remain to be fully elucidated. To identify these genetic factors in E. histolytica, we used Illumina next-generation sequencing to conduct a comparative genomic analysis of two clinical isolates obtained from diarrheal and asymptomatic patients (strains KU50 and KU27, respectively). By mapping KU50 and KU27 reads to the genome of a reference HM-1:IMSS strain, we identified two genes (EHI_089440 and EHI_176590) that were absent in strain KU27. In KU27, a single AIG1 (avrRpt2-induced gene 1) family gene (EHI_176590) was found to be deleted, from a tandem array of three AIG1 genes, by homologous recombination between the two flanking genes. Overexpression of the EHI_176590 gene, in strain HM-1:IMSS cl6, resulted in increased formation of cell-surface protrusions and enhanced adhesion to human erythrocytes. The EHI_176590 gene was detected by PCR in 56% of stool samples from symptomatic patients infected with E. histolytica, but only in 15% of stool samples from asymptomatic individuals. This suggests that the presence of the EHI_176590 gene is correlated with the outcomes of infection. Taken together, these data strongly indicate that the AIG1 family protein plays a pivotal role in E. histolytica virulence via regulation of host cell adhesion. Our in-vivo experiments, using a hamster liver abscess model, showed that overexpression or gene silencing of EHI_176590 reduced and increased liver abscess formation, respectively. This suggests that the AIG1 genes may have contrasting roles in virulence depending on the genetic background of the parasite and host environment.

Erratum: AIG1 affects in vitro and in vivo virulence in clinical isolates of Entamoeba histolytica.

[This corrects the article DOI: 10.1371/journal.ppat.1006882.].

Swimming Pool-Associated Vittaforma-Like Microsporidia Linked to Microsporidial Keratoconjunctivitis Outbreak, Taiwan.

We analyzed 2 batches of environmental samples after a microsporidial keratoconjunctivitis outbreak in Taiwan. Results indicated a transmission route from a parking lot to a foot washing pool to a swimming pool and suggested that accumulation of mud in the foot washing pool during the rainy season might be a risk factor.

Factors associated with isoniazid resistant tuberculosis among human immunodeficiency virus positive patients in Swaziland: a case-control study.

BACKGROUND: Isoniazid resistant tuberculosis is the most prevalent type of resistance in Swaziland and over two-thirds of the isoniazid resistant tuberculosis patients are tuberculosis and human immunodeficiency virus co-infected. The study aimed to determine risk factors associated with isoniazid resistant tuberculosis among human immunodeficiency virus positive patients in Swaziland. METHODS: This was a case-control study conducted in nine healthcare facilities across Swaziland. Cases were patients with isoniazid resistant tuberculosis (including 78 patients with isoniazid mono-resistant tuberculosis, 42 with polydrug-resistant tuberculosis, and 77 with multidrug-resistant tuberculosis). Controls were presumed drug-susceptible tuberculosis patients (n = 203). Multinomial logistic regression was used to determine related factors. RESULTS: The median time lag from diagnosis to tuberculosis treatment initiation was 50 days for isoniazid mono or poly drug-resistant tuberculosis, 17 days for multidrug-resistant tuberculosis compared to 1 day for drug-susceptible tuberculosis patients. History of previous tuberculosis treatment was positively associated with either isoniazid mono or poly drug-resistant tuberculosis (OR = 7.91, 95% CI: 4.14-15.11) and multidrug-resistant tuberculosis (OR = 12.20, 95% CI: 6.07-24.54). Isoniazid mono or poly resistant tuberculosis patients were more likely to be from rural areas (OR = 2.05, 95% CI: 1.23-3.32) and current heavy alcohol drinkers compared to the drug-susceptible tuberculosis group. Multi drug-resistant tuberculosis patients were more likely to be non-adherent to tuberculosis treatment compared to drug-susceptible tuberculosis group (OR = 3.01, 95% CI: 1.56-5.82). CONCLUSION: To prevent and control isoniazid resistant tuberculosis among HIV-positive patients in Swaziland, the tuberculosis program should strengthen the use of rapid diagnostic tests, detect resistance early, promptly initiate supervised tuberculosis treatment and decentralize quality tuberculosis services to the rural areas. Adherence to tuberculosis treatment should be improved.

Etiology and Risk Factors of Acute Gastroenteritis in a Taipei Emergency Department: Clinical Features for Bacterial Gastroenteritis.

BACKGROUND: The causative pathogen is rarely identified in the emergency department (ED), since the results of cultures are usually unavailable. As a result, antimicrobial treatment may be overused. The aim of our study was to investigate the pathogens, risk factors of acute gastroenteritis, and predictors of acute bacterial gastroenteritis in the ED. METHODS: We conducted a matched case-control study of 627 stool samples and 612 matched pairs. RESULTS: Viruses (41.3%) were the leading cause of gastroenteritis, with noroviruses (32.2%) being the most prevalent, followed by bacteria (26.8%) and Giardia lamblia (12.4%). Taking antacids (adjusted odds ratio [aOR] 4.10; 95% confidence interval [CI], 2.57-6.53), household members/classmates with gastroenteritis (aOR 4.69; 95% CI, 2.76-7.96), attending a banquet (aOR 2.29; 95% CI, 1.64-3.20), dining out (aOR 1.70; 95% CI, 1.13-2.54), and eating raw oysters (aOR 3.10; 95% CI, 1.61-5.94) were highly associated with gastroenteritis. Elders (aOR 1.04; 05% CI, 1.02-1.05), those with CRP >10 mg/L (aOR 2.04; 95% CI, 1.15-3.62), or those who were positive for fecal leukocytes (aOR 2.04; 95% CI, 1.15-3.62) or fecal occult blood (aOR 1.97; 95% CI, 1.03-3.77) were more likely to be hospitalized in ED. In addition, presence of fecal leukocytes (time ratio [TR] 1.22; 95% CI, 1.06-1.41), abdominal pain (TR 1.20; 95% CI, 1.07-1.41), and frequency of vomiting (TR 0.79; 95% CI, 0.64-0.98) were significantly associated with the duration of acute gastroenteritis. Presence of fecal leukocytes (aOR 2.08; 95% CI, 1.42-3.05), winter season (aOR 0.45; 95% CI, 0.28-0.74), frequency of diarrhea (aOR 1.69; 95% CI, 1.01-2.83), and eating shrimp or crab (aOR 1.53; 95% CI, 1.05-2.23) were highly associated with bacterial gastroenteritis. The area under the receiver operating characteristic curve of the final model was 0.68 (95% CI, 0.55-0.63). CONCLUSIONS: Acute bacterial gastroenteritis was highly associated with season, frequency of diarrhea, frequency of vomiting, and eating shrimp or crab.

First case of neurognathostomiasis in Taiwan--A Thai laborer presenting with eosinophilic meningitis and intracranial hemorrhage.

We report a case of neurognathostomiasis in a Thai laborer for the first time in Taiwan. For patients with eosinophilic meningitis, neurognathostomiasis should be considered when brain image discloses subarachnoid or intracranial hemorrhage and when an appropriate exposure risk is available, especially a history of raw freshwater fish consumption in endemic areas, even a long time ago.

A novel application of real-time RT-LAMP for body fluid identification: using HBB detection as the model.

We report on a novel application of real-time reverse transcription-loop-mediated isothermal amplification (real-time RT-LAMP) to identify the presence of a specific body fluid using blood as a proof-of-concept model. By comparison with recently developed methods of body fluid identification, the RT-LAMP assay is rapid and requires only one simple heating-block maintained at a single temperature, circumventing the need for dedicated equipment. RNA was extracted from different body fluids (blood, semen, saliva, menstrual blood, sweat, and urine) for use in real-time RT-LAMP reaction. The 18S rRNA locus was used as the internal control and hemoglobin beta (HBB) as the blood-specific marker. Reverse transcription and LAMP reaction were performed in the same tube using a turbidimeter for real-time monitoring the reaction products within a threshold of 60 min. HBB LAMP products were only detected in blood and not in any of the other body fluid, but products from the 18S rRNA gene were detected in all the tested body fluids as expected. The limit of detection was a minimum of 10(-5) ng total RNA for detection of both 18S rRNA and HBB. Augmenting the detection of RT-LAMP products was performed by separation of the products using gel electrophoresis and collecting the fluorescence of calcein. The data collected indicated complete concordance with the body fluid tested regardless of the method of detection used. This is the first application of real-time RT-LAMP to detect body fluid specific RNA and indicates the use of this method in forensic biology.

The hMLH1 -93G>A promoter polymorphism is associates with outcomes in oral squamous cell carcinoma patients.

BACKGROUND: The aim of this study was to investigate the impact of hMLH1 polymorphisms on treatment outcomes in patients with oral squamous cell carcinoma (OSCC). METHODS: Genotypings were performed by direct DNA sequencing in peripheral blood leukocytes from 185 male OSCC patients. Patients received primary surgery with or without adjuvant radiotherapy. Two hMLH1 tag single nucleotide polymorphisms (SNPs)-rs1800734 (-93G>A in the promoter) and rs1540354 (in the third intron)-were chosen from the HapMap project. Overall survival (OS) and disease-free survival (DFS) were compared between different genotypes. RESULTS: The hMLH1 rs1800734 and rs1540354 polymorphisms were in weak linkage disequilibrium (r (2) = 0.456). OSCC patients with the rs1800734 AA genotype had a significantly poor prognosis in both OS and DFS. This SNP can also predict the outcomes of OSCC patients with postoperative adjuvant radiotherapy, especially in advanced stage; however, no significant differences in patient outcomes were found for the hMLH1 rs1540354 genotypes. CONCLUSIONS: Our results demonstrate that the hMLH1 -93G>A SNP is found to be associated with patient outcomes in OSCC. This SNP can also predict their treatment outcome of radiotherapy.

Serpin peptidase inhibitor, clade E, member 2 is associated with malignant progression and clinical prognosis in oral squamous cell carcinoma.

Background/purpose: The serpin peptidase inhibitor, clade E, member 2 (SERPINE2), is upregulated in breast cancer, prostate cancer, and urothelial carcinoma; however, limited information exists regarding its expression in oral cancer. Therefore, this study aimed to analyze the association between SERPINE2 expression and oral squamous cell carcinoma (OSCC) outcomes. Materials and methods: SERPINE2 mRNA and protein expression in patients with head and neck squamous cell carcinoma and OSCC were investigated using online databases and tissue-array analysis. Its relationship with clinicopathological characteristics, OSCC prognosis and its biological function in OSCC cells were explored. Results: Analysis using online databases revealed higher SERPINE2 expression in tumor tissues and its role as a prognostic factor. High SERPINE2 protein levels were significantly correlated with adverse pathological parameters, including advanced clinical stage and tumor status (P < 0.001), lymph nodes (P = 0.014), and distant metastases (P = 0.013). High SERPINE2 expression was associated with worse overall survival (P < 0.001) and was identified as an independent prognostic factor for OSCC. In vitro studies revealed that SERPINE2 knockdown significantly reduced cell proliferation, migration, and invasion in OSCC cell lines. Conclusion: This study suggests that SERPINE2 may serve as a prognostic biomarker and potential therapeutic target for oral cancer.

A fatal case of Naegleria fowleri meningoencephalitis in Taiwan.

After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.

Application of loop-mediated isothermal amplification for malaria diagnosis during a follow-up study in São Tomé.

BACKGROUND: A reliable and simple test for the detection of malaria parasite is crucial in providing effective treatment and therapeutic follow-up, especially in malaria elimination programmes. A comparison of four methods, including nested polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) were used for the malaria diagnosis and treatment follow-up in São Tomé and Príncipe, during a successful pre-elimination campaign. METHOD: During the period September to November 2009, blood samples from 128 children (five to 14 years old) with temperature ≥38°C (tympanic) in the District of Agua Grande were examined using four different methods, i.e., histidine-rich protein 2 (HRP-2) based rapid diagnostic tests (HRP-2-RDTs), optical microscopy, nested PCR, and LAMP. First-line treatment with artesunate-amodiaquine was given for uncomplicated malaria and intravenous quinine was given for complicated malaria. Children with persistent positivity for malaria by microscopy, or either by nested PCR, or by LAMP on day 7 were given second-line treatment with artemether-lumefantrine. Treatment follow-up was made weekly, for up to four weeks. RESULTS: On day 0, positive results for HRP-2-RDTs, microscopy, nested PCR, and LAMP, were 68(53%), 47(37%), 64(50%), and 65(51%), respectively. When nested PCR was used as a reference standard, only LAMP was comparable; both HRP-2-RDTs and microscopy had moderate sensitivity; HRP-2-RDTs had poor positive predictive value (PPV) and a moderate negative predictive value (NPV) for the treatment follow-up. Seventy-one children with uncomplicated malaria and eight children with complicated falciparum malaria were diagnosed based on at least one positive result from the four tests as well as clinical criteria. Twelve of the 79 children receiving first-line treatment had positive results by nested PCR on day 7 (nested PCR-corrected day 7 cure rate was 85%). After the second-line treatment, nested PCR/LAMP-corrected day 28 cure rate was 83% for these 12 children. CONCLUSIONS: HRP-2-RDTs have similar sensitivity as microscopy but less specificity. However, as compared to nested PCR, the poor sensitivity of HRP-2-RDTs indicates that low parasitaemia may not be detected after treatment, as well as the low specificity of HRP-2-RDTs indicates it cannot be applied for treatment follow-up. LAMP has similar sensitivity and specificity to nested PCR. With high PPV and NPV, LAMP is simpler and faster as compared to nested PCR with the advantage of detecting low parasitaemia becoming a potential point-of-care test for treatment follow-up.

Molecular detection and comparison of Acanthamoeba genotypes in different functions of watersheds in Taiwan.

The protistan genus Acanthamoeba is a free-living amoeba existing in various environments. Within this protistan genus, there are some species recognized as potential human pathogens, which may cause granulomatous amoebic encephalitis, Acanthamoeba keratitis and chronic granulomatous lesions of the skin. In this study, 211 water samples were collected from two watersheds in southern Taiwan. We detected Acanthamoeba based on the PCR amplification with a genus-specific primer pair and investigation of Acanthamoeba in Puzih River and Kaoping River in southern Taiwan. Acanthamoeba species were detected in 34 (16.1%) samples. The presence or absence of Acanthamoeba within the water samples showed significant difference with the levels of water temperature and total coliforms. The most frequently identified Acanthamoeba genotype was T4 (n = 19), followed by T5 (n = 8), and then T15 (n = 3). Genotype T6, T7/T8, T11 and T12 were all detected once. Genotype T4, T5, T6, T11 and T15 of Acanthamoeba are responsible for Acanthamoeba keratitis and should be considered a potential health threat associated with human activities in environmental surface water watersheds.

Prevalence, diversity and public health implications of Helicobacter species in pet and stray dogs.

Background: It is probable that humans can acquire H. pylori and non-H. pylori Helicobacter infections via domestic animals. The prevalence and risk factors of infections of Helicobacter species in canines of Taipei city were therefore analysed in this study. Materials and methods: A total of 95 canine faecal samples were collected from different animal shelters and hospitals in Taipei city. Total DNA was extracted for semi-nested PCR detection of Helicobacter species. The PCR products were sequenced for further comparative database and phylogenetic analyses. Results: The overall prevalence of Helicobacter species in canines of Taipei city was 75.79% (72/95). Two gastric, seven enterohepatic and two unclassified Helicobacter species were identified, all of which have been implicated in the aetiology of human diseases. The predominant species detected included H. canis (27.78%), H. pylori (26.39%), H. canicola (18.06%), and H. bilis (13.89%) in decreasing order, while H. canadensis and H. typhlonius were identified for the first time in canines. The genotypes in H. pylori and H. canicola clusters grouped together, with their respective reference strains, showed a close evolutionary distance in the phylogenetic tree, indicating a common ancestry may have existed in these clusters respectively. The residential region of canines, dog living status (pet or stray) and breed (purebred or mixed-breed) are the risk factors associated with Helicobacter infections in the canines examined. Conclusion: The high prevalence of Helicobacter infections in canines highlights a potential public health risk of zoonotic transmission among dogs, humans and other animals, and therefore, the need for proper methods in controlling the transmission routes. In addition, the 16S rRNA gene amplification method was found to be useful for bacterial identification and phylogenetic analysis.

The cecropin-prophenoloxidase regulatory mechanism is a cross-species physiological function in mosquitoes.

This study's aim was to investigate whether the cecropin-prophenoloxidase regulatory mechanism is a cross-species physiological function among mosquitoes. BLAST and phylogenetic analysis revealed that three mosquito cecropin Bs, namely Aedes albopictus cecropin B (Aalcec B), Armigeres subalbatus cecropin B2 (Ascec B2), and Culex quinquefasciatus cecropin B1 (Cqcec B1), play crucial roles in cuticle formation during pupal development via the regulation of prophenoloxidase 3 (PPO 3). The effects of cecropin B knockdown were rescued in a cross-species manner by injecting synthetic cecropin B peptide into pupae. Further investigations showed that these three cecropin B peptides bind to TTGG(A/C)A motifs within each of the PPO 3 DNA fragments obtained from these three mosquitoes. These results suggest that Aalcec B, Ascec B2, and Cqcec B1 each play an important role as a transcription factor in cuticle formation and that similar cecropin-prophenoloxidase regulatory mechanisms exist in multiple mosquito species.

Genetic typing, based on the 56-kilodalton type-specific antigen gene, of Orientia tsutsugamushi strains isolated from chiggers collected from wild-caught rodents in Taiwan.

Orientia tsutsugamushi is the etiological agent of scrub typhus, a mite-borne, febrile illness that occurs in the Asia-Pacific region. We conducted strain characterization of O. tsutsugamushi isolates from chiggers obtained from rodents based the nucleotide sequence of the 56-kDa outer membrane protein gene. With the use of PCR, a total of 68 DNA sequences of 56-kDa antigen genes were amplified. Phylogenetic analysis revealed that there were at least six definable clusters among the 68 isolates: 37% Karp-related strains (25/68), 27% TA763 strains (18/68), 12% JG-related strains (8/68), 19% Kato-related strains (13/68), 4% divergent strains (3/68), and 1% representing a Gilliam prototype strain (1/68). Overall, the O. tsutsugamushi genotypes exhibited a high degree of diversity, similar to that seen in strains from the rest of the areas where scrub typhus is endemic. Moreover, the 56-kDa protein sequence similarity between O. tsutsugamushi isolates from mites and those from human patients (H. Y. Lu et al., Am. J. Trop. Med. Hyg. 83:658-663, 2010) were striking, thus highlighting potential risk factors for this emerging zoonotic disease.

Efficient nested-PCR-based method development for detection and genotype identification of Acanthamoeba from a small volume of aquatic environmental sample.

Acanthamoeba spp. are opportunistic human pathogens that cause granulomatous amoebic encephalitis and keratitis, and their accurate detection and enumeration in environmental samples is a challenge. In addition, information regarding the genotyping of Acanthamoeba spp. using various PCR methods is equally critical. Therefore, considering the diverse niches of habitats, it is necessary to develop an even more efficient genotyping method for Acanthamoeba spp. detection. This study improved the sensitivity of detection to avoid underestimation of Acanthamoeba spp. occurrence in aquatic environmental samples, and to accurately define the pathogenic risk by developing an efficient PCR method. In this study, a new nested genotyping method was established and compared with various PCR-based methods using in silico, lab, and empirical tests. The in silico test showed that many PCR-based methods could not successfully align specific genotypes of Acanthamoeba, except for the newly designed nested PCR and real-time PCR method. Furthermore, 52 water samples from rivers, reservoirs, and a river basin in Taiwan were analysed by six different PCR methods and compared for genotyping and detection efficiency of Acanthamoeba. The newly developed nested-PCR-based method of genotyping was found to be significantly sensitive as it could effectively detect the occurrence of Acanthamoeba spp., which was underestimated by the JDP-PCR method. Additionally, the present results are consistent with previous studies indicating that the high prevalence of Acanthamoeba in the aquatic environment of Taiwan is attributed to the commonly found T4 genotype. Ultimately, we report the development of a small volume procedure, which is a combination of recent genotyping PCR and conventional real-time PCR for enumeration of aquatic Acanthamoeba and acquirement of biologically meaningful genotyping information. We anticipate that the newly developed detection method will contribute to the precise estimation, evaluation, and reduction of the contamination risk of pathogenic Acanthamoeba spp., which is regularly found in the water resources utilised for domestic purposes.

Development of loop-mediated isothermal amplification assay for detection of Entamoeba histolytica.

A novel one-step, closed-tube, loop-mediated isothermal amplification (LAMP) assay for detecting Entamoeba histolytica, one of the leading causes of morbidity in developing countries, was developed. The sensitivity of the LAMP assay is 1 parasite per reaction. A total of 130 clinical samples were analyzed, and the results compared with those of conventional nested PCR to validate the practicability of this assay. No DNA was amplified from other diarrheal pathogens, such as other Entamoeba species, bacteria, and viruses. These results indicate that LAMP is a rapid, simple, and valuable diagnostic tool for epidemiological studies of amebiasis.