The most important health problem is infection by the cysticerci, cysticercosis. One is due to eating undercooked pork that contains the cysts and results in adult worms in the intestines. Restate the basic concepts of parasitology define of the various terms related to basic parasitology discuss briefly the life cycle and pathogenesis of medically important parasites apply the knowledge of the life cycle to the principles of laboratory diagnosis learning outcomes. Neurocysticercosis, the infection of the human nervous system by the cystic larvae of this parasite, has a protean array of clinical manifestations varying from entirely asymptomatic infections to aggressive, lethal courses. Taenia eggs found in human stools wiley online library. People with taeniasis may not know they have a tapeworm infection because symptoms are. The life cycle of taenia solium, the pork tapeworm, is continuously closed in many rural settings in developing countries when free roaming pigs ingest human stools containing t.
Jun 24, 2014 the life cycle of taenia solium, the pork tapeworm, is continuously closed in many rural settings in developing countries when free roaming pigs ingest human stools containing t. We also detected antibodies against cysticercosis, an infection caused by eat ing the eggs of taenia solium, the pork tapeworm. Taenia solium, the pork tapeworm of man, as adult lives in the intestine of man leading an endoparasitic life. Infection with taenia solium adults is usually asymptomatic. Pdf high prevalence of taenia saginata taeniasis and. Taenia solium humans and are usually the definitive host. This chapter describes the life cycle, general morphology and ultrastructure of the larval and adult stages of taenia solium, a parasitic flatworm of humans found in underdeveloped countries. You can see below a clear example of the hooks present in between the four suckers. Taenia saginata, the beef tapeworm, and taenia solium, the pork tapeworm, are the most common tapeworms affecting humans. Adults possess a flat, ribbonlike body shape that is important for absorbing nutrients from its hosts intestine. Taenia species introduction taenia species are the most common cestode parasites of humans.
This flatworm can grow in length from 4 to 12 meters long and 2 milimeters in diameter consisting of a scolex, neck, and strobila. Adult tapeworms have also been found in some species of nonhuman primates. Taenia solium infections taeniasiscysticercosis are a major scourge to most developing countries. Taenia solium commonly known as the pork tapeworm or the armed tapeworm. Taenia solium this species causes cysticercosis in pigs and humans parasite morphology. A characteristic that both tapeworms of these do share is their almost identical eggs. Apr 25, 2019 taenia solium commonly known as the pork tapeworm or the armed tapeworm. Morphology and biochemistry of the pork tapeworm, taenia. Fairley, in mandell, douglas, and bennetts principles and practice of infectious diseases eighth edition, 2015. The list of other animals that may act as definitive or intermediate hosts of taenia solium is large but clinically irrelevant. May 14, 2014 taenia solium completes its life cycle in two different vertebrate hosts, man and pig. Beef tapeworm tapeworm infections have been reported since 1500 b.
Taeniasis is the infection of humans with the adult tapeworm of taenia saginata or taenia solium. This infection type is called taeniasis and is often asymptomatic. Pathogenesis of taenia solium taeniasis and cysticercosis. Taenia solium, surface glycoproteins, ultrastructure, tegument, paramyosin, glycogen, myofibrils, gap junction.
The entire body is called a strobila and may range in size from two to eight meters long. Diagnostic tools for taenia solium and taenia saginata. Gravid proglottids of left taenia saginata and right t. Differentiating taenia solium and taenia saginata infections. Taeniasis, cysticercosis, taenia solium, taenia saginata, cestodes, coproantigens. Humans are the definitive hosts for taenia solium the pork tapeworm and t. It is worldwide in distribution the infection is common amongst those eating raw or insufficiently cooked measly pork. Infection follows consumption of undercooked beef or pork containing cysts.
Pdf morphologic descriptions of taenia asiatica sp. Taenia solium is the cause of neurocysticercosis, which has several forms including parenchymal, subarachnoid, ventricular, and spinal forms. Taenia solium infection is acquired either from human feces that contains taenia solium eggs or from uncooked pork which contains larval cysts. In this small series, egg morphology shape, maximal diameter provided appropriate dif ferentiation between t.
Their number allows differentiation between the two species. Taenia solium is the pork tapeworm, a tapeworm belonging to the cyclophyllid cestode family. Visualization of the branches can be improved by clearing the specimen in lactophenol followed by india ink injection into the lateral genital pore. Pdf s and list of publications there are many examples of various reagents etc. Man is considered to be the definitive host and the pig is considered as the intermediate host.
High prevalence of taenia saginata taeniasis and status of taenia solium cysticercosis in bali, indonesia, 20022004. Taeniasis in humans is a parasitic infection caused by the tapeworm species taenia saginata beef tapeworm, taenia solium pork tapeworm, and taenia asiatica asian tapeworm. Taenia solium completes its life cycle in two different vertebrate hosts, man and pig. Adult worms are rarely pathogenic but the encysted larval stage cysticercus cellulosae of the worm caused a serious disease in.
The morphological characteristics of the adults are distinctive. Taenia solium infection has been recognized since biblical times and the parasite life cycle has been identified by the 1850s. Infection with taenia solium porcine cysticercosis article 15. Humans can become infected with these tapeworms by eating raw or undercooked beef t. Difference between taenia solium and taenia saginata learn. Taenia solium cysticercus is a liquidfilled vesicle measuring from 10 to 20 mm in diameter, with great variation in size. The scolex is globular in outline and has 4 circular. Taenia solium eggs can also cause cysticercosis life cycle. The restellum resembles the conventional figures of the sun, hence the name solium.
The cestodes tapeworms taenia saginata beef tapeworm and t. Adult worms are rarely pathogenic but the encysted larval stage cysticercus cellulosae of the worm caused a serious disease in human called cysticercosis. Injection of india ink in the uterus allows visualization of the primary lateral branches. Humans are the only definitive hosts for these three species. Among them 359 were caused by taenia saginata, three by t. Taenia solium infection and the resulting disease neurocysticercosis are endemic in less developed countries where pigs are raised as a food source. Tim odempsey, in antibiotic and chemotherapy ninth edition, 2010. Except the adult, various stages of its life history are passed in the body of secondary host. Taenia saginata, known as the beef tapeworm, is transmitted to humans in the form of infectious larval cysts found in the meat of cattle, which serve as the parasites usual intermediate host. State of the art of taenia solium as compared to taenia asiatica. It consists of the vesicular wall and the invaginated scolex voge,1963. Eggs are shed into the environment via human feces, and when ingested by pigs, they develop into tissue cysts, causing cysticercosis 5. Taenia solium is the pork tapeworm, a tapeworm belonging to the cyclophyllid cestode family taeniidae. Taenia solium, taenia saginata, taenia asiatica, their.
It is found throughout the world and is most common in countries where pork is eaten. Give the mode of reproduction and egg discharge of taenia. The life cycle of taenia solium involves the pig as the normal intermediate host harboring the larval vesicles, or cysticerci and humans as the definitive host harboring the adult tapeworm. It is a flatribbon like tape worms that causes intestinal taeniasis. Taenia saginata has 1230 primary lateral uterine branches, while t.
Taenia solium infection taeniasis is an intestinal infection with adult tapeworms that follows ingestion of contaminated pork. The usual intermediate hosts are domestic and wild pigs. Cysticercosis is usually asymptomatic unless larvae. Morphology and biochemistry of the pork tapeworm, taenia solium. This experience indicates that molecular analysis is preferable and necessary for precise reidenti. The scolex is armed by a hooked rostrum and four suckers, which help this tiny, only 12mmsized adhesion apparatus which remains firmly attached at the wall of the small intestine. Taenia saginata beef tapeworm, taenia solium pork tapeworm or taenia asiatica asian tapeworm. It is a major public health problem because of the high proportion of seizure cases in endemic areas which are caused by nervous system infection with the larval stage neurocysticercosis, ncc garcia and del brutto, 2005. Taeniasis is the infection of humans with the adult tapeworm of taenia saginata, t. The pork tapeworm, taenia solium, is the most harmful tapeworm in humans. Taeniasis is the parasitic infection of humans caused by adult tapeworm species. Jan 29, 2016 taenia solium infections taeniasiscysticercosis are a major scourge to most developing countries.
Speciesspecific identification of human tapeworm infections is important for public health purposes, because prompt identification of taenia solium carriers may prevent further human cysticercosis infections a major cause of acquired epilepsy. Morphology, tongue palpation, meat inspection ctmri scan. Taenia solium is one of the many species of cestodes tapeworms that can infect humans flisser 1994. Each proglottid of taenia solium has reproductive organs from both sexes and. Diagnostic tools for taenia solium leslie js harrison stakeholder meeting on taenia solium. In the case of taenia solium, humans are the most important definitive hosts, whereas both pigs and humans are the main intermediate hosts. Two practical methods for the differentiation of cestode proglottids, i routine embedding, sectioning, and hematoxylineosin he staining and ii. In general terms, tapeworms are complex organisms having complex life cycles that require at least two hosts for their completion. Aug 16, 2003 taenia solium infection and the resulting disease neurocysticercosis are endemic in less developed countries where pigs are raised as a food source.
Details on the taenia solium life cycle, transmission, and diagnosis can be found in chapter 26. The adult hermaphroditic tapeworm reaches a length of 36 m and lives in contrast to its english trivial name inside the intestine of humans and primates figs. Taenia solium, taenia saginata, cestodos, coproantigenos. General recognition features scolex has four suckers with a rostellum that has a double circle of alternating large and small hooks 2236 proglottid is smaller than t saginata and has. Adult worms may cause mild gastrointestinal symptoms or passage of a motile segment in the stool. Difference between taenia solium and taenia saginata. Eggs are shed into the environment via human feces, and when ingested by pigs, they develop into tissue cysts, causing cysticercosis.
Taenia solium and taenia saginata linkedin slideshare. Taenia solium the common name for taenia solium is pork tapeworm i. Immunology of taenia solium taeniasis and human cysticercosis. Occurrence of taenia solium and cysticercosis in man in egypt of the hands after using toilets and before preparation significantly increases with age and the highest age of food, washing of vegetables before eating, detection group was above 46 years 18 % of infected cases. Differentiating taenia solium andtaenia saginata infections. If larvae are ingested, they mature into adults in the small intestine. This chapter will discuss only neurocysticercosis associated with eosinophilic meningitis. The armed scolex may cause some inflammation of the intestinal wall, and rarely may penetrate the intestine, causing peritonitis.
Humans can also be infected with the larval stage after accidental. Cestodes taenia solium north dakota department of health. It belongs to the phylum platyhelminthes, class cestoidea, order cyclophyllidea, family taeniidae. Taenia solium pork tapeworm infection and cysticercosis. General recognition features scolex has four suckers with a rostellum that has a double circle of alternating large and small hooks 2236 proglottid is smaller than t saginata and has 7 lateral branches off the central uterus. Cannot distinguish species of taenia tapeworms based on morphology of eggs. Taenia solium the adult taenia solium has a head scolex that consists of four suckers and a rostellum with a double crown of hooks, and unsegmented narrow neck, and a large body formed by several hundred proglottids figure 1. Taenia solium, the pork tapeworm, is endemic in most developing countries as well as in developed nations with a high influx of immigrants from endemic areas fig. Taenia solium cysticercosis hector h garcia, armando e gonzalez, carlton a w evans, robert h gilman, for the cysticercosis working group in peru the larval stage of the pork tapeworm taenia solium infects the human nervous system, causing neurocysticercosis.