Comparison of Methods Used for the Diagnosis of Epstein-Barr Virus Infections in Children.

The accurate diagnosis of Epstein-Barr virus (EBV) infections is important, as many other infectious agents or diseases can cause similar symptoms. In this study, sera of pediatric patients who were suspected to have an EBV infection, were sent to Eskisehir Osmangazi University Faculty of Medicine, Department of Clinical Microbiology, and investigated by IFA, ELISA, immunoblotting and Real-time PCR. The performances of these tests were compared with IFA. The rates of agreement between ELISA and IFA were found as 100% for seronegative, 100% for acute primary infection, 22.2% for late primary infection, 92.1% for past infection. The rates of agreement between immunoblotting and IFA were found as 80.8% for seronegative, 68.8% for acute primary infection, 55.6% for late primary infection, 86.6% for past infection. The sensitivity of immunoblotting for anti-VCA IgM was identical with ELISA, and higher for anti-VCA IgG, anti-EBNA IgG, anti-EA antibodies, while the specificity of immunoblotting for these antibodies were found to be lower. The sensitivity and specificity of Real-time PCR for detection of viremia in acute primary infection were found as 56.25% (9/16) and 97.89% (139/142), respectively. The diagnostic methods should be chosen by evaluating the demographic characteristics of patients and laboratory conditions together.

Comparison of the PRNT and an immune fluorescence assay in yellow fever vaccinees receiving immunosuppressive medication.

BACKGROUND: The 17D-yellow fever (YF) vaccination is considered contraindicated in immune-compromised patients; however, accidental vaccination occurs. In this population, measuring the immune response is useful in clinical practice. METHODS: In this study we compare two antibody tests (the Immune Fluorescence Assay and the Plaque Reduction Neutralization Test) in a group of Dutch immune-compromised travellers with a median of 33 days (IQR [28-49]) after primary YF vaccination. RESULTS: We collected samples of 15 immune-compromised vaccinees vaccinated with the 17D yellow fever vaccine between 2004 and 2012. All samples measured in the plaque reduction neutralization test yielded positive results (>80% virus neutralization with a 1:10 serum dilution). Immune Fluorescence Assay sensitivity was 28% (95% CI [0.12-0.49]). No adverse events were reported. CONCLUSIONS: All immune-compromised patients mounted an adequate response with protective levels of virus neutralizing antibodies to the 17-D YF vaccine. No adverse effects were reported. Compared to the plaque reduction neutralization test, the sensitivity of the Immune Fluorescence Assay test was low. Further research is needed to ascertain that 17D vaccination in immune-compromised patients is safe.

Hematological values associated to the serological and molecular diagnostic in cats suspected of Ehrlichia canis infection / Valores hematológicos associados ao diagnóstico sorológico e molecular de gatos suspeitos de infecção por Ehrlichia canis

The literature contains several studies on feline ehrlichiosis. However, information about the characteristics of Ehrlichia infection in cats is still scanty. This study evaluated the association between Ehrlichia spp. infection and the hematologic data of 93 cats treated at the Federal University of Mato Grosso Veterinary Hospital in Cuiabá, state of Mato Grosso, Brazil. The presence of or exposure to Ehrlichia spp. infection was evaluated by Polymerase Chain Reaction (PCR) targeting the dsb and 16S rRNA gene of Ehrlichia, and by detection of anti-Ehrlichia canis IgG antibodies in Indirect Fluorescence Assay (IFA), respectively. Eight (8.6%) cats tested positive by PCR and the partial DNA sequence obtained from PCR products was a 100% match to E. canis. Forty-two (45.1%) cats showed antibody reactivity against Ehrlichia spp. Hematological alterations such as low erythrocyte count, thrombocytopenia, lymphopenia and monocytosis were observed in PCR positive cats. Among them, low erythrocyte counts were associated with IgG antibody titers of 40 to 640 and five cats also tested positive by PCR. Furthermore, PCR-positive cats showed a tendency to be lymphopenic. No correlation was found between age and sex, and no ticks were observed in any of the examined cats.

Diversos estudos sobre erliquiose felina vêm sendo relatados na literatura. No entanto, a caracterização da infecção por Ehrlichia em gatos ainda é escassa. O presente estudo objetivou avaliar a associação entre infecção por Ehrlichia e dados hematológicos em 93 gatos atendidos no Hospital Veterinário da Universidade Federal de Mato Grosso, em Cuiabá, Brasil. A presença de infecção por Ehrlichia spp. foi avaliada pela Reação em Cadeia pela Polimerase (PCR) visando à amplificação dos genes dsb e 16S rRNA de Ehrlichia e por Reação de Imunofluorescência Indireta (RIFI). Oito (8,6%) gatos demonstraram ser positivos pela PCR, sendo suas sequências parciais de DNA 100% idênticas à E. canis. Quarenta e dois gatos (45,1%) apresentaram anticorpos reativos contra Ehrlichia spp. Alterações hematológicas como baixas contagens de eritrócitos, trombocitopenia, linfopenia e monocitose foram observadas em gatos positivos pela PCR. Dentre essas, eritropenia foi associada em gatos com títulos de anticorpos IgG entre 40 e 640, sendo cinco destes positivos pela PCR. Adicionalmente, gatos positivos na PCR apresentaram uma tendência a serem linfopênicos. Não foram observadas associações entre a presença de infecção nos gatos e suas respectivas idades e sexo. Nenhum carrapato foi observado nos gatos examinados.

Detection of anti-Toxoplasma gondii antibodies in experimentally and naturally infected non-human primates by Indirect Fluorescence Assay (IFA) and indirect ELISA / Detecção de anticorpos anti-Toxoplasma gondii por meio das técnicas de Imunofluorescência Indireta e ELISA Indireto em primatas experimentalmente e naturalmente infectados

The Indirect Fluorescence Assay (IFA) and the indirect ELISA were comparatively used to detect IgG and IgM antibodies for Toxoplasma gondii in experimentally and naturally infected primates. In the experimentally infected group, antibodies of diagnostic value were detected at day 9 post-infection (PI) with the IFA (IgG and IgM) and with IgG-ELISA. IgM-ELISA detected antibodies for T. gondii starting at day 3 PI until the end of the experiment (102 days PI). Of the 209 naturally infected sera tested, from many zoos of State of Sao Paulo, 64.59 and 67.94 percent were positive in the IgG-IFA test and IgG-ELISA respectively. IgM-ELISA test detected seropositivity in 52.63 percent of the sera although IgM-IFA test detected it in only in 0.96 percent of the samples. The differential toxoplasmosis diagnosis was accomplished with Neospora caninum by IFA, observing 61 (29.2 percent) seropositive animals for this parasite and 149 (70.8 percent) negative. Sixty animals were positive for both T. gondii and N. caninum. Pneumonia, splenomegaly, and intestinal ulcers were macroscopically observed. Unremarkable interstitial pneumonia, enteritis, colitis, splenitis, and glomerulitis were microscopically observed. The immunohistochemical stain could not detect the presence of T. gondii in the tissues of the animals infected experimentally.

Detectou-se anticorpos das classes IgG e IgM anti-Toxoplasma gondii em primatas experimentalmente e naturalmente infectados, utilizando-se como técnicas comparativas a RIFI e o ELISA-teste. No grupo dos primatas experimentalmente infectados, anticorpos de valor diagnóstico foram detectados a partir do 9º dia de infecção tanto na RIFI (IgG e IgM) como no ELISA-IgG. O ELISA IgM detectou anticorpos a partir do 3º dia de infecção até o final do experimento (102 dias pós-infecção). Dos 209 soros dos primatas naturalmente infectados, de diversos zoológicos do Estado de São Paulo, 64,59 e 67,94 por cento mostraram-se positivos na RIFI-IgG e no ELISA-IgG, respectivamente. O ELISA-IgM detectou soropositividade em 52,63 por cento dos soros ao passo que a RIFI-IgM detectou apenas 0,96 por cento. Foi realizado também diagnóstico diferencial para Neospora caninum, através da RIFI, observando-se 61 (29,2 por cento) animais soropositivos para este parasita e 149 (70,8 por cento) animais negativos. Sessenta animais foram positivos para T. gondii e N. caninum. Pneumonia, esplenomegalia e úlceras intestinais foram observadas macroscopicamente. Pneumonia intersticial, enterite, colite, esplenite e glomerulite foram os achados microscópicos. A imunoistoquímica não revelou a presença do T. gondii nos tecidos dos animais experimentalmente infectados.