MOOSE EXPERIMENTALLY INFECTED WITH GIANT LIVER FLUKE (FASCIOLOIDES MAGNA)

Moose (Alces alces) are abnormal, dead-end hosts of the giant liver fluke Fascioloides magna. The worms migrate extensively in moose causing considerable hepatic tissue damage before eventually dying. Few reach sexual maturity and eggs are seldom, if ever, passed in feces. Occurrence of the parasite in moose depends on the presence of a competent definitive host and suitable aquatic snail intermediate hosts of the genus Lymnaea. There is no clinical evidence that F. magna kills moose although the considerable tissue pathology seen in some heavily infected livers is suggestive that they do. In this study, 2 farm-reared calves (2 months old) and a yearling moose (15 months old) were given 50, 110, and 225 F. magna metacercariae, respectively, and observed for 12.5-16 months. No outward signs of disease were observed. The livers of the 2 animals infected as calves were swollen and contained bloody tracks, extensive fibrosis, and capsules; 1 and 11 immature flukes were recovered. The liver of the animal infected as a yearling had 3 large, thick-walled capsules but no flukes. Weight gain and behaviour of all were similar to those of uninfected farm-reared moose. Known aspects of the biology of this parasite and our experimental results suggest that F. magna is unlikely to have been a major factor in the recent moose decline in northwestern Minnesota

MOOSE EXPERIMENTALLY INFECTED WITH GIANT LIVER FLUKE (FASCIOLOIDES MAGNA)

Moose (Alces alces) are abnormal, dead-end hosts of the giant liver fluke Fascioloides magna. The worms migrate extensively in moose causing considerable hepatic tissue damage before eventually dying. Few reach sexual maturity and eggs are seldom, if ever, passed in feces. Occurrence of the parasite in moose depends on the presence of a competent definitive host and suitable aquatic snail intermediate hosts of the genus Lymnaea. There is no clinical evidence that F. magna kills moose although the considerable tissue pathology seen in some heavily infected livers is suggestive that they do. In this study, 2 farm-reared calves (2 months old) and a yearling moose (15 months old) were given 50, 110, and 225 F. magna metacercariae, respectively, and observed for 12.5-16 months. No outward signs of disease were observed. The livers of the 2 animals infected as calves were swollen and contained bloody tracks, extensive fibrosis, and capsules; 1 and 11 immature flukes were recovered. The liver of the animal infected as a yearling had 3 large, thick-walled capsules but no flukes. Weight gain and behaviour of all were similar to those of uninfected farm-reared moose. Known aspects of the biology of this parasite and our experimental results suggest that F. magna is unlikely to have been a major factor in the recent moose decline in northwestern Minnesota

Parasite infections in a social carnivore: Evidence of their fitness consequences and factors modulating infection load

There are substantial individual differences in parasite composition and infection load in wildlife populations. Few studies have investigated the factors shaping this heterogeneity in large wild mammals or the impact of parasite infections on Darwinian fitness, particularly in juveniles. A host's parasite composition and infection load can be shaped by factors that determine contact with infective parasite stages and those that determine the host's resistance to infection, such as abiotic and social environmental factors, and age. Host–parasite interactions and synergies between coinfecting parasites may also be important. We test predictions derived from these different processes to investigate factors shaping infection loads (fecal egg/oocyte load) of two energetically costly gastrointestinal parasites: the hookworm Ancylostoma and the intracellular Cystoisospora, in juvenile spotted hyenas (Crocuta crocuta) in the Serengeti National Park, in Tanzania. We also assess whether parasite infections curtail survival to adulthood and longevity. Ancylostoma and Cystoisospora infection loads declined as the number of adult clan members increased, a result consistent with an encounter‐reduction effect whereby adults reduced encounters between juveniles and infective larvae, but were not affected by the number of juveniles in a clan. Infection loads decreased with age, possibly because active immune responses to infection improved with age. Differences in parasite load between clans possibly indicate variation in abiotic environmental factors between clan den sites. The survival of juveniles (<365 days old) to adulthood decreased with Ancylostoma load, increased with age, and was modulated by maternal social status. High‐ranking individuals with low Ancylostoma loads had a higher survivorship during the first 4 years of life than high‐ranking individuals with high Ancylostoma loads. These findings suggest that high infection loads with energetically costly parasites such as hookworms during early life can have negative fitness consequences

Angiostrongylosis-related restrictive pneumopathy assessed by arterial blood gas analysis in a dog

Pulmonary angiostrongylosis was diagnosed by the Baermann method and larval identification from faecal and bronchoalveolar lavage samples in a five-month- old male mongrel dog with dyspnoea and cough. Arterial blood gas analysis indicated arterial hypoxaemia and restrictive pneumopathy. In addition to the palliative treatment, fenbendazole was administered (50 mg/kg/24 h per os) for 14 days. The respiratory signs subsided within a short time clinically, but serial arterial blood gas analysis demonstrated an ongoing ventilation disorder. Repeated haematology, thoracic radiography, bronchoscopy and blood gas analysis were performed to follow the course of the disease. The most severe eosinophilia was detected after the beginning of the anthelmintic therapy, and the arterial pO2 level was permanently low. Arterial blood gas analysis provided the most adequate information about the course of the pneumopathy and it greatly facilitated the patient’s medical management

Double blind, randomized controlled trial, to evaluate the effectiveness of a controlled nitric oxide releasing patch versus meglumine antimoniate in the treatment of cutaneous leishmaniasis [NCT00317629]

BACKGROUND: Cutaneous Leishmaniasis is a worldwide disease, endemic in 88 countries, that has shown an increasing incidence over the last two decades. So far, pentavalent antimony compounds have been considered the treatment of choice, with a percentage of cure of about 85%. However, the high efficacy of these drugs is counteracted by their many disadvantages and adverse events. Previous studies have shown nitric oxide to be a potential alternative treatment when administered topically with no serious adverse events. However, due to the unstable nitric oxide release, the topical donors needed to be applied frequently, making the adherence to the treatment difficult. The electrospinning technique has allowed the production of a multilayer transdermal patch that produces a continuous and stable nitric oxide release. The main objective of this study is to evaluate this novel nitric oxide topical donor for the treatment of cutaneous leishmaniasis. METHODS AND DESIGN: A double-blind, randomized, double-masked, placebo-controlled clinical trial, including 620 patients from endemic areas for Leishmaniasis in Colombia was designed to investigate whether this patch is as effective as meglumine antimoniate for the treatment of cutaneous leishmaniasis but with less adverse events. Subjects with ulcers characteristic of cutaneous leishmaniasis will be medically evaluated and laboratory tests and parasitological confirmation performed. After checking the inclusion/exclusion criteria, the patients will be randomly assigned to one of two groups. During 20 days Group 1 will receive simultaneously meglumine antimoniate and placebo of nitric oxide patches while Group 2 will receive placebo of meglumine antimoniate and active nitric oxide patches. During the treatment visits, the medications will be daily administered and the presence of adverse events assessed. During the follow-up, the research group will visit the patients at days 21, 45, 90 and 180. The healing process of the ulcer, the health of the participants, recidivisms and/or reinfection will also be assessed. The evolution of the ulcers will be photographically registered. In case that the effectiveness of the patches is demonstrated, a novel and safe therapeutic alternative for one of the most important public health problems in many countries will be available to patients

A Comparison of the Sensitivity and Fecal Egg Counts of the McMaster Egg Counting and Kato-Katz Thick Smear Methods for Soil-Transmitted Helminths

Currently, in public health, the reduction in the number of eggs excreted in stools after drug administration is used to monitor the efficacy of drugs against parasitic worms. Yet, studies comparing diagnostic methods for the enumeration of eggs in stool are few. We compared the Kato-Katz thick smear (Kato-Katz) and McMaster egg counting (McMaster) methods, which are commonly used diagnostic methods in public and animal health, respectively, for the diagnosis and enumeration of eggs of roundworms, whipworms and hookworms in 1,536 stool samples from children in five trials across Africa, Asia and South America. The Kato-Katz method was the most sensitive for the detection of roundworms, but there was no significant difference in sensitivity between the methods for hookworms and whipworms. The sensitivity of the methods differed across the trials and magnitude of egg counts. The Kato-Katz method resulted in significantly higher egg counts, but these were subject to lack of accuracy caused by intrinsic properties of this method. McMaster provided more reliable estimates of drug efficacies. We conclude that the McMaster is an alternative method for monitoring large-scale treatment programs. It allows accurate monitoring of drug efficacy and can be easily performed under field conditions

DNA multigene characterization of Fasciola hepatica and Lymnaea neotropica and its fascioliasis transmission capacity in Uruguay, with historical correlation, human report review and infection risk analysis

Fascioliasis is a highly pathogenic zoonotic disease emerging in recent decades, in part due to the effects of climate and global changes. South America is the continent presenting more numerous human fascioliasis endemic areas and the highest Fasciola hepatica infection prevalences and intensities known in humans. These serious public health scenarios appear mainly linked to altitude areas in Andean countries, whereas lowland areas of non-Andean countries, such as Uruguay, only show sporadic human cases or outbreaks. To understand this difference, we characterized F. hepatica from cattle and horses and lymnaeids of Uruguay by sequencing of ribosomal DNA ITS-2 and ITS-1 spacers and mitochondrial DNA cox1, nad1 and 16S genes. Results indicate that vectors belong to Lymnaea neotropica instead of to Lymnaea viator, as always reported from Uruguay. Our correlation of fasciolid and lymnaeid haplotypes with historical data on the introduction and spread of livestock species into Uruguay allow to understand the molecular diversity detected. We study the life cycle and transmission features of F. hepatica by L. neotropica of Uruguay under standardized experimental conditions to enable a comparison with the transmission capacity of F. hepatica by Galba truncatula at very high altitude in Bolivia. Results demonstrate that although L. neotropica is a highly efficient vector in the lowlands, its transmission capacity is markedly lower than that of G. truncatula in the highlands. On this baseline, we review the human fascioliasis cases reported in Uruguay and analyze the present and future risk of human infection in front of future climate change estimations