José Guillermo Esteban

Hyperendemic human fascioliasis in Andean valleys: an altitudinal transect analysis in children of Cajamarca province, Peru.

A coprological survey including 476 2-18 year old school children from six rural localities between 2627 and 3061 m altitude was performed in Cajamarca province, Peru. Prevalences of fascioliasis ranging from 6.7 to 47.7% (mean 24.4%) proved to be the highest so far recorded in that human hyperendemic area. Higher prevalences in females and in the 2-5 year old group were not significant. Intensities ranged from 24 to 864 eggs per gram (arithmetic mean: 113; geometric mean: 68), the majority shedding less than 100, and without significant differences according to gender or age group. Fasciola hepatica was the most common helminth within a spectrum of 11-12 protozoan and 9-11 helminth species, 97.3% of the children showing infection with at least one parasite. The highest levels corresponded to coinfection with seven different species in females and subjects older than 5 years. Fascioliasis prevalence correlation with altitude appeared significant. An epidemiological characterisation of the valley transmission pattern of fascioliasis in Cajamarca is made by comparison with other better known hyperendemic areas. Results suggest that human fascioliasis may be widespread throughout different parts of Cajamarca province, even far away from the city, and that long-term fascioliasis chronicity and superimposed repetitive infections may be probably frequent.

Echinostomes: systematics and life cycles

This chapter provides a review of the most significant literature in the last decade on the systematics and biology of echinostomes and echinostome-like digeneans. This review is primarily concerned with members of the genus Echinostoma, although members of other genera (Echinoparyphium, Echinochasmus, Himasthla, Hypoderaeum, Petasiger, Euparyphium, Stephanoprora, Isthmiophora, and Acanthoparyphium) and echinostome-related genera (Parorchis, Philophthalmus and Ribeiroia) are also considered. The literature on molecular systematics and morphometrics of these trematodes is reviewed. Specific mention is made of the life cycle patterns of echinostome and echinostome-like digeneans along with an overview of recent advances on different topics in the biology of these trematodes; the review covers various aspects of the different stages of these organisms, i.e., free-living stages (miracidia and cercariae), and parasitic stages in the invertebrate hosts (sporocysts, rediae, and metacercariae) and vertebrate hosts (adults).

Proteomic analysis of the pinworm Syphacia muris (Nematoda: Oxyuridae), a parasite of laboratory rats

Syphacia muris (Nematoda: Oxyuridae) is a ubiquitous nematode that commonly infects rats in the laboratory which can interfere in the development of biological assays. The somatic extract of S. muris adults collected from infected rats was investigated using a proteomic approach. A shot-gun liquid chromatography/tandem mass spectrometry procedure was used. We used the MASCOT search engine (Matrix-Science) and ProteinPilot software v2.0 (Applied Biosystems) for the database search. A total of 359 proteins were accurately identified from the worms. The largest protein families consisted of metabolic enzymes and those involved in the nucleic metabolism and cell cycle. Proteins of transmembrane receptors and those involved in protein metabolism, chaperones, structural and motor, signalling and calcium-binding proteins also were identified in the proteome of S. muris. Proteome array of S. muris may contribute to further elucidation of biological system of S. muris as well as host-parasite relationships.

Helminth parasites in faecal samples from the endangered Iberian lynx (Lynx pardinus)

The Iberian lynx is the most endangered felid in the world. Enteropathogens may threaten its survival, and therefore we analysed faecal samples from 66 different individuals (37 males and 29 females), the largest population representation studied to date. The samples were obtained from November 2005 to October 2008 in the two areas where the Iberian lynx survives: Sierra Morena and Doñana (Andalusia, southern Spain). A total of 56.1% samples were parasitized with at least 6 species of helminths, including two cestodes (Hymenolepis spp. and Taenia spp.) and four Nematodes (Ancylostoma spp., Toxocara spp., Toxascaris leonina, and Capillaria sp.). In this work, the presence of Hymenolepis is reported for the first time in Lynx pardinus. The relevance of our findings is discussed focussed on the conservation of this endangered felid.

Association between enteric protozoan parasites and gastrointestinal illness among HIV- and tuberculosis-infected individuals in the Chowke district, southern Mozambique

Human immune deficiency virus (HIV) and tuberculosis (TB) infections remain major public health issues globally, particularly in sub-Saharan Africa. Impairment of both cell-mediated and humoral immunity by HIV and/or TB infections may limit the hosts defences against other pathogens, including the diarrheagenic protozoan Cryptosporidium spp., Giardia intestinalis, and Entamoeba histolytica. During September-December 2015 a cross-sectional study was conducted to assess the prevalence and molecular diversity of these enteric parasites among HIV- and/or TB-infected patients at a medical reference centre in Chowke district, southern Mozambique. A total of 99 stool specimens were initially screened by direct microscopy and further confirmed and characterised by molecular methods. DNA sequence analyses of the genes encoding the small subunit ribosomal RNA and the 60-kDa glycoprotein were used for the typing and sub-typing of Cryptosporidium isolates, respectively. G. intestinalis-positive isolates by real-time PCR were subsequently typed at the glutamate dehydrogenase locus. Differential diagnosis of E. histolytica/dispar was achieved by real-time PCR. G. intestinalis (8.1%) was the enteric protozoan more frequently detected, followed by Cryptosporidium spp. (7.1%), and Entamoeba histolytica/dispar (6.1%). Two HIV-infected (but not TB-infected) patients harbour G. intestinalis and Cryptosporidium spp. co-infections. Two (29%) G. intestinalis isolates were successfully characterised, revealing the presence of known AII and novel BIV genotypes. Four (57%) Cryptosporidium isolates were unmistakeable assigned to C. hominis, identifying two (IbA10G2 and IdA22) sub-types. Cryptosporidium infections were not associated to diarrhoea in HIV-positive patients, probably because improved immune function in the affected individuals due to antiretroviral therapy. G. intestinalis was considered a non-opportunistic pathogen, whereas the presence of E. histolytica could not be confirmed by molecular methods. Based on their common presence in the studied clinical population, we recommend the effective diagnosis and treatment of these enteropathogens for improving the management of HIV and TB patients.

Hookworm-like eggs in children's faecal samples from a rural area of Rwanda

BACKGROUNDnHookworm eggs identification and quantification is usually carried out by Kato-Katz method. However various structures present in the smear may be confused with eggs of such parasites.nnnOBJECTIVEnTo document the presence of structures in Kato-Katz slides that could initially be misinterpreted as hookworm eggs.nnnMETHODn497 faecal samples were analysed by Kato-Katz technique, diphasic concentration technique, agar-plate coprocultive and larvae obtained were analysed by PCR and characterized by sequencing.nnnRESULTnHookworm-like eggs were found in 159 (32%) of the samples by Kato-Katz, finally identified as Caenorhabditis elegans by PCR technique.nnnCONCLUSIONnThe diagnosis of human hookworm eggs, only by the use of Kato-Katz technique can lead to false positives because of similarities with eggs of other free-living worms, from wet soils like those of Rwanda that could contaminate stool samples.

Prevalence of intestinal parasites, with emphasis on the molecular epidemiology of Giardia duodenalis and Blastocystis sp., in the Paranaguá Bay, Brazil: a community survey

BackgroundIntestinal protozoan parasites are major contributors to the global burden of gastrointestinal disease causing significant socioeconomic consequences. Children living in resource-poor settings with restricted access to water and sanitary services are particularly at risk of these infections.MethodsA prospective, community-based, cross-sectional survey was conducted in Paraná (southern Brazil) between May 2015 and May 2016. A total of 766 stool samples were individually collected from volunteers (male/female ratio: 0.99; age range: 0–76 years) and used for investigating the presence of intestinal helminth and protozoan species by routine microscopic procedures including the Kato-Katz and modified Ritchie concentration methods and the Ziehl-Neelsen stain technique. Quantitative real-time PCR confirmed microscopy-positive samples for Giardia duodenalis and the assemblages and sub-assemblages determined by multilocus sequence-based genotyping of the glutamate dehydrogenase (gdh) and β-giardin (bg) genes of the parasite. Identification of Blastocystis subtypes was carried out by amplification and sequencing of a partial fragment of the small-subunit ribosomal RNA gene (SSU rDNA) of this heterokont microorganism.ResultsOverall, 46.1% (353/766) of the participants were infected/colonised by at least one intestinal parasite/commensal species. Protozoan and helminth species were detected in 42.7% and 10.1% of the surveyed population, respectively. Blastocystis sp. (28.2%), Endolimax nana (14.9%), and Giardia duodenalis (11.0%) were the most prevalent species found among protozoans and Ascaris lumbricoides (5.0%), Trichuris trichiura (4.6%) and hookworms (1.0%) among helminths. A total of 38 G. duodenalis-positive samples were genotyped at gdh and bg markers, revealing the presence of the sub-assemblages AII (47.4%), AII/AIII (2.6%), BIII (5.3%), BIV (26.3%) and BIII/BIV (13.1%). Two samples (5.3%) were only identified as assemblage B. AII was predominantly found in females aged 5–9 years and was associated with a higher likelihood of reporting gastrointestinal symptoms. A total of 102 Blastocystis-positive samples were successfully subtyped at the SSU rRNA gene revealing the presence of ST1 (36.3%), ST2 (15.7%), ST3 (41.2%), ST4 (2.9%), ST6 (1.0%) and ST8 (2.9%).ConclusionsData presented here indicate that enteric parasites still represent a pressing health concern in Paraná, Brazil, probably due to sub-optimal water, sanitation and hygiene conditions. A mostly anthroponotic origin is suspected for G. duodenalis and Blastocystis sp. infections.

Cestodiasis inusual en infante español

Niño de 17 meses natural de Puzol, municipio situado a 20 km l norte de Valencia, que acude a la Unidad de Pediatría del Hosital comarcal de Sagunto por presentar fiebre (pico máximo de 8,5 ◦C), vómitos y diarrea (4 veces/día), sin dolor abdominal ni angre, y presencia en el pañal de estructuras blanquecinas. Los eses previos había presentado episodios de insomnio nocturno. a exploración física fue normal y no se detectaron alteraciones en os resultados de la analítica básica de hematología y bioquímica. l coprocultivo no demostró enteropatógenos habituales, pero el ntígeno de Rotavirus en heces fue positivo. Las estructuras blanuecinas, un test de Graham y una muestra fecal fueron enviadas a uestro laboratorio para su estudio e identificación.

22. Pure orthostatic hypotension: Neurophysiological assessment and differential diagnosis

Introduction: The surgical removal of tumors from the brainstem through an incision in the floor of the 4th ventricle results in a significant morbidity. The motor nuclei of the facial nerve and the lower cranial nerves (CN) are especially vulnerable since they are difficult to locate in these patients. These tumors distort the reference points for the floor of the 4th ventricle (facial colliculus and stria medullaris). For this reason, it is very helpful to locate these points through electric stimulation. Material and methods: Our protocol includes monitoring the SEP and BAEP to assess brainstem integrity. Cranial nerves VII, IX, X and XII are also monitored in order to locate their nuclei. For recording, we placed EMG electrodes in the posterior wall of the pharynx to record the nerves IX and X; in the lateral surface of the anterior third of the tongue for the XIIth; and in the orbicularis oculi and orbicularis oris muscles for CN VIIth. Using a bipolar stimulator, the surgeon stimulates different zones of the floor of the 4th ventricle until the nuclei are identified. Conclusion: Neurophysiological mapping of the floor of the 4th ventricle is important in order to confirm the integrity of the motor nuclei of the cranial nerves as well as to assess anatomical distortions resulting from the tumor.