Elba Miranda

Cysticercosis as a major cause of epilepsy in Peru

In countries where cysticercosis is endemic, the proportion of epilepsy due to cysticercosis is not well documented. To investigate the association between cysticercosis and epilepsy, we used the enzyme-linked immunoelectrotransfer blot (EITB) assay to detect serum antibodies to Taenia solium in 498 consecutive outpatients at a neurology clinic in Lima, Peru. Every patient was classified as epileptic (n = 189) or non-epileptic (n = 309) after neurological, and where possible electroencephalographic, examination. A substantially higher proportion of epileptic than non-epileptic patients was seropositive in the EITB (22 [12%] vs 8 [3%], p < 0.001). 19% of epileptic patients born outside Lima, 20% of those with late-onset epilepsy, and 29% of patients with both these characteristics were seropositive. Thus, in Peru, cysticercosis is an important aetiological factor for epilepsy.

Diagnosis of cysticercosis in endemic regions

Abstract Taenia solium cysticercosis is a frequent cause of neurological disease in developing countries. Specific diagnosis of cysticercosis is difficult. We obtained serum and/or CSF samples from 204 consecutive patients admitted to a neurological ward in Lima, Peru, and looked for antibodies specific for T solium with the enzyme-linked immunoelectrotransfer blot (EITB) assay. 21 (12%) of 173 serum samples from these patients were EITB-positive. In contrast, only 2 (1·5%) of 135 patients attending a public endoscopy clinic and 1 (1%) of 88 patients attending a private endoscopy clinic were seropositive. 1 (1%) of 98 pregnant women living in a Lima shanty town was EITB-positive. 15 (58%) of 26 neurology patients diagnosed clinically as having cysticercosis were seronegative. Routine screening by EITB of all patients with neurological symptoms from areas of endemic cysticercosis would avoid misdiagnosis of this common and treatable disease.

Etiologic agents in acute vs persistent diarrhea in children under three years of age in peri‐urban Lima, Perú

In a longitudinal study of acute and persistent diarrhea in 677 children less than three years old in a peri‐urban community of Lima, Perú, during 27 months of surveillance, stools were cultured at the beginning of each diarrheal episode and on each subsequent week of illness. Analyzing stool cultures only from children who had not received antibiotic treatment in the 48 h prior to the culture, no association was found between any enteropathogen and persistent diarrhea. We did not find any increase in mixed infections in persistent diarrhea episodes as compared with acute diarrhea, controlling for age, season and anthropometric status. The isolation rate for any given enteropathogen was similar during the first, second, third or later week of illness, but when the presence of a specific enteropathogen was sought in sequential stools within a single episode, no evidence of persistent infection was found. This study shows that in developing countries with a high incidence of diarrheal diseases frequent re‐infections with enteropathogens prevalent in the population are one reason for prolonged illnesses. Host factors that increase susceptibility to infection or decrease recovery from illness may also play a role. Further studies of these factors, such as micronutrient deficiencies, are needed to identify a public health intervention to control persistent diarrhea, a condition associated with mortality in many developing countries.

Parasitosis intestinal en poblaciones urbana y rural en Sandia, Departamento de Puno, Perú

* Instituto de Medicina Tropical Alexander von Humboldt (IMTAvH). Av. Honorio Delgado 430, Urb. Ingieneria,San Marin de Porres. A.P. 4314 - Lima 100, Peru. E-mail: egh@upch.edu.pe** Laboratorio de Parasitologia. Universidad Peruana Cayetano Heredia (UPCH), Lima, Peru.LUIS MARCOS*, VICENTE MACO*, ANGELICA TERASHIMA*, FRINE SAMALVIDES**,ELBA MIRANDA** y EDUARDO GOTUZZO*.

Prevalence and symptoms of Enterobius vermicularis infections in a Peruvian shanty town

The prevalence and symptoms of pinworm infection were determined in a shanty town in Lima, Peru. In 206 families, pinworm infection rates were highest in primary school age children (42%). Approximately one-fourth of pre-school children and secondary school-age children were infected with pinworms. Two examinations detected 74% of patients who were positive after 5 examinations. Symptoms often attributed to pinworm infection, such as perianal itching enuresis, and teeth grinding, occurred in a similar proportion of infected children (15%, 17%, 13%, respectively) and non-infected subjects (11%, 13%, 11%, respectively). Enuresis was more common in primary school-age children with high pinworm egg counts than in their non-infected contemporaries. 52% (28/54) of children under 5 years old became reinfected within 6 months of effective treatment. In a community where water is scarce and hand washing is infrequent, the high rate of perianal itching is probably an important source of faecal-oral contamination. The low morbidity and high reinfection rate make routine treatment of pinworm infection in third world countries a low priority, except when clinically indicated.

The diagnostic importance of species specific and cross-reactive components of Taenia solium, Echinococcus granulosus, and Hymenolepis nana

Sera from patients infected with Taenia solium, Hymenolepis nana and Echinococcus granulosus were tested against homologous and heterologous parasite antigens using an ELISA assay, and a high degree of cross-reactivity was verified. To identify polypeptides responsible for this cross reactivity, the Enzyme Linked Immunoelectro Transfer Blot (EITB) was used. Sera from infected patients with T.solium, H.nana, and E.granulosus were assessed against crude, ammonium sulphate precipitated (TSASP), and lentil-lectin purified antigens of T.solium and crude antigens of H.nana and E.granulosus. Several bands, recognized by sera from patients with T.solium, H.nana, and E.granulosus infections, were common to either two or all three cestodes. Unique reactive bands in H.nana were noted at 49 and 66 K-Da and in E.granulosus at 17-21 K-Da and at 27-32 K-Da. In the crude cysticercosis extract, a specific non glycoprotein band was present at 61-67 K-Da in addiction to specific glycoprotein bands of 50, 42, 24, 21, 18, 14, and 13 K-Da. None of the sera from patients with H.nana or E.granulosus infection cross reacted with these seven glycoprotein bands considered specific for T.solium infection.

Production of monoclonal antibodies for the identification of the eggs of Taenia solium.

Two antibodies, one monoclonal and one polyclonal, were produced and used to identify Taenia solium eggs, using the enzyme-linked immuno-electrotransfer blot technique (EITB). Different life-stages of Taenia solium and T. saginata, including eggs from gravid proglottids recovered, post-treatment, from patients infected with the tapeworms, and eggs of Diphyllobothrium pacificum and Hymenolepis nana from other patients were tested with these antibodies. The monoclonal antibody only recognized the eggs and immature proglottids of T. solium. The polyclonal antibody, however, not only reacted with the eggs, cysticerci and immature proglottids of T. solium but also with the eggs and immature proglottids of T. saginata. The sensitivity and specificity of the EITB were both 100% using the monoclonal antibody but only 78% and 60%, respectively, using the polyclonal antibody. Diagnostic bands for T. solium eggs corresponded to proteins of 22.5 kDa using the polyclonal antibody and 22.5-37 kDa using the monoclonal antibody. Species-specific fluorescence was obtained with an anti-T. solium monoclonal antibody which bound to egg-derived oncospheres of T. solium but not to those of T. saginata.

Anticuerpos IgA secretorios de la leche materna protectores contra la infección por Cryptosporidium parvum

Se evaluo el efecto protector de la leche materna de 150 madres sobre la infeccion por Cryptosporidium parvum en ninos menores de 2 anos. La leche presenta anticuerpos Inmunoglobulinas A Secretoria (IgAs) especificas contra el antigeno de C. parvum por la prueba de Inmunoelectrotransferencia blot (EITB). Cada madre secreto leche con diferente composicion de IgAs especificas contra 15 fracciones proteicas del antigeno de C. parvum con pesos moleculares de 15 a 158 k-Da, permaneciendo constantes durante la lactacion. Existe menor riesgo a la infeccion por C. parvum en ninos que lactaron leche materna con presencia de IgAs especificas contra las fracciones proteicas de alto peso molecular del antigeno de C. parvum (158, 123 y 97 k-Da)