Estimated Prevalence of Viral Hepatitis in the General Population of the Municipality of São Paulo, Measured by a Serologic Survey of a Stratified, Randomized and Residence-Based Population.

The present study was done to estimate the prevalence of Hepatitis A (HAV), B (HBV), C (HCV), and E (HEV) infection in the general population residing in the municipality of São Paulo, and to evaluate the level of knowledge related to the various modes of infection transmission by and protection against the different viruses. Blood samples and health questionnaires were collected from 1,059 individuals. The study design used an inductive method of predictive statistical inferences through randomized sampling stratified by Sex, age and residence region. The estimated prevalence rated found were: Hepatitis A = 66.59% (63.75%-69.44% CI); Hepatitis B = 5.94% (4.50%-7.35%); Hepatitis C = 1.42% (0,70%-2.12%); Hepatitis E = 1.68% (0.91%-2.46%). The frequency of hepatitis was similar in males and females. HAV showed an estimated prevalence of 56.16% in the population up to 17 years old, increasing to 65.30% in individuals between 18 and 29 years. The infection reached its peak of 90% in individuals 40 years of age or older. The study showed a greater tendency of dissemination of HBV among the population between 15 and 17 years. This specific age group showed an estimated prevalence of active infection of 1.04% (0.43%-1.65% CI), and also demonstrated an ascending level of acquired immunity with an estimated prevalence of 4.90% (3.60%-6.20% CI). HCV demonstrated an estimated prevalence of 1.42% (0.70%-2.12% CI). This specific infection occurred more frequently among adults 30 years of age or older, with the prevalence reaching a peak of 3.80% among the group aged 50 to 59 years. HEV showed zero prevalence among the age group between 2 and 9 years. This was followed by a slightly ascending rate starting from age 10, with an estimated prevalence of 1.05% (0.94%-3.04% CI) among those 10 to 14 years of age. This infection reached its peak of 3.00% (0.55%-6.74% CI) at the age of 60 years or older. Individuals with lower educational levels had a higher tendency of acquiring HAV and HCV, while there was no statistically significant difference for this parameter related to HBV and HEV. HBV occurred more frequently among inhabitants of the northern region of the city. All other hepatitis forms occurred at similar frequencies among the five regions of the city. Among the population, 1.90% (1.08%-2.72% CI) demonstrated an elevated hepatic enzyme with no serologic evidence indicating the cause was the viruses studied. This observation suggests the presence of other hepatic diseases, possibly including other viral diseases. It was also estimated that 75.12% of the city's population did not know the modes of transmission of hepatitis viruses and 76.70% did not know how to prevent them. This clearly suggests the need for a full-scale education program combined with public health measures regarding prevention of all forms of vial hepatitis.

Identification and characterization of a new and distinct molecular subtype of human T-cell lymphotropic virus type 2.

Molecular studies have demonstrated the existence of at least two major subtypes of human T-cell lymphotropic virus type 2 (HTLV-2), designated HTLV-2a and HTLV-2b. To further investigate the heterogeneity of this family of viruses, we have characterized the HTLV-2 subtypes present in several urban areas in Brazil. DNAs from peripheral blood mononuclear cells of a large number of infected individuals, the majority of whom were intravenous drug abusers, were analyzed by using PCR with restriction fragment length polymorphism and nucleotide sequencing analysis. Restriction fragment length polymorphism analysis of the env region suggested that all individuals were infected with the HTLV-2a subtype, and this was confirmed by nucleotide sequence analysis. In contrast, nucleotide sequence analysis of the long terminal repeat demonstrated that although the viruses were more related to the HTLV-2a than to the HTLV-2b subtype, they clustered in a distinct phylogenetic group, suggesting that they may represent a new and distinct molecular subtype of HTLV-2. This conclusion was supported by nucleotide sequence analysis of the pX region, which demonstrated that the Tax proteins of the Brazilian viruses differed from that of prototype HTLV-2a isolates but were more similar to that of HTLV-2b in that they would be expected to have an additional 25 amino acids at the carboxy terminus. In transient expression assays, the extended Tax protein of the prototype HTLV-2a subtype. The studies suggest that the Brazilian viruses analyzed in this study, while being phylogenetically related to the prototypic HTLV-2a seen in North America, are phenotypically more related to HTLV-2b and can be justifiably classified as a new molecular subtype, which has been tentatively designated HTLV-2c.

Isolation of Mycobacterium avium complex from bone marrow aspirates of AIDS patients in Brazil.

Mycobacterium avium complex (MAC) infection has not been reported as a major opportunistic infection among patients with AIDS in Latin America or Africa. In this study, 125 AIDS patients who had persistent fever, anemia, and leukopenia were examined among 2628 AIDS patients admitted to Instituto de Infectologia Emilio Ribas between May 1990 and April 1992. From the bone marrow aspirates of the 125 patients, MAC was isolated from 23 (18.4%) and Mycobacterium tuberculosis was isolated from 9 (7.2%). Between 1985 and 1990, only 11 MAC isolations among 60,000 cultures obtained from human immunodeficiency virus-seronegative patients were documented in São Paulo. Hence, the minimal estimated rate of MAC infection in AIDS patients in this city was 23/2628, or 0.88%. These findings suggest that MAC infection is an important opportunistic infection, especially among a subset of patients with AIDS in Brazil who have clinical characteristics and risk activities similar to those associated with MAC infections in North America and Europe.

Aztreonam in the treatment of bacterial meningitis.

The monobactam aztreonam was used to treat 22 young patients with meningitis caused by gram-negative bacilli. Haemophilus influenzae was isolated from the CSF of 21 patients and Salmonella heidelberg from the CSF of 1. Dosages ranged from 100 to 200 mg/kg/day in 4 doses at 6-hour intervals. Minimal inhibitory concentrations were determined by the broth dilution method for all isolated strains, and values ranged from 0.05 to 2.0 micrograms/ml. Blood and CSF drug levels were determined by a microbiologic plate diffusion method, and mean values for CSF and blood were 1.4 and 14.9 micrograms/ml, respectively. The outcome was good in 21 patients; 1 patient died. Complications were mild; subdural effusion occurred in 6 cases and was managed clinically; asymptomatic hydrocephalus was seen in 4; seizure during the acute phase occurred in 6 cases; hypoacusis was noted in 2, and motor impairment was detected at the follow-up in 1 case. Aztreonam achieved good blood and CSF penetration and performed well in the treatment of 20 cases of H. influenzae meningitis and in the one case of S. heidelberg meningitis.

A prospective study of visceral leishmaniasis in an endemic area of Brazil.

The epidemiology, clinical patterns, and risk factors for visceral leishmaniasis were prospectively studied in an endemic area of Brazil. The prevalence of disease was 3.1% for children less than 15 years of age, and the annual incidence was 4.3 cases per 1,000 children. The number of children with disease fluctuated yearly and seasonally, and distribution of the disease varied within the endemic area. Risk factors included young age (median, three years) and malnutrition before the onset of disease. Intestinal parasitism, recent migration into the area, and house location within the area did not influence the progression of infection to disease. Serological testing indicated that 7.5% of children were infected with Leishmania each year and that the ratio of disease to infection was 1:18.5 for the whole area and 1:6.5 for the section with the highest prevalence of disease. Early diagnosis and therapy altered clinical patterns of the disease.

Selection of a skin test antigen for American visceral leishmaniasis.

Studies were designed to examine skin test responses to leishmanial antigens in American visceral leishmaniasis (AVL) in Brazil. We found that after recovery from AVL, patients had positive delayed hypersensitivity reactions to Leishmania. Different amounts of a soluble extract obtained from Leishmania donovani chagasi promastigotes were compared with whole L. d. chagasi promastigotes in persons with past AVL. The most effective soluble preparations tested contained 25 and 50 micrograms leishmanial protein. These produced positive responses in 95%-100% of the individuals with past AVL. The 25 micrograms protein dose was used in further studies. This preparation produced no positive responses in either normal controls, tuberculosis patients, or schistosomiasis patients, and less than 5% positive responses in persons with Chagas' disease. The same amount of soluble extract prepared from L. mexicana amazonensis produced 82% positive skin test responses in persons with past AVL. When persons living in an area endemic for AVL were skin tested with the 25 micrograms preparation of L. d. chagasi extract, 34.1% yielded positive tests with a low number of positive responses in young children and 48% positive in adults. Only 3.1% of the population studied had a history of AVL. We have found that positive delayed hypersensitivity response to a soluble Leishmania extract is a sensitive and specific indicator of previous infection with AVL.

Inquerito com paracoccidioidina em uma populacao da Bahia (Brasil). / Survey with paracoccidioidin in a population of Bahia (Brazil)

No Municipio de Una, localizado ao Sul do Estado da Bahia, em area com registro frequente de casos de leishamaniose tegumentar, foram estudados 177 individuos, na faixa etaria entre tres meses e 73 anos, atraves de provas intradermicas com paracoccidioidina (antigeno peptido-polissacaridico do Paracoccidioides brasiliensis).Positividade foi obtida em dez individuos (5,6%). Somente foi considerada positiva a reacao que apresentava enduracao igual ou maior que 5 mm. Em nenhum dos casos positivos a paracoccidioidina havia evidencia clinica de lesoes blastomicoticas. Com os soros dos individuos positivos a paracoccidioidina, foram realizadas provas de imunodifusao dupla e contraimunoeletroforese, com resultados negativos para anticorpos circulantes anti-P. brasiliensis.Este dado indica que, em nenhum dos reatores a paracoccidioidina, havia processo infeccioso em atividade. O percentual de positividade obtido com a paracoccidioidina, em que pesem eventuais reacoes cruzadas com histoplasmose, sugere a ocorrencia da paracoccidioidomicose na area estudada