Taenia solium taeniasis and cysticercosis:extinction or outbreak

Taenia solium taeniasis and cysticercosis are neglected zoonotic diseases that affect human health and economies of developing countries.In this work,we formulate and analyze deterministic and continuous time Markov chain(CTMC)stochastic models to determine parameters that drive Taenia solium taeniasis and cysticercosis and the likelihood of their extinction.The basic reproduction number R0 is computed by the next generation matrix approach,sensitivity index of each parameter in R0 is derived by the normalized forward sensitivity index and the likelihood of diseases’extinction is computed by the multitype branching process.The analysis shows that humans with Taenia solium taeniasis,infectious pork and Taenia solium eggs in the environment play an important role in the transmission of Taenia solium taeniasis and cysticercosis,and the model exhibits forward bifurcation at R0=1.This implies that R0<1 is a sufficient condition to eliminate Taenia solium taeniasis and cysticercosis.For CTMC model,analysis shows that the probability of Taenia solium taeniasis and cysticercosis extinction is high if the diseases emerge from humans with Taenia solium cysticercosis and there is an outbreak if the diseases emerge from either humans with Taenia solium taeniasis or infectious pork or Taenia solium eggs in the environment.To control Taenia solium taeniasis and cysticercosis,the intervention strategies should focus on improving hygiene and sanitation for reducing shedding rate of Taenia solium eggs in the environment,inspection of pork for reducing the rate of acquiring Taenia solium taeniasis and spraying of insecticides for killing Taenia solium eggs in the environment.

Taeniasis vs cysticercosis infection routes

Although cysticercosis caused by Taenia solium(T. solium) is considered a neglected disease, its life cycle has been well known for more than two centuries. T. solium not only causes cysticercosis but also taeniasis in humans. These two diseases have totally different infection routes. To acquire taeniasis(the presence of the adult stage of T. solium in the intestine), humans have to ingest the larval stage(cysticercus) that infects a variety of organs and viscera in pigs, its intermediate hosts. Therefore, taeniasis is acquired when eating raw or undercooked infected pork. The adult stage in the human intestine release eggs that contain a hexacanth embryo, the oncosphere. If humans accidentally ingest the eggs of T. solium, the released oncospheres penetrate the intestine and become cysticerci. Therefore, cysticercosis is acquired by the ingestion of eggs that contaminate water, vegetables, hands etc. These facts should not be forgotten to avoid misinformation in scientific publications.

Effects of Arecoline Hydrobromide on Taeniasis and Cysticercosis in Domestic Animals

Taeniasis and cysticercosis in domestic animals belong to zoonosis and seriously threaten the public health security. Especially the cysticercosis and echinococcosis caused by the tapeworm eggs have great harms to bodies because they can attack many organs of body. According to the combination of experimental results and literature materials, the morphology and transmission mode of taenia and cysticercus, the prevalence status and monitoring of taeniasis and cysticercosis as well as the antitapeworm mechanism, comparative analysis to other drugs, expelling tapeworm tests in vitro, dose determining tests and usage notes of arecoline hydrobromide were expounded in detail. It provides a theoretical basis for prevention of taeniasis and cysticarcosis and more scientific usage of arecoline hydrobromide and thus relieves the harms of taeniasis and cysticercosis and ensuring the public health security.

Development of a health education intervention strategy using an implementation research method to control taeniasis and cysticercosis in Burkina Faso

Background:Taeniasis and cysticercosis are two diseases caused by Taenia solium,a parasite transmitted between humans and pigs,leading to considerable economic loss and disabilities.Transmission of the parasite is linked to environmental and behavioural factors such as inadequate sanitation and hygiene,poor pig management,and consumption of infected pork.This study used implementation research method to design a health education intervention strategy for reducing T.solium infections in Burkina Faso,a country endemic for the parasite.Methods:Eighteen group discussions were conducted with 8-18 participants each in three villages.In addition,structured interviews were conducted among 4777 participants and 2244 pig owners,who were selected through cluster random sampling in 60 villages of three provinces of Burkina Faso.Both approaches assessed knowledge and practices related to T.solium.The information obtained was used to develop a community-adapted health education intervention strategy to control taeniasis and cysticercosis in Burkina Faso.Results:The group discussions revealed that participants had a poor quality of life due to the diseases as well as inadequate access to latrines,safe water,and healthcare services.In addition,it was found that pig production was an important economic activity,especially for women.Furthermore,financial and knowledge constraints were important limitations to improved pig management and latrine construction.The survey data also showed that open defecation and drinking unboiled water were common behaviours,enhanced by a lack of knowledge regarding the transmission of the parasite,perceived financial barriers to the implementation of control measures,lack of public sensitization,as well as a lack of self-efficacy towards control of the parasite.Nevertheless,the perceived financial benefits of controlling porcine cysticercosis could be emphasized by an education program that discourages open defecation and encourages drinking safe water.The final intervention strategy included a Participatory Hygiene and Sanitation Transformation(PHAST)approach,as well as a 52-min film and an accompanying comic booklet.Conclusions:The main problem in the study communities regarding the transmission of T.solium cysticercosis is the random disposal of human faeces,which can be contaminated with parasite eggs.Prevention of open defecation requires the building of latrines,which can be quite problematic in economically challenged settings.Providing the community with the skills to construct durable latrines using low-cost locally available materials would likely help to resolve this problem.Further studies are required to implement and evaluate the T.solium control strategy developed in this study.

A preliminary analysis of some epidemiological factors involved in porcine cysticercosis in Bafut and Santa subdivisions,North West Region of Cameroon

Objective:To examine the magnitude and some risk factors of porcine eysticercosis in Bafut and Santa,two sub-divisions noted for pig farming in the North West Region of Cameroon.Methods: A total of 499 pigs in 300 households were examined by tongue inspection and serologically by Ag-ELISA.Information was sought on the age and sex of the animals,prevailing husbandry systems,types of feed,the state of each pen and the state of toilets.Futhermore,a questionnaire was administered to the farmers to determine their awareness on taeniasis/cysticercosis and related factors.Results:The prevalence of the disease was significantly higher in Santa(10.2%) than in Bafut(4.2%),although there was a higher level of awareness in both localities(62.3%).Age of pigs,traditional rearing systems(roaming,tethered,earth floor pen,raised floor pen),faecal disposal in the environmenl and poor sanitation significantly influenced the seroprevalence of porcine cysticercosis in both localities.Most farmers(79.7%) used a combination of concentrate, grass and kitchen waste to feed pigs.Financial loss from porcine cysticercosis was estimated at 346 900 CFA representing 2%of total income.Conclusions:Control measures advanced here include sensitization campaigns,periodic examination and treatment of infected pigs by veterinarians,improved husbandry systems,proper use of standard latrines regularly inspected by sanitary officers,and sound hygienic and sanitary practices.