Contribution to the study of cysticercosis: immunologic tests for the detection of serum antibodies

CONTRIBUTION TO THE STUDY OF CYSTICERCOSIS: IMMUNOLOGIC TESTS FOR THE DETECTION OF SERUM ANTIBODIES (ABSTRACT)^*. THESIS. SÃO PAULO, 2001.

LÚCIA MARIA BRAGAZZA^**

Human cysticercosis caused by parasitism with the larval phase of Taenia solium is frequent in developing countries. Considering the impact of cysticercosis on public health, especially the neurological form, neurocysticercosis (NC), the frequency of anti-cysticercus antibody positivity was studied in blood samples of subjects from different geographic areas distributed as follows: Group from Cássia dos Coqueiros, SP (1,863 samples from individuals aged 2 to 88 years), Group from Vitória, ES (311 samples from patients aged 0 to 17 years), Group from Campinas, SP (15 samples from outpatients aged 21 to 69 years). ELISA and immunoblot (WB) with Taenia crassiceps vesicular fluid antigens (ELISA-Tcra and WB-Tcra) were used for antibody detection.

A total of 459 (24.6%) sera reactive to ELISA-Tcra were detected in the Cássia group, with a greater predominance in the adult age range (p<0.05) and with no significant sex differences (p >0.05). Of these sera, 8.7% (n=40) were intensely reactive to WB-Tcra. Considering the use of the WB-Tcra test as confirmatory in view of its high specificity, the frequency of anti-cysticercus antibodies in this group was 2.1%. When the possible relations between serum reactivity for anti-cysticercus antibodies and the variables concerning the sanitary conditions of the population were analyzed, the only relevant association was observed for the variable water source for human consumption, which demonstrated a higher frequency of positivity for anti-cysticercus antibodies when the water consumed originated from collective sources (p<0.05), a finding compatible with the high degree of contamination with fecal coliforms of these sources (p<0.05).

In the Vitória group, 51 (16.4%) sera were reactive to ELISA-Tcra, with the 10 to 14 year age range being most often involved (p<0.05), and with no sex differences. Of these 51 samples, only two (3.9%) were intensely reactive to WB-Tcra. Considering immunoblot to be specific, we may conclude that the frequency of antibodies in this group was 0.64%.

In the Campinas group, 7 (46.7%) sera were reactive to ELISA-Tcra and 42.8% of these (n=3) were strongly reactive to WB-Tcra. The three patients reactive to ELISA and WB presented a clinical-laboratory confirmation of neurocysticercosis.

Although ELISA does not present high specificity when serum samples are assayed, its use with heterologous antigen for serologic screening with later confirmation by immunoblot appears to be a good marker for later epidemiological studies.

KEY WORDS: cysticercosis, immunologic tests, diagnosis, blood serum, cerebrospinal fluid, neurocysticercosis.

*

Contribuição ao estudo da cisticercose: testes imunológicos para a detecção de anticorpos séricos (Resumo). Tese de Doutorado, Faculdade de Ciências Farmacêuticas de Universidade de São Paulo (Área: Análises Clínicas). Orientadora: Adelaide José Vaz.

Publication Dates

• Publication in this collection
  28 Nov 2001
• Date of issue
  Dec 2001