Abstract in English:Dengue is the most important disease caused by an arbovirus (1, 2, 3 and 4 serotypes) worldwide, especially in the tropical and sub-tropical regions. Its clinical manifestations range from asymptomatic infections to a severe disease characterized by hemorrhage and shock. The incidence of dengue virus activity in the Americas has substantially increased from 1980 to 1994. In Brazil, the increase in the incidence of dengue is especially linked to the dissemination of Aedes aegypti. Thus, a rapid and accurate dengue diagnosis is of paramount importance for effective control of dengue outbreaks . Five serological tests have been used for the diagnosis of dengue infection: hemagglutination-inhibition (HI), complement fixation (CF), neutralization test (NT), immunoglobulin M (IgM) capture enzyme linked immunosorbent assay (MAC-ELISA) and indirect immunoglobulin G ELISA. The limitations of these techniques are the high cross-reactivity observed with these tests. Four methods of viral isolation have been routinely used for dengue viruses: intracerebral inoculation of newborn mice, inoculation on mammalian cell cultures, intrathoracic inoculation of adult mosquitoes, and inoculation on mosquito cell cultures. In recent years, several new diagnostic techniques have been developed and have proven very useful in dengue diagnosis, such as: nucleic and acid hybridization, RT-PCR. Currently, dengue diagnosis is based on serology, viral isolation and RNA detection. Enzyme-linked immunosorbent assays (ELISA) are still the most widely used technique for serological diagnosis, but they do not identify the dengue virus serotype responsible for the current infection, so molecular techniques may soon assume a very important role in dengue diagnosis. RT-PCR is definitely the most satisfactory test that can be used on these infections, since it has been shown to be able to detect dengue viruses up to the 10th day after the onset of the symptoms.
Abstract in English:Several strategies aim at characterizing the AIDS epidemic in different parts of the world. Among these, the identification of recent HIV-1 infections using the recently described serologic testing algorithm for recent human immunodeficiency virus (HIV) seroconversion (STARHS) strategy was employed in four testing sites of the City of São Paulo Public Health Department (CSPPHD). Those identified as recently infected were invited to participate in a prospective clinical and laboratory evaluation study. We describe the establishment of the patient identification network and the success in enrolling the participants, as well as their clinical and laboratory characteristics. From May to December 2002, 6,443 persons were tested for HIV in the four participating sites, of whom 384 (5.96%) tested HIV-1 positive; 43 (11.2%) of them were identified as recently infected. Twenty-two were successfully enrolled in the follow-up study, but three of them did not meet clinical and/or laboratory criteria for recent HIV-1 infection. After these exclusions, the laboratory findings revealed a median CD4+ T lymphocyte count of 585 cells/muL (inter-quartile range 25-75% [IQR], 372-754), a CD8+ T lymphocyte count of 886 cells/muL (IQR, 553-1098), a viral load of 11,000 HIV-RNA copies/mL (IQR, 3,650-78,150), log10 of 4.04 (IQR 3.56-4.88). The identification of recent HIV infections is an extremely valuable way to evaluate the spread of the virus in a given population, especially when cohort studies, considered the gold standard method to evaluate incidence, are not available. This work demonstrated that establishing a network to identify such patients is a feasible task, even considering the difficulties in a large, resource-limited country or city.
Abstract in English:A new monoclonal antibody (5F81A4P1.9), which is specific for subtype 9 antigen of meningococci, was studied. The antibodies were raised against a previously non-typable (NT) serogroup B strain from Brazilian patients and were found to react with the subtype antigen of prototype reference strains for subtype 9 (M982), as well as with those of homologous strains. The subtype 9 epitope was found in 6.8% of serogroup B strains among 602 strains of Neisseria meningitidis case isolates, including representative isolates from Brazilian states. Subtype P1.9 was predominantly related to serogroup B in Brazil among the isolates collected during the N. meningitidis epidemic in 1992. No significant differences were observed in the occurrence of subtype P1.9 among strains isolated from several Brazilian states. Fluorescence-activated cell-sorter analysis showed that 5F81A4 MAb recognized a 46 kDa protein on the surface of a homologous strain of N. meningitidis (B:4:P1.9). These results, in association with a bactericidal activity assay for 5F81A4, and with experimental passive protection in mice, demonstrated the importance of subtype 9 class 1 proteins of N meningitidis in Brazil. Serotyping is essential for the development of vaccination strategies.
Abstract in English:Brazil was the first developing country to provide free, universal access to antiretroviral treatment for AIDS patients. The Brazilian experience thus provides the first evidence regarding the impact of such treatment on the survival of perinatally acquired AIDS cases in the developing world. MATERIAL AND METHODS: This retrospective cohort study used medical record reviews to examine characteristics and trends in the survival of a representative sample of 914 perinatally acquired AIDS cases in 10 Brazilian cities diagnosed between 1983 and 1998. RESULTS: Survival time increased steadily and substantially. Whereas half of the children died within 20 months of diagnosis at the beginning of the epidemic, 75% of children diagnosed in 1997 and 1998 were still alive after four years of follow-up. CONCLUSIONS: Advances in management and treatment have made a great difference in the survival of Brazilian children with AIDS. These results argue strongly for making such treatment available to children in the entire developing world.
Abstract in English:Tuberculosis is one of the most important infectious diseases in the world. Only 68% of the estimated new tuberculosis (TB) cases in Brazil are diagnosed. Our aim was to determine the risk of infection among household contacts. Study design. Cohort of tuberculin-negative household contacts followed for 12 Months. Methods. Household contacts of randomly selected index acid-fast bacilli (AFB)-positive TB cases were evaluated through clinical examination, thorax X-ray, tuberculin, AFB smear and culture. Contacts with a negative response to the tuberculin test (less than 10 mm diameter) were retested after 90 days. Tuberculin reversal (used as a parameter of infection risk) was defined as an increase of at least 10 mm from the last measurement. Results. 269 household contacts were followed. The prevalence of disease in this population was 3.7%. The prevalence of infection after the 12-month follow-up period was 63.9%. The risk of infection was 31.1% within 120 ± 48 days. Conclusion. Household contacts of AFB positive tuberculosis patients have a very high prevalence and risk of tuberculosis infection. TB preventive or therapeutic measures directed towards this group should be implemented in Brazil.
Abstract in English:Occult hepatitis B virus (HBV) infections have been identified in patients with chronic hepatitis C virus (HCV) infection, although the clinical relevance of occult HBV infection remains controversial. We searched for serum HBV DNA in 106 HBsAg negative/anti-HBc positive patients with chronic HCV infection and in 150 blood donors HBsAg negative/anti-HBc positive/anti-HCV negative (control group) by nested-PCR. HCV genotyping was done in 98 patients and percutaneous needle liver biopsies were performed in 59 patients. Fifty-two patients were treated for HCV infection with interferon alone (n=4) or combined with ribavirin (n=48) during one year. At the end and 24 weeks after stopping therapy, they were tested for HCV-RNA to evaluate the sustained virological response (SVR). Among the 106 HCV-positive patients, 15 (14%) were HBV-DNA positive and among the 150 HCV-negative blood donors, 6 (4%) were HBV-DNA positive. Liver biopsy gave a diagnosis of liver cirrhosis in 2/10 (20%) of the HBV-DNA positive patients and in 6/49 (12%) of the HBV-DNA negative patients. The degree of liver fibrosis and portal inflammation was similar in HCV-infected patients HBV-DNA, irrespective of HBV-DNA status. SVR was obtained in 37.5% of the HBV-DNA positive patients and in 20.5% of the HBV-DNA negative patients; this difference was not significant. In conclusion, these data suggested that occult HBV infection, which occurs at a relatively high frequency among Brazilian HCV-infected patients, was not associated with more severe grades of inflammation, liver fibrosis or cirrhosis development and did not affect the SVR rates when the patients were treated with interferon or with interferon plus ribavirin.
Abstract in English:Euthanasia of seropositive dogs has been one of the principal measures adopted by the Program for the Control of Leishmaniasis in Brazil for many years. However, its efficacy is currently being questioned. We obtained intact skin samples from 20 Leishmania-reactive dogs from the municipality of Rio de Janeiro that had been referred for euthanasia. The promastigote forms of Leishmania were isolated in culture from 18 of these animals. Fourteen of these isolates were identified as Leishmania (Leishmania) chagasi by isoenzyme electrophoresis; seven of these were from asymptomatic dogs and seven were from symptomatic animals with visceral leishmaniasis. In conclusion, cutaneous parasitism is found in the intact skin of dogs naturally infected with L. (L.) chagasi, irrespective of the presence or absence of clinical signs suggestive of visceral leishmaniasis.
Abstract in English:A guarantee of quality of all steps involved in processing dental materials is essential to achieve security. A descriptive study was made of how Public Dental Medicine Colleges in Brazil process critical materials and determine the patterns of physical, chemical and biological control in their use of hot air ovens and autoclaves to sterilize these materials. The data were obtained with a questionnaire, sent by mail and analyzed with the software EPI-INFO 6.04. Among the 40 Brazilian public Dental Medicine Colleges, only 16 returned the questionnaire. In eight of these, the individuals responsible for the materials and sterilization center had a college degree in a human health field. In 14 institutions, the students were responsible for the cleaning of the instruments, but in six of these they did so outside of the materials and sterilization center. Both the autoclave and the dry heat oven were the method of choice in 13 of the 16 schools. The sterilization routine was routinely monitored by 11 of the institutions. Chemical control through the tape test in the autoclave was used by 13 of the schools, three institutions reported preventive maintenance, and biological indicators were used by seven of the 16 schools. Autoclaves are widely used because of the degree of biological security that this method offers, however physical, chemical and biological controls have not been routinely implemented by most of the institutions.
Abstract in English:Four cases of serious cardiac attacks by autochthonous Trypanosoma cruzi infection from the Brazilian Amazon are reported; three of them occurred in micro-epidemic episodes. The manifestations included sudden fever, myalgia, dyspnea and signs of heart failure. Diagnosis was confirmed by specific exams, especially QBC (Quantitative Buffy Coat) and natural xenodiagnosis. Despite treatment with benznidazol, three patients died with serious myocarditis, renal failure and cardiac tamponade. The authors call attention to the emergence of this disease and reveal a previously unknown pathogenicity of T. cruzi strains in this area, added to a non-usual transmission form.
Abstract in English:Dengue fever is the world's most important viral hemorrhagic fever disease, the most geographically wide-spread of the arthropod-born viruses, and it causes a wide clinical spectrum of disease. We report a case of dengue hemorrhagic fever complicated by acute hepatitis. The initial picture of classical dengue fever was followed by painful liver enlargement, vomiting, hematemesis, epistaxis and diarrhea. Severe liver injury was detected by laboratory investigation, according to a syndromic surveillance protocol, expressed in a self-limiting pattern and the patient had a complete recovery. The serological tests for hepatitis and yellow fever viruses were negative. MAC-ELISA for dengue was positive.
Abstract in English:Tungiasis is caused by the penetration of the female sand flea Tunga penetrans into the epidermis, and subsequent hypertrophy of the parasite. In most cases lesions are confined to the feet. During a cross-sectional study, an unusual case of ectopic tungiasis in the inguinal area was detected. Histological examination of tissue samples showed a remarkable pseudoepitheliomatous aspect of the epidermis. Clinical features and differential diagnoses are discussed.