Editing Cysticercosis (section)

==Prevention==
Cysticercosis is considered as “tools-ready disease” according to WHO.<ref>{{cite web |title=Global Plan to Combat Neglected Tropical Diseases 2008–2015 |date=2007 |publisher=World Health Organization |url=http://whqlibdoc.who.int/hq/2007/who_cds_ntd_2007.3_eng.pdf |at=Box 1. Selected neglected tropical diseases and zoonoses to be addressed within the Global Plan. p. 2 |url-status=live |archive-url=https://web.archive.org/web/20100722225903/http://whqlibdoc.who.int/hq/2007/WHO_CDS_NTD_2007.3_eng.pdf |archive-date=2010-07-22 }}</ref> International Task Force for Disease Eradication in 1992 reported that cysticercosis is potentially eradicable.<ref name=TaskForce92>{{cite journal |title=Update: International Task Force for Disease Eradication, 1992 |journal=MMWR Morb. Mortal. Wkly. Rep. |volume=41 |issue=37 |pages=691, 697–8 |date=September 1992 |pmid=1518501 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/00017648.htm |url-status=live |archive-url=https://web.archive.org/web/20090306044642/http://www.cdc.gov/mmwr/preview/mmwrhtml/00017648.htm |archive-date=2009-03-06 |author1=Centers for Disease Control (CDC) }}</ref> It is feasible because there are no animal reservoirs besides humans and pigs. The only source of ''Taenia solium'' infection for pigs is from humans, a definite host. Theoretically, breaking the life cycle seems easy by doing intervention strategies from various stages in the life cycle.<ref name="eleven">Schantz, P. "Eradication of ''T. solium'' Cysticercosis" International Conference on Emerging Infectious Diseases 2002. CDC.ftp://ftp.cdc.gov/pub/infectious_diseases/iceid/2002/pdf/schantz.pdf</ref>

For example,{{cn|date=May 2021}}
# Massive chemotherapy of infected individuals, improving [[sanitation]], and educating people are all major ways to discontinue the cycle, in which eggs from human feces are transmitted to other humans and/or pigs.
# Cooking of pork or freezing it and inspecting meat are effective means to cease the life cycle
# The management of pigs by treating them or vaccinating them is another possibility to intervene
# The separation of pigs from human faeces by confining them in enclosed piggeries. In Western European countries post World War 2 the pig industry developed rapidly and most pigs were housed.<ref name="Welfare">{{cite book|author=Jeremy N. Marchant-Forde|title=The Welfare of Pigs|url=https://books.google.com/books?id=zNz4-EN4RSkC&pg=PA333|date=2008-11-26|publisher=Springer Science & Business Media|isbn=978-1-4020-8909-1|pages=333–|url-status=live|archive-url=https://web.archive.org/web/20170407061756/https://books.google.com/books?id=zNz4-EN4RSkC&pg=PA333|archive-date=2017-04-07}}</ref> This was the [[Portal:Main|main]] reason for pig cysticercosis largely being eliminated from the region. This of course is not a quick answer to the problem in developing countries.

===Pigs===
The intervention strategies to eradicate cysticercosis includes surveillance of pigs in foci of transmission and massive chemotherapy treatment of humans.<ref name=TaskForce92 /> In reality, control of ''T. solium'' by a single intervention, for instance, by treating only human population will not work because the existing infected pigs can still carry on the cycle. The proposed strategy for eradication is to do multilateral intervention by treating both human and porcine populations.<ref name=Gonzalez03>{{cite journal |vauthors=Gonzalez AE, García HH, Gilman RH, Tsang VC |title=Control of ''Taenia solium'' |journal=Acta Trop. |volume=87 |issue=1 |pages=103–9 |date=June 2003 |pmid=12781384 |doi=10.1016/S0001-706X(03)00025-1}}</ref> It is feasible because treating pigs with [[oxfendazole]] has been shown to be effective and once treated, pigs are protected from further infections for at least 3 months.<ref name="fifteen">{{cite journal |vauthors=Gonzalez AE, Gavidia C, Falcon N, et al. |title=Protection of pigs with cysticercosis from further infections after treatment with oxfendazole |journal=Am. J. Trop. Med. Hyg. |volume=65 |issue=1 |pages=15–8 |date=July 2001 |pmid=11504400 |url=http://www.ajtmh.org/cgi/pmidlookup?view=long&pmid=11504400|doi=10.4269/ajtmh.2001.65.15 |doi-access=free }}</ref>

===Limitations===
Even with the concurrent treatment of humans and pigs, complete elimination is hard to achieve. In one study conducted in 12 villages in Peru, both humans and pigs were treated with praziquantel and oxfendazole, with the coverage of more than 75% in humans and 90% in pigs<ref>Garcia, H.H., 2002. "Effectiveness of an interventional control program for human and porcine ''Taenia solium'' cysticercosis in field conditions." In: International Health. Johns Hopkins University, Baltimore, p. 250.</ref> The result shows a decrease in prevalence and incidence in the intervention area; however the effect did not completely eliminate ''T. solium''. The possible reason includes the incomplete coverage and re-infection.<ref>{{cite book |author=Gilman, R.H. |author2=Garcia, H.H. |author3=Gonzalez, A.E. |author4=Dunleavy, M. |author5=Verastegui, M. |chapter=Short cuts to development: methods to control the transmission of cysticercosis in developing countries |editor-last=García |editor-first=H.H. |editor2-last=Martínez |editor2-first=M. |title=''Taenia solium'' taeniasis/cysticercosis |publisher=Editorial Universo |location=Lima |year=1999 |isbn=978-9972910203 |pages=313–326 }}</ref> Even though ''T. solium ''could be eliminated through mass treatment of human and porcine population, it is not sustainable.<ref name=Gonzalez03 /> Moreover, both tapeworm carriers of humans and pigs tend to spread the disease from endemic to non-endemic areas resulting in periodic outbreaks of cysticercosis or outbreaks in new areas.<ref>{{cite journal |vauthors=Margono SS, Subahar R, Hamid A, et al. |title=Cysticercosis in Indonesia: epidemiological aspects |journal=Southeast Asian J. Trop. Med. Public Health |volume=32 |issue=Suppl 2|pages=79–84 |year=2001 |pmid=12041608 }}</ref><ref>{{cite journal |vauthors=Wandra T, Subahar R, Simanjuntak GM, et al. |title=Resurgence of cases of epileptic seizures and burns associated with cysticercosis in Assologaima, Jayawijaya, Irian Jaya, Indonesia, 1991–95 |journal=Trans. R. Soc. Trop. Med. Hyg. |volume=94 |issue=1 |pages=46–50 |year=2000 |pmid=10748897 |doi=10.1016/s0035-9203(00)90433-4}}</ref>

===Vaccines===
Given the fact that pigs are part of a life cycle, vaccination of pigs is another feasible intervention to eliminate cysticercosis. Research studies have been focusing on vaccine against cestode parasites, since many immune cell types are found to be capable of destroying cysticercus.<ref name="twenty">{{cite journal |vauthors=Sciutto E, Fragoso G, de Aluja AS, Hernández M, Rosas G, Larralde C |title=Vaccines against cysticercosis |journal=Curr Top Med Chem |volume=8 |issue=5 |pages=415–23 |year=2008 |pmid=18393905 |doi=10.2174/156802608783790839 }}</ref> Many vaccine candidates are extracted from antigens of different cestodes such as ''Taenia solium'', ''T. crassiceps'', ''T. saginata'', ''T. ovis'' and target oncospheres and/or cysticerci. In 1983, Molinari et al. reported the first vaccine candidate against porcine cysticercosis using antigen from cysticercus cellulosae drawn out from naturally infected.<ref>{{cite journal |vauthors=Molinari JL, Meza R, Suárez B, Palacios S, Tato P, Retana A |title=''Taenia solium'': immunity in hogs to the Cysticercus |journal=Exp. Parasitol. |volume=55 |issue=3 |pages=340–57 |date=June 1983 |pmid=6852171 |doi=10.1016/0014-4894(83)90031-0}}</ref> Recently, vaccines extracted from genetically engineered 45W-4B antigens have been successfully tested to pigs in an experimental condition.<ref>{{cite journal |vauthors=Luo X, Zheng Y, Hou J, Zhang S, Cai X |title=Protection against Asiatic ''Taenia solium'' induced by a recombinant 45W-4B protein |journal=Clin. Vaccine Immunol. |volume=16 |issue=2 |pages=230–2 |date=February 2009 |pmid=19091992 |pmc=2643551 |doi=10.1128/CVI.00367-08 }}</ref> This type of vaccine can protect against cysticercosis in both Chinese and Mexican type of ''T. solium''. However, it has not been tested in endemic field conditions, which is important because the realistic condition in the field differ greatly from experimental condition, and this can result in a great difference in the chances of infection and immune reaction.<ref name="twenty" />

Even though vaccines have been successfully generated, the feasibility of its production and usage in rural free ranging pigs still remains a challenge. If a vaccine is to be injected, the burden of work and the cost of vaccine administration to pigs will remain high and unrealistic.<ref name="twenty" /> The incentives of using vaccines by pig owners will decrease if the vaccine administration to pigs takes time by injecting every single pig in their livestock. A hypothetical oral vaccine is proposed to be more effective in this case as it can be easily delivered to the pigs by food.<ref name="twenty" />

====S3PVAC vaccine====
The vaccine constituted by 3 [[peptide]] synthetically produced (S3Pvac) has proven its efficacy in natural conditions of transmission.<ref name="Huerta M 2001">{{cite journal | vauthors = Huerta M, De Aluja AS, Fragoso G, Toledo A, Villalobos N, Hernandez M, Gevorkian G, Acero G, Diaz A et al. | year = 2001 | title = Synthetic peptide vaccine against ''Taenia solium'' pig cysticercosis: successful vaccination in a controlled field trial in rural Mexico | journal = Vaccine| volume = 20 | issue = 1–2| pages = 262–6 | doi = 10.1016/S0264-410X(01)00249-3 | pmid = 11567772 }}</ref> The S3PVAC vaccine so far, can be considered as the best vaccine candidate to be used in endemic areas such as Mexico (20). S3Pvac consists of three protective peptides: KETc12, KETc1 and GK1, whose sequences belong to native [[antigen]]s that are present in the different developmental stages of ''T. solium'' and other cestode parasites.<ref name="twenty" /><ref>http://www-lab.biomedicas.unam.mx/cistimex/s1.html#capitulo6 {{webarchive|url=https://web.archive.org/web/20090307202025/http://www-lab.biomedicas.unam.mx/cistimex/s1.html |date=2009-03-07 }}</ref>

Non-infected pigs from rural villages in Mexico were vaccinated with S3Pvac and the vaccine reduced 98% the number of cysticerci and 50% the number of prevalence.<ref name="Huerta M 2001"/><ref>{{cite journal | vauthors = Sciutto E, Morales J, Martinez JJ, Toledo A, Villalobos MN, Cruz-Revilla C, Meneses G, Hernandez M, Diaz A et al. | year = 2007 | title = Further evaluation of the synthetic peptide vaccine S3Pvac against ''Taenia solium'' cysticercosis in pigs in an endemic town of Mexico | journal = Parasitology | volume = 134 | issue = Pt 1| pages = 129–33 | doi = 10.1017/S0031182006001132 | pmid = 16948875 | s2cid = 27758572 }}</ref> The diagnostic method involves necropsy and tongue inspection of pigs. The natural challenge conditions used in the study proved the efficacy of the S3Pvac vaccine in transmission control of ''T. solium'' in Mexico.<ref name="twenty" /> The S3Pvac vaccine is owned by the National Autonomous University of Mexico and the method of high scale production of the vaccine has already been developed.<ref name="twenty" /> The validation of the vaccine in agreement with the Secretary of Animal Health in Mexico is currently in the process of completion.<ref name="twenty seven">E-mail interview with Edda Sciutto. Feb 26 2009.</ref> It is also hoped that the vaccine will be well-accepted by pig owners because they also lose their income if pigs are infected cysticercosis.<ref name="twenty seven" /> Vaccination of pigs against cysticercosis, if succeeded, can potentially have a great impact on transmission control since there is no chance of re-infection once pigs receive vaccination.{{cn|date=November 2020}}

===Other===
Cysticercosis can also be prevented by routine inspection of meat and condemnation of measly meat by the local government and by avoiding partially cooked meat products. However, in areas where food is scarce, cyst-infected meat might be considered as wasted since pork can provide high quality protein.<ref>CWGESA. 5th General Assembly of the Cysticercosis Working Group in Eastern and Southern Africa. 2007. CIRADhttp://pigtrop.cirad.fr/sp/recursos/publications/procedimientos/5th_general_assembly_of_the_cysticercosis_working_group_in_eastern_and_southern_africa</ref> At times, infected pigs are consumed within the locality or sold at low prices to traffickers who take the uninspected pigs at urban areas for sale.<ref>{{cite journal |vauthors=Morales J, Martínez JJ, Garcia-Castella J, et al. |s2cid=5707291 |title=''Taenia solium'': the complex interactions, of biological, social, geographical and commercial factors, involved in the transmission dynamics of pig cysticercosis in highly endemic areas |journal=Ann Trop Med Parasitol |volume=100 |issue=2 |pages=123–35 |date=March 2006 |pmid=16492360 |doi=10.1179/136485906x86275 }}</ref>