{{Short description|Parasitic disease due to infection with tapeworms belonging to the genus Taenia}} {{About|the infection by the adult worms|the organism|Taenia (flatworm)}} {{Infobox medical condition (new) | name = Taeniasis | synonyms = | image = Taenia saginata LifeCycle.gif | caption = The life cycle of ''Taenia saginata'', the beef tapeworm | pronounce = | field = Infectious disease | symptoms = None, weight loss, abdominal pain<ref name=CDC2019FAQ/> | complications = Pork tapeworm: cysticercosis<ref name=CDC2019FAQ/> | onset = | duration = | types = ''Taenia solium'' (pork tapeworm), ''Taenia saginata'' (beef tapeworm), ''Taenia asiatica'' (Asian tapeworm)<ref name=CDC2019/> | causes = Infection with adult tapeworms<ref name=CDC2019/><ref name=CDC2019Def/> | risks = Eating contaminated undercooked pork or beef<ref name=CDC2019FAQ/> | diagnosis = Examination of stool samples<ref name=CDC2019Diag/> | differential = | prevention = Properly cooking meat<ref name=CDC2019FAQ/> | treatment = Praziquantel, niclosamide<ref name=CDC2019FAQ/> | medication = | prognosis = | frequency = 50 million (with cysticercosis)<ref name=Gri2010/> | deaths = }} <!-- Definition and symptoms --> '''Taeniasis''' is an infection within the intestines by adult tapeworms belonging to the genus ''Taenia''.<ref name=CDC2019/><ref name=CDC2019Def>{{cite web |title=CDC - Taeniasis - Biology |url=https://www.cdc.gov/parasites/taeniasis/biology.html |website=www.cdc.gov |access-date=16 December 2019 |language=en-us |date=24 April 2019}}</ref> There are generally no or only mild symptoms.<ref name=CDC2019>{{cite web |title=CDC - Taeniasis |url=https://www.cdc.gov/parasites/taeniasis/ |website=www.cdc.gov |access-date=16 December 2019 |language=en-us |date=24 April 2019}}</ref> Symptoms may occasionally include weight loss or abdominal pain.<ref name=CDC2019FAQ/> Segments of tapeworm may be seen in the stool.<ref name=CDC2019FAQ>{{cite web |title=CDC - Taeniasis - General Information - Frequently Asked Questions (FAQs) |url=https://www.cdc.gov/parasites/taeniasis/gen_info/faqs.html |website=www.cdc.gov |access-date=16 December 2019 |language=en-us |date=24 April 2019}}</ref> Complications of pork tapeworm may include cysticercosis.<ref name=CDC2019FAQ/>
<!-- Cause and diagnosis --> Types of ''Taenia'' that cause infections in humans include ''Taenia solium'' (pork tapeworm), ''Taenia saginata'' (beef tapeworm), and ''Taenia asiatica'' (Asian tapeworm).<ref name=CDC2019/> ''Taenia saginata'' is due to eating contaminated undercooked beef while ''Taenia solium'' and ''Taenia asiatica'' is from contaminated undercooked pork.<ref name=CDC2019/> Diagnosis is by examination of stool samples.<ref name=CDC2019Diag>{{cite web |title=CDC - Taeniasis - Diagnosis |url=https://www.cdc.gov/parasites/taeniasis/diagnosis.html |website=www.cdc.gov |access-date=17 December 2019 |language=en-us |date=24 April 2019}}</ref>
<!-- Treatment and epidemiology --> Prevention is by properly cooking meat.<ref name=CDC2019FAQ/> Treatment is generally with praziquantel, though niclosamide may also be used.<ref name=CDC2019FAQ/> Together with cysticercosis, infections affect about 50 million people globally.<ref name=Gri2010>{{cite book |last1=Griffiths |first1=Jeffrey |last2=Maguire |first2=James H. |last3=Heggenhougen |first3=Kristian |last4=Quah |first4=Stella R. |title=Public Health and Infectious Diseases |date=2010 |publisher=Elsevier |isbn=978-0-12-381507-1 |page=216 |url=https://books.google.com/books?id=bjcycxFpqEwC&pg=PA216 |language=en}}</ref> The disease is most common in the developing world.<ref name=CDC2019FAQ/> In the United States fewer than 1,000 cases occur annually.<ref name=CDC2019FAQ/>
== Signs and symptoms ==
Taeniasis generally has few or no symptoms.<ref name=WHO2019Fact/> It takes about 8 weeks from infection for adult worms to form and can last for years without treatment.<ref name=WHO2019Fact>{{cite web |title=Taeniasis/Cysticercosis |url=https://www.who.int/news-room/fact-sheets/detail/taeniasis-cysticercosis |website=www.who.int |access-date=17 December 2019 |language=en}}</ref>
Infection may be suspected when a portion of the worm is passed in the stool.<ref name=CDC2019Diag/> It is not generally fatal.<ref name=garcia>{{cite book|last=Garcia|first=Oscar H. Del Brutto, Hector H.|title=Cysticercosis of the Human Nervous System.|publisher=Springer-Verlag Berlin and Heidelberg GmbH & Co. KG|location=Berlin|isbn=978-3-642-39021-0|pages=11–21|edition=1., 2014|chapter=Taenia solium: Biological Characteristics and Life Cycle|year=2014}}</ref><ref name="WHOtaeniasis">{{cite web|title=About Taeniasis/cysticercosis|url=https://www.who.int/taeniasis/about_disease/en/|archive-url=https://web.archive.org/web/20140314014913/http://www.who.int/taeniasis/about_disease/en/|url-status=dead|archive-date=March 14, 2014|access-date=13 March 2014}}</ref><ref name="WHOtaeniasisTreatment">{{cite web|title=Signs, symptoms and treatment of taeniasis/cysticercosis|url=https://www.who.int/taeniasis/symptoms/en/|archive-url=https://web.archive.org/web/20140314001109/http://www.who.int/taeniasis/symptoms/en/|url-status=dead|archive-date=March 14, 2014|access-date=13 March 2014}}</ref>
===Pork tapeworm=== thumb|''Taenia solium'' adult Infection in the intestines by the adult ''T. solium'' worms is normally asymptomatic. Heavy infection can result in anaemia and indigestion.{{citation needed|date=January 2021}}
A complication, known as cysticercosis, may occur if the eggs of the pork tapeworm are eaten. This typically occurs from vegetables or water contaminated by feces from someone with pork tapeworm taeniasis. The eggs enter the intestine where they develop into larvae which then enter the bloodstream and invade host tissues. This is the most frequent and severe disease caused by any tapeworm. It can lead to headaches, dizziness, seizures, dementia, hypertension, lesions in the brain, blindness, tumor-like growths, and low eosinophil levels. It is a cause of major neurological problems, such as hydrocephalus, paraplegy, meningitis, and death.<ref>{{cite journal|last=Flisser|first=A. |author2=Avila G |author3=Maravilla P |author4=Mendlovic F |author5=León-Cabrera S |author6=Cruz-Rivera M |author7=Garza A |author8=Gómez B |author9=Aguilar L |author10=Terán N |author11=Velasco S |author12=Benítez M |author13=Jimenez-Gonzalez DE|title=Taenia solium: current understanding of laboratory animal models of taeniosis|journal=Parasitology|volume=137|issue=3|pages=347–57|doi=10.1017/S0031182010000272|pmid=20188011|year=2010|s2cid=25698465 }}</ref>
===Beef tapeworm=== ''Taenia saginata'' infection is usually asymptomatic, but heavy infection causes weight loss, dizziness, abdominal pain, diarrhea, headaches, nausea, constipation, chronic indigestion, and loss of appetite. It can cause antigen reaction that induce allergic reaction.<ref name=who>{{cite web|title=Taeniasis/Cysticercosis|url=https://www.who.int/mediacentre/factsheets/fs376/en/|work=WHO Fact sheet N°376|publisher=World Health Organization|access-date=7 February 2014|year=2013}}</ref> It is also a rare cause of ileus, pancreatitis, cholecystitis, and cholangitis.<ref>{{cite journal|last=Uygur-Bayramiçli|first=O|author2=Ak, O |author3=Dabak, R |author4=Demirhan, G |author5= Ozer, S |title=''Taenia saginata'' a rare cause of acute cholangitis: a case report|journal=Acta Clinica Belgica|volume=67|issue=6|pages=436–7|pmid=23340150|year=2012 |doi=10.1179/ACB.67.6.2062709|doi-access=free}}</ref>
===Asian tapeworm===
''Taenia asiatica'' is also usually asymptomatic. It is unclear if ''T. asiatica'' can cause cysticercosis.<ref name=CDC2019FAQ/> In pigs, the cysticercus can produce cysticercosis. Cysts develop in liver and lungs. (''T. saginata'' does not cause cysticercosis.)<ref>{{cite journal|last=Galán-Puchades|first=M.T.|author2=Fuentes, M.V. |title=''Taenia asiatica'' and pig cysticercosis|journal=Veterinary Parasitology|volume=157|issue=1–2|pages=160–161|doi=10.1016/j.vetpar.2008.07.008|pmid=18752896|year=2008|hdl=10550/97062 |hdl-access=free}}</ref>
== Transmission ==
Taeniasis is contracted after eating undercooked pork or beef that contains the larvae. The adult worms develop and live in the lumen of the intestine. They acquire nutrients from the intestine. The gravid proglottids, body segments containing fertilised eggs, are released in the faeces.{{citation needed|date=July 2020}}
If consumed by an intermediate host such as a cow or pig, they hatch within the duodenum to become larvae, penetrate through the intestinal wall into nearby blood vessels, and enter the bloodstream. Once they reach organs such as the skeletal muscles, liver, or lungs, the larvae then develop into a cyst, a fluid-filled cysticercus. These contaminated tissues are then consumed through raw or undercooked meat.<ref name=garcia/>
Cysticercosis occurs when contaminated food, water, or soil that contains ''T. solium'' eggs is eaten.<ref>{{cite book|last1=Roberts|first1=Larry S.|last2=Janovy|first2=John Jr.|title=Gerald D. Schmidt & Larry S. Roberts' Foundations of Parasitology|url=https://archive.org/details/foundationsparas00robe|url-access=limited|date=2009|publisher=McGraw-Hill Higher Education|location=Boston|isbn=978-0-07-302827-9|pages=[https://archive.org/details/foundationsparas00robe/page/n366 348]–351|edition=8}}</ref><ref name="WHOtaeniasisTransmission">{{cite web|title=Transmission of taeniasis/cysticercosis|url=https://www.who.int/taeniasis/transmission/en/|archive-url=https://web.archive.org/web/20140314011833/http://www.who.int/taeniasis/transmission/en/|url-status=dead|archive-date=March 14, 2014|access-date=13 March 2014}}</ref>
==Diagnosis== thumb|Egg of ''T. solium'' Diagnosis of taeniasis is mainly using stool sample, particularly by identifying the eggs. However, this has limitations at the species level because tapeworms have similar eggs. Examination of the scolex or the gravid proglottids can resolve the exact species.<ref name="schmidt">{{cite book|last1=Roberts|first1=Larry S.|last2=Janovy|first2=John Jr.|title=Gerald D. Schmidt & Larry S. Roberts' Foundations of parasitology|publisher=McGraw-Hill|location=Boston|isbn=978-0-07-128458-5|edition=8th |year=2009}}</ref> But body segments are not often available, therefore, laborious histological observation of the uterine branches and PCR detection of ribosomal 5.8S gene are sometimes necessary.<ref>{{cite journal |vauthors=González LM, Montero E, Harrison LJ, Parkhouse RM, Garate T |title=Differential diagnosis of Taenia saginata and Taenia solium infection by PCR. |journal=J Clin Microbiol |volume=38 |issue=2 |pages=737–744 |year=2000 |doi=10.1128/JCM.38.2.737-744.2000 |pmid=10655377 |pmc=86191 }}</ref><ref>{{cite journal |author=Zarlenga DS. |title=The differentiation of a newly described Asian taeniid from Taenia saginata using enzymatically amplified non-transcribed ribosomal DNA repeat sequences. |journal=Southeast Asian J Trop Med Public Health. |volume=22 |issue=suppl |pages=251–255 |year=1991 |pmid=1822899 }}</ref> Ziehl–Neelsen stain is also used for ''T. saginata'' and ''T. solium'', in most cases only the former will stain, but the method is not entirely reliable.<ref>{{cite journal |vauthors = Jimenez JA, Rodriguez S, Moyano LM, Castillo Y, García HH|year=2010 |title=Differentiating Taenia eggs found in human stools - Does Ziehl Neelsen staining help? |journal=Tropical Medicine & International Health |volume=15 |issue=9 |pages=1077–1081 |doi=10.1111/j.1365-3156.2010.02579.x|pmc=3428859 |pmid=20579318}}</ref> Loop-mediated isothermal amplification (LAMP) is highly sensitive (~2.5 times that of multiplex PCR), without false positives, for differentiating the taenid species from faecal samples.<ref>{{cite journal |title= Evaluation of a loop-mediated isothermal amplification method using fecal specimens for differential detection of ''Taenia'' species from humans |pmid= 20631114 |year= 2010 |last1= Nkouawa |first1= A |last2= Sako |first2= Y |last3= Li |first3= T |last4= Chen |first4= X |last5= Wandra |first5= T |last6= Swastika |first6= IK |last7= Nakao |first7= M |last8= Yanagida |first8= T |last9= Nakaya |first9= K |last10= Qiu |first10= D |last11= Ito |first11= A |volume= 48 |issue= 9 |pages= 3350–2 |doi= 10.1128/JCM.00697-10 |pmc= 2937673 |journal= Journal of Clinical Microbiology }}</ref>
To date the most relevant test for ''T. asiatica'' is by enzyme-linked immunoelectrotransfer blot (EITB). EITB can effectively identify asiatica from other taenid infections since the serological test indicates an immunoblot band of 21.5 kDa exhibited specifically by ''T. asiatica''.<ref>{{cite journal |title=Immunoblot Patterns of ''Taenia asiatica'' Taeniasis |journal=The Korean Journal of Parasitology |pmid=19290097 |doi=10.3347/kjp.2009.47.1.73 |year=2009 |last1=Jeon |first1=Hyeong-Kyu |last2=Eom |first2=Keeseon S. |volume=47 |pages=73–7 |issue=1 |pmc=2655338}}</ref> Even though it gives 100% sensitivity, it has not been tested with human sera for cross-reactivity, and it may show a high false positive result.{{citation needed|date=January 2021}}
== Prevention ==
Prevention efforts include properly cooking meat, treating active cases in humans, vaccinating and treating pigs against the disease, stricter meat-inspection standards, health education, improved sanitation, and improved pig-raising practices.<ref name=CDC2019FAQ/><ref name=WHO2019Fact/>
Preventing human faeces from contaminating pig feeds also plays a role. Infection can be prevented with proper disposal of human faeces around pigs, cooking meat thoroughly and/or freezing the meat at −10 °C for 5 days. Contaminated hands are the primary method of transmission for human cysticercosis, especially in populations like food handlers.<ref name=garcia/>
Proper cooking of meat is an effective prevention. For example, cooking (56 °C for 5 minutes) of beef viscera destroys cysticerci. Refrigeration, freezing (−10 °C for 9 days) or long periods of salting is also lethal to cysticerci.<ref name=who/>
==Treatment== Praziquantel is the treatment of choice.<ref name=dpd>{{Cite web|url = http://www.dpd.cdc.gov/DPDx/|title = CDC - DPDX Homepage|date = 2019-05-14|access-date = 2014-11-28|archive-date = 2013-07-10|archive-url = https://web.archive.org/web/20130710103131/http://www.dpd.cdc.gov/DPDx/|url-status = dead}}</ref> Usual treatments are with praziquantel (5–10 mg/kg, single-administration) or niclosamide (adults and children over 6 years: 2 g, single-administration after a light breakfast, followed after 2 hours by a laxative; children aged 2–6 years: 1 g; children under 2 years: 500 mg).<ref name=who/> One study showed albendazole is effective against animal beef tapeworm cysticercosis.<ref>{{cite journal|vauthors = Lopes WD, Cruz BC, Soares VE, Nunes JL, Teixeira WF, Maciel WG, Buzzulini C, Pereira JC, Felippelli G, Soccol VT, de Oliveira GP, da Costa AJ |title=Historic of therapeutic efficacy of albendazole sulphoxide administered in different routes, dosages, and treatment schemes, against ''Taenia saginata'' cysticercus in cattle experimentally infected|journal=Experimental Parasitology|year= 2014|volume=137|issue=1|pages=14–20|doi=10.1016/j.exppara.2013.11.007|pmid=24309372}}</ref> Mepacrine is quite effective but has adverse effects in humans.<ref name=ooi>{{cite journal |title= Historical overview of ''Taenia asiatica'' in Taiwan |pmid=23467308 |pmc= 3587746 |doi= 10.3347/kjp.2013.51.1.31 |year= 2013 |last1= Ooi |first1= Hong Kean |last2= Ho |first2= Chau-Mei |last3= Chung |first3= Wen-Cheng |journal= The Korean Journal of Parasitology |volume= 51 |pages= 31–6 |issue= 1}}</ref>
==Epidemiology== The total global infection is estimated to be between 40 and 60 million people.<ref name="eck">{{cite book|title=Medical Microbiology|publisher=Thieme|location=Stuttgart|isbn=9781588902450|pages=560–562|author=Eckert, J.|editor=Kayser, F.H. |editor2=Bienz, K.A. |editor3=Eckert, J. |editor4=Zinkernagel, R.M.|chapter=Helminths|url=https://books.google.com/books?id=L6OCIwb08LwC|year=2005}}</ref> In the US, the incidence of infection is low, but 25% of cattle sold are still infected.<ref name="schmidt" />
=== Regions === Taeniasis is predominantly found in Asia, Africa, and Latin America, particularly on farms in which pigs are exposed to human excrement. At a low level though, it occurs everywhere where beef and pork are eaten, even in countries with strict sanitation policies such as the United States. ''Taenia saginata'' is relatively common in Africa, some parts of Eastern Europe,<ref name=east_europe>{{cite journal | last1 = Trevisan | first1 = C. | last2 = Sotiraki | first2 = S. | last3 = Laranjo-González | first3 = M. | last4 = Dermauw | first4 = V. | last5 = Wang | first5 = Z. | last6 = Kärssin | first6 = A. | last7 = Cvetkovikj | first7 = A. | last8 = Winkler | first8 = A.S. | last9 = Abraham | first9 = A. | last10 = Bobić | first10 = B. | last11 = Lassen | first11 = B. | last12 = Cretu | first12 = C.M. | last13 = Vasile | first13 = C. | last14 = Arvanitis | first14 = D. | last15 = Deksne | first15 = G. | last16 = Boro | first16 = I. | last17 = Kucsera | first17 = I. | last18 = Karamon | first18 = J. | last19 = Stefanovska | first19 = J. | last20 = Koudela | first20 = B. | last21 = Pavlova | first21 = M.J. | last22 = Varady | first22 = V. | last23 = Pavlak | first23 = M. | last24 = Šarkūnas | first24 = M. | last25 = Kaminski | first25 = M. | last26 = Djurković-Djaković | first26 = O. | last27 = Jokelainen | first27 = P. | last28 = Jan | first28 = D.S. | last29 = Schmidt | first29 = V. | last30 = Dakić | first30 = Z. | last31 = Gabriël | first31 = S. | last32 = Dorny | first32 = P. | last33 = Devleesschauwer | first33 = B. | title = Epidemiology of taeniosis/cysticercosis in Europe, a systematic review: eastern Europe | doi = 10.1186/s13071-018-3153-5 | year = 2018 | journal = Parasit Vectors | volume = 11 | issue = 1 | pages = 569 | pmid = 30376899 | pmc = 6208121 | doi-access = free }}</ref> the Philippines, and Latin America.<ref name="lange">{{cite book|last=Somers|first=Kenneth D.|title=Lange Microbiology and Infectious Diseases Flash Cards|publisher=Lange Medical Books/ McGraw-Hill|location=New York|isbn=9780071628792|pages=184–186|edition=2nd|author2=Morse, Stephen A. |year=2010}}</ref> It is most prevalent in Sub-Saharan Africa and the Middle East.<ref name="ort">{{cite book|title=Foodborne parasites|url=https://archive.org/details/foodborneparasit00orte|url-access=limited|publisher=Springer|location=New York|isbn=9780387311975|pages=[https://archive.org/details/foodborneparasit00orte/page/n219 207]–210|author=Ortega, Ynes R.|year=2006}}</ref> ''Taenia asiatica'' is restricted to East Asia, including Taiwan, Korea, Indonesia, Nepal, Thailand and China.<ref>{{cite journal |title=Geographical distribution of ''Taenia asiatica'' and related species |journal=The Korean Journal of Parasitology |pmid=19885327 |doi=10.3347/kjp.2009.47.S.S115 |pmc=2769216 |year=2009 |last1=Eom |first1=Keeseon S. |last2=Jeon |first2=Hyeong-Kyu |last3=Rim |first3=Han-Jong |volume=47 |pages=S115–24 |issue=Suppl}}</ref><ref>{{cite journal|last=Ale|first=Anita|author2=Victor, Bjorn |author3=Praet, Nicolas |author4=Gabriël, Sarah |author5=Speybroeck, Niko |author6=Dorny, Pierre |author7= Devleesschauwer, Brecht |title=Epidemiology and genetic diversity of Taenia asiatica: a systematic review|journal=Parasites & Vectors|volume=7|issue=1|pages=45|doi=10.1186/1756-3305-7-45|pmid=24450957|year=2014 |pmc=3900737 |doi-access=free }}</ref>
==See also== * Tapeworm infection
==References== {{Reflist}}
== External links == {{Medical resources | DiseasesDB = 12875 | ICD11 = {{ICD11|1F76}} | ICD10 = {{ICD10|B|68||b|65}} | ICD9 = {{ICD9|123.3}} | ICDO = | OMIM = | MedlinePlus = 001391 | eMedicineSubj = ped | eMedicineTopic = 2201 | MeshID = D013622 }}
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Category:Foodborne illnesses Category:Parasitic diseases Category:Helminthiases Category:Zoonotic parasitic diseases Category:Tropical diseases Category:Parasitic diseases associated with beef and pork consumption Category:Wikipedia medicine articles ready to translate