Sushi Delights and Parasites: The Risk of Fishborne and Foodborne Parasitic Zoonoses in Asia

Because of the worldwide popularization of Japanese cuisine, the traditional Japanese fish dishes sushi and sashimi that are served in Japanese restaurants and sushi bars have been suspected of causing fishborne parasitic zoonoses, especially anisakiasis. In addition, an array of freshwater and brackish-water fish and wild animal meats, which are important sources of infection with zoonotic parasites, are served as sushi and sashimi in rural areas of Japan. Such fishborne and foodborne parasitic zoonoses are also endemic in many Asian countries that have related traditional cooking styles. Despite the recent increase in the number of travelers to areas where these zoonoses are endemic, travelers and even infectious disease specialists are unaware of the risk of infection associated with eating exotic ethnic dishes. The aim of this review is to provide practical background information regarding representative fishborne and foodborne parasitic zoonoses endemic in Asian countrie

Neurognathostomiasis, a Neglected Parasitosis of the Central Nervous System

Gnathostomiasis is a foodborne zoonotic helminthic infection caused by the third-stage larvae of Gnathostoma spp. nematodes. The most severe manifestation involves infection of the central nervous system, neurognathostomiasis. Although gnathostomiasis is endemic to Asia and Latin America, almost all neurognathostomiasis cases are reported from Thailand. Despite high rates of illness and death, neurognathostomiasis has received less attention than the more common cutaneous form of gnathostomiasis, possibly because of the apparent geographic confinement of the neurologic infection to 1 country. Recently, however, the disease has been reported in returned travelers in Europe. We reviewed the English-language literature on neurognathostomiasis and analyzed epidemiology and geographic distribution, mode of central nervous system invasion, pathophysiology, clinical features, neuroimaging data, and treatment options. On the basis of epidemiologic data, clinical signs, neuroimaging, and laboratory findings, we propose diagnostic criteria for neurognathostomiasis

IDENTIFICATION OF MAJOR STREPTOCOCCUS SUIS SEROTYPES 2, 7, 8 AND 9 ISOLATED FROM PIGS AND HUMANS IN UPPER NORTHEASTERN THAILAND

Abstract. Streptococcus suis serotype 2 infections occur in many provinces of northeastern Thailand. However, knowledge concerning the prevalence of the common S. suis serotypes (1, 1/2, 2, 5, 7, 8, 9, 14 and 16) among healthy and diseased pigs in upper northeastern Thailand remains limited. This study investigated S. suis isolates from pigs (healthy and diseased) and also from humans using 11 conventional biochemical tests, 16S rDNA PCR and sequence analysis and multiplex PCR genotyping of porcine cps and gdh. Thirty-three isolates were obtained between 2009 and 2012 from blood or cerebrospinal fluid of patients from northeastern Thailand previously diagnosed with S. suis infection, based on clinical symptoms and laboratory diagnosis using 11 biochemical tests and PCR detection of 16S rDNA and cps. Eleven S. suis isolates were obtained between 2006 and 2009 from diseased pigs with clinical signs and laboratory diagnoses. In addition, 43 isolates obtained from 741 nasal swab cultures of slaughtered pigs between 2011 and 2012 were included. All three methods showed similar sensitivity in detection of S. suis from clinical and diseased pig specimens, although in healthy pigs, the 11 conventional biochemical methods yielded 2.3% false positives, and the gdh PCR detection method exhibited 31% false negatives. S. suis was present among healthy pigs in 8 of 10 provinces in upper northeastern Thailand, giving an average prevalence of 5.7% (range 1%-17%) using conventional methods together with 16S rDNA PCR assay. False positives by conventional methods were due to species with similar phenotypes, such as viridian streptococci, and are not statistically different from those obtained with the 16S rDNA PCR method, and the false negatives using gdh PCR assay will require further investigation. As S. suis was recovered from both diseased and healthy pigs, raw or undercooked pork products should be considered unsafe for handling or consumption in these regions of Thailand

Confirmation of the paraphyletic relationship between families Opisthorchiidae and Heterophyidae using small and large subunit ribosomal DNA sequences

Opisthorchiidae and Heterophyidae are classified into different families based on morphological identification. However, recent molecular phylogenetic studies suggested the possible paraphyletic relationship between these two families. In this study, the paraphyletic relationship between these two families was confirmed further by maximum likelihood and Bayesian inference analyses using the combined sequences of SSU and LSU rDNA

Families Opisthorchiidae and Heterophyidae: are they distinct?

Superfamily Opisthorchioidea Looss, 1899 consists of three well-known families, Opisthorchiidae, Heterophyidae, and Cryptogonimidae, with basic similarities in morphology and life-cycles. Many species in the first two of these families are human pathogens, such as Opisthorchis viverrini, O. felineus, Clonorchis sinensis, Haplorchis spp. and Metagonimus spp. Recently, a molecular phylogenetic study on the classification of Digenea revealed a paraphyletic relationship between Opisthorchiidae and Heterophyidae. For our study, we gathered and analyzed all available data in GenBank, together with new data of nuclear 185 ribosomal DNA and ribosomal internal transcribed spacer 2 (ITS2) sequences of the families within the Opisthorchioidea. Maximum likelihood and Bayesian inference analyses suggested that families Opisthorchiidae and Heterophyidae are inseparable from each other, with the former nested within the latter. Groupings in molecular trees are generally consistent with morphological features used in taxonomy