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Parasitic infections continue to be a burden for developing countries—the lack of hygiene measures and clean water results in dangerous scenarios that can lead to challenging problems. Most Ascaris lumbricoides infections are usually mild; nonetheless, in rare cases in endemic regions, they can migrate to the bile duct and cause severe complications requiring surgery. We present the case of a 43-year-old woman who had severe cholangitis due to A. lumbricoides. The worm migrated from the bowel and obstructed the bile duct; after surgery, the patient fully recovered. [ABSTRACT FROM AUTHOR]

This paper reviews several aspects of immunoendocrinology and ecoimmunology in Brazilian species of anurans under investigation for more than a decade, including (1) patterns of annual covariation of circulating steroids, calling behavior and innate immunity, (2) endocrine and immune correlates of calling performance, (3) behavioral and physiological correlates of parasite load, (4) thermal sensitivity of immune function, and (5) endocrine and immunomodulation by experimental exposure to acute and chronic stressors, as well as to endocrine manipulations and simulated infections. Integrated results have shown an immunoprotective role of increased steroid plasma levels during reproductive activity in calling males. Moreover, a higher helminth parasite load is associated with changes in several behavioral and physiological traits under field conditions. We also found anuran innate immunity is generally characterized by eurythermy, with maximal performance observed in temperatures close to normal and fever thermal preferendum. Moreover, the aerobic scope of innate immune response is decreased at fever thermal preferendum. Experimental exposure to stressors results in increased corticosterone plasma levels and immune redistribution, with an impact on immune function depending on the duration of the stress exposure. Interestingly, the fate of immunomodulation by chronic stressors also depends in part on individual body condition. Acute treatment with corticosterone generally enhances immune function, while prolonged exposure results in immunosuppression. Still, the results of hormonal treatment are complex and depend on the dose, duration of treatment, and the immune variable considered. Finally, simulated infection results in complex modulation of the expression of cytokines, increased immune function, activation of the Hypothalamus-Pituitary-Interrenal axis, and decreased activity of the Hypothalamus-Pituitary-Gonadal axis, as well as reduced melatonin plasma levels, suggesting that anurans have a functional Immune-Pineal axis, homologous to that previously described for mammals. These integrated and complementary approaches have contributed to a better understanding of physiological mechanisms and processes, as well as ecological and evolutionary implications of anuran immunoendocrinology. [ABSTRACT FROM AUTHOR]

The Baltimore-Bullock's Oriole hybrid zone is one of the best-studied avian hybrid zones in North America, yet our understanding of the causes of selection against hybrids remains poor. We examine if endohelminth parasites may cause selection against hybrid orioles but found no evidence for this hypothesis. Of the 139 male orioles we examined, 43 individuals contained endohelminth parasites from at least 1 of these groups: Cestoda, Acanthocephala, or Nematoda. Across the hybrid zone, Baltimore Orioles (Icterus galbula) and Bullock's Orioles (I. bullockii) differed in their parasite communities, such that Baltimore Orioles frequently contained both Acanthocephala and Cestoda parasites whereas Bullock's Orioles primarily contained Cestoda parasites. Despite these differences in parasite communities between parental species, the frequency of hybrid orioles with parasites was similar to parentals, suggesting that hybrids were as susceptible to endohelminth parasites as parentals. Using a subset of 99 adult male orioles, we explored how parasites may be associated with the expression of orange carotenoid-based plumage in hybrids and parentals. Associations between carotenoid-based plumage color and parasites were most strongly expressed in Bullock's Orioles, but patterns were subtle and counterintuitive because individuals with parasites often had more enhanced color measures compared to individuals without parasites. Taken together, these data suggest that endohelminth parasites impose little fitness costs to male orioles on the breeding grounds and likely do not cause selection against hybrids. [ABSTRACT FROM AUTHOR]

Parasitic worms (i.e., helminths) commonly infect multiple hosts in succession. With every transmission step, they risk not infecting the next host and thus dying before reproducing. Given this risk, what are the benefits of complex life cycles? Using a dataset for 973 species of trophically transmitted acanthocephalans, cestodes, and nematodes, we tested whether hosts at the start of a life cycle increase transmission and whether hosts at the end of a life cycle enable growth to larger, more fecund sizes. Helminths with longer life cycles, that is, more successive hosts, infected conspicuously smaller first hosts, slightly larger final hosts, and exploited trophic links with lower predator–prey mass ratios. Smaller first hosts likely facilitate transmission because of their higher abundance and because parasite propagules were the size of their normal food. Bigger definitive hosts likely increase fecundity because parasites grew larger in big hosts, particularly endotherms. Helminths with long life cycles attained larger adult sizes through later maturation, not faster growth. Our results indicate that complex helminth life cycles are ubiquitous because growth and reproduction are highest in large, endothermic hosts that are typically only accessible via small intermediate hosts, that is, the best hosts for growth and transmission are not the same. [ABSTRACT FROM AUTHOR]

If every metazoan species has at least one host-specific parasite, as several local scale studies have suggested, then half of all species could be parasites. However, host specificity varies significantly depending on host phylogeny, body size, habitat, and geographic distribution. The best studied hosts tend to be vertebrates, larger animals, and/or widespread, and thus have a higher number of parasites and host-specific parasites. Thus, host specificity for these well-known taxa cannot be simply extrapolated to other taxa, notably invertebrates, small sized, and more endemic species, which comprise the major portion of yet to be discovered species. At present, parasites of animals comprise about 5% of named species. This article analyzed the rate of description of several largely parasitic taxa within crustaceans (copepods, amphipods, isopods, pentastomids, cirripeds), marine helminths (nematodes, acanthocephalans, flukes), gastropod molluscs, insects (ticks, fleas, biting flies, strepispterans), and microsporidia. The period of highest discovery has been most recent for the marine helminths and microsporids. The number of people describing parasites has been increasing since the 1960s, as it has for all other taxa. However, the number of species being described per decade relative to the number of authors has been decreasing except for the helminths. The results indicate that more than half of all parasites have been described, and two-thirds of host taxa, although the proportion varies between taxa. It is highly unlikely that the number of named species of parasites will ever approach that of their hosts. This contrast between the proportion that parasites comprise of local and global faunas suggests that parasites are less host specific and more widespread than local scale studies suggest. [ABSTRACT FROM AUTHOR]

A trade-off between resource-specialization and the breadth of the ecological niche is one of the most fundamental biological characteristics. A true generalist (Jack-of-all-trades) displays a broad ecological niche with little resource specialization while the opposite is true for a resource-specialist that has a restricted ecological niche that it masters. Parasites that manipulate hosts’ behavior are often thought to represent resource-specialists based on a few spectacular examples of manipulation of the host’s behavior. However, the determinants of which, and how many, hosts a manipulating parasite can exploit (i.e., niche breadth) are basically unknown. Here, I present an analysis based on published records of the use of hosts by 67 species from 38 genera of helminths inducing parasite increased trophic transmission, a widespread strategy of parasites that has been reported from many taxa of parasites and hosts. Using individual and multivariate analyses, I examined the effect of the host’s and parasite’s taxonomy, location of the parasite in the host, type of behavioral change, and the effect of debilitation on host-specificity, measured as the mean taxonomic relatedness of hosts that a parasite can manipulate. Host-specificity varied substantially across taxa suggesting great variation in the level of resource-specialization among manipulating parasites. Location of the parasite, level of debilitation, and type of host were all significant predictors of host-specificity. More specifically, hosts’ behavioral modification that involves interaction with the central nervous system presumably restricts parasites to more closely related hosts than does manipulation of the host’s behavior via debilitation of the host’s physiology. The results of the analysis suggest that phylogenetic relatedness of hosts is a useful measure of host-specificity in comparative studies of the complexity of interactions taking place between manipulating parasites and their hosts. [ABSTRACT FROM AUTHOR]

Concurrent infections with multiple parasites are ubiquitous in nature. Coinfecting parasites can interact with one another in a variety of ways, including through the host’s immune system via mechanisms such as immune trade-offs and immunosuppression. These within-host immune processes mediating interactions among parasites have been described in detail, but how they scale up to determine disease dynamic patterns at the population level is only beginning to be explored. In this review, we use helminth–microparasite coinfection as a model for examining how within-host immunological effects may influence the ecological outcome of microparasitic diseases, with a specific focus on disease invasion. The current literature on coinfection between helminths and major microparasitic diseases includes many studies documenting the effects of helminths on individual host responses to microparasites. In many cases, the observed host responses map directly onto parameters relevant for quantifying disease dynamics; however, there have been few attempts at integrating data on individual-level effects into theoretical models to extrapolate from the individual to the population level. Moreover, there is considerable variability in the particular combination of disease parameters affected by helminths across different microparasite systems. We develop a conceptual framework identifying some potential sources of such variability: Pathogen persistence and severity, and resource availability to hosts. We also generate testable hypotheses regarding diseases and the environmental contexts when the effects of helminths on microparasite dynamics should be most pronounced. Finally, we use a case study of helminth and mycobacterial coinfection in the African buffalo to illustrate both progress and challenges in understanding the population-level consequences of within-host immunological interactions, and conclude with suggestions for future research that will help improve our understanding of the effects of coinfection on dynamics of infectious diseases. [ABSTRACT FROM AUTHOR]

Parasitic helminthes are endemic in Nigeria, owing to poor environmental sanitation, pollution, and contamination of water and air. Children in Nigeria are highly exposed and very vulnerable to these infections, and these infections have adverse effects on their physical and mental development. School children, then, are good targets for mass-treatment programs against intestinal worms; treating children has been shown to reduce transmission to untreated members in communities. This study determines the effectiveness of deworming school children with a view to improving the planning and implementation of control programs in the study area and reveals that regular use of broad-spectrum anti-helminth medication is advocated for effective deworming programs. [ABSTRACT FROM AUTHOR]

Parasitic helminths (worms) co-evolved with vertebrate immune systems to enable long-term survival of worms in infected hosts. Among their survival strategies, worms use their glycans within glycoproteins and glycolipids, which are abundant on helminth surfaces and in their excretory/ secretory products, to regulate and suppress host immune responses. Many helminths express unusual and antigenic (nonhost-like) glycans, including those containing polyfucose, tyvelose, terminal GalNAc, phosphorylcholine, methyl groups, and sugars in unusual linkages. In addition, some glycan antigens are expressed that share structural features with those in their intermediate and vertebrate hosts (host-like glycans), including LeX (Galβ1-4[Fucα1-3]GlcNAc-), LDNF (GalNAcβ1-4[Fucα1-3]GlcNAc-), LDN (GalNAcβ1-4GlcNAc-), and Tn (GalNAcα1-O-Thr/Ser) antigens. The expression of host-like glycan determinants is remarkable and suggests that helminths may gain advantages by synthesizing such glycans. The expression of host-like glycans by parasites previously led to the concept of “molecular mimicry,” in which molecules are either derived from the pathogen or acquired from the host to evade recognition by the host immune system. However, recent discoveries into the potential of host glycan-binding proteins (GBPs), such as C-type lectin receptors and galectins, to functionally interact with various host-like helminth glycans provide new insights. Host GBPs through their interactions with worm-derived glycans participate in shaping innate and adaptive immune responses upon infection. We thus propose an alternative concept termed “glycan gimmickry,” which is defined as an active strategy of parasites to use their glycans to target GBPs within the host to promote their survival. [ABSTRACT FROM PUBLISHER]

Parasite-mediated selection on major histocompatibility complex (MHC) genes has mainly been explored at the intraspecific level, although many molecular studies have revealed trans-species polymorphism. Interspecific patterns of MHC diversity might reveal factors responsible for the long-term evolution of MHC polymorphism. We hypothesize that host taxa harbouring high parasite diversity should exhibit high levels of MHC genetic diversity. We test this assumption using data on rodent species and their helminth parasites compiled from the literature. Controlling for similarity due to common descent, we present evidence indicating that high helminth species richness in rodent species is associated with increased MHC class II polymorphism. Our results are consistent with the idea that parasites sharing a long-term coevolutionary history with their hosts are the agents of selection explaining MHC polymorphism. [ABSTRACT FROM AUTHOR]

Much has been written concerning diagnostic pitfalls in microscopic examination of stool for ova and parasites but very little pertaining to macroscopic mimics of parasites in stool samples. Though much more common in some locations than others, parasitic infections are found in nearly all populations; consequently, familiarity with the gross appearance of parasites and common distractors is important to ensure quality patient care. This review of the literature on macroscopic mimics, along with photographs of mimics and true parasites for comparison, will facilitate accurate and timely recognition of a parasitic mimic. In the current age of frequent and easy travel, both the likelihood and suspicion of patients contracting an "exotic" illness have increased, making a sound understanding of parasitology all the more importantAfter reading this article, readers should be able to discuss macroscopic objects in stool that can mimic parasitic infection and how to differentiate a parasite from a doppelganger accuratelyMicrobioloby Exam 70801 questions are located after the CE Update section on page 119 [ABSTRACT FROM AUTHOR]

Background. We wanted to quantify the impact that polyparasite infections, including multiple concurrent lowintensity infections, have on anemia. Methods. Three stool samples were collected and read in duplicate by the Kato-Katz method in a cross-sectional sample of 507 children from Leyte, The Philippines. The number of eggs per gram of stool was used to define 3 infection intensity categories-uninfected, low, and moderate/high (M+)-for 3 geohelminth species and Schistosomiasis japonicum. Four polyparasite infection profiles were defined in addition to a reference profile that consisted of either no infections or low-intensity infection with only 1 parasite. Logistic regression models were used to quantify the effect that polyparasitism has on anemia (hemoglobin level <11 g/dL). Results. The odds of having anemia in children with low-intensity polyparasite infections were nearly 5-fold higher (P=.052) than those in children with the reference profile. The odds of having anemia in children infected with 3 or 4 parasite species at M+ intensity were 8-fold greater than those in children with the reference profile (P<.001). Conclusion. Low-intensity polyparasite infections were associated with increased odds of having anemia. In most parts of the developing world, concurrent infection with multiple parasite species is more common than single-species infections. This study suggests that concurrent low-intensity infections with multiple parasite species result in clinically significant morbidity. [ABSTRACT FROM AUTHOR]

The study of the singular hypersensitivity reactions to Anisakis simplex ( A.s) proteins, may help us to undestand many of the unknown immune interactions between helmiths infections and allergy. We have developed a murine model of allergy to A. simplex, that mimics human A. simplex allergy to study the specific aspects of anaphylaxis induced by parasites. Male C3H/HeJ mice were intraperitoneally sensitized to A. simplex. Mice were then intravenous or orally challenged with A. simplex. Antigen-specific immunoglobulins, polyclonal IgE, anaphylactic symptoms, plasma histamine levels and cytokine profiles were determined. Comparative IgE immunoblot analyses were also performed. Specific IgE, IgG1 and IgG2a were detected in sensitized mice since week 3. Polyclonal IgE raised and peaked with different kinetics. Intravenous A. simplex challenge produced anaphylaxis in mice, accompanied by plasma histamine release. Oral A. simplex challenge in similarly sensitized mice did not caused symptoms nor histamine release. Numerous A. simplex allergens were recognized by sensitized mouse sera, some of them similar to human serum. The A. simplex stimulated splenocytes released IL-10, IFN-γ, IL-4, IL-13 and IL-5. We describe a new animal model of anaphylaxis. It exhibits characteristics of type I hypersensitivity reactions to Anisakis simplex similar to those observed in allergic humans. Different responses to i.v. or oral A. simplex challenges emerged, which did not reflect a window tolerization period. The cytokine profile developed (mixed Th1/Th2 pattern) differed from the observed in classical models of anaphylaxis or allergy to food antigens. This model may permit to investigate the peculiar allergic reactions to parasitic proteins. [ABSTRACT FROM AUTHOR]

Background. Infection with intestinal helminths may stimulate dysfunctional immune responses in human immunodeficiency virus (HIV)-infected persons. Studies have yielded conflicting results regarding the impact of antihelminthic treatment on plasma concentrations of HIV-1 RNA. Methods. We conducted a prospective study of 54 HIV-1- and helminth-coinfected and 57 HIV-1-infected, helminth-uninfected asymptomatic adults living in Lusaka, Zambia, to assess the impact of antihelminthic treatment on plasma concentrations of HIV-1 RNA. Results. Median baseline viral load was 0.33 log10 copies/mL lower in the helminth-infected group than in the uninfected group. Mean viral load between pretreatment and posttreatment visits increased in the helminthinfected (mean, 4.23 vs. 4.29 log10 copies/mL; ) and helminth-uninfected (mean, 4.39 vs. 4.52 log10 copies/ P =.2 ) groups. Helminth-infected participants with high pretreatment viral loads had a mean 0.25-log10 copies/mL decrease after treatment ( P = .3), and helminth-uninfected participants had a mean 0.02-log10 copies/mL decrease (P = .8 ). Conclusions. We did not find an overall association between treatment of intestinal helminth infections and reduction in viral load in coinfected adults. Future studies may need to focus on adults with intense helminth infections who live in rural areas or on adults or children who harbor higher helminth burdens and plasma concentrations of HIV-1 RNA. [ABSTRACT FROM AUTHOR]

Total and Ascaris-specific serum IgE levels were measured in a group of 98 Ascaris-infected children from a slum area of Caracas. Venezuela, in whom the infections were eliminated by regular treatment for 22 months with the anthelmint Oxantel/Pyrantel ('Quantrel'). The children were re-evaluated at the end of the treatment programme, and then 8 months later, at which time reinfection was assessed. Total IgE levels at the beginning of the study were significantly higher in the children who became reinfected after treatment, compared with those who did not. The anthelmint treatment caused a significant decrease in the total IgE levels in most of the children, and after a period of 8 months without treatment these continued lo decrease in the non-reinfected group, but increased again in the reinfected children. The reverse pattern was found for Ascaris -specific IgE antibody levels, and in fact an inverse correlation was found between total and anti-Ascaris IgE levels. Striking associations were found between reinfection and high pretreatment values of total IgE, but low levels of specific IgE antibody. These data support the concept that specific IgE antibody may participate in the protection against helminthic infection, and suggest that the polyclonal stimulation of IgE synthesis caused by these parasites may reduce the effectiveness of such responses. The results also indicate that different individuals have varying propensities to respond polyclonally to the helminths, and this influences their resistance lo infection. [ABSTRACT FROM AUTHOR]

Helminth parasites induce production of high levels of IgE antibodies but the immunoregulatory mechanisms determining this IgE biosynthesis are poorly understood. To investigate these mechanisms, peripheral blood mononuclear cells were obtained from six normal controls, six atopic patients and eight patients with parasitic helminth infections (three with schistosomiasis, two with loiasis. three with onchocerciasis). Cells were cultured at 1 × 106 cells/ml for 8 days in the presence of media alone or media supplemented with pokeweed mitogen (PWM) or cycloheximide; the supernatant fluids from these cultures were then assayed quantitatively for total and parasite specific IgE and IgG using an avidin-biotin amplified (for IgE) or standard (for IgG) microelisa assay. The geometric mean spontaneous IgE production was markedly elevated in peripheral blood mononuclear cells from parasitized individuals (2,487 pg/ml) when compared to those from atopics (358 pg/ml) or normals (152 pg/ml). Spontaneous IgG synthesis was equivalent in all three groups (range 140-420 ng/ml). PWM did not induce IgE production in any group and in the parasitized group even caused significant suppression of total IgE synthesis. Antigen specific antibody production (both IgE and IgG) paralleled total immunoglobulin synthesis. These findings demonstrate for the first time spontaneously enhanced IgE production in vitro in patients with helminth infections and provide a model system for studying the suppressive and regulatory mechanisms controlling IgE secretion. [ABSTRACT FROM AUTHOR]

In 2007, the rate of intestinal helminth infection in primary school-aged children in a rural village in Southwestern Kenya was estimated to be at least 68%, based on direct stool smear. Since the 2007 survey, these same school children have been treated with 400-mg albendazole every 3 months. We repeated a cross-sectional stool survey in the same area in 2010 (i.e. 3 years later) to estimate the current parasite prevalence. While only 44.5% of children were infected in 2010, the decline was not as marked as one might expect from a well-managed quarterly deworming campaign. Due to the relative insensitivity of the technique utilized here—the direct smear examination of a single stool sample—we were only able to identify heavy infections, and the true rate of parasitism is likely much higher, suggesting heavy environmental contamination and rapid re-infection rates. Community education and sanitation improvements are needed for more definitive impact. [ABSTRACT FROM PUBLISHER]

Hydatid disease is caused by a tape worm Echinococcus Granulosus that lives in the intestines of the definitive host which is the dog or other carnivore. Human is the accidental intermediate host and become infected by ingesting contaminated vegetables or water with the eggs of the parasite. A-37-year old male presented with right side abdominal pain for 2 months. Abdominal examination showed a large right side abdominal mass extending from the right subcostal region to the right iliac fossa. CT-scan showed two cystic lesions in the right lobe of the and a third one extending to the pelvis. During surgery aspiration of 10 liters of bile stained fluid done. Excision of the cysts done. Tube drain put inside the cyst cavity with omentoplasty. There was bile leak to the drain which stopped over one month. The patient received anthelminthic medication for 3 months. [ABSTRACT FROM AUTHOR]