A comparison of Kato-Katz technique to three other methods for diagnosis of Amphimerus spp. liver fluke infection and the prevalence of infection in Chachi Amerindians of Ecuador

Background Recently, a high prevalence of infection by the liver fluke Amphimerus spp. has been documented in the Chachi Amerindians of Ecuador. For diagnosis, no studies exist that compare the sensitivity of different coproparasitological detection techniques. The present study compares the Kato-Katz technique with three other coproparasitological methods for detecting eggs of Amphimerus in stools, as well as determines the prevalence of infection in Chachi residents in a Tropical rain forest area in the northwest coast of Ecuador. Methodology/Results A total of 105 samples, utilizing the Kato-Katz technique (KK), the spontaneous sedimentation technique in tube (SSTT), the formalin-ether concentration technique (FEC), and direct smear microscopy (DM), were examined. Combining the four methods (fixed ªgoldº standard), 38 samples were positive with a prevalence of infection of 36.2%. The sensitivities of individual methods were 71%, 58%, 50% and 3% for KK, SSTT, FEC, and DM respectively. Our results indicated that KK alone had the best performance, detecting 27 (71%) of the 38 positive samples. The combination of KK and SSTT detected amphimeriasis in 36 (95%) samples, and KK and FEC in 31 (82%) samples. Conclusions DM showed the lowest sensitivity, which raises concern for its value, because it is the standard technique for stool examination for detection of parasites in both public and private laboratories in Ecuador. SSTT alone detected eggs in 22 samples (58%) and would be recommended for field studies because of its simplicity. Performing two techniques on a single sample enhances the detection of Amphimerus infection. Its sensitivity is relative to a fixed ªgoldº standard, determined as the combined results of the four techniques performed. This study confirms the high prevalence of human infection by Amphimerus in the indigenous Chachi group where the first human cases were described.CUP 91750000.0000.374072KAKENHI: Grant No.16H0582

Hypolobocera guayaquilensis (Decapoda: Pseudothelphusidae): A New Crab Intermediate Host of Paragonimus mexicanus in Manabí Province, Ecuador

To determine that Paragonimus sp. is actively transmitted in a tropical area of the Pacific region of Ecuador where human cases of pulmonary paragonimiasis have recently been documented, a total of 75 freshwater crabs were collected from 2 different streams in the Pedernales area of Manabí Province, Ecuador. All collected crabs were identified as Hypolobocera guayaquilensis based on morphological characteristics of the male gonopods. The hepatopancreas of each crab was examined by compressing it between 2 glass plates followed by observation under a stereomicroscope. Excysted Paragonimus metacercariae were detected in 39 (52.0%) crabs and their densities varied from 1 to 32 per infected crab. There was a positive relationship between crab size and metacercarial density. Sequences of the second internal transcribed spacer region of the ribosomal RNA gene of the Paragonimus metacercariae obtained in this study were identical to those of Paragonimus mexicanus deposited in the DDBJ/EMBL/GenBank database. Thus, the present study is the first to confirm that the crab species H. guayaquilensis is the second intermediate host of P. mexicanus in Manabí Province, Ecuador. Because this crab might be the possible source of human infections in this area, residents should pay attention to improper crab-eating habits related with a neglected parasitic disease, i.e., paragonimiasis

Leishmania species and clinical characteristics of Pacific and Amazon cutaneous leishmaniasis in Ecuador and determinants of health-seeking delay: a cross-sectional study

Ecuador; Leishmaniasis; PhylogenyEquador; Leishmaniosi; FilogèniaEcuador; Leishmaniosis; FilogeniaBackground Cutaneous Leishmaniasis (CL) affects up to 5.000 people in Ecuador each year. L. guyanensis and L. braziliensis are the most common of the eight CL-causing Leishmania species. Earlier CL research concentrated on the easily accessible Pacific region. This study aims to describe the Leishmania species in Pacific and Amazon ecoregions, to analyze regional differences in CL patient clinical presentation, and to identify determinants of health-seeking delay. Methods All cases in this cross-sectional study were diagnosed using smear slide microscopy, PCR, or both. Cytochrome B gene sequencing was used to identify the causative Leishmania species in qPCR-positive samples. Results This study included 245 patients, with 154 (63%) infected in the Pacific region and 91 (37%) infected in the Amazon. Causative Leishmania species were identified in 135 patients (73% of qPCR positives). L. guyanensis was identified in 76% (102/135) of the samples and L. braziliensis in 19% (26/135). The Pacific region had a low prevalence of 6% (5/89) of L. braziliensis. For the first time, we report L. guyanensis from the central Amazon, L. braziliensis from the northern Pacific, and L. lainsoni from both the central Amazon and northern Pacific. Amazon cases had a longer median health-seeking delay in months (2.0, IQR 3.0) than Pacific cases (1.0, IQR 1.5). Prolonged health-seeking delay was associated with older age, Amerindian ethnicity, infection at lower altitudes, non-ulcerative lesions, and lesions on the lower limbs. Conclusions In the Pacific region, health-seeking delay is relatively short and L. braziliensis prevalence remains low. Limited access to health care and stigma might explain the prolonged health-seeking delay in the Amazon. We recommend larger studies on the distribution of Leishmania species in Amazon CL cases and additional regional research into diagnostic test accuracy. Furthermore, the determinants of health-seeking delay in Ecuador should be investigated further.Foundation Latin Link Nederland provided funding for the current study

Detection and identification of Leishmania species within naturally infected sand flies in the Andean areas of Ecuador by a polymerase chain reaction

The surveillance of prevalent Leishmania and sand fly species in endemic areas is important for prediction of the risk and expansion of leishmaniasis. In this study, we developed a polymerase chain reaction (PCR)-based method for detection of Leishmania minicircle DNA within individual sand flies. Using this method, we detected minicircle DNA in 6 (3.3%) of 183 sand flies, while 5 (3.5%) of 143 were positive for Leishmania promastigotes in the same areas by microscopic examination. The species were identified as Leishmania (Leishmania) mexicana by nucleotide sequencing of the cytochrome b gene. Additionally, all the Leishmania-positive sand flies were identified as Lutzomyia ayacuchensis by the restriction enzyme digestion of the PCR-amplified 18S ribosomal RNA gene fragments. Since this combined method is relatively easy and can process a large number of samples, it will be a powerful tool for the rapid identification of prevalent sand fly and Leishmania species as well as monitoring the infection rate in sand fly populations in endemic areas.Fil: Kato, Hirotomo. Yamaguchi University; JapónFil: Uezato, Hiroshi. University of the Ryukyus; JapónFil: Katakura, Ken. Hokkaido University; JapónFil: Calvopina, Manuel. Kochi University. Kochi Medical School; JapónFil: Marco, Jorge Diego. Kochi University. Kochi Medical School; Japón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Barroso, Paola Andrea. Kochi University. Kochi Medical School; Japón. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Gomez, Eduardo. Universidad Católica de Guayaquil; EcuadorFil: Mimori, Tatsuyuki. Kumamoto University; JapónFil: Korenaga, Masataka. Kochi University. Kochi Medical School; JapónFil: Iwata, Hiroyuki. Yamaguchi University; JapónFil: Nonaka, Shigeo. University ok the Ryukyus; JapónFil: Hashiguchi, Yoshihisa. Kochi University. Kochi Medical School; Japó

Diagnostic accuracy of qPCR and microscopy for cutaneous leishmaniasis in rural Ecuador: A Bayesian latent class analysis

Precisión diagnóstica; Leishmaniasis cutánea; Ecuador ruralPrecisió diagnòstica; Leishmaniosi cutània; Equador ruralDiagnostic accuracy; Cutaneous leishmaniasis; Rural EcuadorBackground Clinical and laboratory diagnosis of cutaneous leishmaniasis (CL) is hampered by under-ascertainment of direct microscopy. Methods This study compared the diagnostic accuracy of qPCR on DNA extracted from filter paper to the accuracy of direct smear slide microscopy in participants presenting with a cutaneous lesion suspected of leishmaniasis to 16 rural healthcare centers in the Ecuadorian Amazon and Pacific regions, from January 2019 to June 2021. We used Bayesian latent class analysis to estimate test sensitivity, specificity, likelihood ratios (LR), and predictive values (PV) with their 95% credible intervals (95%CrI). The impact of sociodemographic and clinical characteristics on predictive values was assessed as a secondary objective. Results Of 320 initially included participants, paired valid test results were available and included in the diagnostic accuracy analysis for 129 from the Amazon and 185 from the Pacific region. We estimated sensitivity of 68% (95%CrI 49% to 82%) and 73% (95%CrI 73% to 83%) for qPCR, and 51% (95%CrI 36% to 66%) and 76% (95%CrI 65% to 86%) for microscopy in the Amazon and Pacific region, respectively. In the Amazon, with an estimated disease prevalence among participants of 73%, negative PV for qPCR was 54% (95%CrI 5% to 77%) and 44% (95%CrI 4% to 65%) for microscopy. In the Pacific, (prevalence 88%) the negative PV was 34% (95%CrI 3% to 58%) and 37% (95%CrI 3% to 63%). The addition of qPCR parallel to microscopy in the Amazon increases the observed prevalence from 38% to 64% (+26 (95%CrI 19 to 34) percentage points). Conclusion The accuracy of either qPCR on DNA extracted from filter paper or microscopy for CL diagnosis as a stand-alone test seems to be unsatisfactory and region-dependent. We recommend further studies to confirm the clinically relevant increment found in the diagnostic yield due to the addition of qPCR

Liver fluke infections by Amphimerus sp. (Digenea: Opisthorchiidae) in definitive and fish intermediate hosts in Manabí province, Ecuador

This work is licensed under a Creative Commons Attribution 4.0 International License.Amphimerus sp. is a fluke that dwells in the biliary tracts of vertebrate definitive hosts including humans, domestic, and wild mammals in Latin America. Opisthorchiid liver infections are rarely studied in the Americas confirming its status as a neglected tropical disease. In Ecuador, small trematode eggs were reported in human cases from the province of Manabí in 1949, and recently, Amphimerus sp. adults were recovered from human and reservoir hosts in the province of Esmeraldas. Due to the lack of research on the infectious sources of Amphimerus sp. in the continent, we have developed a series of epidemiological studies with parasitological and molecular techniques to elucidate the endemicity of opisthorchiid fluke infections. We developed a cross-sectional study in three communities at Pedro Pablo Gómez parish in the province of Manabí, Ecuador. We examined a total of 176 fecal samples to detect opisthorchiid eggs, and four fish species to find opisthorchiid metacercariae. To study adult worms, we treated and purged seven patients in a family and dissected the livers of a dog and a cat infected. We observed morphological features of adults and metacercariae and used polymerase chain reaction with restricted fragment length polymorphism (PCR-RFLP) and DNA sequencing of a section of the ITS2 gene for identification. Small trematode eggs were detected in 63 (35.8%) out of 176 fecal samples of residents in the three study sites. Adult opisthorchiid flukes were recovered from human patients, a dog and a cat, and they were morphologically and molecularly identified as Amphimerus sp. Opisthorchiid metacercariae were also identified molecularly as Amphimerus sp. in four fish species, i.e., Rhoadsia altipinna, Bryconamericus bucay, Andinoacara rivulatus, and Piabucina aureoguttata. Metacercariae of the heterophyid Haplorchis pumilio were also found in the four fish species examined. This is the first study to confirm the current endemicity of Amphimerus sp. in Pedro Pablo Gómez, Manabí, Ecuador. The adult worms isolated here shared morphological characteristics with previous Amphimerus sp. descriptions and were molecularly similar to Amphimerus sp. described in the province of Esmeraldas. Moreover, this study is the first to document four fish species as infection sources of Amphimerus sp. detected via a molecular protocol targeting the metacercariae of the parasite. Fish species identified here should be targeted for public health campaigns to avoid further human liver-fluke infections by Amphimerus sp. or potential intestinal-fluke infections by H. pumilio or others.Japan Society for the Promotion of Science (25305011 and 16H05820)Emerging and Re-emerging Infectious Diseases from the Ministry of Health, Labour and Welfare, Japanese government (H23-Shinko-ippan-014 and H26-Shinko-ippan-009)Japan Agency for Medical Research and Development (20fk0108136j0101)Dirección General de Investigaciones, Universidad de las Américas, Quit

Leishmania isoenzyme polymorphisms in Ecuador: Relationships with geographic distribution and clinical presentation

Background: Determinants of the clinical presentation of the leishmaniases are poorly understood but Leishmania species and strain differences are important. To examine the relationship between clinical presentation, species and isoenzyme polymorphisms, 56 Leishmania isolates from distinct presentations of American tegumentary leishmaniasis (ATL) from Ecuador were analyzed. Methods: Isolates were characterized by multilocus enzyme electrophoresis for polymorphisms of 11 isoenzymes. Patients were infected in four different ecologic regions: highland and lowland jungle of the Pacific coast, Amazonian lowlands and Andean highlands. Results: Six Leishmania species constituting 21 zymodemes were identified: L. (Viannia) panamensis (21 isolates, 7 zymodemes), L. (V.) guyanensis (7 isolates, 4 zymodemes), L. (V.) braziliensis (5 isolates, 3 zymodemes), L. (Leishmania) mexicana (11 isolates, 4 zymodemes), L. (L.) amazonensis (10 isolates, 2 zymodemes) and L. (L.) major (2 isolates, 1 zymodeme). L. panamensis was the species most frequently identified in the Pacific region and was associated with several clinical variants of cutaneous disease (CL); eight cases of leishmaniasis recidiva cutis (LRC) found in the Pacific highlands were associated with 3 zymodemes of this species. Mucocutaneous leishmaniasis found only in the Amazonian focus was associated with 3 zymodemes of L. braziliensis. The papular variant of CL, Uta, found in the Andean highlands was related predominantly with a single zymodeme of L. mexicana. Conclusion: Our data show a high degree of phenotypic variation within species, and some evidence for associations between specific variants of ATL (i.e. Uta and LRC) and specific Leishmania zymodemes. This study further defines the geographic distribution of Leishmania species and clinical variants of ATL in Ecuador

miRNA-Seq identifies a serum miRNA panel, which combined with APRI can detect and monitor liver disease in paediatric Cystic Fibrosis

Cystic fibrosis (CF)-associated liver disease (CFLD) is a hepatobiliary complication of CF. Current diagnostic modalities rely on non-specific assessments, while liver biopsy is the gold standard to assess severity of fibrosis. MicroRNAs (miRNAs) regulate liver disease pathogenesis and are proposed as diagnostic biomarkers. We investigated the combined use of serum miRNAs and aspartate aminotransferase to platelet ratio (APRI) to diagnose and assess CFLD severity. This was a cross-sectional cohort study of the circulatory miRNA signature of 124 children grouped by clinical, biochemical and imaging assessments as follows: CFLD (n=44), CF patients with no evidence of liver disease (CFnoLD, n=40) and healthy controls (n=40). Serum miRNAs were analysed using miRNA-sequencing. Selected differentially expressed serum miRNA candidates were further validated by qRT-PCR and statistical analysis performed to evaluate utility to predict CFLD and fibrosis severity validated by liver biopsy, alone or in combination with APRI. Serum miR-122-5p, miR-365a-3p and miR-34a-5p levels were elevated in CFLD compared to CFnoLD, while miR-142-3p and let-7g-5p were downregulated in CFLD compared to CFnoLD. Logistic regression analysis combining miR-365a-3p, miR-142-3p and let-7g-5p with APRI showed 21 times greater odds of accurately predicting liver disease in CF with an AUROC=0.91 (sensitivity=83%, specificity=92%;

A collaboratively derived environmental research agenda for Galapagos

Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation. This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced. </jats:p

In Vitro and In Vivo Efficacy of Ether Lipid Edelfosine against Leishmania spp. and SbV-Resistant Parasites

Leishmaniasis represents a major international health problem, has a high morbidity and mortality rate, and is classified as an emerging and uncontrolled disease by the World Health Organization. The migration of population from endemic to nonendemic areas, and tourist activities in endemic regions are spreading the disease to new areas. Unfortunately, treatment of leishmaniasis is far from satisfactory, with only a few drugs available that show significant side-effects. Here, we show in vitro and in vivo evidence for the antileishmanial activity of the ether phospholipid edelfosine, being effective against a wide number of Leishmania spp. causing cutaneous, mucocutaneous and visceral leishmaniasis. Our experimental mouse and hamster models demonstrated not only a significant antileishmanial activity of edelfosine oral administration against different wild-type Leishmania spp., but also against parasites resistant to pentavalent antimonials, which constitute the first line of treatment worldwide. In addition, edelfosine exerted a higher antileishmanial activity and a lower proneness to generate drug resistance than miltefosine, the first drug against leishmaniasis that can be administered orally. These data, together with our previous findings, showing an anti-inflammatory action and a very low toxicity profile, suggest that edelfosine is a promising orally administered drug for leishmaniasis, thus warranting clinical evaluation