The occurrence of different viruses in nasopharyngeal secretions from children less than 5 years old with acute respiratory infections (ARI) was investigated over a period of 4 years (1982-1985) in Rio de Janeiro. Of the viruses known to be associated with ARI, all but influenza C and parainfluenza types 1, 2 and 4 were found. Viruses were found more frequently in children attending emergency or pediatric wards than in outpatients. This was clearly related to the high incidence of respiratory syncytial virus (RSV) in the more severe cases of ARI. RSV positive specimens appeared mainly during the fall, over four consecutive years, showing a clear seasonal occurrence of this virus. Emergency wards provide the best source of data for RSV surveillance, showing sharp increase in the number of positive cases coinciding with increased incidence of ARI cases. Adenovirus were the second most frequent viruses isolated and among these serotypes 1, 2 and 7 were predominant. Influenza virus and parainfluenza virus type 3 were next in frequency. Influenza A virus were isolated with equal frequency in outpatient departments, emergency and pediatric wards. Influenza B was more frequent among outpatients. Parainfluenza type 3 caused outbreaks in the shanty-town population annually during the late winter or spring and were isolated mainly from outpatients. Herpesvirus, enterovirus and rhinovirus were found less frequently. Other viruses than RSV and parainfluenza type 3 did not show a clear seasonal incidence.

We reviewed data collected between January 1987 and December 1989 on the etiology of acute respiratory infections (ARI) among 827 children in two low-income communities and a hospital in Rio de Janeiro. Respiratory syncytial virus was identified in 38% of cases of ARI, influenza A virus in 1%, parainfluenza 3 virus in 1%, and multiple viruses in 1%. Respiratory syncytial virus was most prevalent among hospitalized children, with seasonal increases in the late fall and winter. The principal bacterial pathogens were Staphylococcus aureus, gram-negative bacteria, Streptococcus pneumoniae, and alpha-hemolytic streptococci. Specimens that were most often positive were pleural fluid (46%) and specimens from other normally sterile sites (24%); normally sterile sites included the CSF, trachea, and lungs. Urine counterimmunoelectrophoresis for S. pneumoniae and Haemophilus influenzae polysaccharide antigens was positive in 3% and 2% of cases, respectively. Pharyngeal cultures yielded low numbers of S. pneumoniae and H. influenzae organisms and higher numbers of gram-negative bacteria. This study demonstrates the high incidence of ARI (4.5 cases per 100 child-weeks) among children in Rio de Janeiro and the high morbidity associated with the illness (ARI is responsible for 25%-50% of all pediatric hospitalizations) and the fact that continued attention must be paid to both viral and bacterial agents of ARI.

Detection of rotavirus RNA by polyacrylamide gel electrophoresis (PAGE) proved to be a highly sensitive and rapid diagnostic test. A comparison of this assay with immuno-electron microscopy (IEM) and enzyme immunoassay (EIA) in 245 faeces from children with gastroenteritis revealed complete agreement between the three assays in 238 (97.14%) samples. Among 75 samples positive in at least one of the three assays, negative results were observed in 5 (6.48%) by PAGE, in 6 (6.76%) by EIA and in none by IEM. Silver staining greatly increased the sensitivity of the PAGE assay. We conclude that although IEM remains the most sensitive and rapid rotavirus diagnostic assay, the PAGE technique has many advantages in its favour, including the non-requirement of expensive equipment, the use of only chemically defined reagents and the capacity to distinguish virus subgroup and variants and to detect non-crossreactive rotaviruses which are missed in serological assays.

SUMMARYIn May 1980 an extensive outbreak ofgastroenteritis occurred in a private school in the city of Rio de Janeiro. Examination of faeces and paired sera showed that this outbreak was caused by both rotavirus and a virulent strain of Shigella sonnei.In the first 19 stool samples collected seven (37 %) had rotavirus only, six (32 %) had Sh. sonnei only, while four (21 %) had both agents. Examination of the second and third stool collections revealed only the presence of Sh. sonnei. The 18 paired sera showed seroconversion for rotavirus in four cases (22 %) and in seven cases (39 %) for Sh. sonnei. The overall attack rate ofthe disease was approximately 75 %, the nursery and kindergarten having higher attack rates. Students in all grades became sick at the same time, and the unimodal curve of the onset dates of symptoms indicates a common source outbreak. Evidence suggested a contaminated water supply.

The present study addresses sociodemographic characteristics, knowledge and attitudes regarding HIV/AIDS, as well as risk behaviour and perception of vulnerability to HIV infection, in the first 295 homosexual and bisexual volunteers (excluding male commercial sex workers and transvestites) taking part in a cohort study in Rio de Janeiro. The sample has a higher socio-economic level than the remainder of the cohort, and than comparable strata of the general population, and a sound knowledge about how to protect themselves against HIV infection. In addition, an association between perception of vulnerability to infection and the practice of unprotected anal sex was observed. An association was also observed between higher levels of formal education and perception of vulnerability; however no association was found with markers for past and recent exposure to sexually transmitted infections (hepatitis B, HbsAG and syphilis). The results of the present study suggest that knowledge and awareness of risk do not easily translate into behaviour change, since significant proportions of the cohort continue to practise unprotected sex with both principal and casual partners, despite their awareness of HIV infection risks as well as preventive measures.

The initial effort of the Brazilian Ministry of Health to be an active partner in the world

To evaluate the relation between illicit drug use, sexual practices, and socioeconomic status, we analyzed data from the baseline interview of a cohort of 675 men who have sex with men conducted from 1994 to 1999 in Rio de Janeiro, Brazil. Bivariate analyses of factors associated with crack/cocaine use with sex revealed that men who reported crack/cocaine use were significantly ( p <.05) more likely than men who did not report drug use to be unemployed (42.7% vs. 29.1%), to have an income of <$250 per month (70.7% vs. 60.9%), to have <8 years of education (69.5% vs. 50.9%), to report bisexual activity (81.7% vs. 41.7%), and to engage in commercial sex (72.0% vs. 37.9%). Multivariate analysis of factors associated with unprotected anal sex with casual male partners in the last 6 months demonstrated that the following variables were associated with this outcome: an income <$250 per month (adjusted odds ratio [AOR] = 1.73, 95% confidence interval [CI]: 1.04-2.87), less than 8 years of education (AOR = 2.21, CI: 1.38-3.53), a greater sense of vulnerability (AOR = 2.58, CI: 1.54-4.33), a willingness to participate in vaccine trials (AOR = 1.91, CI: 1.20-3.05), and use of crack/cocaine (AOR = 1.91, CI: 1.05-3.46). Our findings suggest that HIV prevention programs for these men need to address drug use and how drug use may influence sexual behaviors.

The human immunodeficiency virus type 1 (HIV-1), the etiological agent of the acquired immunodeficiency syndrome (AIDS), shows a variety of biological properties, which may constitute an obstacle to development of effective vaccines or antiretroviral therapy. To characterize Brazilian strains of HIV-1, we studied 24 viruses isolated from blood samples of HIV-1-positive patients from different regions of the country. To examine the cell tropism and the virus ability to form syncytia, primary macrophages and the CD4 1 T cell line MT-2 were infected with these viruses. We found that 22 isolates replicated well in macrophages (macrophage-tropic isolates), 2 infected only MT-2 cells (T cell line tropic variants), while 6 of them grew in both cells. We found 8 syncytium-inducing (SI) and 16 non-SI (NSI) isolates. Continuous cultures of 18 isolates were established in the CCR51 /CXCR4 1 cell line PM-1, and SI/NSI features of these viruses were confirmed by cell fusion assay with uninfected CD4 1 T cell lines (PM-1, MT-2, H9, and SUP-T1). The coreceptor usage of 18 isolates was investigated by infecting U87 cells transfected with CD4 and chemokine receptors, and we found that 11 isolates infected only CCR5 1 cells, 3 only CXCR4 1 cells, whereas 4 used both coreceptors. We also observed that X4 isolates were more sensitive to neutralization by dextran sulfate than R5 or R5X4 viruses. Our findings show that the Brazilian isolates are phenotypically similar to those prevalent in other regions, which could mean that therapeutic strategies based on HIV-1 phenotypic properties would be efficient in Brazil, as in other countries. 1241