Detection of immunoglobulin G antibodies to Neospora caninum in humans: High seropositivity rates in patients who are infected by human immunodeficiency virus or have neurological disorders

Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients

Suspected acute toxoplasmosis in pregnant women Suspeita de toxoplasmose aguda em gestantes

OBJECTIVE: To determine the prevalence of reagent serology for suspected acute toxoplasmosis in pregnant women and to describe clinical, laboratory and therapeutic profiles of mothers and their children. METHODS: A retrospective study was conducted with IgM-anti-Toxoplasma gondii-reagent pregnant women and their children who attended the public health system in the state of Paraná, Southern Brazil, from January 2001 to December 2003. Information were obtained from clinical, laboratory (ELISA IgM/IgG) and ultrasonographic data and from interviews with the mothers. To test the homogeneity of the IgM indices in relation to the treatment used, the Pearson's Chi-square test was applied. Comparisons were considered significant at a 5% level. RESULTS: Two hundred and ninety (1.0%) cases of suspected IgM-reagent infection were documented, with a prevalence of 10.7 IgM-reagent women per 1,000 births. Prenatal care started within the first 12 weeks for 214/290; 146/204 were asymptomatic. Frequent complaints included headaches, visual disturbance and myalgia. Ultrasonography revealed abnormalities in 13 of 204 pregnancies. Chemoprophylaxis was administered to 112/227; a single ELISA test supported most decisions to begin treatment. Pregnant women with IgM indices =2.000 tended to be treated more often. Among exposed children, 44/208 were serologically followed up and all were IgG-reagent, and three IgM-reagent cases showed clinical symptoms. CONCLUSIONS: The existence of pregnant women with laboratorially suspected acute toxoplasmosis who were not properly followed up, and of fetuses that were not adequately monitored, shows that basic aspects of the prenatal care are not being systematically observed. There is need of implementing a surveillance system of pregnant women and their children exposed to T. gondii.<br>OBJETIVO: Determinar a prevalência de gestantes com sorologia reagente suspeita de toxoplasmose aguda e descrever as variáveis maternas e do concepto relacionadas ao perfil clínico, laboratorial e terapêutico. MÉTODOS: Estudo retrospectivo com gestantes IgM anti-Toxoplasma gondii reagentes e conceptos atendidos em serviço público de saúde do Paraná, de janeiro/2001-dezembro/2003. Foram obtidas informações a partir de dados dos registros clínicos, laboratoriais (ELISA IgM/IgG), ultrassonográficos e de entrevista materna. Para testar a homogeneidade dos indices de IgM em relação ao tratamento usado, aplicou-se o qui-quadrado de Pearson. O nível de significância adotado foi de 5%. RESULTADOS: Ocorreram 290 casos (1,0%) IgM reagentes, evidenciando prevalência de 10,7 gestantes com sorologia reagente a cada 1.000 nascimentos. Duzentos e quatorze de 290 gestantes iniciaram o pré-natal até a 12ª semana de gestação; 146/204 foram assintomáticas; cefaléia, distúrbios visuais e mialgia foram queixas freqüentes; 13/204 gestantes apresentaram anormalidades ao ultrassom; 112/227 gestantes receberam quimioprofilaxia; um único teste ELISA apoiou a maioria das tomadas de decisão para a quimioprofilaxia. Houve tendência em tratar gestantes com índices de IgM=2.000. Dentre as crianças expostas, 44/208 tiveram algum acompanhamento sorológico, das quais todas foram IgG reagentes e três casos IgM reagentes apresentaram manifestações clínicas. CONCLUSÕES: A existência de gestantes com suspeita laboratorial de toxoplasmose aguda não devidamente investigada e de conceptos sem monitoração adequada evidenciam que aspectos fundamentais da assistência pré-natal não estão sendo sistematicamente observados. Aponta-se a necessidade de implementar o sistema de vigilância para gestantes e crianças expostas ao T. gondii