North American paragonimiasis (Caused by Paragonimus kellicotti) in the context of global paragonimiasis

Pleural parasite infection presenting with an isolated pleural effusion misdiagnosed as tuberculosis: a case report

Pleural parasitic infection is an extremely rare disease of the pleura caused by a variety of parasites, with paragonimiasis infection being the most common. The lack of specific clinical symptoms for paragonimiasis makes it easy to misdiagnose as tuberculosis, causing unnecessary drug-related adverse effects and financial burdens from incorrect treatment. We report a case of a pediatric patient presenting with an isolated pleural effusion that was misdiagnosed as tuberculosis; the patient was eventually diagnosed with pleuropulmonary paragonimiasis infection after immunologic and serologic tests. The patient finally recovered after anti-parasitic treatment involving praziquantel administration. This report will help increase awareness of this disease among medical practitioners to avoid misdiagnosis and treatment delays which may lead to disease progression.

Amphistome Infection and Species Diversity of Freshwater Snails Collected from Selected Wildlife Drinking Water Sources in Matebeleland Region of Zimbabwe

This study aimed at determining the identity of freshwater snails collected from selected water habitats frequented by wildlife as source of drinking water in the Matebeleland region of Zimbabwe and further screening the identified snails for natural infections with amphistomes using PCR. A total of 487 freshwater snails were collected from six areas in the Matebeleland region of Zimbabwe for identification and screening of amphistome infection. Eight freshwater snail species were morphologically identified and Biomphalaria pfeifferi, Bul. tropicus, Bul. truncatus, Bul. globosus, and L. (R.) natalensis were confirmed using the COI gene. Bulinus tropicus and Phy. acuta were the most abundant species at 33.9% (165/487) and 31.2% (155/487), respectively. DNA of amphistome was detected in 11.9% (58/487) of the collected snails. The highest infection rate was detected in Bul. globosus (44.4%). West Nicholson recorded the highest infection rate (33.9%), and infection was not detected in L. (R.) natalensis, Phy. acuta, and Bellamya spp. Amphistome DNA from M. tuberculata was successfully sequenced and identified as Calicophoron microbothrium. An additional band was detected in M. tuberculata, Bul. tropicus, and Bul. trancatus, which showed a 96.42% similarity to Paragonimus sp. sequence in the GenBank.

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Large Mediastinal Mass as a Rare Presentation of Schistosomiasis

A 39-year-old woman originally from Northeast Africa sought medical attention for positional dyspnea. Computed tomography of the chest revealed an 8.5 cm hypodense anterior mediastinal mass with peripheral calcifications that raised a wide differential diagnosis including infectious and neoplastic lesions. Following surgical resection, a large cavitary necrotizing and calcified granuloma involving the thymus was identified on histopathological examination. The changes were associated with parasitic eggs that based on their morphology suggested infection due to trematode species. The diagnosis was further corroborated by identification of the increased IgG titers for Schistosoma species (ELISA Kit, NovaTec). The patient's symptoms improved following surgery and praziquantel therapy. This unique presentation emphasizes an unusual manifestation of schistosomiasis that can pose a diagnostic challenge, especially in non-endemic regions. It suggests that mediastinal involvement by schistosomiasis is likely due to an ectopic deposition of the parasitic eggs within a definitive host. Suspicion for schistosomiasis should be heightened based on patient demographics and travel to endemic areas.

Paragonimiasis

Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species. Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex. Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 6.1).

Epidemiology and Geographical Distribution of Human Trematode Infections

Digenetic trematodes infecting humans are more than 109 species that belong to 49 genera all over the world. According to their habitat in the definitive hosts, they are classified as 6 blood flukes (Schistosoma japonicum. S. mekongi, S. malayensis, S. mansoni, S. intercalatum, and S. haematobium), 15 liver flukes (Fasciola hepatica, F. gigantica, Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Dicrocoelium dendriticum, D. hospes, Metorchis bilis, M. conjunctus, M. orientalis, Amphimerus sp., A. noverca, A. pseudofelineus, Pseudamphistomum truncatum, and P. aethiopicum), nine lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. skrjabini miyazakii, P. kellicotti, P. mexicanus, P. africanus, P. uterobilateralis, and P. gondwanensis), 30 heterophyid intestinal flukes (Metagonimus yokogawai, M. takahashii, M. miyatai, M. suifunensis, M. katsuradai, M. pusillus, M. minutus, Heterophyes heterophyes, H. nocens, H. dispar, Haplorchis taichui, H. pumilio, H. yokogawai, H. vanissinus, Centrocestus formosanus, C. armatus, C. cuspidatus, C. kurokawai, Procerovum calderoni, P. varium, Pygidiopsis genata, P. summa, Stictodora fuscata, S. lari, Stellantchasmus falcatus, Heterophyopsis continua, Acanthotrema felis, Apophallus donicus, Ascocotyle longa, and Cryptocotyle lingua), 24 echinostome intestinal flukes (Echinostoma revolutum, E. cinetorchis, E. mekongi, E. paraensei, E. ilocanum, E. lindoense, E. macrorchis, E. angustitestis, E. aegyptica, Isthmiophora hortensis, I. melis, Echinochasmus japonicus, E. perfoliatus, E. lilliputanus, E. caninus, E. jiufoensis, E. fujianensis, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Acanthoparyphium tyosenense, Echinoparymphium recurvatum, Himasthla muehlensi, and Hypoderaeum conoideum), 23 miscellaneous intestinal flukes (Brachylaima cribbi, Caprimolgorchis molenkampi, Phaneropsolus bonnei, P. spinicirrus, Cotylurus japonicus, Fasciolopsis buski, Gastrodiscoides hominis, Fischoederius elongatus, Watsonius watsoni, Gymnophalloides seoi, Gynaecotyla squatarolae, Microphallus brevicaeca, Isoparorchis hypselobagri, Nanophyetus salmincola, N. schikobalowi, Neodiplostomum seoulense, Fibricola cratera, Plagiorchis muris, P. vespertilionis, P. harinasutai, P. javensis, P. philippinensis, and Prohemistomum vivax), one throat fluke (Clinostomum complanatum), and one pancreatic fluke (Eurytrema pancreaticum). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) or ingestion of raw or improperly cooked food, including fish (liver flukes, heterophyid flukes, echinostomes, and throat flukes), snails (echinostomes, brachylaimids, and gymnophallid flukes), amphibia, reptiles (neodiplostomes), aquatic vegetables (fasciolids and amphistomes), and insect larvae or adults (lecithodendriids, plagiorchiids, and pancreatic flukes). Praziquantel has been proven to be highly effective against almost all kinds of trematode infections except Fasciola spp. Epidemiological surveys and detection of human infections are required for a better understanding of the prevalence, intensity of infection, and geographical distribution of each trematode species.

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In the present chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

Risk factors and clinical features for pulmonary paragonimiasis-associated pneumothorax

BACKGROUND

Pulmonary paragonimiasis, a food-borne zoonotic helminthiasis, is a parasitic disease of the lung caused by infection with trematodes species of the genus Paragonimus. Although pneumothorax has been reported as occuring with paragonimiasis, to date no study has been performed concerning the clinical features and predictive risk factors for this condition.

METHODS

This retrospective study, which aims to fill this gap, was conducted at Jeonbuk National University Hospital. All patients (aged ≥19 years) were diagnosed with paragonimiasis between May 2011 and December 2021. Medical records were reviewed and information concerning age, sex, vital signs, underlying diseases, clinical signs and symptoms, laboratory findings, radiologic findings, treatment, and clinical outcomes was collected. An odds ratio (OR) for the risk factors associated with pneumothorax was calculated using the binary logistic regression model.

RESULTS

Among 179 consecutive patients diagnosed with pulmonary paragonimiasis, the postive rate of pneumothorax was 10.6% (19/179). Pneumothorax occurred mostly in the right lung (78.9%, 15/19), and intrapulmonary parenchymal lesions showed an ipsilateral relationship with pneumothorax (94.7%, 18/19). Fifteen patients (78.9%, 15/19) of pneumothorax associated with pulmonary paragonimiasis are accompanied by pleural effusion. Most of patients with pneumothorax (89.5%, 17/19) underwent chest tube insertion as a first treatment. Three patients (15.8%) showed relapses but in no case was a death recorded. Asthma (odds ratio [OR] 8.10, 95% confidence interval [CI] 1.43-45.91), chest pain (OR 8.15, 95% CI 2.70-24.58), and intrapulmonary lesions (OR 8.94, 95% CI 1.12-71.36) were independent risk factors for pulmonary paragonimiasis-associated pneumothorax.

CONCLUSIONS

Our findings suggest that clinicians should keep in mind the possibility of pneumothorax when approached by patients with pulmonary paragonimiasis complaining of chest pain, accompanied by intrapulmonary lesions or with asthma as an underlying disease.

The Landscape of Parasitic Infections in the United States

The landscape of parasitic infections in the United States has shifted dramatically over the past century. Although infections such as malaria have been successfully eliminated, others remain endemic and pose a significant public health risk. Numerous parasitic infections are also imported each year. This article focuses on endemic parasitic infections that may be commonly seen in anatomical pathology preparations and discusses their biology, diagnostic histopathological features, and epidemiology.

A case of spontaneous pneumothorax due to paragonimiasis in North America with literature review

The species, Paragonimus kellicotti , causes human paragonimiasis in North America. As a foodborne disease, human infection with P. kellicotti occurs after eating raw or undercooked crayfish containing metacercariae. Many risk factors have been described in the literature, including young adult age, male, alcohol consumption, outdoor activities involving rivers within Missouri, and ingesting raw or partially cooked crayfish. Here, we report a case of a 41-year-old male with a 5-year history of cough who presented with acute shortness of breath. Further workup showed mild eosinophilia and spontaneous pneumothorax. A definitive diagnosis was made with a lung biopsy, which showed P. kellicotti eggs. Further questioning revealed that the patient took a hunting and river rafting trip on a river in Missouri 5 years ago, though the history was negative for any crayfish consumption. Paragonimiasis should be considered in those with associated clinical features, including cough and eosinophilia, with a history of a river raft float trip in Missouri, even if the history is negative for crayfish ingestion or travel.

Endemic Paragonimus kellicotti infections in animals and humans in USA and Canada: Review and personal perspective

Infections with the lung fluke, Paragonimus kellicotti, have been diagnosed in a variety of domestic and wild animals and humans in USA and Canada. Although there are many species of Paragonimus in other parts of the world; P. kellicotti is the only species definitively diagnosed in USA and Canada. Fresh water snails (several species) and crayfish (mainly Orconectes spp.) are its intermediate hosts. Humans and animals become infected with P. kellicotti only by ingesting metacercariae encysted in the heart of crayfish. After ingestion, the fluke penetrates intestinal wall, enters peritoneal cavity, and reaches pleural cavity by direct penetration of diaphragm, 2-3 weeks post inoculation (p.i.). Young flukes penetrate lungs and become encysted in pulmonary tissue, often in pairs. Time to maturity is around 4-7 weeks p.i. Eggs are coughed up, swallowed, and are excreted in feces. Although the parasite has been known for more than a century, there has been an upsurge of human infections in the USA. Here, I review P. kellicotti infections in naturally infected hosts. Pathogenesis, diagnosis, and treatment in parasite-free cats and dogs experimentally infected P. kellicotti are reviewed to shed light on the pathogenesis of human paragonimiasis. Problems and challenges facing diagnosis of paragonimiasis, especially non-pulmonary infections, are discussed. Fluke stages are deposited in Smithsonian Museum.

Pulmonary Paragonimiasis in Native Community, Esmeraldas Province, Ecuador, 2022

Paragonimiasis is a food-borne infection caused by several species of the Paragonimus fluke. Clinical manifestations can mimic tuberculosis and contribute to diagnostic delay. We report a cluster of paragonimiasis in a community in Ecuador, where active surveillance was set up after detection of the first 2 cases.

A clinical review of human disease due to Paragonimus kellicotti in North America

Human autochthonous infections with the trematode Paragonimus kellicotti are increasingly being reported in North America, but the true prevalence and geographic distribution are unknown. Ingestion of raw crayfish is reported in most human cases, typically in the context of alcohol intoxication. Risk of infection varies depending on what part of the crayfish is ingested as metacercariae of P. kellicotti (>50% mature to adults) localize to the heart and pericardium of the crayfish. Reported human cases have manifested primarily in otherwise healthy young adults presenting with severe eosinophilic pneumonia, pleuritis, systemic symptoms, dermatologic lesions and cerebral involvement. However, it is likely that many infections go unreported due to lack of awareness, mild illness or the absence of rapid commercially available diagnostic tests. Promising advances have been made related to novel diagnostic targets. Conservation of these antigen targets among at least four Paragonimus species could make these antigens viable for diagnostic testing of P. kellicotti specifically as well as other Paragonimus species, but additional studies and funding investments are required. Public and physician awareness may have improved due to targeted education campaigns, but ongoing activities to raise awareness are needed, particularly in areas where cases have not been frequently reported to date.

General overview of the current status of human foodborne trematodiasis

Foodborne trematodes (FBT) of public health significance include liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Fasciola hepatica and F. gigantica), lung flukes (Paragonimus westermani and several other Paragonimus spp.) and intestinal flukes, which include heterophyids (Metagonimus yokogawai, Heterophyes nocens and Haplorchis taichui), echinostomes (Echinostoma revolutum, Isthmiophora hortensis, Echinochasmus japonicus and Artyfechinostomum malayanum) and miscellaneous species, including Fasciolopsis buski and Gymnophalloides seoi. These trematode infections are distributed worldwide but occur most commonly in Asia. The global burden of FBT diseases has been estimated at about 80 million, however, this seems to be a considerable underestimate. Their life cycle involves a molluscan first intermediate host, and a second intermediate host, including freshwater fish, crustaceans, aquatic vegetables and freshwater or brackish water gastropods and bivalves. The mode of human infection is the consumption of the second intermediate host under raw or improperly cooked conditions. The major pathogenesis of C. sinensis and Opisthorchis spp. infection includes inflammation of the bile duct which leads to cholangitis and cholecystitis, and in a substantial number of patients, serious complications, such as liver cirrhosis and cholangiocarcinoma, may develop. In lung fluke infections, cough, bloody sputum and bronchiectasis are the most common clinical manifestations. However, lung flukes often migrate to extrapulmonary sites, including the brain, spinal cord, skin, subcutaneous tissues and abdominal organs. Intestinal flukes can induce inflammation in the intestinal mucosa, and they may at times undergo extraintestinal migration, in particular, in immunocompromised patients. In order to control FBT infections, eating foods after proper cooking is strongly recommended.

The role of helminths in the development of non-communicable diseases

Non-communicable diseases (NCDs) like cardiovascular disease, chronic respiratory diseases, cancers, diabetes, and neuropsychiatric diseases cause significant global morbidity and mortality which disproportionately affect those living in low resource regions including low- and middle-income countries (LMICs). In order to reduce NCD morbidity and mortality in LMIC it is imperative to understand risk factors associated with the development of NCDs. Certain infections are known risk factors for many NCDs. Several parasitic helminth infections, which occur most commonly in LMICs, have been identified as potential drivers of NCDs in parasite-endemic regions. Though understudied, the impact of helminth infections on the development of NCDs is likely related to helminth-specific factors, including species, developmental stage and disease burden. Mechanical and chemical damage induced by the helminth in combination with pathologic host immune responses contribute to the long-term inflammation that increases risk for NCD development. Robust studies from animal models and human clinical trials are needed to understand the immunologic mechanisms of helminth-induced NCDs. Understanding the complex connection between helminths and NCDs will aid in targeted public health programs to reduce helminth-induced NCDs and reduce the high rates of morbidity that affects millions of people living in parasite-endemic, LMICs globally.

Cerebral paragonimiasis: Clinicoradiological features and serodiagnosis using recombinant yolk ferritin

Cerebral paragonimiasis (CP), caused by aberrant migration of Paragonimus worms, frequently invokes serious illness. The causal relationship between the lesion characteristics and patients’ symptoms has poorly been understood. CP serodiagnosis has not been properly evaluated to date. A total of 111 CP cases were diagnosed in our laboratory between 1982 and 2003. This study retrospectively assessed the clinical and imaging characteristics of the 105 patients along with the evaluation of diagnostic potentials of recombinant P. westermani yolk ferritin (rPwYF) by enzyme-linked immunosorbent assay (ELISA) employing patients’ sera and cerebrospinal fluids (CSFs). We analyzed 60 male and 45 female patients; 50 early-stage patients with non-calcified enhancing nodule(s) (median age, 38 years; interquartile range [IQR], 24.75–52; median symptom duration, 0.75 years; IQR, 0.2–2) and 54 chronic cases having calcified lesion(s) (median age, 33 years; IQR, 25–41; median symptom duration, 10 years; IQR, 5–20). One patient showed a normal neuroimage. The patients were largely diagnosed in their 30s. The parietal lobe was most commonly affected, followed by occipital, frontal, and temporal lobes. Twenty-six patients had lesions encompassing ≥ two lobes. The patients complained mainly of seizures, headaches, hemiparesis, and focal neurologic deficits (P < 0.001). Seizures and visual defects were predominant in patients with calcified lesion(s) (P < 0.001). The diagnostic sensitivity and specificity of rPwYF against serum/CSF were 100%/97% and 97.2%/92.5%, respectively. The specific IgG antibody levels against rPwYF in sera and CSFs showed a positive correlation (r = 0.59). The clinical manifestations of the early-stage patients might be associated with cortical lesions or meningeal irritation, while those in the chronic stage were caused by conglomerated space-occupying lesions. rPwYF would be useful for the serodiagnosis of both early and chronic CP cases.

Paragonimiasis, caused by the lung fluke Paragonimus spp., is a global foodborne zoonosis of great public health concern. Paragonimiasis is primarily a pleuropulmonary disease. However, the worms sometimes migrate aberrantly to other parts of the body, thereby causing the granulomatous lesion(s). The most serious condition elicited by ectopic migration is cerebral paragonimiasis. This study retrospectively analyzed the clinical and imaging features of the largest number of 105 cases diagnosed between 1982 and 2003 in our laboratory. We also evaluated diagnostic feasibility of recombinant P. westermani yolk ferritin by ELISA. The patients were largely diagnosed in their 30s with the chief complaints of seizures, headaches, hemiparesis, and focal neurologic deficits. Seizures and visual defect were significant in the chronic stage patients having calcified lesion(s). The diagnostic sensitivity and specificity of recombinant P. westermani yolk ferritin by ELISA against patients’ sera or CSFs were 100% or 97%, and 97.2% or 92.5%, respectively. The diverse neurological manifestations of patients might be related to the nature and/or location of the lesions. P. westermani yolk ferritin is a promising antigen for serodiagnosis of both early-stage patients with non-calcified lesion(s) and chronic calcified cerebral paragonimiasis cases.

Granulomatous Diseases of the Central Nervous System

PURPOSE OF REVIEW

To discuss the pathophysiology, key clinical features, necessary diagnostic evaluation, and current treatment regimens for granulomatous diseases of the central nervous system.

RECENT FINDINGS

The diagnosis and management of granulomatous disease of the central nervous system has been revolutionized by advances in diagnostic imaging. Nevertheless, tissue and/or cerebrospinal fluid (CSF) sampling remains necessary to establish the diagnosis in most cases. Establishing a specific diagnosis is critical because treatment selection needs to focus on the granulomatous process centering on either antibiotic or immunosuppressive agents. Particular for non-infectious granulomatous disease more aggressive immunotherapies may help in clinical outcome. There are multiple non-infectious and infectious etiologies for granulomatous disease of the central nervous system. Clinical manifestations result from local structural invasion of granulomas or granulomatous inflammation of the blood vessels and meninges. Rapid diagnosis and specific treatment is essential.

Case Report: Intermittent Chest Pain With Cough, Fever, and Pericardial Effusion Over the Course of 1 Year in an 11-Year-Old Girl

An 11-year-old girl presented with frequent chest pain, fever, and a cough that she had had for more than 13 months, as well as pleural effusion and large pericardial effusion. She was misdiagnosed with tuberculosis and received anti-tuberculosis drugs for 6 months. Within the past year, she also underwent two more thoracotomies and a thoracoscopic partial pericardiectomy. The final diagnosis of pulmonary paragonimiasis was established once it was known that she had eosinophilia, always drank stream water, and tested positive for antibodies against Paragonimus. Since antiparasitic praziquantel therapy was effective, paragonimiasis should be considered as a possibility in the differential diagnosis of tuberculosis in children.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

High-Throughput Sequencing of Environmental DNA as a Tool for Monitoring Eukaryotic Communities and Potential Pathogens in a Coastal Upwelling Ecosystem

The marine environment includes diverse microeukaryotic organisms that play important functional roles in the ecosystem. With molecular approaches, eukaryotic taxonomy has been improved, complementing classical analysis. In this study, DNA metabarcoding was performed to describe putative pathogenic eukaryotic microorganisms in sediment and marine water fractions collected in Galicia (NW Spain) from 2016 to 2018. The composition of eukaryotic communities was distinct between sediment and water fractions. Protists were the most diverse group, with the clade TSAR (Stramenopiles, Alveolata, Rhizaria, and Telonemida) as the primary representative organisms in the environment. Harmful algae and invasive species were frequently detected. Potential pathogens, invasive pathogenic organisms as well as the causative agents of harmful phytoplanktonic blooms were identified in this marine ecosystem. Most of the identified pathogens have a crucial impact on the aquacultural sector or affect to relevant species in the marine ecosystem, such as diatoms. Moreover, pathogens with medical and veterinary importance worldwide were also found, as well as pathogens that affect diatoms. The evaluation of the health of a marine ecosystem that directly affects the aquacultural sector with a zoonotic concern was performed with the metabarcoding assay.

Paragonimus and its hosts in China: An update

Paragonimiasis is an important foodborne parasitic disease. Over 50 species of Paragonimus have been reported worldwide, and China has the widest distribution and largest number of species. The detection of Paragonimus metacercariae from second intermediate hosts has been reported in 22 provinces and municipalities. The most frequently reported species are P. westermani, P. skrjabini, P. heterotremus and Euparagonimus cenocopiosus. In this review, we collected and reviewed relevant reports on the detection of Paragonimus metacercariae in second intermediate hosts from 1937 to 2020 from all areas of China. We provide an updated and current summary of Paragonimus species and their hosts in China. Data on the geographical range, species distribution, and second intermediate host species of Paragonimus were extracted. ArcGIS10.2 software was used to generate distribution maps of Paragonimus for four time periods: 1937-1990, 1991-2005, 2006-2020 and 1937-2020. We analyzed the geographic and spatiotemporal dynamics of Paragonimus prevalence in natural foci and provided a basis for further research and paragonimiasis prevention strategies in China.

The effect of landscape and human settlement on the genetic differentiation and presence of Paragonimus species in Mesoamerica

Foodborne diseases are a neglected research area, and despite the existence of many tools for diagnosis and genetic studies, very little is known about the effect of the landscape on the genetic diversity and presence of parasites. One of these foodborne disease is paragonimiasis, caused by trematodes of the genus Paragonimus, which is responsible for a high number of infections in humans and wild animals. The main Paragonimus sp reported in Mesoamerica is Paragonimus mexicanus, yet there are doubts about its correct identification as a unique species throughout the region. This, together with a lack of detailed knowledge about their ecology, evolution and differentiation, may complicate the implementation of control strategies across the Mesoamerican region. We had the goal of delimiting the species of P. mexicanus found throughout Mesoamerica and determining the effect of landscape and geology on the diversity and presence of the parasite. We found support for the delimitation of five genetic groups. The genetic differentiation among these groups was positively affected by elevation and the isolation of river basins, while the parasite's presence was affected negatively only by the presence of human settlements. These results suggest that areas with lower elevation, connected rivers basins, and an absence of human settlements have low genetic differentiation and high P. mexicanus presence, which may increase the risk of Paragonimus infection. These demonstrate the importance of accurate species delimitation and consideration of the effect of landscape on Paragonimus in the proposal of adequate control strategies. However, other landscape variables cannot be discarded, including temperature, rainfall regime, and spatial scale (local, landscape and regional). These additional variables were not explored here, and should be considered in future studies.

A 48 year old male with wandering pleural effusion and pulmonary infiltration

We reported a case of pulmonary paragonimiasis presenting as wandering pleural effusion and pulmonary infiltration. The patient had an explicit history of eating raw freshwater crabs 6 months earlier, and a test for serum antibodies to paragonimus was positive. This case illustrates the complex nature of pathological processes and immunological responses in the lungs and highlights the need to consider the existence of paragonimus infection.

Paragonimiasis: A missed diagnosis from Nepal

Paragonimiasis, or Oriental lung fluke is a parasitic infestation seen in Asia, Africa and South America which is spread by the consumption of crabs and crayfish. To date four cases have been reported from Nepal. Here, we report a case of paragonimiasis in a young male from Kathmandu valley who presented with symptoms of fever, on and off for 1 month, shortness of breath and cough. He was found to have pleural effusion. Sputum examination did not reveal acid fast bacilli, However, based on clinical features, he was started on antitubercular treatment. There was initial improvement, but later, he continued to have cough and hemoptysis over the next 2 years and on subsequent High-Resolution Computerized Tomography (HRCT) he was found to have a cavitary lung lesion in the superior segment of lower lobe of left lung. A possibility of aspergillosis was considered for which he underwent a lobectomy. The gross examination of the lung showed a small cavity measuring 5 mm which revealed on histology a parasitic structure with serous glands within it. In addition, there were many foreign body granulomas with ova within them. A diagnosis of paragonimiasis was made and the patient was started on Praziquantal. He recovered well and is currently asymptomatic. We can learn from this case that the signs and symptoms of paragonimiasis mimic that of tuberculosis and the mistaken diagnosis can lead to unnecessary treatment, prolonged morbidity and loss of time and resources.

Spectrum of pleuropulmonary paragonimiasis: An analysis of 685 cases diagnosed over 22 years

OBJECTIVES

Paragonimiasis is a global foodborne zoonosis. Overlapping clinical and imaging features with other lung pathologies hamper correct diagnosis and require differential diagnosis.

METHODS

During 1982-2003, 49,012 samples were referred for immunodiagnosis of helminthiases. We detected paragonimiasis cases by enzyme-linked immunosorbent assay (ELISA). We assessed clinical, radiographical and laboratory characteristics, and diagnostic dilemmas associated with delayed diagnosis.

RESULTS

We analyzed 685 pleuropulmonary paragonimiasis cases. ELISA-positive was 665. Eggs were detected in 50. Symptom duration correlated well with the appearance of chest radiographs; 359 pleural, 33 pleuroparenchymal, and 264 parenchymal lesions (P < 0.001). Twenty-nine had normal chest images. Eosinophilia, seen in 304, was common in pleural and pleuroparenchymal patients (P < 0.05). Chest pain and dyspnea were characteristic for pleurisy patients. Sputum (odds ratios [OR]: 6.79; 95% CI: 4.41-10.47), blood-tinged sputum (OR: 5.62; 95% CI: 3.75-8.42), and foul-odor (OR: 2.70; 95% CI: 1.42-5.16) were significant in parenchymal patients. Delayed diagnosis (119) for ≥ 25 weeks was attributed mainly to misdiagnosis as tuberculosis, malignancy, or chronic obstructive pulmonary disease (COPD) (OR: 111.75; 95% CI: 43.25-288.74).

CONCLUSIONS

Variable symptoms and radiographs of pleuropulmonary paragonimiasis depended on the stage of infection. Suspicion of tuberculosis, malignancy, or COPD was major cause of delayed diagnosis.

Intracranial Pseudoaneurysm Caused by Cerebral Paragonimiasis in Pediatric Patients

BACKGROUND

We investigated the proportion of pediatric patients with cerebral paragonimiasis and intracranial hemorrhage who have intracranial pseudoaneurysms.

METHODS

Images of 17 pediatric patients with cerebral paragonimiasis that first manifested as secondary intracranial hemorrhage were evaluated. All patients underwent computed tomographic angiography before surgery. A diagnosis of cerebral paragonimiasis was confirmed based on a positive Paragonimus-specific antibody test in serum samples from all 17 patients. Cerebral paragonimiasis in five of the 17 patients was further confirmed by histopathological examination of surgical specimens.

RESULTS

Computed tomographic angiographic images for six of the 17 patients (35.3%) showed the presence of intracranial pseudoaneurysms. Follow-up computed tomographic angiographic scans two years later showed that two of the six patients had persistent pseudoaneurysms and underwent aneurysmectomy. The diagnosis of pseudoaneurysm was confirmed by histopathological examination postsurgery. In another two of the six patients, the pseudoaneurysm lesions were absorbed and could no longer be seen on three- to six-month follow-up scans. The final two patients with pseudoaneurysms are still under follow-up. Intracranial pseudoaneurysms with various degrees of surrounding hemorrhage were frequently observed at first manifestation.

CONCLUSIONS

The rupture of intracranial pseudoaneurysms is a common characteristic feature of secondary intracranial hemorrhage caused by cerebral paragonimiasis in pediatric patients.

Pleuropulmonary Paragonimiasis with Multiple Nodules in the Pleura

An asymptomatic 47-year-old woman was admitted with pleural effusion and pulmonary infiltrates 1 month after ingesting raw wild boar and deer meat. Both her blood and pleural fluid were eosinophilic. Thoracoscopy revealed multiple nodules of the pleura, and biopsy samples of the nodules showed necrosis with epithelioid cell granulomas. An enzyme-linked immunosorbent assay was positive for antibodies against Paragonimus westermani, and the patient was successfully treated with praziquantel. This is the first reported case of pulmonary or pleuropulmonary paragonimiasis where several pleural nodules were observed. The detection of pleural nodules on thoracoscopy can contribute to the prompt and accurate diagnosis of paragonimiasis.

An initial coprological survey of parasitic fauna in the wild Amur leopard (Panthera pardus orientalis)

The Amur leopard, one of nine recently recognized subspecies of leopard, is still the most threatened by a stochastic procession of extinction. Evaluation of the potential danger to the conservation of the Amur leopard originating from disease urgently needs to be studied. Unfortunately, research on the potential risk to Amur leopards caused by disease is rare. In terms of parasitic diseases that affect this species, even basic data for parasitic fauna are absent. The aim of this study is to acquire this knowledge to improve the general understanding of Amur leopard parasites. Seven parasite species, including 3 nematodes (Toxocara cati, a capillarid-type parasite, and a Metastrongyloidea-type parasite), 2 cestodes (Spirometra sp. and Taenia sp.), 1 trematode (Paragonimus sp.), and 1 protozoan (Cystoisospora felis), were found in this research. Toxocara cati occurred most frequently, followed by Spirometra sp.

A case of group infections with Paraginimus species in Henan, Central China

In July of 2012, mass infections with Paragonimus species were detected in the Henan province sickening 11 of 51 people. In May 2011, these individuals had participated in an excursion during which freshwater crabs were caught and served after being toasted. Before the group infections with Paraginimus species was confirmed, 5 of the 11 patients had been misdiagnosed as tuberculosis (TB) and treated with an anti-TB drug regimen for six months. The most common and typical manifestations were eosinophilia (11/11, 100%) and pulmonary manifestations including, among others, stethalgia and cough (7/11 63.6%). Sero-examination revealed that all 11 patients were seropositive for Paragonimus species. Surprisingly, in our case, one patient presented with hemoptysis and eggs in respiratory secretions, and this is the first time P. skrjabini eggs are detected in the sputum of a patient from the Henan province. Paragonimus metacercariae were collected from 6 of 11 (54.5%) crabs caught at the infection site and were identified as Paraginiumus skrjabini by morphological and molecular examinations. Epidemiological and laboratory evidence confirmed that this is a case of group infection with P. skrjabini. As one of the most neglected tropical diseases (NTD), paragonimiasis should be differentiated diagnosed from TB to avoid the delay of treatment. To our knowledge, this is the second report of a case of group infections with Paraginimus species in Henan, Central China. The first case was reported in 1995. As a kind of food-borne parasitic disease, paragonimiasis should be included in the public health education agenda.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

Diagnosis of Human Trematode Infections

Digenetic trematodes form a major group of human parasites, affecting a large number of humans, especially in endemic foci. Over 100 species have been reported infecting humans, including blood, lung, liver, and intestinal parasites. Traditionally, trematode infections have been diagnosed by parasitological methods based on the detection and the identification of eggs in different clinical samples. However, this is complicated due to the morphological similarity between eggs of different trematode species and other factors such as lack of sensitivity or ectopic locations of the parasites. Moreover, the problem is currently aggravated by migratory flows, international travel, international trade of foods, and changes in alimentary habits. Although efforts have been made for the development of immunological and molecular techniques, the detection of eggs through parasitological techniques remains as the gold standard for the diagnosis of trematodiases. In this chapter, we review the current status of knowledge on diagnostic techniques used when examining feces, urine, and sputum and also analyze the most relevant characteristics used to identify eggs with a quick key for the identification of eggs.

Molecular identification of two cestodes species parasitizing freshwater fishes in India

In the present study, molecular identification of two species of cestodes, Lytocestus indicus and Senga lucknowensis infecting freshwater fishes Clarias magur and Channa punctata, respectively in Manipur is carried out. To ascertain the taxonomic status of these helminth parasites, 18S gene marker was used. Phylogenetic analysis of 18S of Lytocestus sp. showed that it claded with L. indicus from Indian Isolate with a sequence similarity index of 99%. In case of Senga sp., the phylogenetic analysis revealed that it formed a separate clade with S. lucknowensis and Senga vishakapatnamensis, and the sequence similarity index showed maximum homogeneity with S. lucknowensis i.e., 99.8%. Thus, molecular characterization revealed that the two species of cestodes belong to L. indicus and S. lucknowensis.

Diagnosis and surgical management of pericardial effusion due to paragonimiasis

OBJECTIVES

The pericardial effusion (PE) caused by paragonimiasis is rarely reported. This study aims to present experience in the diagnosis and surgical management of PE due to paragonimiasis.

METHODS

Medical records of 57 children who were diagnosed with PE due to paragonimiasis and underwent surgery at Children's Hospital of Chongqing Medical University between January 2012 and August 2018 were retrospectively reviewed.

RESULTS

The average age of this group was 7.6 ± 3.0 years. Patients were mainly from Chongqing and Sichuan areas. ELISA for Paragonimus skrjabini in all 57 patients showed positive results. Moderate or large PE were identified in 12 and 45 patients, respectively. All patients underwent surgery either by pericardectomy or thoracoscopic surgery. Pathological exams indicated massive eosinophil infiltration in all 57 specimens. After 3-4 courses of praziquantel therapy, the clinical outcomes were satisfactory.

CONCLUSIONS

Typical endemic history, eosinophilia and multiple serous effusion raise suspicions of paragonimiasis. Once moderate to large PE is identified in patients with paragonimiasis, surgical treatment is necessary.

Large Pericardial Effusion Due to Paragonimiasis in a 4-Year-Old Chinese Boy

Large pericardial effusion (PE) and bilateral pleural effusion were found in a 4-year-old Chinese boy. An emergent surgery was performed. The biopsy showed massive eosinophil infiltration. Serologic test for Paragonimus skrjabini was positive. Postoperative praziquantel therapy was effective.

Parasites and epilepsy: Understanding the determinants of epileptogenesis

There is a large body of evidence suggesting that parasites could be a major preventable risk factor for epilepsy in low- and middle-income countries. We review potentially important substrates for epileptogenesis in parasitic diseases. Taenia solium is the most widely known parasite associated with epilepsy, and the risk seems determined mainly by the extent of cortical involvement and the evolution of the primary cortical lesion to gliosis or to a calcified granuloma. For most parasites, however, epileptogenesis is more complex, and other favorable host genetic factors and parasite-specific characteristics may be critical. In situations where cortical involvement by the parasite is either absent or minimal, parasite-induced epileptogenesis through an autoimmune process seems plausible. Further research to identify important markers of epileptogenesis in parasitic diseases will have huge implications for the development of trials to halt or delay onset of epilepsy.

Paragonimiasis

Paragonimiasis is a zoonotic disease caused by lung flukes of the genus Paragonimus. Humans usually become infected by eating freshwater crabs or crayfish containing encysted metacercariae of these worms. However, an alternative route of infection exists: ingestion of raw meat from a mammalian paratenic host. Adult worms normally occur in pairs in cysts in the lungs from which they void their eggs via air passages. The pulmonary form is typical in cases of human infection due to P. westermani, P. heterotremus, and a few other species (Table 5.1). Worms may occupy other sites in the body, notably the brain, but lung flukes have made their presence felt in almost every organ. Ectopic paragonimiasis is particularly common when infection is due to members of the P. skrjabini complex (Table 5.1). Human paragonimiasis occurs primarily in the tropics and subtropics of Asia, Africa, and the Americas, with different species being responsible in different areas (Table 5.1).

Epidemiology of Trematode Infections: An Update

Digenetic trematodes infecting humans are more than 91 species which belong to 46 genera all over the world. According to their habitat in definitive hosts, they are classified as blood flukes (Schistosoma japonicum. S. mekongi, S. mansoni, S. haematobium, and S. intercalatum), liver flukes (Clonorchis sinensis, Opisthorchis viverrini, O. felineus, Metorchis conjunctus, M. bilis, M. orientalis, Fasciola hepatica, F. gigantica, Dicrocoelium dendriticum, and D. hospes), lung flukes (Paragonimus westermani, P. heterotremus, P. skrjabini, P. miyazakii, P. kellicoti, P. mexicanus, P. africanus, and P. uterobilateralis), throat fluke (Clinostomum complanatum), pancreatic fluke (Eurytrema pancreaticum), and intestinal flukes (Metagonimus yokogawai, M. miyatai, M. takahashii, Heterophyes nocens, H. heterophyes, Haplorchis taichui, H. pumilio, H. yokogawai, Centrocestus formosanus, Echinostoma revolutum, E. ilocanum, Isthmiophora hortensis, Echinochasmus japonicus, E. lilliputanus, Artyfechinostomum malayanum, A. sufrartyfex, A. oraoni, Fasciolopsis buski, Gymnophalloides seoi, Neodiplostomum seoulense, Caprimolgorchis molenkampi, Phaneropsolus bonnei, and Plagiorchis muris). The mode of transmission to humans includes contact with cercariae contaminated in water (schistosomes) and ingestion of raw or improperly cooked fish (liver and throat flukes, heterophyids, and echinostomes), snails (echinostomes and gymnophallids), amphibia, reptiles (neodiplostomes), aquatic vegetables (amphistomes), or insect larvae or adults (plagiorchiids, lecithodendriids, and pancreatic fluke). Praziquantel has been proved to be highly effective against most species of trematode infections except fascioliasis. Epidemiological surveys and detection of human infections are required for better understanding of the geographical distribution and endemicity of each trematode species.

Respiratory Infections

Respiratory tract infections (RTIs) are a common health problem of international travelers. Travelers may be at increased risk of RTIs due to travel itself (mingling and close quarters in airports, airplanes, cruise ships, and hotels), and due to unique exposure at travel destinations. The clinical spectrum of RTIs in travelers is broad and includes upper RTIs, pharyngitis, otitis, laryngitis, bronchitis, and pneumonia. Most travelers who acquire an RTI only develop mild disease, and only a minority seek medical attention. All travelers should be up to date on any indicated vaccines based on age and medical condition that prevent RTIs, including influenza, measles, pneumococcal diseases, Haemophilus influenzae b, Neisseria meningitidis, diphtheria, and pertussis.

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Respiratory tract infections (RTIs) are among the most common illnesses reported by travelers. Most RTIs are viral, involve the upper respiratory tract, and do not require specific diagnosis or treatment.

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Influenza is often considered the most important travel-related infection. Travelers play an integral role in the yearly and global spread of influenza.

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Lower RTIs, including pneumonia, often require antimicrobial therapy.

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High-risk groups such as infants, small children, the elderly, and subjects with chronic tracheobronchial or pulmonary disease are at increased risk of developing severe clinical consequences should infection occur. All international travelers should be immunized for seasonal influenza unless otherwise contraindicated, and travelers should be instructed in hand hygiene and sneeze and cough hygiene.

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All travelers should be up to date on any indicated vaccines that prevent RTIs, including measles, pneumococcal diseases, Haemophilus influenzae b (Hib), meningococcal disease, diphtheria, and pertussis.

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Travelers may be at increased risk of geographically restricted RTIs, and clinicians should be familiar with the major manifestations of these illnesses.

A Systematic Overview of Zoonotic Helminth Infections in North America

Zoonotic helminths are frequent human parasites that generally complete their natural life cycle in the absence of humans. This review encompasses 30 common or clinically relevant zoonotic helminth infections that are endemic to North America. For each organism or disease, the following information is briefly reviewed: taxonomy, biology, and life cycle, epidemiology, route of transmission for the human host, clinical manifestations, pathologic features, treatment, and laboratory diagnosis. Illustrations are provided for select parasites.

Scrotal Paragonimiasis in adults: Two case reports and review of literature

RATIONALE

Paragonimiasis is a parasitic disease caused by Paragonimus in the lungs; it can be divided into intrapulmonary type and extrapulmonary type. Adult patients with scrotal paragnonimus are rarely seen clinically and not widely reported in the literature. Here, we report 2 cases of scrotal paragonimiasis in adults and their treatment process.

PATIENT CONCERNS

Two young males sought medical advice because of scrotal masses. Both patients had the previous history of eating uncooked river crabs and presented with palpable quasicircular nodules of about 1.5 × 1.0 cm in testicles, which were well-defined, resilient in tenderness. The bilateral inguinal lymph nodes were not enlarged.

DIAGNOSIS AND INTERVENTIONS

The 2 patients underwent scrotal mass resection; postoperative pathology examination confirmed scrotum paragonimiasis. Both the patients were administered praziquantel after operation.

OUTCOMES

They were followed up for 1 year and 4 years, respectively; both recovered well, free from recurrence. Scrotum color Doppler ultrasound examination found no obvious abnormality.

LESSONS

Adult patients with scrotum paragonimiasis are rarely seen clinically. Moreover, its clinical manifestations are not typical that leads to missed diagnosis and misdiagnosis. Diagnosis of the disease needs to combine with disease histories, manifestations, and relevant auxiliary examinations. But the diagnosis can be confirmed only by histopathological examination. The main method for treatment of scrotal paragonimiasis is antiparasitic treatment. However, health education is crucial to prevent this disease and relapse.

Eosinophilic Meningitis Due to Infection With Paragonimus kellicotti

Paragonimus kellicotti is an emerging pathogen in the United States with 19 previously reported cases, most in Missouri. Pulmonary symptoms with eosinophilia are most common, though 1 case did involve the central nervous system with few symptoms. We describe the first 2 cases of eosinophilic meningitis due to Paragonimus kellicotti.

New Nodule Type Found in the Lungs of Pomacea canaliculata, an Intermediate Host of Angiostrongylus cantonensis

BACKGROUND

Pomacea canaliculata (P.canaliculata) lung nodules, were commonly caused by Angiostrongylus cantonensis infection. Here, we found a new nodule type without any parasites.

METHODS

Overall, 447 P. canaliculata snails were collected in Ning Bo, Zhe Jiang, China in 2018. In order to exhibit the similarities and differences between two nodules types (2018, Huzhou Zhejiang, China), both types were collected in formalin for tissue pathological sectioning. Besides, to obtain the microbial community of the new nodule, the 18S ribosomal RNA (rRNA) gene of it was amplified and analyzed using the Illumina second-generation sequencing platform.

RESULTS

Although two nodules were found in the lungs of P. canaliculata, they were different in shape and pathology. Illumina sequencing indicated Poterioochromonas sp., a species of golden algae, might be the causing agent of the new nodule.

CONCLUSION

We firstly found a new pathological nodule type in the lungs of P. canaliculata, and this nodule might be induced by golden algae infection, however, the direct link between the golden algae and the new nodules, as well as the nodules' impact on the snails' physiology and A. cantonensis infection require further study.

Electromagnetic Navigational Bronchoscopy Spares a Drunken Crab From the Surgeon's Knife

Surgical resection is traditionally the preferred treatment for fluorodeoxyglucose-avid peripheral pulmonary nodules that grow over time. However, new technologies, including electromagnetic navigational bronchoscopy (ENB), provide an opportunity to confirm or possibly exclude a cytologic cancer diagnosis, before resection. We present a case of a 56-year-old North American man who presented with a fluorodeoxyglucose-avid pulmonary nodule and sought a second opinion after being recommended thoracotomy with lobectomy. The peripheral nodule was biopsied using ENB and pathologic evaluation of the lesion demonstrated parasitic eggs with features of Paragonimus westermani. No evidence of malignancy was found. The radiographic abnormalities resolved after treatment with praziquantel. Using a minimally invasive procedure with ENB, we successfully diagnosed pulmonary infection with P. westermani, a rare infectious cause of peripheral pulmonary lesions in a patient without travel to an endemic area. Furthermore, an alternative diagnosis to cancer was established, sparing this patient an unnecessary thoracotomy with right middle lobectomy.

Case series of paragonimiasis from Nepal

Paragonimiasis is an important food-borne parasitic zoonosis caused by trematodes of genus Paragonimus. We report case series of paragonimiasis with common symptoms of cough with blood tinged sputum, shortness of breath, chest pain with occasional fever, eosinophilia and radiological findings mimicking pulmonary tuberculosis and had taken anti-tubercular drug despite all investigation negative for tuberculosis without improvement. They all had common history of consumption of raw/undercooked crab. There is a local belief in remote villages of Nepal that eating raw crab helps in healing bone fracture and cure jaundice. Microscopic examination of sputum sample revealed the ova of Paragonimus species. All patients were treated with praziquantel and got improved. Pulmonary paragonimiasis is endemic in Southeast Asia including Nepal. So, it has to be differentiated from pulmonary tuberculosis in the patient with symptoms of cough, chest pain and hemoptysis with eosinophilia and having history of consumption of raw/undercooked crabs or crayfish.

Where are we after 60 years of paragonimiasis research? A bibliometric assessment

Paragonimiasis is highly prevalent endemic food-borne disease in Southeast Asia and Latin America, and constitutes a major public health concern. A bibliometric analysis was performed about the worldwide scientific production of paragonimiasis. We browsed in the Science Citation Index-Expanded (SCI-E) (1957-2015), Scopus (1976-2015), Medline/PubMed/GoPubMed® (1970-2015), ScIELO (1981-2014) and LILACS (1985-2011). All types of articles were included and categorized by year of publication, number, type of scientific article, city and institution of origin, international cooperation, scientific journal, impact factor, language of publication, authors and H index. In SCI-E, 1,028 manuscripts were recovered, while Japan (21.9%) and the USA (17.7%) were the countries with highest scientific production. In this database, Asian region studies received 5,454 citations (H index=32). In Scopus 2161 items were recovered, corresponding to 45.8% of Asian countries. Japan (18.2%) was the first with the University of Miyazaki (11.7% of the country); South Korea (9.5%) was second with the Seoul National University (11.2% of the country). In SciELO 29 items were found, with no contributions from the Asian region. In LILACS 1487 articles were found (22.9% covering Asia). Among the databases, the Journal of Parasitology (Impact factor=1.227) showed the highest number of manuscripts and "Agatsuma T", from Japan, was the author with most records. Japan and South Korea lead global scientific production on paragonimiasis. By contrast, in Latin America, production has been extremely low especially in the last five years.

Cardiopulmonary and Gastrointestinal Manifestations of Eosinophil- associated Diseases and Idiopathic Hypereosinophilic Syndromes: Multimodality Imaging Approach

Eosinophil-associated diseases (EADs) are a diverse group of disorders characterized by an increase in circulating or tissue eosinophils. Cardiopulmonary and gastrointestinal system involvement can be due to primary EAD with no known cause or can be secondary to known systemic disease. The cardiopulmonary spectrum of EADs comprises simple pulmonary eosinophilia, acute eosinophilic pneumonia, chronic eosinophilic pneumonia, Churg-Strauss syndrome, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis, parasitic infections, and idiopathic hypereosinophilic syndrome. Eosinophilic gastrointestinal disorders include eosinophilic esophagitis, eosinophilic gastroenteritis, and eosinophilic colitis. Diagnosis is often challenging and requires a combination of clinical and imaging features along with laboratory findings. The absolute eosinophil count in peripheral blood and the percentage of eosinophils in bronchoalveolar lavage fluid are crucial in evaluation of various eosinophilic lung diseases. Although chest radiography is the initial imaging modality used in suspected cases of pulmonary EAD, multidetector computed tomography may demonstrate more characteristic pulmonary patterns, nodules, and subtle parenchymal abnormalities. Barium esophagography is used to assess mucosal abnormalities and the length and diameter of esophageal strictures. Magnetic resonance imaging is superior in providing valuable information in select patients, especially in evaluation of cardiac and gastrointestinal system involvement. Many patients require a multimodality imaging approach to enable diagnosis, guide treatment, and assess treatment response. Knowledge of the clinical features and imaging findings of the spectrum of EADs involving the lungs, heart, and gastrointestinal tract permits optimal patient care.