Synonyms: Taeniasis
Larval stage of Taenia solium is called cysticercus cellulosae commonly known as cysticercosis.
The cysticercosis is a major public health problem in various developing and underdeveloped countries of Asia, Africa and Latin America. Around 4 million people of the world are infected with adult tapeworms of pig.
Distribution
The parasite was described in pigs as early as 4th century B.C. by Hippocrates. The prevalence of this problem depends on socio-economic and cultural moites of the population. Migration of rural population to urban areas also intend to increase prevalence of cysticercosis of pig to man. As per WHO taeniasis is a serious problem when 71% of people are infected, Verma and Gaur (2002) reported 39% of cases from Uttaranchal as vegetarian and 17.6% as pork caters. It indicates that vegetable diet might be infected.
Pathak (1984) could found 2% stool of pigs positive to Taenia solium in Uttar Pradesh. In Chandigarh a bit higher concentration was noted. Selvam (2005) observed 12% and 26% prevalence of taeniosis with sedimentation and formalin either method respectively from faeces of 100 people associated with pig slaughter in Bangalore.
Sawhney (1996) pointed out that most common cause of epilepsy in man is due to neurocysticercosis. Children used to suffer more frequently with CNN.
In pigs, cysticerci are generally observed in muscles of shoulder. thigh, neck, brain, tongue, lungs, liver, intercostal muscles. It may also be found in eye and eye orbital. Free ranging pigs suffer most over indoor organised pigs.
This parasite degrades the quality of meat resulting to condemnation of it incurring huge economic loss. The amount was estimated to be around 64,600 rupees as reported in 1989 by Pathak and Gaur.
Life Cycle
The adult tapeworm causes taeniasis in man and larval stage C. cellulosae causes cysticercosis in pigs and wild boars. The infected pig with C. cellolosae is generally known as measly pork. The adult tapeworm remains in the small intestine of man. The length of the tapeworm is 3-5 meters and it can survive about 25 years.
The pig acquires the infestation through ingestion of eggs or gravid segments excreted in faeces of man. The oncospheres escapes from eggs and attach to the intestinal mucosa with the help of hooks. They penetrate the intestinal wall enter the lymphatics and veins, dissminate further to muscles and various visceral organs. The maturation of cystecerci takes place in 3 weeks to 2 months. The life cycle becomes complete while man eat raw or uncooked meat – measley of pig. The scolex gets attached to the mucosa of the small intestine and mature in around 5-10 weeks.
Susceptible Hosts
Pig is the important intermediate host. But, animals like dog, cat, sheep, goat, monkey may occasionally be infected.
Transmission
Man may act as intermediate host following ingestion of Taenia solium eggs either directly via hands contaminated with tapeworm eggs or through food prepared by carriers or contaminated vegetables route. On the other hand man may get the infection through ingestion of infected pork.
Pathogenesis
Bladder worm causes serious inflammatory changes. The changes include infiltration of eosinophils, neutrophils, lymphocytes, plasma cells and giant cells. Later on fibrosis and necrosis occurs followed by caseation and calcification.
Clinical Findings
The infection with Taenia solium is asymptomatic in the initial phage. But, may show the symptoms like nausea, abdominal discomfort, diarrhoea and weight loss. Larvae usually lodge in almost all organs, tissues, subcutaneous space, intramuscular tissues, brain, eyes, liver, lungs, tongue, etc.
Clinical symptoms vary depending on the organs/tissues involved.
Porcine cysticercosis in man causes:
- Neuro cysticercosis (NCC)
- Opthalmo cysticercosis (OCC)
- Disseminated cysticercosis (DCC)
- Mixed cysticercosis (MCC)
Epilepsy is the common manifestation of NCC. The affected one suffers from headache, vomiting and seizures. Obstruction of CSF may lend to hydrocephalus – manifested by headache, nausea, vomiting, dizziness, change in vision, ataxia, papilledema.
Animal. The signs in hosts like pig is generally asymptomatic. Despite heavy infection, animals do not show any overt clinical manifestations. But, if the larvae lodges in eye or brain in that case clinical manifestation concerning those organs are obvious.
Diagnosis
It can be detected in the following manners.
- Detection of eggs/proglottids in stool.
- NCC can be detected by (a) Computed tomography, (b) Magnetic resonance imaging, (c) Single small enhancing computed tomography lesion a dying parasite could be detected.
- Serologicals tests like (a) Enzyme linked immuno absorbent assay, (b) Enzyme linked immuno electro transfer biot assay
- Post mortem lesions
Treatment
Albendazole @ 30 mg/kg and praziquantel @ 50-200 mg/kg body weight are recommended against C. cellulosae in pigs. But, Gongalez (2003) are of the opinion that oxfenbendazole @ 30 mg/kg body weight is more effective and confer protection for 3 months.
In case of man, Taenia solium can be treated with a single dose of praziquantel @ 5-10 mg/kg. Supportive treatment for seizure is to be rendered depending on the situation.
Control
- Pigs should be reared away from the human inhabitation.
- Pigs are to be reared at periodical interval.
- Children should not be allowed to come in contact with the faecal matter of pigs.
- Guido line of WHO (2003) to be followed. Adequate management facilities should be made available at the health service centres. Some of the measres are as follows:
- There should have adequate sanitation arrangement for disposal of human night soil.
- The people should be made aware about the potential danger to acquire the infection from pork. People should be discouraged to eat partially cooked pork. Heating of pork to more than 50 C prior to eating or freezing at 10 C for 12 days are advisable.
- Adequate inspection of meat at abattoir need to be made. There should be stringent regulation for marketing of measely pork.
- Comprehensive studies are to be made in the pig raising areas to assess the porcine cysticercosis. This will enable better understanding on the epidemiology of the disease, which will further aid to make strategy to overcome this problem.
- Mass anthelmintic treatment should be executed in pigs. Man should not be given opportunity to come in contact with pig excreta.
