**2. Vaccination of pigs**

After having agreed upon the day of vaccination, the owners keep their pigs confined and their tongues are examined by members of the team and each animal is registered in a data base, appointing the name of the owner, his or her address, age and sex of the animal, and where it was borne. All pigs are then vaccinated. If cysticerci were detected in the tongue, the pig is carefully examined with ultrasonography and if found positive, we try to purchase it from the owner. An attempt has been made to exchange it for a better bred animal, but this has not been very successful as these newly introduced piglets do not resist the hardship of their new lives and often die. The vaccine is applied subcutaneously, and repeated 3 times, with 3 months interval between each.

### **3. Education**

The teams make appointments with the village authorities, with teachers, schools, parents, medical staff and nurses in order to explain how to improve their hygiene, how to keep their pigs, the importance of using latrines and other topics that may arise during the discussions. The importance of detecting a *T. solium* carrier is of course stressed and people are advised to get treatment for intestinal parasites, which the government offers free of charge in the health centers, whenever possible.

In order to determine how much people know about the disease and also what their living conditions are, before the programme gets under way, a questionnaire is distributed and people who know how to read and write are asked to answer it. The team members help those who cannot to fill it out. The same questionnaire will be distributed at the end of the project and compared with the initial one, which will show whether the educational campaign was successful. At present (August 2011) we have finished with vaccination and 3 months after the last application we shall start to examine all pigs in the communities and compare the frequency of infected animals with the one registered at the beginning.

During our work we have found the attitude of the people very positive. They are grateful for the dedication of the teams, and for the time they spend with them to show how they can improve their pig breeding methods and their own hygienic habits. The children are thrilled with the audiovisual presentations offered in their schools and go home to explain to their family what they have learnt. It is our conviction that to invest time to teach children is most rewarding, as they are more open to new knowledge than the older

A Programme to Control Taeniosis-Cysticercolsis (*Taenia solium*) in Mexico 329

Eddi C, Nari A, Amanfu W. (2003). *Taenia solium* cysticercosis/taeniosis: potential linkage with FAO activities; FAO support possibilities. Acta Trop. 87(1): 145-8. Engels, D., Urbani, C., Beloto, A., Meslin, F., Savioli, L. (2003). The control of human (neuro)

Escobar A. (1983). The Pathology of Neuro-cysticercosis. In: E. Palacios, J. Rodríguez

Fleury A., Gomez T., Alvarez I., Meza D., Huerta M., Chavarria A., Carrillo Mezo R. A.,

Fleury A., Morales J., Bobes R.J., Dumas M., Yánez O., Piña J., Carrillo-Mezo R., Martínez

Fleury A., Moreno Garcia J., Valdez Aguerrebere P., de Sayve Duran M., Becerril Rodriguez

Flisser A., Gauci C. G., Zoli A., Martinez-Ocana J., Garza-Rodriguez A., Dominguez-Alpizar

Flisser A., Correa D. (2010). Neurocysticercosis May No Longer Be a Public Health Problem in Mexico. Plos Negl Trop Dis, 4(12):e8831 doi:10.1371/journal.pntd.0000831 Flores Pérez I., Aluja A. S. de y Martínez J. J. (2006). Efectos en el desarrollo del metacestodo

González AE, Gauci CG, Barber D, Gilman RH, Tsang VC, Garcia HH, Verastegui M,

Harrison L.J., Garate T., Bryce D. M., Gonzalez L. M., Foster-Cuevas M., Wamae L. W.,

Herrera G. C., Aluja A. S. de y Méndez A. R. (2007). El uso de la ultrasonografía para el diagnóstico de la cisticercosis porcina. Rev. Vet. México 38;1:125-133. Huerta M, Aluja A. S. de, Fragoso G, Toledo A, Villalobos N, Hernandez M, Gevorkian G, Acero

vaccination in a controlled field trial in rural Mexico. Vaccine. 20(1-2):262-6. Instituto Nacional de Estadística Geografía e Informática, Censo de Población y Vivienda

Carbajal, J. M. Traveras (eds). Cysticercosis of the Nervous System. Charles C.

Lloyd C., Dessein A., Preux P. M., Dumas M., Larralde C., Sciutto E. (2003). High prevalence of calcified silent neurocysticercosis in a rural village of Mexico.

J.J., Fragoso G., Dessein A., Larralde C., Sciutto E. (2006). An epidemiological study of familial neurocysticercosis in an endemic Mexican community. Trans R Soc Trop

P., Larralde C., Sciutto E. (2010). Neurocysticercosis, a persisting health problem in

J. L., Maravilla P., Rodriguez-Canul R., Avila G., Aguilar-Vega L., Kyngdon C., Geerts S., Lightowlers M. W. (2004). Induction of protection against porcine cysticercosis by vaccination with recombinant oncosphere antigens. Infect Immun.,

de *Taenia solium* inducidos por dosis bajas de radiación Gamma. Rev. Vet. Méx. ,

Lightowlers MW. (2005). Vaccination of pigs to control human neurocysticercosis.

Onyango-Abuje J. A., Parkhouse R. M. (2005). Ag-ELISA and PCR for monitoring the vaccination of cattle against *Taenia saginata* cysticercosis using an oncospheral adhesion protein (HP6) with surface and secreted localization. Trop Anim Health

G, Diaz A, Alvarez I, Avila R, Beltran C, Garcia G, Martinez JJ, Larralde C, Sciutto E. (2001). Synthetic peptide vaccine against *Taenia solium* pig cysticercosis: successful

cysticercosis: which way forward? Acta Trop., 87:177-82.

Thomas, Springfield, Cap. 4:27-54.

Neuroepidemiology. 22(2):139-145.}

Mexico. PLoS Negl Trop Dis. 4(8): e805

Am J Trop Med Hyg., 72(6):837-9.

Med Hyg. 100(6):551-8.

72: 5292-97.

Vol. 37:3

Prod. 37:103-20.

2010. INEGI, México.

generations, who often resist change arguing that "their ancestors have done it this way and why should they do it differently".

Problems may arise identifying pigs. We ask the owners not to introduce new ones into their group during the vaccination period and not to sell or kill animals without letting us know, but this has proven to be almost impossible as some get lost or die according to the owners and others that have been added to the group. We try to identify each animal by their special colors or markings, but inevitably there are failures with this system and to mark all pigs with microchips would be too costly. The possibility thus exists that not all pigs get the 3 planned vaccinations but we hope to be able to cover the majority.

By vaccinating as many pigs as possible, we hope to interrupt the cycle of the zoonosis and by educating the population we are confident that people will acquire the habit of using correct latrines, of washing their hands whenever possible before preparing food and of abstaining from ingesting meat with cysticerci, also of building correct stalls for their pigs.

#### **4. Acknowledgement**

We thank SENASICA-SAGARPA for their interest in the programme and for their financial support. Ms Isabel Aguilar for her competent secretarial help and all the authorities, peasants and their families and all other inhabitants of the communities for their collaboration. We are grateful to all members of the working teams, most particularly to Juanita Pérez, Antonio Celis, Arturo López, Alfredo Figueroa and Raul Suárez for their dedication.

#### **5. References**


generations, who often resist change arguing that "their ancestors have done it this way

Problems may arise identifying pigs. We ask the owners not to introduce new ones into their group during the vaccination period and not to sell or kill animals without letting us know, but this has proven to be almost impossible as some get lost or die according to the owners and others that have been added to the group. We try to identify each animal by their special colors or markings, but inevitably there are failures with this system and to mark all pigs with microchips would be too costly. The possibility thus exists that not all pigs get the

By vaccinating as many pigs as possible, we hope to interrupt the cycle of the zoonosis and by educating the population we are confident that people will acquire the habit of using correct latrines, of washing their hands whenever possible before preparing food and of abstaining from ingesting meat with cysticerci, also of building correct stalls for their pigs.

We thank SENASICA-SAGARPA for their interest in the programme and for their financial support. Ms Isabel Aguilar for her competent secretarial help and all the authorities, peasants and their families and all other inhabitants of the communities for their collaboration. We are grateful to all members of the working teams, most particularly to Juanita Pérez, Antonio Celis, Arturo López, Alfredo Figueroa and Raul Suárez for their

Acevedo H. (1989). Epidemiología de la cisticercosis porcina. En: Cisticercosis Humana y Porcina, pp 251-253. (Editor. Flisser A, Malagón F) Limusa, Noriega. México, D.F Aluja A. S. de, et al. (1987). *Cisticercosis: una recopilación actualizada de los conocimientos básicos* 

Aluja A. S. de, Villalobos N. (2000). Cisticercosis por *Taenia solium* en cerdos de México.

Aluja, A. S. de,M. J.Martínez y A. N.Villalobos (1998). Cysticercosis in young pigs: Age at first Infection and histological characteristics", *Veterinary Parasitology* 76:71-79. Assana E, Kyngdon CT, Gauci CG, Geerts S, Dorny P, De Deken R, Anderson GA, Zoli AP,

trial of the HP6-TSOL18 vaccine in Cameroon. Int J Parasitol. 40(5):515-9. Boa M, Mukaratirwa S, Willingham AL, Johansen MV. (2003).Regional action plan for

Comisión Económica Para América Latina – CEPAL- 2010. América Latina: evolución de la

Copado, B. F., A. S. de Aluja, L.Mayagoitia y F. Galindo (2004). The behaviour of free

consumption. Applied Animal Behaviour Science 88:243-252.

Aluja A.S. de. (2008). Cysticercosis in pigs. Curr Top Med Chem. 8(5):368-74.

*para el manejo y control de Taenia solium*. Biblioteca de la Salud. ISP and Fondo de

Lightowlers MW. (2010). Elimination of *Taenia solium* transmission to pigs in a field

combating *Taenia solium* cysticercosis/taeniosis in Eastern and Southern Africa.

ranging pigs in the Mexican tropics and its relationships with human faeces

3 planned vaccinations but we hope to be able to cover the majority.

Cultura Económica, México, D. F.

*Veterinaria México*. 31(3):239-244

pobreza y la indigencia, 1980-2010.

Acta Trop. 87(1):183-6.

and why should they do it differently".

**4. Acknowledgement** 

dedication.

**5. References** 


A Programme to Control Taeniosis-Cysticercolsis (*Taenia solium*) in Mexico 331

Ortiz-Trejo J.M., Correa-Chacón A.J., Sctelo-Ham E.I., Torres-Valenzuela A., Alvarado-

Pawlowski Z. S., Allan J., Sarti E. (2005). Control of *Taenia solium* taeniasis/cysticercosis:

Plancarte A., Flisser A., Gauci C.G., Lightowlers M.W. (1999). Vaccination against *Taenia* 

Quiroz R.H. (2002). Parasitologia y enfermedades parasitarias de animales domésticos.

Rassy D., Bobes R. J., Rosas G., Anaya V. H., Brehm K., Hernandez B., Cervantes J., Pedraza

Rodríguez L. G. y Del Moral B.L.E. (2010). Perspectivas del sector porcícola mexicano para

Rosas G., Cruz-Revilla C., Fragoso G., López-Casillas F., Pérez A., Bonilla M. A., Rosales R.,

Rosas G., Fragoso G., Garate T., Hernandez B., Ferrero P., Foster-Cuevas M., Parkhouse R.

cysticercosis", *Annals of Tropical Medicine and Parasitology* 93(3A):247-258. Sarti E., Flisser A., Schantz P., Gleizer M., Loya M., Plancarte A., Ávila G., Allan J., Craig P.,

Sarti E., P. M. Schantz, R. Lara-Aguilera, H. Gómez y A. Flisser (1988), "*Taenia solium* 

Sarti E., P. Schantz, A. Plancarte, M. Wilson, I. Gutiérrez, A. López, J. Roberts y A. Flisser

Sciutto E., Aluja A., Fragoso G., Rodarte L.F., Hernández M., Villalobos M.N., Padilla A.,

against cysticercosis. Curr Top Med Chem. 8(5):415-23.

protection elicited by DNA immunization. J Parasitol. 84(3): 516-23

hospital in México. Gac Med Mex. May-Jun;142(3):175-9. Spanish.

from research towards implementation. Int J Parasitol. 35, 1221-32.

Parasitol, 9:643-7.

Abril-Junio.

Grupo Noriega Editores, Editorial Limusa.

cestodiasis vaccine. PLoS-One. 5(6):e11287

Tropl Med Hyg. 56(2):127-132.

*Medicine and Hygiene* 46:677-685.

39(3):194-198.

Esquivel C. (2006). Risk factors associated with neurocysticercosis in a public

*solium* cysticercosis in pigs using native and recombinant oncosphere antigens. Int J

S., Morales J., Villalobos N., de Aluja A. S., Laclette, J. P. Nunes, C. M. Biondi, G. F. Fragoso, G. Hernández, M. Sciutto, E. (2010). Characterization of S3Pvac anticysticercosis vaccine components: implications for the development of an anti-

2010: recuperación de los efectos de la crisis económica y de la influenza (A)H1/N1. Revista Trimestral de Análisis de Coyuntura Económica, Vol. III, No. 2,

Sciutto E. (1998). *Taenia crassiceps* cysticercosis: humoral immune response and

M., Harrison L. J., Briones S. L., Gonzalez L. M., Sciutto E. (2002). Protective immunity against *Taenia crassiceps* murine cysticercosis induced by DNA vaccination with a *Taenia saginata* tegument antigen. Microbes Infect., 4, 1417-26. Sánchez,A. L., J. Lindback, P. M. Schantz, M. Sone, H. Sakai, M. T. Medina y I. Ljungstrom

(1999), "A population-based, case-control study of *Taenia solium* taeniasis and

Bronfman M., Wijeyaratne P. (1997). "Development and evaluation of a health education intervention against *Taenia solium* in a rural community in Mexico". Am J

taeniasis and cysticercosis in a Mexican village", *Tropical Medicine and Parasitology* 

(1992). Prevalence and risk factors for *Taenia solium* taeniasis and cysticercosis in humans and pigs in a village in Morelos, México. *American Journal of Tropical* 

Keilbach N., Baca M., Govezensky T. (1995). Immunization of pigs against *Taenia solium* cysticercosis factors related to effective protection. Vet Parasitol, 60(1-2):53-67. Sciutto E., Fragoso G., de Aluja A.S., Hernández M., Rosas G., Larralde C. (2008). Vaccine


Johnson K.S., Harrison G.B., Lightowlers M.W., O'Hoy K.L., Cougle W.G., Dempster R.P.,

Larralde C., y Aluja A. S. de (2006). Cisticercosis guía para profesionales de la salud. México:

Manoutcharian K., Díaz-Orea A., Gevorkian G., Fragoso G., Acero G., González E., Aluja A.

Manoutcharian K, Terrazas L.I., Gevorkian G., Acero G., Petrossian P., Rodriguez M.,

Manoutcharian K. Rosas, G. Hernández, M. Fragoso, G. Aluja, A. Villalobos, N. Rodarte, L.

Martínez, M. J., Aluja A. S. de y Gemmell M. (2000), Failure to incriminate domestic flies

Martínez, M. J., A. S. de Aluja, A. N. M. Villalobos, A. C. Jaramillo y M. Gemmell. (1997).

Martínez, M. J., Aluja A. S. de, R. G. Ávila, V. L. Aguilar, C. A. Plancarte y A. C. Jaramillo

comunidad rural del estado de Guerrero. *Salud Pública de México* 45(2):84-89. Molinari J. L.; Meza R.; Suarez B.; Palacios S.; Tato P.; Retana A. (1983). *Taenia solium*:

Morales J., Martínez J.J., Rosseti M. Fleury A., Maza V., Hernández M, Villalobos N, Fragoso

Morales J. T. Velasco, V. Tovar, G. Fragoso, A Fleury, C. Beltran, N. Villalobos, A. Aluja, L.F.

Morales J., Martínez J.J. García-Castella. J., Peña N., Maza V., Villalobos N., Aluja AS.,

Mexico. Salud Pública Mex. 34(2): 197-210.

Vet Immunol Immunopathol. May; 99(1-2):11-24.

recombinant antigens. J Parasitol. 82(2): 250-4.

tested in murine cysticercosis. Infect Immun. 67(9):4764-70.

rural Mexico. *Journal of Medical Entomology* 37(4):489-491.

immunity in hogs to the Cysticercus. Exp Parasitol., 55, 340-57.

Guerrero, México", Veterinaria México 28(4):281-286.

cysticercosis. Veterinary Parasitol., June, 108:41-48.

para la Salud.

2(9):e284. Sep 3.

Med Parasitol, 100(2):123-35.

Lawrence S.B., Vinton J.G., Heath D.D., Rickard M.D. (1989). Vaccination against ovine cysticercosis using a defined recombinant antigen. Nature, 338: 585-587. Keilbach N, Aluja A, Sarti E. (1989). A programme to control teniosis and cyticercosis (*Taenia solium*), experiences in a Mexican village. Acta Leiden. 57(2):181-189. Larralde C., Padilla A., Hernández M., Govezensky T., Sciutto E., Gutiérrez G., Tapia-

Conyer R., Salvatierra B., Sepúlveda J. (1992). Seroepidemiology of cysticercosis in

FCE, Secretaría de Salud, Instituto Nacional de Salud Pública, Fundación Mexicana

S. de, Villalobos N., Gómez-Conde E., Sciutto E. (2004). Recombinant bacteriophage-based multiepitope vaccine against *Taenia solium* pig cysticercosis.

Govezensky T. (1999). Phage-displayed T-cell epitope grafted into immunoglobulin heavy-chain complementarity-determining regions: an effective vaccine design

F. Sciutto, E. (1996). Cysticercosis: identification and cloning of protective

*(Diptera: Muscidae)* as mechanical vectors of *Taenia* eggs *(Cyclophillidea: Taeniidae)* in

"Epidemiología de la cisticercosis en cerdos de una comunidad rural del estado de

(2003). Teniosis y detección de anticuerpos anticisticercos en personas de una

G, de Aluja AS, Larralde C, Sciutto E. (2008). Spatial Distribution of Taenia solium Porcine Cysticercosis within a Rural Area of Mexico. PloS. NeGL. Trop. Dis.,

Rodarte, E. Sciutto. and C. Larralde. (2002). Castration and pregnancy of rural pigs significantly increase the prevalence of naturally acquired *Taenia solium*

Fleury A., Fragoso G., Sarralde C. Sciutto E. (2006). *Taenia solium*: the complex interactions, of biological, social, geographical and commercial factors, involved in the transmission dynamics of pig cysticercosis in highly endemic areas. Ann Trop


**20** 

*Brazil* 

Josué de Moraes

**Antischistosomal Natural Compounds:** 

*Supervisão de Vigilância em Saúde, SUVIS Casa Verde,* 

*Secretaria de Saúde da Cidade de São Paulo, Rua Ferreira de Almeida, São Paulo, SP* 

**Present Challenges for New Drug Screens** 

Schistosomiasis, or bilharzias, is a neglected disease that remains a considerable public health problem in tropical and subtropical regions. This parasitic disease is the most important human helminth infection in terms of morbidity and mortality and is a growing concern worldwide. It is estimated that more than 200 million people have been infected and that 779 million are at risk of infection, resulting in 280,000 deaths annually (van der Werf et al., 2003; Steinmann et al., 2006). Schistosomiasis is caused by blood-dwelling uke worms of the genus *Schistosoma* and is endemic in African, Asian and South American countries. The main disease-causing species are *S. mansoni*, *S. haematobium*, and *S. japonicum. S. mansoni* is the most widely distributed, affecting people in Africa, the Middle East, South America, and the Caribbean, while *S. japonicum* is confined to China, Indonesia, and the Philippines. *S. haematobium* is found in Africa and the Middle East. The adult worms colonise the veins of either the portal system (*S. mansoni* and *S. japonicum*) or the urinary bladder plexus (*S. haematobium*) and can live for years or even decades in human hosts; thus, the disease runs a chronic and debilitating course. Egg production is responsible for both the transmission of the parasite and the aetiology of the disease. Schistosomal species are distinguished by differences in their morphology, both in their parasite stages and in their eggs; further species distinction is made by the species of intermediate host snails that

The global strategy for the control of schistosomiasis is by chemotherapy. Systematic searching for chemotherapeutic drugs began almost a century ago, and the development of praziquantel (PZQ) in 1970 was essential for a reduction in morbidity and mortality due to schistosomiasis. Currently, treatment is still based on the use of PZQ, but the long-term application of PZQ results in decreased efficiency and serious concerns regarding the onset of resistance. In addition, PZQ has no prophylactic properties and is ineffective against larval stages of parasites (schistosomula), meaning that for effective treatment and sustainable control, PZQ must be given on a regular basis. Thus, it is prudent to search for novel therapeutics, and recent discussions have focused on reawakening the need to search for alternatives to PZQ (Caffrey, 2007; Doenhoff et al., 2008; Fenwick et al., 2003; Hagan et

support transmission of the parasite (Gryseels et al., 2006).

al., 2004; Keiser & Utzinger, 2007).

**1. Introduction** 

