An Overview of Fish-borne Nematodiases among Returned Travelers for Recent 25 Years– Unexpected Diseases Sometimes Far Away from the Origin

Abstract

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.

<i>Contracaecum<i> spp. (NEMATODA: ANISAKIDAE) AND <i>Eustrongylides<i> spp. (NEMATODA: DIOCTOPHYMATIDAE) NEMATODE LARVAE WITH ZOONOTIC POTENCIAL FOUND IN TWO FISH SPECIES FROM TRAMANDAÍ RIVER BASIN, SOUTHERN BRAZIL

“…Many nematodes species are reported to be parasitizing fish, however, only some species can infect humans (Adams et al, 1997). In freshwater fish, among the nematode families that cause most zoonoses, the Anisakidae family (Abdallah et al, 2012;Santana et al, 2017) and Dioctophymatidae (Spalding and Forrester, 1993;Narr et al;1996;Eiras et al, 2018) stand out.…”

Gnathostomiasis Acquired by Visitors to the Okavango Delta, Botswana

“…In endemic areas, the diagnosis of gnathostomiasis is usually made by the combination of clinical features and history of consuming undercooked aquatic food items, or sometimes, unusual risk items such as raw snake meat or live fish [1,14]. The rdiagnosis is supported by the finding of eosinophilia in blood (or cerebrospinal fluid, in the case of central nervous system involvement); however, eosinophilia is not invariable, as in our probable case where the differential leucocyte count was normal.…”

“…Humans are sometimes accidentally infected with Gnathostoma species, which are nematode parasites of fish-eating animals, usually wild and domestic cats and dogs, but the host range of this parasite genus extends to pigs, rodents, raccoons, opossums, otters, weasels and other mustelids, and bears. Among 13 recognised species worldwide, there are at least six that infect humans, the most common of which is Gnathostoma spinigerum (reviewed in [1,3]). The species are traditionally differentiated on morphological features, but modern nucleic acid-based methods have also been utilised.…”

“…This is particularly so when they are food-or water-associated, as visitors cannot easily avoid these vehicles of transmission, or may even pursue them in the interests of adventurous eating. Further increasing the risk of infection, local foods may traditionally be consumed raw or incompletely cooked [1]. Importation or local cultivation of exotic food species may greatly extend the geographic range of associated pathogens [2].…”

Studies on the distribution and diversity of helminth infection in Xenentodon cancila (Hamilton, 1822) in Mizoram, Northeast India

“…Many studies were performed on the helminth parasitic fauna of freshwater fishes, its frequency and distribution in many parts of the world. Fish borne helminth zoonoses is an important part of food borne helminth zoonoses (Eiras et al, 2018). At least 13 species of Diphyllobothrium have been reported from humans, with infections by D. latum and D. dentriticum being the most prevalent, (Adam et al, 1997).…”