Childhood pentastomiasis: A report of three cases with the following-up data

Pentastomiasis, a zoonotic parasitic disease, has been reported commonly in Africa and Asia. It is caused by pentastomes, which are annulated but unsegmented blood-sucking endoparasites. Fewer than 20 cases have been reported during the past two decades in China, and cases in children have been especially rare. Herein, we report three cases of pediatric patients with severe systemic symptoms, focusing on the clinical features, diagnosis, and therapy of this disease. The patients were two boys and one girl aged 3 to 13 years. They all had a history of snake or worm ingested from snake and initial symptoms of fever, abdominal pain, diarrhea, and weight loss. Eosinophilia, anemia and elevated serum IgE levels were noted. Moreover, the large numbers of nodules, or even calcification, in the liver and/or lungs were noted by ultrasound, CT or MRI scans. These pentastomes were identified as Armillifer moniliformis, Porocephalus taiwana and Armillifer agkistrodontis. Praziquantel and mebendazole deworming treatments were adopted for the patients. Hence, pentastomiasis should be considered in the differential diagnosis for patients with multiple organ or system lesions, especially abdominal signs, that develop after the ingestion of snakes. Ultrasound, CT and MRI scans and laparoscopic approaches might be helpful for the diagnosis.     

Human pentastomiasis in China: case report and literature review

A 13-yr-old boy was admitted because of persistent fever, abdominal pain and diarrhea for 3 mo. Abdomen CT revealed hepatomegaly and multiple nodular low-density pathological changes. At laparotomy considerable yellow and turbid ascites were seen in the abdominal cavity and miliary nodules were noted on the surface of the omentum majus, liver, and small intestine wall. Histological examination revealed parenchymal tubercles containing several worms. Pathological diagnosis was parasitic granuloma. These parasites were identified as Porocephalus taiwana sp.nov. The patient made an uneventful recovery after therapy and was discharged. Moreover, another 17 cases of human pentastomiasis reported from China were reviewed. Human pentastomiasis is an extremely rare disease and this is only the second case of human Porocephalus taiwana sp.nov infection. Pentastomiasis should be considered in differential diagnosis of patients with a history of abdominal symptoms and eating of poorly-cooked snakes.     

A syndromic approach to common parasitic diseases

Standard textbooks discuss parasitic disease according to specific organisms. In contrast, patients with parasitic infections present to physicians with a variety of clinical manifestations that may involve any of several organ systems and that often mimic nonparasitic diseases. A syndromic approach to the clinical situation may help the physician in considering the most important parasitic agents. Many parasitic infections can be acquired in temperate climates. While often considered tropical or exotic, other parasitic diseases are now seen more frequently in developed countries because of immigration and increased world travel. In this review the clinical syndromes associated with common parasitic diseases in North America are discussed, with an emphasis on risk factors and diagnosis of specific infections.     

Chaconia heliconiae and C. clusiae sp. novae from French Guiana with notes on the genus Chaconia (Uredinales/Pucciniales) in the neotropics

Chaconia clusiae on Clusia cf. palmicida (Clusiaceae) and C. heliconiae on Heliconia psittacorum, H. bihai and Heliconia sp. (Heliconiaceae) are described as new from French Guiana in northern South America. Clusiaceae and Heliconiaceae are new host families for members of Chaconia, Heliconiaceae is the first one from Monocotyledoneae. Chaconia clusiae, C. heliconiae and C. maprouneae formed tuberous to worm-like D-haustoria originating from haustorial mother cells that were part of the intercellular parasitic mycelium. A key to the recognized Chaconia spp. is provided.     

Ocular Pentastomiasis in the Democratic Republic of the Congo

Ocular pentastomiasis is a rare infection caused by the larval stage of pentastomids, an unusual group of crustacean-related parasites. Zoonotic pentastomids have a distinct geographical distribution and utilize reptiles or canids as final hosts. Recently, an increasing number of human abdominal infections have been reported in Africa, where pentastomiasis is an emerging, though severely neglected, tropical disease. Here we describe four ocular infections caused by pentastomids from the Democratic Republic of the Congo. Two cases underwent surgery and an Armillifer grandis infection was detected by morphological and molecular approaches. Thus far, 15 other cases of ocular pentastomiasis have been reported worldwide. Twelve cases were caused by Armillifer sp., recorded almost exclusively in Africa, where such infections occur as a consequence of hunting and consuming snakes, their final hosts. Seven further cases were caused by Linguatula serrata, a cosmopolitan pentastomid whose final hosts are usually canids. Intraocular infections caused permanent visual damage in 69% and a total loss of vision in 31% of reported cases. In contrast, ocular adnexal cases had a benign clinical course. Further research is required to estimate the burden, therapeutic options and pathogenesis of this neglected disease.     

Highly Sensitive Quantitative PCR for the Detection and Differentiation of Pseudogymnoascus destructans and Other Pseudogymnoascus Species

White-nose syndrome is a fungal disease that has decimated bat populations across eastern North America. Identification of the etiologic agent, Pseudogymnoascus destructans (formerly Geomyces destructans), in environmental samples is essential to proposed management plans. A major challenge is the presence of closely related species, which are ubiquitous in many soils and cave sediments and often present in high abundance. We present a dual-probe real-time quantitative PCR assay capable of detecting and differentiating P. destructans from closely related fungi in environmental samples from North America. The assay, based on a single nucleotide polymorphism (SNP) specific to P. destructans, is capable of rapid low-level detection from various sampling media, including sediment, fecal samples, wing biopsy specimens, and skin swabs. This method is a highly sensitive, high-throughput method for identifying P. destructans, other Pseudogymnoascus spp., and Geomyces spp. in the environment, providing a fundamental component of research and risk assessment for addressing this disease, as well as other ecological and mycological work on related fungi.     

Two Distinct Triatoma dimidiata (Latreille, 1811) Taxa Are Found in Sympatry in Guatemala and Mexico

Approximately 10 million people are infected with Trypanosoma cruzi, the causative agent of Chagas disease, which remains the most serious parasitic disease in the Americas. Most people are infected via triatomine vectors. Transmission has been largely halted in South America in areas with predominantly domestic vectors. However, one of the main Chagas vectors in Mesoamerica, Triatoma dimidiata, poses special challenges to control due to its diversity across its large geographic range (from Mexico into northern South America), and peridomestic and sylvatic populations that repopulate houses following pesticide treatment. Recent evidence suggests T. dimidiata may be a complex of species, perhaps including cryptic species; taxonomic ambiguity which confounds control. The nuclear sequence of the internal transcribed spacer 2 (ITS2) of the ribosomal DNA and the mitochondrial cytochrome b (mt cyt b) gene were used to analyze the taxonomy of T. dimidiata from southern Mexico throughout Central America. ITS2 sequence divides T. dimidiata into four taxa. The first three are found mostly localized to specific geographic regions with some overlap: (1) southern Mexico and Guatemala (Group 2); (2) Guatemala, Honduras, El Salvador, Nicaragua, and Costa Rica (Group 1A); (3) and Panama (Group 1B). We extend ITS2 Group 1A south into Costa Rica, Group 2 into southern Guatemala and show the first information on isolates in Belize, identifying Groups 2 and 3 in that country. The fourth group (Group 3), a potential cryptic species, is dispersed across parts of Mexico, Guatemala, and Belize. We show it exists in sympatry with other groups in Peten, Guatemala, and Yucatan, Mexico. Mitochondrial cyt b data supports this putative cryptic species in sympatry with others. However, unlike the clear distinction of the remaining groups by ITS2, the remaining groups are not separated by mt cyt b. This work contributes to an understanding of the taxonomy and population subdivision of T. dimidiata, essential for designing effective control strategies.     

DomesticatedChenopodium of the Ozark Bluff Dwellers

Previous suggestions that prehistoric agriculturalists of the Ozark Bluff Dweller culture utilized a fully domesticated form ofChenopodium have been confirmed. Comparative examination of infructescence and fruit structure indicates that archaeological material is assignable toC. berlandieri ssp.nuttalliae, a product of Mexican agriculture. Large-fruited chenopod remains from other sites in eastern North America, often identified as those of wild species, may also belong to the Mexican domesticated form. A related, wild species of northeastern North America,C. bushianum, shows similarities to the Mexican weed-crop complex that may reflect prehistoric genetic interaction. This is the first documented report of domesticatedChenopodium from prehistoric North America.     

Pasteurella Septica Infections in Humans

Five instances of infection by Pasteurella septica, an organism which closely resembles H. influenzae on methods of presumptive bacteriology, are reported from an acute treatment general hospital practice over a period of three months. This infection decidedly outnumbers those caused by other Pasteurella species in North America. The organism is apt to be identified as H. influenzae, Friedlander''s bacillus or Mima polymorpha. Unlike these, it shows extreme sensitivity to penicillin, sometimes combined with resistance to antibiotics that inhibit or kill these other organisms.While in the past Pasteurella septica infection was considered to be characterized by persistent local infection following domestic animal scratches or bites, it is clear that it is more often found in cases of respiratory tract infection and peripheral septic disease. In three of the five cases reported, exposure to animals was the source of infection.Because mixed infection with confusingly similar organisms may occur, lack of awareness of extreme penicillin sensitivity of Pasteurella septica may account for persistent failure of antibiotic therapy.     

Focus: Zoonotic Disease: Biology,Epidemiology, Clinical Features,Diagnosis, and Treatment of Selected Fish-borne Parasitic Zoonoses

Fish-borne parasites have been part of the global landscape of food-borne zoonotic diseases for many decades and are often endemic in certain regions of the world. The past 20 years or so have seen the expansion of the range of fish-borne parasitic zoonoses to new geographic regions leading to a substantial public health burden. In this article, we summarize current knowledge about the biology, epidemiology, clinical characteristics, diagnosis, treatment and control of selected fish-borne helminthic diseases caused by parasitic roundworm (Anisakis), tapeworm (Dibothriocephalus), and fluke (Metagonimus). Humans acquire infection via consumption of raw or improperly cooked fish or fish products. The burden from these diseases is caused by morbidity rather than mortality. Infected patients may present with mild to severe gastrointestinal (eg, abdominal pain, diarrhea, and indigestion) or allergic manifestations. Patients are often admitted to the hospital or clinic with acute symptoms and no prior health problems and no travel history. Diagnosis is often established based on the detection of the diagnostic parasite stages (eg, eggs or tapeworm segments) in the patient’s feces. Sometimes imaging is required to exclude other causes and avoid unnecessary surgery. Dibothriocephalus and Metagonimus are mainly treated with praziquantel. Extraction of adult Dibothriocephalus or Anisakis larvae from the bowel ensures complete elimination of the parasites and prevents a relapse of infection. The development and implementation of more efficient food safety and public health strategies to reduce the burden of zoonotic diseases attributable to fish-borne parasites is highly desirable.     

Changing patterns of parasitic disease: old enemies and new invaders--the battle wages on

• 1.A. The classic parasitic diseases—malaria, schistosomiasis, the filariases, and many other familiar “old enemies”—continue to be the major parasitic causes of morbidity and morality and the continuing objects of our research and control efforts. Although all have been receptive to control interventions under certain circumstances, most of these infections continue to be transmitted without apparent restrictions in the rural, developing regions where nearly one-half of all the world's people live. New technologie achievements will improve the chances for treatment and control of these infections, but more important, may be improved administrative capacity and the commitment of political will and economic resources toward these goals.
• 2.B. The emergence of resistance to drugs and chemical control agents as a result of selection of resistant strains in the face of exposure to the chemical is a growing phenomenon among parasites with very serious public health implications. Strains of Plasmodium falciparum resistant to most drugs formerly effective for prophylaxis and treatment have appeared in Africa, Asia and parts of South and Central America at a faster pace than new compounds can be made available. Similar problems have been reported with gastrointestinal nematodes of livestock animals and many insect vectors.
• 3.C. Cryptosporidiosis emerged dramatically as a human disease when it appeared as one of the many opportunistic infections suffered by patients with AIDS. Increased clinical awareness and improved diagnostic procedures have now implicated Cryptosporidium as an important worldwide cause of diarrheal illness in persons with normal immunologic function. Zoonotic and various forms of person-to-person transmission are now recognized as important modes of spread for this protozoan.
• 4.D. Development and widespread use of specific serodiagnostic tests for human toxocariasis has revealed that zoonotic transmission of the common dog and cat ascarids is widespread in populations in industrialized societies. Serologic studies suggest that human Toxocara infection is even more common in tropical, developing areas but the health impact of this has not yet been measured. New nematode agents of larva migrans have been identified recently. One of them, the racoon ascarid, Baylisascaris procyonis, may increase in importance as its host extends its range as a commensal resident.
• 5.E. In developed countries where social and environmental conditions limit opportunities for transmission of most protozoal and helminthic disease agents, parasitic diseases are seen often as imported infections in returning tourists or immigrants who became infected in foreign endemic areas. One of these, imported malaria, has been exacerbated in the past decade by the resurgence of malaria transmission in Asia, the resettlement, in many countries, of refugees from Southeast Asia, and the spread of chloroquine-resistant P. falciparum in Africa.
• 6.F. Other special problems of parasitic diseases in developed countries include the increase in opportunistic parasitic pathogens (Pneumocystis, Toxoplasma, Strongyloides and others) in patients with AIDS and iatrogenically-caused immunodepression and the occurrence of infections resulting from changing dietary preferences and “fads”, e.g. diphyllobothriasis from “Shushi” and “Sashimi” (Japan, United States and Canada) and gnathostomiasis from imported fish (Japan).

     

Horizontal transmission of a parasitic nematode from a non-native to a native woodwasp?

In eastern North America, the exotic invasive woodwasp, Sirex noctilio, attacks pines (Pinus spp.) and often shares larval habitat with the native woodwasp, Sirex nigricornis. The parasitic nematode, Deladenus siricidicola, has been used widely in the southern hemisphere as a biological control agent because it sterilizes female S. noctilio. This nematode was introduced accidentally to North America along with S. noctilio. Historical reports indicate nematode-woodwasp fidelity: the parasitic nematode, D. siricidicola, exclusively infects S. noctilio, and the native nematode, Deladenus proximus, exclusively infects S. nigricornis. From two sites in southern Ontario, separated by 225 km, we collected woodwasps from three Pinus sylvestris, and identified the nematode species present in the abdomens of infected wasps. Both wasp species co-occurred in all three trees. D. siricidicola was present in the haemocoel, but not inside the eggs, of infected S. noctilio and S. nigricornis. This evidence suggests horizontal transmission of D. siricidicola likely occurred from S. noctilio to S. nigricornis.     

Specific chemotherapy of Chagas disease: controversies and advances

Chagas disease, caused by Trypanosoma cruzi, is a major public health problem in Latin America, where it constitutes one of the largest parasitic disease burdens. Specific treatment of this condition has been controversial, but there is a growing consensus that elimination of T. cruzi could be a prerequisite to arrest the evolution of the disease. Currently available chemotherapy, based on a nitrofuran (nifurtimox) and a nitroimidazole (benznidazole), is unsatisfactory because of their limited efficacy in the prevalent chronic stage of the disease and their toxic side effects. New approaches to specific chemotherapy are being advanced. Biochemical routes such as the de novo sterol biosynthesis pathway, cruzipain-mediated proteolysis and pyrophosphate metabolism have been chemically validated, and the selective in vitro and in vivo anti-T. cruzi activities of inhibitors of these pathways have been demonstrated. Several of these compounds have now completed pre-clinical studies and are poised for clinical trials in the near future. Other promising approaches include interference with trypanothione synthesis and redox metabolism, in addition to inhibition of purine salvage, dihydrofolate reductase, phospholipid biosynthesis, and protein prenylation and acylation.     

Strongyloidiasis—An Insight into Its Global Prevalence and Management

Background

Strongyloides stercoralis, an intestinal parasitic nematode, infects more than 100 million people worldwide. Strongyloides are unique in their ability to exist as a free-living and autoinfective cycle. Strongyloidiasis can occur without any symptoms or as a potentially fatal hyperinfection or disseminated infection. The most common risk factors for these complications are immunosuppression caused by corticosteroids and infection with human T-lymphotropic virus or human immunodeficiency virus. Even though the diagnosis of strongyloidiasis is improved by advanced instrumentation techniques in isolated and complicated cases of hyperinfection or dissemination, efficient guidelines for screening the population in epidemiological surveys are lacking.

Methodology and Results

In this review, we have discussed various conventional methods for the diagnosis and management of this disease, with an emphasis on recently developed molecular and serological methods that could be implemented to establish guidelines for precise diagnosis of infection in patients and screening in epidemiological surveys. A comprehensive analysis of various cases reported worldwide from different endemic and nonendemic foci of the disease for the last 40 years was evaluated in an effort to delineate the global prevalence of this disease. We also updated the current knowledge of the various clinical spectrum of this parasitic disease, with an emphasis on newer molecular diagnostic methods, treatment, and management of cases in immunosuppressed patients.

Conclusion

Strongyloidiasis is considered a neglected tropical disease and is probably an underdiagnosed parasitic disease due to its low parasitic load and uncertain clinical symptoms. Increased infectivity rates in many developed countries and nonendemic regions nearing those in the most prevalent endemic regions of this parasite and the increasing transmission potential to immigrants, travelers, and immunosuppressed populations are indications for initiating an integrated approach towards prompt diagnosis and control of this parasitic disease.     

TWO NEW SOREDIATE TAXA OFPELTIGERA

Examination of specimens ofPeltigera didactyla, from Africa, Asia, Europe and North America revealed that this sorediate species includes three entities that can be separated on morphological characters. A new species,P. lambinonii, is described from East Africa, and a new combinationP. didactylavar.extenuata, is proposed to accommodate morphs from mesic forest habitats in Asia, Europe and North America. Despite this taxonomic reduction,P. didactylavar.didactylaremains a ubiquitous taxon. The former two taxa often produce methyl gyrophorate, which can co-occur with traces of gyrophoric acid. These tridepsides were only rarely detected in var.didactyla; their occasional presence seems to be best explained by hybridization. The taxonomic and ecological significance of these substances is discussed.     

Large Shift in Symbiont Assemblage in the Invasive Red Turpentine Beetle

Changes in symbiont assemblages can affect the success and impact of invasive species, and may provide knowledge regarding the invasion histories of their vectors. Bark beetle symbioses are ideal systems to study changes in symbiont assemblages resulting from invasions. The red turpentine beetle (Dendroctonus valens) is a bark beetle species that recently invaded China from its native range in North America. It is associated with ophiostomatalean fungi in both locations, although the fungi have previously been well-surveyed only in China. We surveyed the ophiostomatalean fungi associated with D. valens in eastern and western North America, and identified the fungal species using multi-gene phylogenies. From the 307 collected isolates (147 in eastern North America and 160 in western North America), we identified 20 species: 11 in eastern North America and 13 in western North America. Four species were shared between eastern North America and western North America, one species (Ophiostoma floccosum) was shared between western North America and China, and three species (Grosmannia koreana, Leptographium procerum, and Ophiostoma abietinum) were shared between eastern North America and China. Ophiostoma floccosum and O. abietinum have worldwide distributions, and were rarely isolated from D. valens. However, G. koreana and L. procerum are primarily limited to Asia and North America respectively. Leptographium procerum, which is thought to be native to North America, represented >45% of the symbionts of D. valens in eastern North America and China, suggesting D. valens may have been introduced to China from eastern North America. These results are surprising, as previous population genetics studies on D. valens based on the cytochrome oxidase I gene have suggested that the insect was introduced into China from western North America.     

Mini-FLOTAC,an Innovative Direct Diagnostic Technique for Intestinal Parasitic Infections: Experience from the Field

Background

Soil-transmitted helminths and intestinal protozoa infection are widespread in developing countries, yet an accurate diagnosis is rarely performed. The aim of this study was to evaluate the recently developed mini–FLOTAC method and to compare with currently more widely used techniques for the diagnosis of intestinal parasitic infections in different settings.

Methodology/Principal Findings

The study was carried out in Dharamsala, Himachal Pradesh, India, and in Bukumbi, Tanzania. A total of 180 pupils from two primary schools had their stool analyzed (n = 80 in Dharamsala and n = 100 in Bukumbi) for intestinal parasitic infections with three diagnostic methods: direct fecal smear, formol-ether concentration method (FECM) and mini-FLOTAC. Overall, 72% of the pupils were positive for any intestinal parasitic infection, 24% carried dual infections and 11% three infections or more. The most frequently encountered intestinal parasites were Entamoeba coli, Entamoeba histolytica/dispar, Giardia intestinalis, hookworm, (and Schistosoma mansoni, in Tanzania). Statistically significant differences were found in the detection of parasitic infections among the three methods: mini-FLOTAC was the most sensitive method for helminth infections (90% mini-FLOTAC, 60% FECM, and 30% direct fecal smear), whereas FECM was most sensitive for intestinal protozoa infections (88% FECM, 70% direct fecal smear, and 68% mini-FLOTAC).

Conclusion/Significance

We present the first experiences with the mini-FLOTAC for the diagnosis of intestinal helminths and protozoa. Our results suggest that it is a valid, sensitive and potentially low-cost alternative technique that could be used in resource-limited settings — particularly for helminth diagnosis.     

Tongue worm (subclass: Pentastomida) infection and treatment in two domesticated reptiles – A case report

Tongue worms (Subclass: Pentastomida) are endoparasites found in carnivorous reptiles, fish, amphibians, birds, and mammals. Several pentastomids cause pentastomiasis, a zoonotic disease. We encountered tongue worm infection in two reptiles imported into Japan: a Wahlberg's velvet gecko (Homopholis wahlbergii) bred in Germany and a wild-caught green tree python (Morelia viridis) from the Republic of Indonesia. The infecting tongue worms were identified as Raillietiella sp. and Armillifer sp. in the gecko and python, respectively, based on morphological and molecular analyses. Gecko is a newly recorded definitive host harboring Raillietiella tongue worm. Live tongue worms were first detected in domestic reptiles in Japan, and this indicates a risk that these tongue worms could be spread to other animals, as well as humans. Therefore, the diagnosis and treatment of infected pets are of importance. In the case of the two infected reptiles, the availability of fecal egg examination for diagnosis was shown. In addition, the effectiveness of treatment with 200 μg/kg/day ivermectin orally once weekly was demonstrated, without no side-effects and no re-detection of eggs after the cessation of treatment.     

Analysis of molecular diversity of the Trypanosoma cruzi trypomastigote small surface antigen reveals novel epitopes, evidence of positive selection and potential implications for lineage-specific serology

Chagas disease, marked by life-long chronic infection with Trypanosoma cruzi, remains a major parasitic disease in Latin America. Genetically heterogeneous, T. cruzi is divided into six discrete typing units (DTUs), most recently grouped as TcI-VI. The trypomastigote small surface antigen (TSSA) of T. cruzi has been described as the only known serological marker to identify infection by TcII-VI, as distinct from TcI. Here, by comparative analysis of a cohort of 25 reference strains representing all the known DTUs, we show that TSSA intra-specific diversity is greater than previously reported. Furthermore, TcIII and IV TSSA PCR products are, contrary to expectation, both digested by PvuII, revealing a more nuanced genotyping pattern. Amino acid sequence diversity reveals that the TSSA epitope considered to be serologically characteristic of TcII-VI is restricted to TcII, V and VI, but not of III or IV, and that the diagnostic peptide described as TcI-specific shares key features with TcIII and IV. Notably, TSSA sequences inferred greater phylogenetic affinities of TcIII and IV to TcI than to TcII, V or VI. A high ratio of non-synonymous to synonymous nucleotide substitutions (ω = 1.233) indicates that the TSSA gene has been under positive selection pressure. The demonstration of lineage-specific epitopes within TcII-VI has implications for sero-epidemiological studies of Chagas disease based on this antigen.     

Honey bee colony collapse disorder is possibly caused by a dietary pyrethrum deficiency

Industrialized farming relies on bee keepers transporting hives to the vicinity of large areas of mono-crops for crop pollination. Hives are typically moved multiple times per growing season to satisfy the pollination need. A phenomenon wherein colonies of honey bees collapse in large numbers has been threatening crops in North America. Honey bees are hosts to at least two pathogenic mites; Varroa destructor and Acarapis woodi (a tracheal mite). Pyrethrums are a group of flowering plants which include Chrysanthemum coccineum, Chrysanthemum cinerariifolium, Chrysanthemum marschallii, and related species. These plants produce potent insecticides, also named pyrethrums, which are powerful mite toxins. We believe that a honey bee dietary deficiency of pyrethrums and other micro-nutrients from pyrethrum producing plants allows parasitic mites to either kill the honey bees directly or reduce honey bee resistance to other pathogens. Intermittent feeding of honey bees on pyrethrum producing plants might reverse or prevent colony collapse disorder.