Taenia solium causes taeniasis and cysticercosis, a zoonotic complex associated with a significant burden of epilepsy in most countries. Reliable diagnosis and efficacious treatment of taeniasis are needed for disease control. Currently, cure can be confirmed only after a period of at least 1 month, by negative stool microscopy. This study assessed the performance of detection by a coproantigen enzyme-linked immunosorbent assay (CoAg-ELISA) for the early evaluation of the efficacy of antiparasitic treatment of human T. solium taeniasis. We followed 69 tapeworm carriers who received niclosamide as standard treatment. Stool samples were collected on days 1, 3, 7, 15, 30, and 90 after treatment and were processed by microscopy and CoAg-ELISA. The efficacy of niclosamide was 77.9%(53/68). Thirteen patients received a second course of treatment and completed the follow-up. CoAg-ELISA was therefore evaluated for a total of 81 cases (68 treatments, 13 retreatments). In successful treatments (n = 64), the proportion of patients who became negative by CoAg-ELISA was 62.5% after 3 days, 89.1% after 7 days, 96.9% after 15 days, and 100% after 30 days. In treatment failures (n = 17), the CoAg-ELISA result was positive for 70.6% of patients after 3 days, 94.1% after 7 days, and 100% after 15 and 30 days. Only 2 of 17 samples in cases of treatment failure became positive by microscopy by day 30. The presence of one scolex, but not multiple scolices, in posttreatment stools was strongly associated with cure (odds ratio [OR], 52.5; P < 0.001). CoAg-ELISA is useful for the assessment of treatment failure in taeniasis. Early assessment at day 15 would detect treatment failure before patients become infective.

Bovine cysticercosis is caused by the larval stage of the human tapeworm Taenia saginata. According to European data on meat inspection, the prevalence ranges from 0.007% to 6.8%, but the real prevalence is considered to be at least 10 times higher. Laboratory confirmation of the etiological agent is based on gross, stereomicroscopic, and histological examination of submitted specimens. False identifications may occur, possibly because of death and degeneration of cysts, or because taeniid larvae and other tissue parasites, such as Sarcocystis spp., may cause similar macroscopic morphological lesions. Therefore, tests that can warrant sure identification of taeniid lesions and calcified cysts in the muscle are needed. The focus of our study was to develop a suitable postmortem test that could be applied on putative lesions by T. saginata cysticerci, as ambiguously diagnosed after routine meat inspection. In particular, we proposed a biomolecular assay targeting the mitochondrial cytochrome c oxidase subunit I gene (COI). For developing the polymerase chain reaction assay, viable cysts of Cysticercus bovis (n = 10) were used as positive reference samples, and those of Echinococcus granulosus (n = 3), Cysticercus tenuicollis (n = 3), and Sarcocystis spp.(n = 4) as reference negative controls. Further, to evaluate the applicability of the proposed assay, 171 samples of bovine muscular tissue, obtained from local slaughterhouses and containing lesions recognized as T. saginata cysticerci by macroscopic examination, were tested. The proposed test confirmed the diagnosis at postmortem inspection in 94.7%(162/171) of samples. In conclusion, the assay developed in this study, amplifying a short fragment from the mitochondrial gene COI, showed to be suitable for samples containing both viable and degenerating T. saginata cysticerci, yielding an unequivocal diagnosis.

The prevalence of Taenia saginata cysticercosis in cattle slaughtered for meat in Addis Ababa Abattoir, Ethiopia between September 2004 and August 2005 was reported. The examination of various organs of 11227 cattle in Addis Ababa Abattoir showed that 842 (7.5%) were infected with T. saginata cysticercosis. The tongue, masseter muscles, cardiac muscles, triceps muscles and thigh muscles were the main predilection sites of the cysts. The cysts of bovine cysticercosis were also identified on the spleen, intercostal muscles, diaphragm and liver. Out of 10,329 male cattle, examined, 783 (7.6%) had cysts of bovine cysticercosis while 59 (6.6%) of the 898 female animals investigated were infected. The animals slaughtered were all adults. No significant difference in prevalence rates was recorded between the sexes. The prevalence of bovine cysticercosis was higher in local zebu cattle breeds than Holstein-Frisian cattle.

SUMMARYTaenia saginata cysticercosis causes financial losses to the beef industry and farmers, and represents a significant source for human infection in many countries. A case-control study was conducted to identify risk factors for bovine cysticercosis on farms in Switzerland. The case group (n=119) consisted of farms with infected cattle identified at slaughter in 2005 and 2006. Infections were confirmed by morphological or molecular diagnosis. The control group (n=66) comprised randomly selected farms with cattle slaughtered in the same period but with no evidence or history of infection. In personal structured interviews with the farmers, information regarding local surroundings and farm management was collected. Logistic regression revealed the following 5 factors as being positively associated with the occurrence of bovine cysticercosis: the presence of a railway line or a car park close to areas grazed by cattle, leisure activities around these areas, use of purchased roughage and organized public activities on farms attracting visitors. This information is considered useful for government authorities to direct control strategies as well as for farmers to take measures tailored to local situations.

Bovine cysticercosis is an important food safety issue that is of economic concern. In Belgium, in the last years an increase in the number of cases, mostly light infections, was observed. The role of contact with contaminated surface water has been hypothesized as the main route of transmission. Based on abattoir records from 2001 till 2003 the distribution and risk factors of bovine cysticercosis among dairy and mixed farms were studied in four provinces, using Geographic Information Systems (GIS) and questionnaires. The risk factors were analysed using a case-control study design. The case group consisted of herds from which homebred cattle with cysticercosis had been detected at the abattoir; the control group was composed of herds where no cases had been detected. Case herds were distributed over the study area. A logistic regression analysis revealed that the location (province), the number of slaughtered cattle, the flooding of pastures, free access of cattle to surface water and the proximity of wastewater effluent were significant explanatory variables for bovine cysticercosis to be recorded in a herd.

The incidence of cysticercosis due to Taenia saginata in both local and exotic breeds of cattle slaughtered for meat in southeastern Nigeria between November 1999 and April 2002 is reported. The examination of various organs of 25,800 cattle in 10 major abattoirs of this region showed that 6750 (26.2%) were infected with Cysticercus (C.) bovis. The prevalence rates varied from one abattoir to another while the rates of cysticercosis in local and exotic breeds varied significantly (P > 0.05). Sixty percent of all the infected animals had cysts. The tongue, cardiac, and masseter muscles were the main predilection sites of the cysts. Out of 11,720 male cattle, examined, 3215 (27.4%) had cysts of C. bovis while 160 (13.6%) of the 1180 female animals investigated were infected. There was an inverse relationship between the ages of the animals and prevalence of infection with C. bovis (r =-0.8743, P < 0.05). Monthly occurrence of the cysts in the animals revealed an upsurge of infected animals during the dry season. The epidemiology and epizootiology of Taenia saginata and C. bovis in relation to the veterinary service agencies and public health planners in southeastern Nigeria are highlighted.

Molecular diagnosis for taeniasis and cysticercosis in humans on the basis of mitochondrial DNA analysis was reviewed. Development and application of three different methods, including restriction fragment length polymorphism analysis, base excision sequence scanning thymine-base analysis and multiplex PCR, were described. Moreover, molecular diagnosis of cysticerci found in specimens submitted for histopathology and the molecular detection of taeniasis using copro-DNA were discussed.

Neurocysticercosis (NC) is a serious public health problem in Taenia solium endemic areas and in some immigrants and international travelers. A key intervention in preventing NC is elimination of taeniasis by chemotherapy. Currently, two safe and effective taenicides, namely niclosamide and praziquantel, are available. Both are on WHO Essential Drug list, but are often inaccessible in T. solium endemic areas. Natural remedies, still widely used in some endemic areas, are frequently carcinogenic or highly toxic and as such should be discontinued. Chemotherapeutic intervention to control T. solium taeniasis/cysticercosis, whilst theoretically feasible, has several practical obstacles. These include poor public awareness, problems with diagnosing Taenia carriers, poor availability of taenicides where needed and low priority afforded to the control of NC. These can be overcome, respectively, by effective health education, wider use of newly developed coproantigen tests, strengthening of health services infrastructure and essential drugs distribution, and increasing the priority given to prevention of NC, as a leading cause of epilepsy in T. solium endemic areas. Information is accumulating on rational approaches to population-based short-term chemotherapeutic control measures. These are: widely available modern diagnostic tools and taenicides, treatment of any case of taeniasis, confirmed or probable, focus-oriented chemotherapy, irrespective of Taenia species implicated, improved sanitation, cooperation of veterinary and medical services, linkage with programs against epilepsy and cooperation of better educated communities. Now, it remains to take an advantage of existing tools and experience.

Toeniids are large tapeworms, common throughout the world. Two species, Taenia saginata and T. solium are common parasites of man. The adult worms parasitize the small intestine, while immature stages (metacestodes or cysticerci) develop mainly in cattle in the case of T. saginata or pigs in the case of T. solium. Cysticerci of T. saginata rarely develop in man, although humans are easily infected with those of T. solium after eating raw or undercooked infected pork-producing the disease known as cysticercosis. In Taiwan, both the pork and beef tapeworms have been documented among aboriginal peoples - with T. saginata considered the most prevalent species. But, as P.C. Fan discusses here, the 'Taiwan Taenia' has several unusual features - not least the fact that beef is not part of the traditional diet of Taiwan oboriginols.

The tapeworms of the genus Taenia that infect human beings are T. solium, T. saginata and T. saginata asiatica. Taenia solium and T. saginata exhibit unequivocal features that characterize them; in contrast, only recent DNA studies, morphological characteristics, and epidemiological and sanitary aspects indicate that T. saginata asiatica is a subspecies of T. saginata. These 3 tapeworms occur in humans in their adult stage, and the intermediate hosts are pigs for T. solium and T. saginata asiatica and cows for T. saginata. Their identification is crucial considering the migratory increase from Asia to the Western Hemisphere and the fact that these tapeworms coexist in the same environment in Asia; furthermore, it is estimated that movement in both directions across the United States-Mexico border exceeds 200 million persons per yr, and thus, opportunities for acquiring and transporting T. solium infections are multiplied. It is not easy to distinguish among these tapeworms; therefore, a comparative diagram of the 3 parasites is shown in this article, which will facilitate their identification. All morphological features, some of which allow for identification, are clear and can be easily distinguished among the 3 tapeworms.

A new scheme of clarifying clinical forms of toxocariasis is proposed to include:(i) systemic forms: classical VLM and incomplete VLM;(ii) compartmentalized forms: ocular and neurological toxocariasis;(iii) covert toxocariasis; and (iv) asymptomatic toxocariasis. The following markers are helpful in defining clinical forms namely, patient characteristics and history, clinical symptoms and signs, positive serology, eosinophilia and increased levels of IgE. Amongst the available drugs albendazole is the most commonly used, although other benzimidazole compounds have a similar efficacy. The recommended dose of albendazole is 15 mg kg(-1) body weight daily for 5 days and in some cases with VLM syndrome the treatment needs to be repeated. An evaluation of treatment efficacy can be made by observing a rise in eosinophilia within a week followed by any improvement in clinical symptoms and signs, lower eosinophilia and serological tests taken over a period of at least 4 weeks. In addition to clinical rationales for the specific treatment of VLM and OLM, preventive treatment needs to be considered bearing in mind the increasing risk of larvae localizing in the brain during the course of an infection. To reduce migration of Toxocara larvae a single course of albendazole is suggested in cases where eosinophilia and serology are at least moderately positive.

A communitywide outbreak of gastrointestinal illness due to Giardia lamblia infection occurred in the city of Berlin, New Hampshire, during April and May 1977. The clinical, epidemiologic, and laboratory aspects of this outbreak are described here. In 213 predominantly symptomatic cases of G. lamblia infection diagnosed at a local hospital laboratory in a 6-week period, illness was characterized by prolonged diarrhea (median duration 10 days) and 13% of symptomatic infections required hospitalization. Treatment with either quinacrine or metronidazole was generally followed by symptomatic improvement. A communitywide survey of the city residents revealed that the majority (76%) of G. lamblia infections occurring during the epidemic period were asymptomatic and ran a self-limited course without treatment. No significant secondary, person-to-person spread occurred and no enteric pathogens other than G. lamblia were implicated. Water was epidemiologically implicated as the most likely source of infection with Giardia cysts being demonstrated in samples of treated water as well as raw source water. Evidence supported the occurrence of two simultaneous outbreaks in this city which is supplied by two largely independent water supply systems. Inspection of the two water treatment facilities revealed several defects which permitted untreated (raw) water to mix with treated water. Human or beaver could have been responsible for contaminating source water with Giardia in this outbreak. A marked reduction in both clinical and subclinical giardiasis was apparent two months after onset of the outbreak, apparently as a result of measures applied to interrupt waterborne transmission of Giardia.

Ascaris lumbricoides, the roundworm, is one of the largest parasites of man and probably infects one in four persons in the world. Despite its prevalence, ascariasis is a largely neglected public health problem that has attracted relatively little scientific inquiry. Frequently, a number of biases contribute to the uncritical conclusion that infection with A. lumbricoides adversely affects the nutritional status of the host. This situation is exacerbated by number of studies that have confirmed these biases but have employed questionable methods, such as the use of small samples and indistinct categories, the neglect of the double-blind safeguard, the selection of inadequate controls, and the performance of experiments that are not reproducible in a variety of circumstances. It is interesting to note that studies claiming positive correlation between ascariasis and protein energy malnutrition have not found a significant difference in weight between infected and uninfected children before intervention. Furthermore, several recent studies have shown no significant improvement in nutritional status after intervention. Thus, the causal relationship between ascariasis and protein energy malnutrition is not clearly proved, and it is premature to advocate mass treatment of children in ascariasis-endemic areas as a method to enhance their growth and development.

Three taeniid tapeworms infect humans in Asia and the Pacific: Taenia solim, Taenia saginata, and Taenia asiatica. Although there is continuing debate about the definition of a new species, phylogenetic analyses of these parasites have provided multiple lines of evidence that T. asiatica is an independent species and the sister species of T. saginata. Here we review briefly the morphology, pathology, molecular biology, distribution and control options of taeniasis/cysticercosis in Asia and the Pacific and comment on the potential role which dogs may play in the transmission of T. solium. Special attention is focused on Indonesia: taeniasis caused by T. asiatica in North Sumatra, taeniasis/cysticercosis of T. solium and taeniasis of T. saginata in Bali, and taeniasis/cysticercosis of T. solium in Papua (formerly Irian Jaya). Issues relating to the spread of taeniasis/cysticercosis caused by T. solium in Papua New Guinea are highlighted, since serological evidence suggests that cysticercosis occurs among the local residents. The use of modern techniques for detection of taeniasis in humans and cysticercosis in humans, pigs and dogs, with the possible adoption of new control measures will provide a better understanding of the epidemiology of taeniasis/cysticercosis in Asia and the Pacific and lead to improved control of zoonotic and simultaneously meat-borne disease transmission.

CONTEXT: Human Taeniasis caused by the pork, Taenia solium, or beef, T saginata, tapeworm arises after eating pork or beef contaminated with metacestodes, the larval stage of these parasites. Taeniasis with T solium can lead to neurocysticercosis and threaten others by accidental ingestion of eggs released from asymptomatic Taeniasis patients. The 2003 World Health Assembly declared that T solium is of worldwide public-health importance, and that it is an eradicable parasitic disease worldwide. Adult taeniid tapeworms expelled from people in almost all Asian countries appeared to be T saginata (the so-called Asian Taenia), even though they ate pork. The organism is now named T asiatica, and has been found in Taiwan, Korea, China, Vietnam, and Indonesia. But it has been difficult to differentiate T saginata from beef and Asian Taenia from pork. STARTING POINT: Marshall Lightowlers and colleagues (Int J Parasitol 2003; 33: 1207-17) recently demonstrated that recombinant oncosphere vaccines against several taeniid cestodes, including T ovis, T saginata, T solium, and Echinococcus granulosus, are highly effective. Protection was almost 100%, in the laboratory and in the field. These researchers found several common features, including a predicted secretory signal sequence, and one or two copies of a fibronectin type III domain, each encoded by separate exons within the associated gene. WHERE NEXT? Molecular and immunological techniques, including vaccine research and development of animal models for differentiation of taeniid species in humans, have greatly advanced over the past decade. The clinical importance of infections by these taeniids, including T asiatica, in humans, and the potential for cysticercosis attributable to T asiatica in humans, needs further study.

Taenia solium is endemic in the Andean region of Ecuador. The recent rediscovery of Taenia saginata in humans urges to reconsider some assumptions in relation to the epidemiology of the taeniosis/cysticercosis complex in this country.Therefore, data were compiled on the infection of both tapeworms in man and animals in Pichincha and Imbabura provinces in the Andean region, north of Quito. On post mortem inspection 3 out of 806 (0.37%) carcasses had T. saginata metacestodes, however, 35 sera out of 869 (4.03%) showed circulating antigen in a monoclonal antibody-based sandwich ELISA (Ag-ELISA). Porcine cysticercosis was detected in 15 out of 2896 (0.52%) carcasses and 93 out of 1032 serum samples (9.01%) were positive in Ag-ELISA. In humans, 4.99%(215 out of 4306) cases of antigen positives were found, whereas coprological examination of 1935 stools resulted in 30 positive cases (1.55%). The limited number of adult tapeworms (29) that were collected does not allow firm conclusions on the proportion of each species, but in total 21 specimen were identified as T. saginata and 8 as T. solium. These data have been discussed in view of the epidemiology of human cysticercosis.

Urban sewage production is increasing and its agronomical use as a fertiliser has been advocated. Considerable defiance is prevalent in consumers and among farmers on the use of such fertilisers due to unknown pathological or environmental risks. The aim of the present review was to consider which pathological risk is major. Cysticercosis due to Taenia saginata appears to be one of the major pathological threats when sewage sludge is used to fertilise cattle pastures in temperate areas. The situation is different in Africa (Taenia solium and T. saginata are both highly prevalent) and Asia (Taeniasaginata-like are prevalent). The processing of sludge and the delay between its application onto a pasture and grazing are probably major risk factors. Little data are available on the influence of processing, delay between processing and the use of sludge on the pathogenic risk. Producers and consumers will be more confident on the use of sludge if objective data are gained on risk. Most of the cases of cysticercosis (North America, United-Kingdom, Germany or Denmark) are related to poor human hygiene or accidental overflooding of sewage plants onto pastures. The standard application of sludge on pastures is apparently at low risk. This low risk does not mean that surveillance should cease since outbreaks of cysticercosis have been reported. Future investigations should concentrate on the most sustainable means of reducing risk (length of storage before use, composting, other treatments).

A sero-epidemiological survey of Taenia saginata cysticercosis was carried out to determine the prevalence of the infection in cattle presented for slaughter in Belgium. Between November 1997 and June 1998, a total of 1164 serum samples were collected in 20 export abattoirs. Meat inspection was routinely carried out by veterinary inspectors. Serum samples were examined for circulating parasite antigen using a monoclonal antibody-based sandwich enzyme-linked-immunosorbent assay (Ag-ELISA). Thirty six serum samples (3.09%) were found positive in the Ag-ELISA, while by meat inspection on the same animals cysticerci were detected in only three carcasses (0.26%). Sero-prevalence was positively correlated with the age of the animals. The sero-prevalence found in this study was more than 10 times higher than the annual prevalence (0.26%) reported by the Institute for Veterinary Inspection. This study clearly indicates that the classical meat inspection techniques detect only a minor fraction of the carcasses infected with cysticerci.

Human taeniasis and cysticercosis are zoonotic parasites of considerable public health problem. A total of 6434039 slaughtered animals over a period of four years (1994-1997) showed 0.72% cysticercosis (bovis and cellulosae) infections. Individual animal species infection was 0.23% in native breed cattle, 7.25% in imported cattle, 0.14 in buffaloes and 0.09% in pigs. The highly infested parts were the heart (64.2%) followed by the head (34.5%), the whole body (1.1%) and lastly, the quarter (0.2%) in both types of cattle and the heart (64.3%), the head (34.9%), the whole body (0.6%) and the quarter (0.2%) in buffaloes. In pigs, the highly infested parts were the whole body (55.4%) followed by the heart (37.8%) and lastly the head (6.8%). Some interesting cysticercosis were macroscopically and microscopically parasitologically and histopathologically studied. A general discussion on taeniasis and cysticercosis was given.

Cysticercosis is a parasitic disease commonly observed in developing countries in Latin America, Africa, and Asia. Many cases involving cerebral injury have been reported on Reunion Island, a French department in the Indian Ocean. The present article describes the findings of a seroprevalence survey performed from September 1990 to May 1992 using an ELISA technique. Out of a total of 1010 individuals randomly selected from the voter registration records of the island's 24 polling districts, 993 agreed to be interviewed and undergo blood testing. Samples from 14 individuals were positive for cysticercosis, indicating a seroprevalence of 1.4% with 95% confidence interval from 0.7 to 2.1%. Seropositive individuals were evenly distributed throughout the island with no statistical difference regarding sex and age. A retrospective study showed that diagnosis of taeniasis was uncommon (less than 0.02% of stool examinations for parasites). Meat inspection records showed that no pork had be seized due to taeniasis since 1993 but raising of pigs by private citizens without veterinarian control is still widespread. Living conditions are improving and eradication of endemic cysticercosis seems achievable by enforcing zoning codes and educating people about the need for proper meat handling and treatment of taeniasis.

A comprehensive study was undertaken in a rural community in the state of Morelos, Mexico to evaluate health education as an intervention measure against Taenia solium. An educational program was developed to promote recognition and knowledge of the transmission of the parasite and to improve hygienic behavior and sanitary conditions that foster transmission. The effects of educational intervention were evaluated by measuring changes in knowledge and practices and prevalence of human taeniasis and swine cysticercosis before and after the campaign. The health education strategy was implemented with the active participation of the population based on the information obtained from a sociologic study. A questionnaire was designed and used before, immediately after the intervention, and six months later. Statistically significant improvements occurred in knowledge of the parasite, its life cycle, and how it is acquired by humans; however, changes in behavior related to transmission were less dramatic and persistent. The prevalences of cysticercosis in pigs at the start of the education intervention were 2.6% and 5.2% by lingual examination and antibody detection (immunoblot assay), respectively, and approximately one year after the intervention they were 0% and 1.2%(P < 0.05). These changes were accompanied by significant reductions in the reported access of pigs to sources of infection and freedom to roam. We conclude that health education, developed along with community involvement, reduced opportunities for transmission of T. solium in the human-pig cycle.