Detection of Astrovirus-like in diarrhoeic stool and its coexistence with Rotavirus

A clinical case is described in this paper in that a 5-month old baby girl severely malnourished and dehydrated presented a prolonged acute diarrhoea. No enteropathogenic bacteria or parasites were demonstrated. Virological study by electron microscopy (EM) showed that the patient shed both astrovirus-like and rotavirus in the watery stool as long as 12 days after the onset. Immune electron microscopy (IEM) performed with the patient serum revealed clumps of both viruses. It is suggest that this may be a case of mixed infection due to astrovirus-like and rotavirus.

Prevalence of antibody to hepatitis B virus in an urban population of northeast Brazil

A sample of 1,288 inhabitants of Salvador, Bahia, Brazil, were submitted to the determination of anti-HBs using radioimmunoassay procedure, and analysed according to age, sex and income. Overall prevalence of anti-HBs was 11,8%. ranging from 6,7% among children aged less than three years old to 26,1% among those aged 30 years and older. Males presented prevalence of anti-HBs similar to female individuals, and those with a higher income showed frequencies of anti-HBs greater than those with a lower income level. The following conclusions were drawn: The high prevalence of anti-HBs observed among children suggests early contact with hepatitis B virus, possibly due to vertical transmission and intrafamiliar dissemination of the disease; the frequency of anti-HBs increases with age; the lower prevalence of anti-HBs among those with low income suggests that this group may present higher prevalence of carriers of the hepatitis B virus surface antigen.

Serologic studies on the behaviour of influenza virus type A in persons of greater São Paulo during 1976, 1978 and 1979

Sera of persons of different age groups collected in 1976, 1978 and 1979 were tested for the presence of HI antibodies against various strains of the H3N2 and H1N1 subtypes of influenza virus. The occurrence of infection by H3N2 subtype was recorded during the 1976-1978 period but in 1979, circulation of this subtype of virus was limited. The prevalence of antibody against A/São Paulo/1/78 (H1N1) was significantly higher than that of antibody to A/USSB/90/77 (HIND in 1978. However in 1979 the predominant strain was A/USSR/90/77 (HIND. Persons under 20 years of age were the most affected by H1N1 subtype. Antibodies to H1N1 subtype were detected in sera of individuals older than 20 years in 1976, before the re-emergence of this strain. Serological results indicate that infections by H3N2 subtype in 1978 occurred in 65.4% of young children (0-4 year group). About 47.0% of children from the 0-4 year group had antibodies to H1N1 subtype in 1979. Antibodies to swine influenza virus were detected in 60% of 60+ year old people.

Replicação de sendai virus em células epiteliais primárias de camundongo

Células epiteliais primárias obtidas do trato respiratório de camundongos jovens foram infectadas com o Vírus Hemaglutinante do Japão (HVJ, Sendai Virus) e, a progénie viral, tratada ou não com tripsina foi titulada através do método de Imunofluorescência Indireta. A progénie de Sendai Virus obtida de células epiteliais primárias de camundongo apresentou um título considerável, demonstrando-se que há ativação das partículas virais, capazes de infectar células LLC-MK 2, nas quais, a progénie viral foi titulada.

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.

Radiometric detection of metabolic activity of Paracoccidioides brasiliensis and its susceptibility to amphotericin B and diethylstilbestrol

Paracoccidioidomycosis (South American blastomycosis) is a systemic disease, strikingly more frequent in males, caused by the dimorphic fungus Paracoccidioides brasiliensis. A radiometric assay system has been applied to study the metabolic activity and the effect of drugs on this fungus "in vitro". The Y form of the yeast, grown in liquid Sabouraud medium was inoculated into sterile reaction vials containing the 6B aerobic medium along with 2.0 μCi of 14C-substrates. Control vials, prepared in the same way, contained autoclaved fungi. To study the effects of amphotericin B (AB) (0.1 and 10 μg/ml) and diethylstilbestrol (DSB) (1.0, 5.0 and 10 μg/ml) extra controls with live fungi and no drug were used. All vials were incubated at 35°C and metabolism measured daily with a Bactec instrument. 14CO2 production by P. brasiliensis was slow and could be followed for as long as 50 days. AB at 10mg/ml and DSB at 5 μg/ml inhibited the metabolism and had a cidal effect on this fungus. The results with DSB might explain the low incidence of the disease in females. This technique shows promise for studying metabolic pathways, investi gating more convenient 14C-substrates to expedite radiometric detection and for monitoring the effects of other drugs and factors on the metabolism of P. brasiliensis "in vitro".

Lectins for the detection of IgM antibodies to T. gondii in the diagnosis of acute toxoplasmosis by immunofluorescence test

Lectins were labeled with fluorescein and tried as conjugates in the immunofluorescence (IP) test for the detection of IgM antibodies to T. gondii, in the diagnosis of acute toxoplasmosis. This approach was an attempt to find alternative reagents for anti-human IgM fluorescent conjugates (AHIgMFC), which contain quite frequently anaibcdies to toxoplasma, as contaminants, due to natural T. gondii infections among animals used for imunization. Lentil (Lens culinaris) lectin fluorescence conjugates (LcFC) provided most satisfactory results. The evaluation of LcFC carried out in a total of 179 sera from patients with acute and chronic toxoplasmosis, with non-related infections or healthy subjects, gave high values of relative efficiency, co-positivity and co-negativity indices, respectively 0.989, 0.969 and 1.000, in reference to the conventional AHIgMFC. Moreover, three batches of LcFC successively prepared gave reproducible test results. The advantage of LcFC as an alternative reagent for the serodiagnosis of acute toxoplasmosis is supported by practical aspects of its preparation.

Passive haemagglutination test for human neurocysticercosis immunodiagnosis: I. Standardization and evaluation of the passive haemagglutination test for the detection of anti-Cysticercus cellulosae antibodies

A passive haemagglutination test (PHA) for human neurocysticercosis was standardized and evaluated for the detection of specific antibodies to Cysticercus cellulosae in cerebrospinal fluid (CSF). For the assay, formaldehyde-treated group O Rh-human red cells coated with the cysticerci crude total saline extract (TS) antigen were employed. A total of 115 CSF samples from patients with neurocysticercosis was analysed, of these 94 presented reactivity, corresponding to 81.7% sensitivity, in which confidence limit of 95% probability (CL95%) ranged from 74.5% to 88.9%. Eighty-nine CSF samples derived from individuals of control group presented as nonreactive in 94.4% (CL95% from 89.6% to 99.2%). The positive and negative predictive values were 1.4% and 99.9%, respectively, considering the mean rate of that this assay provide a rapid, highly reproducible, and moderately sensitive mean of detecting specific antibodies in CSF samples.

Passive haemagglutination test for human neurocysticercosis immunodiagnosis: II - Comparison of two standardized procedures for the passive haemagglutination reagent in the detection of anti-Cysticercus cellulosae antibodies in cerebrospinal fluids

A comparison of two different standardized reagent procedures for the passive haemagglutination test (PHA) in the detection of specific antibody to Cysticercus cellulosae in cerebrospinal fluid (CSF) was carried out. The formaldehyde-treated group O Rh-human red blood cells (HuRBC) and glutaraldehyde-treated sheep red blood cells (SRBC) were the supplies for the reagents preparation and, in the tests, they were designated as PHA-1 and PHA-2, respectively. For both reagents the cells were coated with the cysticerci total saline extract (TS) antigen. PHA-1 and PHA-2 were assessed in a total of 204 CSF from patients with neurocysticercosis, from non-related infections and from healthy individuals. The positivity and specificity indices obtained were respectively 81.7% and 94.4% for PHA-1 and for PHA-2, 88.7% and 96.6%. Since no significant differences were observed between the results provided by two reagents, at level of significance of 0.05, either processes of cell sensitization can alternatively be used according to the own laboratory convenience.

Detection of circulating polysaccharide antigen of Schistosoma mansoni in hamster sera by crossed immunoelectrophoresis

Crossed immunoelectrophoresis (IEC) was used for detection of free and complexed circulating polisaccharide anodic antigen (AgCA) of Schistosoma mansoni in sera of infected hamsters. An attempt was also done to detect AgCA in human sera from patients infected with S. mansoni. The conditions for isolation and detection of complexed AgCA were established. The sensitivity of IEC was increased by incorporation of 2% polyethylene glicol (PEG) to the agarose and by maintaining the system at 4°C during the electrophoretic run. Free AgCA was detected in 12 and the complexed in 30 of the 37 hamsters sera analysed. Correlation between AgCA (free and complexed) and the parasite load was observed. AgCA was not detected, under the experimental conditions used, in human sera from 7 patients in the acute and 23 in the chronic phase of infection.

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.

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.

Simplification of Immune Adherence Hemagglutination test for detection of rabies antibodies in human serum

In the present work the immune adherence hemagglutination test (IAHA) was standardized in a simplified procedure. This test showed good reproducibility, better than the classical mice serum neutralization test (SN). The tests showed high correlation degree: high titers in one test corresponded to high titers in the other one, and the same occured with low titers. The IAHA test is extremely simple, fast to perform, and of low cost when compared to tests such as SN or indirect immunofluorescense (IIF). It also proved to be useful in less sophisticated laboratories or even as a screening test for the titration of rabies antibodies.

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.