The presence of antibodies for hepatitis a virus in amazonia Didelphis marsupialis (Vertebrata, Marsupialia)

Anti-HAV was detected by enzyme - immunoassay in sera collected from 6 (18,75%) of 32 Didelphis marsupialis trapped in the Amazon region. No anti-HAV were found in the sera from 136 other wild animals, including small rodents, reptiles and other marsupials.

Active immunization against hepatitis B virus (HBV) with low-doses of plasma-derived vaccine by intradermal route

Schedule for vaccination against HBV infection has usually been based on three separate injections of 20 meg of the vaccine by intramuscular route. One of the main shortcomings to its use in large scale programs has been its high cost. Ninety out of 300 health workers were submitted to three injections of 2 meg of plasma-derived vaccine (PDV) by intradermal (ID) route on days 0, 30, and 180. Anti-HBs was detected in 74 (82.2%) after the second dose and in 80 (88.9%) after the third dose, a non-significant difference. However, levels above 10 times the cut-off were observed in 29 (32.2%) and 77 (85.5%), respectively (p < 0.001). The results showed that a low-dose schedule is effective when used in health workers and should be tried with other risk groups.

Relationship between the prevalence of antibodies to arbovirus and hepatitis B virus in the Vale do Ribeira region, Brazil

280 students, between 6 and 14 years old, residents in the Iguape county, southern coast of the State of São Paulo, were studied in order to identify the existence of a possible association between the prevalence of specific antibodies to the hepatitis B virus and the exposure to haematophagous mosquitoes, evaluated indirectly through the prevalence of antibodies to 17 arboviruses isolated in Brazil. The children were from 4 areas with different topographical characteristics: 89 of the children were from the urban zone of the town of Iguape, 89 were from the periurban zone, 30 were from the rural area with extensive banana plantations, and 72 were from the jungle zone. Previous studies had shown significantly higher prevalence of antibodies to different arboviruses in the cultivated zone and the jungle zone, when compared to the urban and periurban zones of Iguape. The detection of antibodies to the HBV surface antigen (HBs Ag) was done through the radioimmunoassay (Ausab, Abbott Laboratory). The cases considered positive were confirmed through the presence of anti-core HBV antibodies (anti-HBc-EIA Roche). A significantly higher prevalence of anti-HBV antibodies was observed in children from the jungle zone (26/72 = 36,1% ) when compared to those from the urban zone (5/89 = 5,6%), peri-urban (6/89 = 6,7%) or from the cultivated zone (0/30 = 0%). The result suggest the existence of a common factor in the dissemination of the arboviruses and the hepatitis B virus, supporting the hypothesis that mosquitoes may play an important role in the HBV transmission in tropical forested region.

Paracoccidioidomicose e infecção pelo virus da imunodeficiência humana

São apresentados dois casos de paracoccidioidomicose, um em paciente com a síndrome da imunodeficiência adquirida e o outro em paciente com infecção pelo HIV. Trata-se dos primeiros relatos em que esta associação é descrita na literatura. No primeiro, a micose se evidenciou durante o acompanhamento de paciente com AIDS, que passou a apresentar hépato-esplenomegalia e febre elevada. A ecografia, radiografia simples e tomografia computadorizada do abdômen, demonstraram nódulos sólidos, alguns calcificados, no parênquima esplénico. A punção aspirativa da medula óssea confirmou o diagnóstico; o conjunto dos achados caracterizou a forma aguda disseminada da paracoccidioidomicose, a qual levou o paciente ao óbito. No segundo relato, em paciente com infecção pelo HIV, a propósito de investigação de tumoração na região inguinal e fossa ilíaca à direita, constatou-se a associação de doença de Hodgkin, tipo celularidade mista e paracoccidioidomicose. Avalia-se a importância destes relatos frente a expansão da infecção pelo HIV e estima-se que mais casos venham a ser relatados em pacientes com AIDS, procedentes de áreas endêmicas desta micose. Propõe-se a inclusão da paracoccidioidomicose como infecção oportunística potencial em pacientes HIV positivos nestas áreas.

Prevention of electrocardiographic and histopathologic alterations in the murine model of Chagas' disease by preinoculation of an attenuated Trypanosoma cruzi strain

The effects of infection with Trypanosoma cruzi on the electrocardiographic tracings of mice were studied in 4.groups of animals: (1) normal; (2) infected with a pathogenic T. cruzi strain (TS COB); (3) immunized with 3 intraperitoneal inocula of 10(6) attenuated T. cruzi epimastigotes (TCC) and (4) immunized-infected, which sequentially received the treatments of groups 3 and 2. Infection and protection were confirmed by xenodiagnosis and histopathology. Isolated alterations such as extrasystolia, 1st degree atrioventricular block, arrhythmia and ST elevation were observed in normal as well as infected mice. However, tracings taken repeatedly on each mouse over a 293 day period revealed a set of alterations which were more frequently seen in infected (14/22) than in normal (4/27) animals (p = 0.00048). These alterations consisted of supraventricular tachycardia, sinus bradycardia and persisting, first degree AV blocks, often associated to pacemaker changes. Inoculation of attenuated T. cruzi (group 3) did not increase these alterations (2/27 mice) but significantly prevented their development after challenge with the pathogenic strain (1/19 versus 14/22 mice, p = 0.000095). Thus, preimmunization reduced not only parasitemia but also a pathogenic consequence of T. cruzi infection. This evidence is relevant for immunoprevention studies against Chagas' disease.

Comparison of serum hepatitis B virus replication markers in patients with chronic hepatitis B: studies on HBeAg/Anti-HBe system, viral dna polymerase and HBV-DNA

The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker of replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV - related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.

B and Delta hepatitis virus infection in a population of West Africa

Among the 424 serum samples examined, the prevalence of hepatitis virus infection turned out to be 89.6%, with 15.6% of HBsAg positivity. Some of the samples belonged to an afferent population and some other to workers of a West Africa rural hospital (Pop. Rep. of Benin). 27.3% of the positive subjects presented active replication of the virus, shown by the presence of HBeAg. Among the HBcAb positive subjects the anti-delta antibodies showed a positivity frequency of 19.7%. HBsAg presence in 15% of pregnant women suggested the importance of HBV mother-foetal transmission in the district. The examined results can be compared with those obtained in other African areas, with similar socio-economic conditions.

Preliminar characterization of a new virus isolated from the spinal fluid of patients with meningitis in São Paulo, Brazil

A total of 138 patients with the age of 4 months to 57 years were attended in different hospitals of São Paulo State with aseptic meningitis. A probable new agent was isolated from the cerebrospinal fluid of 35 of 53 specimens examined. Replication of the agent with similar characteristics was detected by CPE produced in the MDCK cell line. Virus-like particles measuring about 40 nm in diameter were observed by negative staining electron microscopy. No hemaglutinating activity was detected at pH 7.2 by using either human, guinea pig, chicken and at pH ranged 6.0 - 7.2 with goose red blood cells. The agent was not pathogenic to newborn or adult mice. Virus infectivity as measured by CPE was sensitive to chloroform and not inhibited by BuDR, suggesting that agent is an enveloped virus with RNA genome.

Antibody to human T-lymphotropic virus in a patient with Guillain-Barré syndrome (case report)

Serum sample obtained from a male, 12 year old patient suffering from Guillain-Barré syndrome (GBS) was positive for human T-lymphotropic virus (HTLV-I) antibody by the enzyme-linked immunosorbent assay (ELISA) and the Western Blot analysis (WB). Attempts to isolate enteroviruses (including poliovirus) from faecal material in both tissue culture and suckling mice were unsuccessful; in addition, acute and convalescent paired serum samples did not show any evidence of recent poliovirus infection when tested against the three serotypes. Specific tests for detection of Epstein-Barr virus infection were not performed; however, the Paul-Bunnel test yielded negative results. ELISA for detection of anti-cytomegalovirus IgM was also negative. The concomitant occurrence of either adult T cell leukemia (ATL) or lymphoma was not recorded in this case.

Fractional Dynamics of Computer Virus Propagation

We propose a fractional model for computer virus propagation. The model includes the interaction between computers and removable devices. We simulate numerically the model for distinct values of the order of the fractional derivative and for two sets of initial conditions adopted in the literature. We conclude that fractional order systems reveal richer dynamics than the classical integer order counterpart. Therefore, fractional dynamics leads to time responses with super-fast transients and super-slow evolutions towards the steady-state, effects not easily captured by the integer order models.

Comportamentos de sexo seguro em individuos infectados por VIH

A investigação científica que se seguiu à descoberta da infecção pelo vírus da imunodeficiência humana (VIH) representou um marco histórico importante, permitindo a instituição de terapêutica e alterando a história natural da infecção, melhorando as expectativas dos indivíduos infectados.Se, por um lado, a terapêutica antirretroviral de alta eficácia (do inglês, Highly Active Antiretroviral Theraphy: HAART), nos países desenvolvidos, teve um enorme impacto na melhoria da qualidade de vida e esperança média de vida dos indivíduos infectados, permitindo-lhes encarar a infecção como uma doença crónica, por outro lado, introduziu-se uma nova dinâmica epidemiológica na transmissão de VIH e um novo desafio para a sua prevenção.Os comportamentos sexuais são o factor-alvo através do qual se pode, de uma forma mais eficaz, prevenir a possibilidade de infectar um qualquer indivíduo na comunidade. Parece, pois, importante haver necessidade de um olhar atento da Saúde Pública sobre a vida sexual dos indivíduos infectados, não só na tentativa de, promover a sua qualidade de vida, como também, de prevenir a disseminação da doença, e, ainda mais importante, prevenir a disseminação do vírus nas suas formas resistentes.O objectivo deste estudo foi analisar a consistência do uso de preservativo/práticas de sexo seguro, em indivíduos infectados por VIH, seguidos em Consulta de Imunodepressão, do Serviço de Doenças Infecciosas, do Hospital de Santa Maria. Pretende-se avaliar, no âmbito da “Educação para a Saúde”, a necessidade de aconselhamento aos indivíduos infectados, relativamente aos seus comportamentos sexuais.Para o efeito, realizou-se um estudo descritivo e transversal. A população envolvida compreendeu todos os indivíduos infectados seguidos na Consulta de Imunodepressão. A amostra foi seleccionada através de aleatorização simples e constituída por 98 elementos. A colheita de dados foi efectuada através do método de entrevista, a qual só teve início após a assinatura do consentimento informado. O estudo decorreu entre 14 de Março e 27 de Junho de 2008.Foram analisados os dados relativamente às variáveis: sócio-demográficas, estado serológico da infecção, história sexual, consumo de substâncias, comportamento sexual e percepção de risco da transmissão da infecção por VIH.Os comportamentos de sexo não seguro foram associados ao número de parceiros sexuais/ano (p=0,007), ter parceiro sexual habitual (p=0,010), ter múltiplos parceiros sexuais ocasionais (p=0,000) e à prática de sexo oral (sexo oral receptivo, p=0,001; sexo oral activo, p=0,006).Os resultados demonstraram a importância da prevenção secundária nos indivíduos infectados por VIH. A necessidade dos centros de atendimento estarem providos de mensagem de prevenção, ensinos e aconselhamento a todas as pessoas infectadas e, também, aos seus parceiros sexuais, aumentando-lhes a qualidade de vida e reduzindo o risco de transmissão da infecção por HIV. ABSTRACT: The scientific research that followed the finding of human immunodeficiency virus (HIV) infection represented an important historical mark, allowing therapeutic institution and changing the natural history of the infection, thus improving the expectations of infected individuals. If by one side the Highly Active Antiretroviral Therapy (HAART) had an enormous impact on the improvement of life quality and life expectancy of the infected individuals on the developed countries, allowing them to face the infection as a chronic disease, on the other side it was introduced a epidemiologic dynamic on the HIV transmission and a new challenge for its prevention. Sexual behaviour is the main factor through which is possible to prevent more efficiently the possibility of infection of a community’s individual. Thus it appears important the need of Public Health to have a careful look into the sexual life of infected individuals, not only to try to promote their life quality but as well to prevent the dissemination of the disease and more importantly prevent the dissemination of the virus in its resistant forms. The objective of this study was to analyse the consistency of the use of condoms/safe sex by individuals infected by HIV that are followed by the Infectious Disease Service of the Santa Maria Hospital through Immune-depression Appointments. The goal was to evaluate the need of advisement to the infected individuals relatively to their sexual behaviours. For that it was done a descriptive and transversal study. The involved population included all infected individuals followed in the Immune-depression Appointments. The sample was selected by simple randomisation and was composed by 98 elements. The data was obtained by interview method, which was initiated after signing the informed consent. The study was took place between 14 March and 27 June 2008. It was analysed the data relative to the variables: socio-demographics, serologic state of the infection, sexual history, substances consumption, sexual behaviour and risk perception on the transmission of HIV infection. The unsafe sexual behaviours were associated to the number of sexual partners/year (p=0,007), having steady partner (p= 0,010), having occasional sexual partners (p=0,000) and oral sex practice (receptive oral sex, p=0,001; active oral sex, p= 0,006).The results demonstrated the importance of the secondary prevention on individuals infected by HIV. It also demonstrated the need of providing the attendance centres with a prevention message, teachings and advises to all infected persons as well as to their sexual partners, increasing their life quality and reducing the transmission risk of HIV infection.

Respiratory complications in Brazilian patients infected with human immunodeficiency virus

PURPOSE: To determine how often and by what means an indentifiable pulmonary pathogen can be recognized in human immunodeficiency virus (HIV) infected patients with respiratory disorders in Brazil, which are the most frequently observed microorganisms and what impact specific therapy has on these agents. PATIENTS AND METHODS: Thirty-five HIV seroposiüve subjects with respiratory complaints were studied. All patients had a complete history, physical examination and blood counts. The pulmonary assessment included chest radiograms; sputum examination for bacterial and fungal pathogens; bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. Patients with treatable complications received standard antimicrobial therapy. RESULTS: One or more microorganisms were found in 24 subjects and another 3 individuals showed nonspecific interstitial pneumonitis. The sputum examination identified the pulmonary pathogens in 7 cases. The bronchoalveolar lavage and the histopathologic examination were diagnostic in 14% and 83%, respectively, of the 28 individuals that were submitted to bronchoscopy. The most frequently identified microorganism was P. carinii (55%), followed by M. tuberculosis (41%) and cytomegalovirus (8%). The clinical, laboratory and radiographic findings failed to distinguish the specific pulmonary pathogens. Twenty-three individuals with P. carinii pneumonitis and/or tuberculosis received specific therapy; among the evaluable patients the therapeutic response rates were 79% for PCP and 100% for TB. CONCLUSIONS: We have determined that tuberculosis, P. carinii and cytomegalovirus pneumonitis are the most common respiratory opportunistic diseases in Brazilian patients infected with HIV. The histologic evaluation was crucial in order to identify the pulmonary pathogens. Tuberculosis in AIDS individuals displayed clinical and radiographic findings atypical for reactivation disease. However, most of the features observed in HIV infected patients had been previously described in infection of the normal host. Furthermore, the AIDS subjects showed a good therapeutic response to anti-tuberculous drugs.

Rotavírus, adenovírus, astrovírus, calicivírus e "Small Round Virus Particles" em fezes de crianças, com e sem diarréia aguda, no período de 1987 a 1988, na Grande São Paulo

No período de agosto de 1987 a setembro de 1988, 193 amostras de fezes de crianças, com e sem sintomatologia diarréica aguda, foram submetidas às provas diagnósticas do ensaio imunoenzimático (EIE), eletroforese em gel de poliacrilamida (EGPA) e microscopia eletrônica (ME) para a detecção de vírus. A positividade para Rotavírus, Adenovírus, Astrovírus, Calicivírus e "Small Round Virus Particles" (SRVP) foi encontrada nas 97 crianças com diarréia aguda em 11,3%, 3,1%, 2,1%, l,0%e4,l%, respectivamente. Das 96 crianças sem diarréia, 4,2% foram positivas para Rotavírus, 1,0% para Calicivírus e 7,3% para SRVP. Das 15 amostras positivas para Rotavírus, 14 apresentaram perfil eletroforético característico do Grupo A e 1 amostra do Grupo C. A análise dos eletroforotipos demonstrou a grande heterogeneidade de perfis e a predominância do perfil "longo". A associação de vírus, bactéria e parasita foi encontrada tanto em crianças com diarréia como em crianças sem diarréia.