Valor do teste de avidez da IgG como marcador de doença aguda ou crônica e de transmissão vertical na toxoplasmose

• Ano de defesa: 2009
• Autor(a) principal: Alvarenga, Fernanda Rassi
• Orientador(a): Avelino, Mariza Martins
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Medicina Tropical e Saúde Pública (IPTSP)
• Departamento: Instituto de Patologia Tropical e Saúde Pública - IPTSP (RG)
• País: Brasil
• Palavras-chave em Português: Toxoplasmose; Teste de avidez da IgG; Toxoplasmose congênita
• Palavras-chave em Inglês: Toxoplasmosis; IgG-avidity test; Congenital toxoplasmosis
• Área do conhecimento CNPq: CLINICA MEDICA::DOENCAS INFECCIOSAS E PARASITARIAS
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/3517

Toxoplasmosis is a parasitic disease widespread around the world caused by Toxoplasma gondii. Infection acquired during pregnancy may cause intrauterine damage and sequelae in the newborn. Serological testing for IgG/IgM anti-Toxoplasma antibodies may fail to differentiate between recent and past infection. Despite that, rapid diagnosis of acute infection during pregnancy allows rapid treatment and prevents or attenuates congenital toxoplasmosis. PURPOSE: to establish the frequency of acute toxoplasmosis in pregnant women, the vertical transmission rate and the value of specific IgG-avidity test to date infection in pregnancy; to evaluate the relationship between IgG-avidity and congenital toxoplasmosis. MATERIAL AND METHODS: this report summarizes a retrospective study performed on 235,993 pregnant women attended by “The Pregnancy Protection Program” – public health system (SUS) of the State of Goiás – Brazil, from January 2004 to December 2007. ELISA (IgG / IgM) and IgG-avidity test were performed for maternal screening of toxoplasmosis. Fetal and newborn investigation of the infection was performed by “The Toxoplasmosis Vertical Transmission Control Program” protocols. The association between data was statistically analyzed by the x2 test (p < 0,05 was considered statistically significant). RESULTS: the frequency of IgM-positive among pregnant women studied population was 0,7%. Among IgM-positive women, only 207 (12,5%) performed the screening test in first 3-month period of pregnancy and 91% of pregnant women presented high avidity ( > 40%). The vertical transmission rate was 62%. There was no statistically significant relationship between higher (> 40%) or lower (≤ 25%) IgG-avidity test and presence of congenital infection (p= 0,08 e p= 0,57, respectively). There was no statistically significant association between maternal diagnosis in first trimester, low avidity and vertical transmission rate. CONCLUSIONS: the frequency of IgM-positive in pregnant women was lower than Brazilian rates founded in other studies. The study showed high persistent vertical transmission rate besides prenatal management and treatment. The IgG-avidity was not useful to predict vertical transmission. These results indicate that the IgG-avidity test must be not carried out in all IgM-positive pregnant women in the State of Goiás-Brazil, as a confirmatory test for the diagnosis of maternal toxoplasmosis.