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Neglected rare human parasitic infections: Part III: Acanthocephaliasis Review Article Wael M Lotfy Department of Community Health Nursing, Faculty of Nursing, Matrouh University, Egypt ABSTRACT Human acanthocephaliasis is a zoonotic parasitic infection with acanthocephalan species. Reports documenting human infection with acanthocephalans are relatively rare in the literature. Nonetheless, man has been infected with acanthocephalans since ancient times. Despite their economic and medical significance, acanthocephalans were found to be good indicators of environmental pollution. This review summarizesKeywords: Acanthocephala, current knowledge Acanthocephalus, of acanthocephalans Bolbosoma, Corynosoma as human Macracanthorhynchus,parasites and their beneficial Moniliformis, uses. Plagiorhynchus, Pseudoacanthocephalus Received: 23 October, 2020, Accepted: 10 December, 2020. Corresponding Author: Wael M Lotfy, Tel.: +20 1272688624, E-mail: [email protected] Print ISSN: 1687-7942, Online ISSN: 2090-2646, Vol. 13, No. 3, December, 2020. Acanthocephalans (Phylum Acanthocephala) are a Adults of the class Archiacanthocephala are mysterious group of parasites. Adults are cylindrical microscopic parasites that attach themselves to the unsegmented worms. They vary greatly in length from intestinal wall of terrestrial vertebrates. They infect a few millimetres to 65 cm as in Macracanthorhynchus mainly predacious birds and mammals. Adults of hirudinaceus. However, most of the known species have an average length of 10-35 mm. Worms are and less frequently amphibians and reptiles. The characterized by having an invaginable proboscis classthe class Palaeacanthocephala Eoacanthocephala is are the parasites largest andof fishesmost armed with spines used to attach to the intestinal wall of the vertebrate host. They have a hollow trunk which contains the excretory, reproductive and nervous anddiversified mammals class throughoutof acanthocephalans. the world. Adults The of class this Polyacanthocephalaclass parasitize fishes, comprises amphibians, only one reptiles, monogeneric birds, are dioecious, with separate male and female worms. Theysystems lack in an psuedocoelomic alimentary tract, fluid. and Acanthocephalansthe absorption of South America and Africa, respectively[4-7]. nutrients occurs entirely through the body wall. They family that parasitizes crocodiles and probably fish in have a pair of oval bodies called lemnisci, which hang Human acanthocephaliasis from the anterior wall of the body and extend into Humans have been associated with acanthocephalans since antiquity. Their eggs were when the proboscis is invaginated, and may also have detected in fossilized human excrement (coprolites) athe function trunk. Eachin fat lemniscusmetabolism serves[1,2]. Phylogenetic as a fluid reservoir studies that was dated to the prehistoric era[8, 9]. Human have indicated that acanthocephalans are highly cases of acanthocephaliasis are only common in derived rotifers[3]. certain foci in China, and remain sporadic in the rest of the world[10]. Many acanthocephalan species are Acanthocephalans are exclusively parasitic in all for ecological reasons, are not likely to be ingested They have complex life cycles which involve at least byknown man [11]to . haveMan lowwas hostreported specificity to be infectedbut fortunately, with at twoclasses hosts of vertebrates,(Figure 1). especiallyIn species inwith fish knownand birds. life least nine acanthocephalan species, among them, cycle, juveniles colonise arthropods (crustaceans Macracanthorhynchus hirudinaceus and Moniliformis moniliformis are the most common species[12,13]. Most amphibians, reptiles, birds or mammals). The eggs reported cases of acanthocephaliasis have involved or insects), and adults colonise vertebrates (fish, the gastrointestinal tract. Acanthocephalans of intermediate host. Some species have more than one medical importance are found only in two classes, intermediateare passed in faeceshost. Some of the vertebrates final host to act be aseaten paratenic by the Archiacanthocephala, and Palaeacanthocephala. hosts for the larval stages that need to be ingested by Species of the former class are relatively large, while the appropriate vertebrate host in order to develop species of the latter are small. into adults[1]. 1. Class: Archiacanthocephala The phylum Acanthocephala comprises four Macracanthorhynchus hirudinaceus (Pallas, 1781) classes: Archiacanthocephala, Eoacanthocephala, Synonyms: Taenia hirudinaceus (Pallas, 1781); Palaeacanthocephala, and Polyacanthocephala. Gigantorhynchus gigas (Pallas, 1781). Personal non-commercial use only. PUJ copyright © 2020. All rights reserved DOI: 10.21608/PUJ.2020.47335.1090 145 PARASITOLOGISTS UNITED JOURNAL Acanthocephala Acanthor Acanthelia Cystacanth 2a 2b 2c (5) Aberrant human (3) infection Definitive host becomes infected by ingestion of infected intermediate host [I] (2) M. moniliformis Eggs are ingested by Macracanthorhynchus sp. an intermediate host M. moniliformis Macracanthorhynchus sp. M. moniliformis Macracanthorhynchus sp. I: Infective stage (1) Eggs are shed in the feces D: Diagnostic stage [D] (4)Adults in small intestine Fig. 1. The life cycles of Macracanthorhynchus sp. and Moniliformis moniliformis, and transmission of human acanthocephaliasis (source: https://www.cdc.gov) This species has a cosmopolitan distribution[14]. reported from Russia[18-20], Brazil[21], Thailand[22-25], Madagascar[26], Papua New Guinea[27], and China[16,28]. suids, and very rarely dogs and human. Adult worms colonizeThe definitive the small hosts intestine of this species of the are mammalian pigs and otherhost, Macracanthorhynchus ingens Meyer, 1933 and embryonated eggs, containing a fully developed This species exists almost exclusively in North acanthor, are expelled with the faeces. To continue America[29]. The life cycle of M. ingens is greatly like that their development, the egg must be ingested by a beetle, of M. hirudinaceus M. ingens include usually a dung beetle. Inside the intermediate host, raccoons, wolves, badgers, foxes, skunks, opossums, the egg hatches in the midgut and the freed acanthor mink, bears, ring-tailed. Definitive cats, hosts moles for and dogs[30,31]. larva migrates to the body cavity of the insect, where it continues its development to reach the acanthellae intermediate host, a millipede, containing the infective stage, then encysts to form the cystacanth stage. When cystacanthThe definitive stage host of becomes the parasite infected or byby ingestingingesting ana paratenic host, such as a rodent or a snake, containing sheds its cystic envelope and, after 2-3 months, reaches encysted cystacanths. After ingestion, the cystacanth maturitya definitive and host begins ingests oviposition a parasitized[15]. insect, the larva hatches in the small intestine of the host, attaches its proboscis deep into the intestinal wall, and matures to Human infection usually occurs in regions of high the adult stage[32]. It was reported that M. ingens was prevalence of M. hirudinaceus in pigs and human habits of consumption of raw or under roasted insects, for few cases of children in Texas, USA[29,33]. dietary or medicinal purposes[10]. After ingestion, the not a significant zoonotic parasite but was diagnosed in Moniliformis moniliformis (Bremser, 1811) Travassos, 1915 andparasite granuloma attaches formation. itself firmly The to parasite the intestinal may penetrate mucosa This species is a common parasite found in most theby using intestinal its proboscis. wall to reach This the may peritoneum. result in inflammation Mechanical parts of the world[12]. The life cycle is like the above damage caused by the insertion of the armed proboscis into the intestinal wall may result is acute abdominal host for M. moniliformis is typically a rat, although pain, eosinophilic enteritis and possibly intestinal othermentioned rodents, two carnivores, archiacanthocephalans. and primates includingThe definitive man, perforation with peritonitis and abscess formation. may serve as accidental hosts. The parasite’s eggs are Some cases in China have had acute abdominal colic ingested by an intermediate host (typically a cockroach with multiple perforations in the jejunum[16]. host, resulting in infection. Infected cockroaches showedor beetle), reduced which is subsequentlypredator avoidance eaten by behaviour,the definitive a acanthocephaliasis in man when he diagnosed a child infectionIn 1859, in Prague,Lambl Czechdocumented lands[17] the. More first cases report were of increasing the likelihood that its cockroach host will be phenomenon that presumably benefits the parasite by 146 Acanthocephaliasis Lotfy ingested by a rodent, a necessary event for the parasite Corynosoma strumosum (Rudolphi, 1802) Lühe, 1904 to complete its life cycle[34]. Amphibians and reptiles The precise biogeography of this parasite is may serve as paratenic hosts[35]. eating mammals, particularly seals, and birds. The Humans, especially children, may acquire the intermediateunknown. Definitive host is hostsprobably of this a crustacean.species are Manyfish- infection by ingesting cockroaches and beetles [62]. This species containing infective larvae[36,37]. It is probable that was reported once from man, but accidental parasitism human infection is acquired by eating a raw paratenic ofspecies Eskimos of fish is probably serve as common. paratenic One hosts juvenile specimen host. In infected human hosts, the worms seldom mature was recovered from the stools of an Eskimo