Search for antibodies to Taenia solium cysticerci in paediatric patients with seizures.

Neurocysticercosis is a leading cause of seizures in adults, but in paediatric patients, the diagnosis is controversial. The aim of this study was to search for antibodies to Taenia solium cysticerci in paediatric patients with seizures. We retrospectively studied a cohort of 41 serum samples from paediatric patients and 40 serum samples from healthy children. Antibodies were analysed by ELISA (vesicular fluid) and by Western blot (glycoproteins). Clinical, image and socio-demographic data were obtained from the medical records. The frequency of positive by ELISA was of 12% (n=5) in patients with seizures, while no positive samples were found in the healthy group. Results of Western blot were negatives. The analysis of the medical records showed a cyst of unknown origin in 2/5 ELISA positive samples. According to the diagnostic criteria for neurocysticercosis, three minor criteria (positive serology, active seizures and compatible image) were associated to an epidemiological condition (Mexico is endemic for neurocysticercosis); thus, the probable frequency of neurocysticercosis in the studied sample of patients with seizures was 4.9% (2/41 patients). The three remaining positive samples were associated with problems of noninfectious origin. The positivity was associated with the identification of cysts by magnetic resonance imaging (p = 0.047; chi-square), but found no association with the socio-economic characteristics of the patients, family history or to clinical symptoms. In conclusion, scarce frequency of antibodies to T. solium cysticerci was determined in paediatric patients with seizures. The low prevalence of antibodies detected in children is an indirect indicator of the interruption of T. solium transmission. Further studies are needed to design an algorithm for the conclusive diagnosis of seizures.

The seroprevalence of Taenia solium cysticercosis among epileptic patients in León, Nicaragua, as evaluated by ELISA and western blotting.

The Taenia solium taeniasis/cysticercosis complex is an important public-health problem in several countries, where many epileptic seizures appear to be associated with neurocysticercosis. As few data on this problem in Nicaragua exist, the seroprevalence of antibodies reacting with antigens from T. solium cysticerci was investigated among 88 Nicaraguan epileptics (45 males and 43 females, aged 6-53 years). In questionnaire-based interviews, each adult subject and a caregiver of each child investigated were asked about potential risk factors for taeniasis/cysticercosis. When a serum sample from each subject was then checked for anti-cysticercus antibodies, 8.0% of the subjects were found seropositive by ELISA and 14.8% by western blotting. Five samples (all from individuals who had been epileptic for > 5 years) were positive in both tests. When the level of association between each potential risk factor and seropositivity (in ELISA or by blotting) was evaluated, the only statistically significant association detected was that between a positive ELISA and the subject living in a household where pigs were raised (odds ratio = 5.18; 95% confidence interval = 0.8-41.6; P = 0.05). The bands most frequently recognized in the western blots (of 50, 42-39, 24 and 14 kDa) were those previously reported. The results indicate that, in the city of Léon, cysticercosis may be endemic and the cause of a significant proportion of the epilepsy recorded.

Cysticercosis in epileptic patients of Mulungu do Morro Northeastern Brazil.

With the aim to study the magnitude of infection by the metacestode of Taenia solium in a population of epileptic patients in the arid region of Bahia, Northeastern Brazil, we examined 200 consecutive cases who attended an ambulatory clinic in the disctrict of Mulungu do Morro. Sixty-six of the patients had a diagnosis of epilepsy. From them 10 (15.2%) presented antibodies against a specific fraction of antigens in Western blot, and 4 (6.0%) had circulating parasite products, as tested by capture ELISA. Only 1 case was positive for antibodies and antigens. We found that the frequency of seropositivity was related to the time without epileptic seizure. We conclude that cysticercosis is endemic in the region of Mulungu do Morro and that it is related to a benign form of epilepsy.

Search for an IgG response against neural antigens in experimental spinal cord injury.

In order to determine if a specific response is induced after spinal cord injury, we performed a kinetic search for IgG antibodies against various spinal cord antigenic preparations in a rat contusion model. Even though spinal cord injured animals showed two reactive bands, these could be originated by the reaction of natural antibodies, since they were also observed before lesion. Thus, these antibodies would not be of relevance in the pathogenic events of spinal cord injury in this rat model. Our findings do not demonstrate the existence of a specific IgG response against spinal cord constituents after injury.

Prevalence and risk of cysticercosis and taeniasis in an urban population of soldiers and their relatives.

To determine markers of Taenia solium transmission and risk factors in an urban community, we studied 1,000 soldiers from a military camp in Mexico City and their relatives. Serum samples were used to detect antigens and antibodies and fecal specimens were examined for Taenia coproantigens and helminth eggs. Prevalences of 12.2% and 5.8% for cysticercosis were found among soldiers and their relatives, respectively. Taeniasis was found in 0.5% and none of the groups, respectively. Relatives of soldiers positive for cysticercosis and taeniasis markers ate more pork from street stores than restaurants or markets compared with relatives of soldiers without these indicators of infection. Also, 12.0% of the relatives of positive soldiers had a history of expelling tapeworm proglottids in the feces in contrast to 3.7% of the family members of the control group. Prevalence values and risk factors in this urban population are similar to those of previous studies performed in rural populations.

Human neurocysticercosis: comparison of enzyme immunoassay capture techniques based on monoclonal and polyclonal antibodies for the detection of parasite products in cerebrospinal fluid.

Current diagnosis of neurocysticercosis relies mostly on computerized tomography and nuclear magnetic resonance, with detection of antibodies being confirmatory rather than decisive. An assay which detects parasite products in cerebrospinal fluid would conclusively demonstrate a current infection and could be important when decisions regarding treatment must be made. Cerebrospinal fluid from patients with neurocysticercosis was used in 4 enzyme immunoassay capture tests designed to detect parasite products. Of the systems tested, one, based on the use of a monoclonal antibody reactive with a surface and secretion component of the metacestode, was particularly promising, giving a sensitivity of 72%. The assay has the double advantage of a very low background and a proved specificity for the products of living cysticerci. The other 3 systems (monoclonal anti-vesicular fluid antibody, polyclonal antibody against a saline extract and polyclonal anti-antigen B antibody) were less sensitive. Results with the anti-antigen B system support the proposal that products of low immunogenicity are the most appropriate targets for the serological detection of the parasite.

Immunodiagnosis of human and porcine cysticercosis. Detection of antibodies and parasite products.

In this paper we report the immunodiagnosis of cysticercosis by the detection of antibodies in the cerebrospinal fluid (CSF) of patients, by standard enzyme immunoassay (EIA) which gave 90% sensitivity. We are also showing the results obtained with a double homologous polyclonal or monoclonal antibody based EIA that detects parasite products: we analysed CSF of patients and obtained sensitivities ranging from 14% to 75% for single antibody systems and 90% when analysing the samples with two or three systems simultaneously. The sera of infected pigs were also evaluated; with one monoclonal antibody we could detect 79% of positive samples. The good results obtained encourage the standardization and improvement of the technique for diagnostic as well as for epidemiologic purposes.