Persistence of experimental Rocio virus infection in the golden hamster (Mesocricetus auratus)

ABSTRACT: Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection.

Evaluation of the therapeutic response of hepatitis C in coinfected patients (HIV/HCV): a study of cases from a hospital for chronic liver diseases in the Eastern Brazilian Amazon

INTRODUCTION: The aim of this study was to evaluate the therapeutic response of hepatitis C in patients coinfected with human immunodeficiency virus (HIV-1). METHODS: A retrospective study of 20 patients coinfected with HIV-1/HCV who were treated in the outpatient liver clinic at the Sacred House of Mercy Foundation Hospital of Pará (Fundação Santa Casa de Misericórdia do Pará - FSCMPA) from April 2004 to June 2009. Patients were treated with 180µg PEG interferon-α2a in combination with ribavirin (1,000 to 1,250mg/day) for 48 weeks. The end point was the sustained virological response (SVR) rate (HCV RNA negative 24 weeks after completing treatment). RESULTS: The mean age of the patients was 40±9.5 years, of which 89% (n=17) were male, and the HCV genotypes were genotype 1 (55%, n=11/20), genotype 2 (10%, n=2/20) and genotype 3 (35%, n=7/20). The mean CD4+ lymphocyte count was 507.8, and the liver fibrosis stages were (METAVIR) F1 (25%), F2 (55%), F3 (10%) and F4 (10%). The early virological response (EVR) was 60%, the end-of-treatment virological response (EOTVR) was 45% and the SVR was 45%. CONCLUSIONS: The median HCV viral load was high, and in 85% of cases in which highly active antiretroviral therapy (HAART) was used, none of the patients with F3-F4 fibrosis responded to treatment. Of the twenty patients treated, 45% achieved SVR and 45% achieved EOTVR. Studies that include cases from a wider region are needed to better evaluate these findings.

Identification of human T-cell lymphotropic virus infection in a semi-isolated Afro-Brazilian quilombo located in the Marajó Island (Pará, Brazil)

ABSTRACT: Antibodies to human T-cell lymphotropic virus-1 and 2 (HTLV-1 and 2) were tested in 259 inhabitants (98 males and 161 females) of four villages of the Marajó Island (Pará, Brazil) using enzyme immunoassays (ELISA and Western blot). Types and subtypes of HTLV were determined by nested polymerase chain reaction (PCR) targeting the pX, env and 5´LTR regions. HTLV-1 infection was detected in Santana do Arari (2.06%) and Ponta de Pedras (1%). HTLV-2 was detected only in Santana do Arari (1.06%). Sequencing of the 5´LTR region of HTLV-1 and the phylogenetic analysis identified the virus as a member of the Cosmopolitan Group, subgroup Transcontinental. Santana do Arari is an Afro-Brazilian community and the current results represent the first report of HTLV-1 infection in a mocambo located in the Brazilian Amazon region.

Estudo soroepidemiológico de Brucella abortus, Toxoplasma gondii e vírus da artrite encefalite caprina em rebanhos caprinos nas unidades produtoras dos estados do Pará e Maranhão

Pesquisou-se a frequência da ocorrência de anticorpos anti-Brucella abortus, Toxoplasma gondii e vírus da artrite encefalite caprina (CAEV) em caprinos de 14 unidades produtoras localizadas dos Estados do Pará e Maranhão. No Estado do Pará foram analisados animais dos municípios de Benevides, Castanhal, Santa Izabel do Pará e Moju e no Estado do Maranhão, o município de Chapadinha. Os testes sorológicos realizados para o diagnóstico da brucelose foi o teste do Antígeno Acidificado Tamponado (AAT), como teste de triagem, e o 2- Mercaptoetanol (2-Me), como teste confirmatório. Para as análises de toxoplasmose foi utilizado a Reação de Imunofluorescência Indireta (RIFI) e para CAEV Imunodifusão de Gel de Agarose (IDGA). O resultado das análises de brucelose mostrou-se negativo para 100,0% das amostras analisadas. Para toxoplasmose e CAEV a frequência obtida foi 23,5% (97/412) e 21,6% (85/393), respectivamente. Foi observada diferença estatística na relação entre a ocorrência de anticorpos anti-Toxoplasma gondii e a faixa etária dos caprinos, mostrando que animais com idade superior a 24 meses tiveram mais risco de estarem infectados quando comparados com animais mais novos OR= 2,15 (IC 95% 1,19 – 3,88). Já os fatores de risco encontrados para CAEV foram: falta de conhecimento da doença OR=6,45 (IC 95% 2,88-14,47); a não utilização de material descartável, OR=10,85 (IC 95% 4,85-24,28); sistema de criação extensivo OR=10,85 (IC 95% 4,85-24,28); sistema de criação semi-extensivo OR=3,71(IC 95% 1,64-8,39) e manejo OR=11,4 (IC 95% 5,51-23,60). Conclui-se que as unidades produtoras de caprinos dos Estados do Pará e Maranhão apresentam positividade em seus rebanhos para toxoplasmose e CAEV.