Sparganosis is one of the common zoonotic diseases caused by infection with the larval plerocercoids (spargana) of the cestode genus Spirometra. While this parasite distributes globally in canine and feline hosts, human infection is predominantly reported in East Asia, especially China, Korea, Japan, and Thailand. Maybe related to the behavior and food culture, this zoonotic disease is rather rare in South Asia to the Middle East. In these areas, sporadic case reports have been appeared mostly in the local medical journals. To draw a solid picture of sparganosis in these non-endemic areas of Asia, we made an extensive literature survey to gather sparganosis cases in the Indian subcontinent and the Middle East.

Dipylidium caninum is a cosmopolitan parasite of companion animals such as dogs and cats. Accidental infection in humans occur mostly in children. Although considerable number of cases were reported from Europe and the Americas, case reports of this zoonotic disease are rather scarce from Asian countries. The aim of this study is to report the results of literature survey on dipylidiasis cases in humans in Japan. Conclusively, we have found a total of 17 cases since the first case report in from Aichi Prefecture in 1925.

During the mobile clinic activities in Tak Province, Thailand, Paragonimus sp. eggs were found in a fecal sample of a 72-year-old Karen resident. Paragonimus DNA was amplified from the stool sample and identified to P. heterotremus. The patient did not have any symptoms. Apparent pulmonary lesion was not found on the chest X-ray. The patient admitted habitual consumption of semi-cooked or roasted waterfall crabs for several years. The waterfall crabs collected from stream near the village were found negative for Paragonimus metacercariae. In northern Thailand, paragonimiasis remains as one of the public health concerns and should be ruled out for asymptomatic pulmonary patients.

BACKGROUND: Sparganosis is a larval cestodiasis caused by the plerocercoid of Spirometra spp. Since the first description of human sparganosis in 1924, several hundred cases have been reported in Korea. However, systematic approaches for literature surveys of Korean sparganosis have seldom appeared. METHODS: We searched publicly available databases such as PubMed, Research Information Sharing Service, and Korea Medical Citation Index with relevant Medical Subject Headings. RESULTS: At least 438 Korean sparganosis cases have been described from 1924 to 2015. Preoperative diagnosis has been significantly increased since the 1980s due to popularization of serological and imaging diagnostics. Cases were largely detected from fifth decades in general, but cerebral sparganosis was detected in relatively young age groups (third and fourth decades). Sparganosis was prevalent in men (75.9%). Consumption of frog/snake and drinking unfiltered water were found in 63.4% and 16.9% of patients, respectively. Most frequently affected sites were subcutaneous tissues (49.9%), followed by the central nervous system (36.2%). Involvements of visceral organs (7.6%), ocular regions (3.6%), and muscles (2.7%) were noticed. In women, breast sparganosis constituted a large proportion (34.2%). Sparganosis associated with immunocompromised patients has recently been reported. CONCLUSION: Sparganosis has been continuously reported in Korea during the past 90 years, although its incidence has decreased during the last 20 years. The disease is mostly characterized by subcutaneous nodule, but infection of the worm in vital organs often results in serious illness. Continuous awareness is warranted to monitor sparganosis occurrence and associated clinical consequences.
Breast ; Central Nervous System ; Diagnosis ; Drinking ; Female ; Humans* ; Immunocompromised Host ; Incidence ; Information Dissemination ; Korea* ; Male ; Medical Subject Headings ; Muscles ; Sparganosis* ; Sparganum ; Spirometra ; Subcutaneous Tissue ; Water

Along with globalization of traveling and trading, fish-borne nematodiases seems to be increasing in number. However, apart from occasional and sporadic case reports or mini-reviews of particular diseases in particular countries, an overview of fish-borne nematodiasis among travelers have never been performed. In this review, we gathered fish-borne nematodiasis among travelers for recent 25 years by an extensive global literature survey using appropriate keywords, e.g. travelers diseases, human infection, anisakiasis, gnathostomiasis, capillariasis, sushi, sashimi, ceviche, Gnathostoma, Pseudoterranova, Anisakis, Capillaria, etc., as well as various combinations of these key words. The Internet search engines PubMed, Medline, Google and Googler Scholar were used as much as possible, and the references of every paper were checked in order to identify useful and reliable publications. The results showed unexpectedly high incidence of gnathostomiasis and low incidence of anisakidosis. The different incidence values of the infection with several fish-borne zoonotic nematode species are discussed, as well as some epidemiological aspects of the infections. The difficulties of differential diagnosis in non-endemic countries are emphasized. It is concluded that travelers must avoid risky behaviors which can lead to infection and that physicians and health authorities must advice travelers on the risks of eating behaviors during travel.
Anisakiasis ; Anisakis ; Capillaria ; Diagnosis, Differential ; Feeding Behavior ; Gnathostoma ; Gnathostomiasis ; Humans ; Incidence ; Internationality ; Internet ; Public Health ; Search Engine

Paragonimiasis is a food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. In Vietnam, research on Paragonimus and paragonimiasis has been conducted in northern and central regions of the country. Using a combination of morphological and molecular methods, 7 Paragonimus species, namely P. heterotremus, P. westermani, P. skrjabini, P. vietnamensis, P. proliferus, P. bangkokenis and P. harinasutai, have been identified in Vietnam. Of these, the first 3, P. heterotremus, P. westermani and P. skrjabini, are known to infect humans in other countries. However, in Vietnam, only P. heterotremus, found in some northern provinces, has been shown to infect humans. Even nowadays, local people in some northern provinces, such as Lai Chau and Yen Bai, are still suffering from P. heterotremus infection. In some provinces of central Vietnam, the prevalence and infection intensity of P. westermani metacercariae in freshwater crabs (the second intermediate hosts) are extremely high, but human cases have not been reported. Likewise, although P. skrjabini was found in Thanh Hoa Province, its pathogenicity to humans in Vietnam still remains uncertain. The results of molecular phylogenetic analyses of Vietnamese Paragonimus species provides new insights on the phylogeny and taxonomy of the genus Paragonimus. Comprehensive molecular epidemiological and geobiological studies on the genus in Vietnam and adjacent countries are needed to clarify the biodiversity and public health significance of the lung flukes.
Animals ; Humans ; Paragonimiasis/*epidemiology ; Paragonimus/classification/genetics/*isolation & purification ; Phylogeny ; Prevalence ; Sequence Analysis, DNA ; Shellfish/parasitology ; Vietnam/epidemiology

Angiostrongyliasis, caused by Angiostrongylus cantonensis infection, is a food-borne parasitic disease. Its larvae evoke eosinophilic inflammation in the central nervous system, but can also cause pathological changes in the eyes. Among ocular angiostrongyliasis cases, the incidence of optic neuritis is low and only few sporadic reports exist. Some patients with optic neuritis developed obvious hypopsia or even vision loss, which would seriously influence the quality of life of patients. Prompt treatment of optic neuritis caused by A. cantonensis is the key factor for minimizing the incidence of serious complications of this disease. In this review, we first provide a comprehensive overview of ocular angiostrongyliasis, and then focus on the clinical features of optic neuritis caused by A. cantonensis.
Angiostrongylus cantonensis/*isolation & purification ; Animals ; Asia/epidemiology ; Eye Diseases/*epidemiology/*parasitology/pathology ; Humans ; Incidence ; Optic Neuritis/*epidemiology/*parasitology/pathology ; Strongylida Infections/*epidemiology/*parasitology/pathology

Neurognathostomiasis is a severe form of human gnathostomiasis which can lead to disease and death. Diagnosis of neurognathostomiasis is made presumptively by using clinical manifestations. Immunoblotting, which recognizes antigenic components of molecular mass 21 kDa and 24 kDa in larval extracts of Gnathostoma spinigerum (Gs 21/24), has high sensitivity and specificity for diagnosis of neurognathostomiasis. However, only very small amounts of the Gs 21/24 antigens can be prepared from parasites harvested from natural or experimental animals. To overcome this problem, we recently produced a recombinant matrix metalloproteinase (rMMP) protein from G. spinigerum. In this study, we evaluated this rMMP alongside the Gs 21/24 antigens for serodiagnosis of human neurognathostomiasis. We studied sera from 40 patients from Srinagarind Hospital, Khon Kaen University, Thailand, with clinical criteria consistent with those of neurognathostomiasis, and sera from 30 healthy control adults from Thailand. All sera were tested for specific IgG antibodies against both G. spinigerum crude larval extract and rMMP protein using immunoblot analysis. The sensitivity and specificity for both antigenic preparations were all 100%. These results show that G. spinigerum rMMP protein can be used as an alternative diagnostic antigen, in place of larval extract, for serodiagnosis of neurognathostomiasis.
Adult ; Animals ; Antibodies, Helminth/blood ; Antigens, Helminth/*diagnostic use/genetics/isolation & purification ; Central Nervous System Parasitic Infections/*diagnosis/parasitology ; Gnathostoma/enzymology/immunology/*isolation & purification ; Gnathostomiasis/*diagnosis/parasitology ; Healthy Volunteers ; Humans ; Immunoblotting/methods ; Immunoglobulin G/blood ; Matrix Metalloproteinases/*diagnostic use/genetics/isolation & purification ; Parasitology/*methods ; Prospective Studies ; Recombinant Proteins/diagnostic use/genetics/isolation & purification ; Sensitivity and Specificity ; Serologic Tests/methods ; Thailand

Among Paragonimus species, P. paishuihoensis is one of the most mysterious and poorly understood species. Metacercariae are characterized by having a unique dendritically branched excretory bladder. However, the morphology of the adult worm remains unknown. To date, metacercariae of this species have been reported only in China and Thailand. In this study, we first found P. paishuihoensis metacercariae in freshwater crabs, Potamon lipkei, in Hinheub District, Vientiane, Lao PDR, with a prevalence of 77.7% and the average intensity of 10.3 (range 1-28) metacercariae per crab. The molecular data based on ITS2 and CO1 markers indicated that P. paishuihoensis from Laos and Thailand were almost completely identical and were close to members of the Paragonimus bangkokensis/Paragonimus harinasutai complex. Attempts to infect experimental animals (cats, dogs, and rats) with P. paishuihoensis were unsuccessful, suggesting that these animals might be unsuitable definitive hosts for the species. Further studies are necessary to elucidate the taxonomic status and life cycle of P. paishuihoensis.
Animals ; Brachyura/*parasitology ; Cluster Analysis ; DNA, Ribosomal Spacer/chemistry/genetics ; Electron Transport Complex IV/genetics ; Fresh Water ; Laos ; Metacercariae/*isolation & purification ; Molecular Sequence Data ; Paragonimus/*isolation & purification ; Phylogeny ; Polymerase Chain Reaction ; Prevalence ; Sequence Analysis, DNA ; Sequence Homology

Paragonimiasis is an important food-borne parasitic zoonosis caused by infection with lung flukes of the genus Paragonimus. Of the 7 members of the genus known in Thailand until recently, only P. heterotremus has been confirmed as causing human disease. An 8th species, P. pseudoheterotremus, has recently been proposed from Thailand, and has been found in humans. Molecular data place this species as a sister species to P. heterotremus, and it is likely that P. pseudoheterotremus is not specifically distinct from P. heterotremus. In this study, we collected metacercariae of both nominal species (identification based on metacercarial morphology) from freshwater crabs from Phetchabun Province in northern Thailand, Saraburi Province in central Thailand, and Surat Thani Province in southern Thailand. In addition, we purchased freshwater crabs imported from Myanmar at Myawaddy Province, western Thailand, close to the Myanmar-Thailand border. The DNAs extracted from excysted metacercariae were PCR-amplified and sequenced for ITS2 and cox1 genes. The ITS2 sequences were nearly identical among all samples (99-100%). Phylogenies inferred from all available partial cox1 sequences contained several clusters. Sequences from Indian P. heterotremus formed a sister group to sequences from P. pseudoheterotremus-type metacercariae. Sequences of P. heterotremus from Thailand, Vietnam, and China formed a separate distinct clade. One metacercaria from Phitsanulok Province was distinct from all others. There is clearly considerable genetic variation in the P. heterotremus complex in Thailand and the form referred to as P. pseudoheterotremus is widely distributed in Thailand and the Thai-Myanmar border region.
Animals ; Cluster Analysis ; DNA, Ribosomal Spacer/chemistry/genetics ; Electron Transport Complex IV/genetics ; *Genetic Variation ; Metacercariae/genetics/isolation & purification ; Molecular Sequence Data ; Myanmar ; Paragonimus/*classification/*genetics/isolation & purification ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Homology ; Shellfish/parasitology ; Thailand