Biomedical subjects

L T Figueiredo

Publications and source records attributed to L T Figueiredo.

At least 19 recordsLinked to original sources

PubMed2001

Occurrence and severity of infections caused by subgroup A and B respiratory syncytial virus in children in southeast Brazil.

The frequency and severity of infections caused by respiratory syncytial virus (RSV) were assessed in children <2 years of age seen at the emergency department. The frequency of RSV detection in the clinical virology laboratory during the past 3 years was also analyzed retrospectively. RSV was found in 21.6% (188/869) of the samples collected from children seen at the emergency department and was found to be more frequent during the autumn, being less frequent or negligible by midwinter. RSV subgroups A and B co-circulated within the same time period in children seen at the emergency department, with varying predominance of either subgroup. There was no significant association of RSV subgroup with disease severity, but only a trend for RSV subgroup B being more frequent in children with risk factors for severe disease.

Acute Disease↗

PubMed2001

Usefulness of blood and urine samples collected on filter paper in detecting cytomegalovirus by the polymerase chain reaction technique.

A rapid test for the diagnosis of congenital CMV infection is still needed. This study evaluated the usefulness of dried blood and urine samples collected on filter paper for detecting cytomegalovirus (CMV) by the polymerase chain reaction (PCR) assay compared with the use of liquid urine. Samples were obtained from 332 infants aged 1-7 days. Liquid urine samples were collected into bags, cultured in human fibroblasts, and processed using a multiplex PCR technique. Dried urine samples were obtained by placing a piece of filter paper in contact with the infant's genitals. The heels of neonates were punctured and capillary blood was blotted onto filter paper and dried. Dried blood and urine specimens were analyzed by multiplex PCR and nested-PCR assays. A diagnosis of congenital CMV infection was established by isolating the virus, and by detecting viral DNA in the liquid urine. Of the 332 liquid urine samples collected from 332 neonates, seven (2.1%) were positive for CMV and 325 were negative, by both cell culture and PCR assay. In dried samples, CMV DNA was detectable only with a nested PCR assay. Compared with known CMV infection status, 5/7 (71.4%) neonates were positive for congenital CMV infection using dried blood samples. All 325 uninfected neonates were negative. In the dried urine samples, 4/4 CMV-infected infants gave positive tests, and all 262 uninfected infants were negative. Although further improvements in sample collection and/or processing are still needed, PCR testing on dried urine or blood collected on filter paper is a promising approach in the diagnosis of neonatal CMV infection.

Blood Specimen Collection↗

PubMed2001

Phylogenetic analysis of Brazilian Flavivirus using nucleotide sequences of parts of NS5 gene and 3' non-coding regions.

Viruses of the genus Flavivirus, which are arboviruses, of the Flaviviridae family, are amongst the most important agents of infectious disease in Brazil, causing human infections with a high morbility and mortality. In this work, the phylogeny of 14 virus amplicon sequences that were obtained by RT-PCR with universal primers for mosquito-borne Flavivirus were studied. The amplicons included a region of the Flavivirus genome of 129 nucleotides at the 3' terminus of the NS5 gene and the 145 initial nucleotides of the 3' non-coding region (NS5-3'NCR). Based on phylogenetic trees, most Brazilian Flaviviruses were grouped into two main branches, including a yellow-fever branch and a second main branch divided into a dengue branch that in its turn is subdivided into serotype 1, 2 and 4 branches, and another (Japanese Encephalitis Virus Complex) branch including SLE and Ilhéus. Rocio and Cacipacoré viruses were included in the Japanese Encephalitis Virus Complex branch in one of the two phylogenetic trees. Iguape virus appears in phylogenetic trees as a separate distant branch.

3' Untranslated Regions↗

PubMed2001

Cytomegalovirus infection in renal transplant recipients diagnosed by nested-PCR.

A prospective study of cytomegalovirus (CMV) infection was carried out on 34 renal transplant recipients managed at a General Hospital in Ribeirão Preto, SP, Brazil. Serologic tests showed that all patients were infected with CMV before renal transplantation. Two nested-PCR techniques with primers that recognize sequences of the glycoprotein B (gB) and H (gH) genes were used for CMV detection in blood and urine samples during the post-transplantation period. CMV was detected more frequently in blood samples than in urine samples (P<0.001). Thirty-three patients had CMV detected at least once in blood and/or urine samples. Seven of these patients (21.2%) were diagnosed as having symptomatic CMV infection and showed a worse clinical outcome, with a higher death rate (P = 0.03). No association between CMV viremia and graft rejection was observed. Nested-PCR was not useful to identify patients at risk for symptomatic CMV infection since only 21.2% of the patients with CMV infection were symptomatic.

Antibodies, Viral↗

PubMed2000

The Brazilian flaviviruses.

Ten flaviviruses occur in Brazil: Bussuquara, Cacipacoré, dengue 1, 2 and 4, Iguape, Ilhéus, Rocio, Saint Louis encephalitis and yellow fever. Aspects of sylvatic maintenance cycles and human diseases caused by these viruses are analyzed. Large dengue outbreaks are occurring in Brazil and there is a risk of yellow fever urbanization.

Animals↗

PubMed2000

High prevalence of renal transplant recipients infected with more than one cytomegalovirus glycoprotein B genotype.

A prospective analysis of cytomegalovirus (CMV) glycoprotein B (gB) genotypes was conducted on 34 renal transplant recipients using peripheral blood leukocytes (PBLs) and urine specimens. The CMV gB genotypes were analyzed by polymerase chain reaction (PCR) followed by enzyme digestion. PBLs and urine samples showed almost equal proportions of the 4 known gB genotypes, as well as equal proportions of gB genotype mixtures. The gB genotypes 1, 2 and 3 were equally distributed in the patients. Twenty-four (70.6%) patients had more than one gB genotype during follow-up. There was no association of gB genotypes with the development of symptomatic CMV infection.

Cytomegalovirus↗

PubMed2000

A study of infectious endocarditis in Ribeirão Preto, SP-Brazil. Analysis of cases occurring between 1992 and 1997.

OBJECTIVE: To analyze the epidemiology, diagnosis, clinical aspects causes and evolution of infectious endocarditis. METHODS: The patients analyzed were treated at the University Hospital of the Faculdade de Medicina of Ribeirão Preto-USP and had a diagnosis of infectious endocarditis defined by Duke's criteria, which classifies infectious endocarditis as native, prosthetic valve or that occurring in intravenous drug users. RESULTS: One hundred and eighty episodes of infectious endocarditis in 168 patients were observed. Echocardiograms in 132 (73.3%) provided a diagnosis of infectious endocarditis in 111 (84%) patients; mitral valves were affected in 55 (30.5%), tricuspid valves in 30 (16.6%) and the aortic valve in 28 (15.5%) patients. Hemocultures were performed in 148 (93.8%) episodes of IE. The most commonly isolated infectious organisms were Staphylococcus aureus in 46 (27.2%) patients and Streptococcus viridans in 27 (15.9%). Complications occurred in 116 (64.4%) patients and 73 (40.5%) of the patients died. CONCLUSION: The general profile of the observed infectious endocarditis was similar to that reported in studies performed in other countries and included users of intravenous drugs. The high degree of mortality observed is not compatible with progress in diagnosis and treatment of infectious endocarditis and is probably due to the absence of diagnostic suspicion. The high frequency of fatal cases of septicemia (45.1% of deaths) in the patients studied indicates that unnoticed cases of infectious endocarditis had only been diagnosed at necropsy.

Adult↗

PubMed1999

[Dengue fever: a post-epidemic sero-epidemiological survey in an urban area setting at a northwestern county of São Paulo State, Brazil].

OBJECTIVE: The objective of this study was to evaluate the real size of the epidemics registered in the urban area of the county of Santa Bárbara D'Oeste, SP, Brazil, from April to June, 1995. The measurement of the epidemiological validity of the official surveillance system criteria and its positive predicted value were adopted as specific goals. METHODS: A sero-epidemiological survey was carried out over a sample of 1,113 sera from citizens of Santa Barbara D'Oeste, through a systematic random sampling of houses, five months after the end of the epidemics. Infection rates were compared with the infestation indexes by Aedes aegipty and the notified cases amongst the county sections. The importance of submitting patients with clinical suspicion of dengue to laboratory tests was discussed. RESULTS AND DISCUSSION: It was found that infection rates by dengue virus varied in the same direction and proportion as the presence of Aedes aegipty larvae reported by the "Breteau Index", as well as the number of cases reported by the official notifiable diseases surveillance system during the epidemics. A prevalence of 630 by 100 thousand inhabitants was found, a 15-fold rate when compared to the laboratory positive sera from cases detected by the surveillance system during the epidemics. A retrospective comparison with the surveillance reports, using serological results as a gold standard, also showed that the majority of dengue specific serum-positive individuals were not detected during the epidemics, otherwise cases that did not present serological reaction were notified exhibiting a low positive predictive value of clinical diagnosis (15,6).

Adolescent↗

PubMed1999

Detection of cytomegalovirus infections by PCR in renal transplant patients.

Cytomegalovirus (CMV) is the single most important infectious agent affecting recipients of organ transplants. To evaluate the incidence and the clinical importance of CMV infection in renal transplants in Brazil, 37 patients submitted to renal allograft transplants were tested periodically for the presence of cytomegalovirus DNA in urine using the polymerase chain reaction (PCR), and for the presence of IgM and IgG antibodies against CMV by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF). The PCR-amplified products were detected by gel electrophoresis and confirmed by dot-blot hybridization with oligonucleotide probes. Thirty-two of the 37 patients (86.4%) were positive by at least one of the three methods. In six patients, PCR was the only test which detected the probable CMV infection. Ten patients had a positive result by PCR before transplantation. In general, the diagnosis was achieved earlier by PCR than by serologic tests. Active infection occurred more frequently during the first four months after transplantation. Sixteen of the 32 patients (50%) with active CMV infection presented clinical symptoms consistent with CMV infection. Five patients without evidence of active CMV infection by the three tests had only minor clinical manifestations during follow-up. Our results indicate that PCR is a highly sensitive procedure for the early detection of CMV infection and that CMV infection in renal transplant patients is a frequent problem in Brazil.

Cytomegalovirus↗

PubMed1998

Congenital and perinatal cytomegalovirus infection in infants born to mothers infected with human immunodeficiency virus.

OBJECTIVES: To determine the rates of congenital and perinatal cytomegalovirus (CMV) infection among infants born to mothers infected with HIV compared with infants born to mothers not infected with HIV from a CMV-immune, low-income population. STUDY DESIGN: A total of 325 newborns from CMV-seropositive mothers were enrolled and evaluated for congenital CMV infection (150 infants from HIV+ mothers and 175 infants from HIV- mothers. A total of 101 infants from HIV+ mothers and 33 infants from HIV- mothers were evaluated for perinatal CMV infection. The virus was isolated from urine by culture in human fibroblasts and was detected by polymerase chain reaction at birth and at 15 days and 12 weeks of age. RESULTS: Only 13 of 150 HIV+ mothers (8.7%) had an AIDS-defining condition, and none had a late-stage HIV infection. Congenital CMV infection was detected in 4 of 150 (2.7%) infants from HIV+ mothers and in 5 of 175 (2.9%) infants from HIV- mothers (p = 1.00). Perinatal CMV infection was diagnosed in 8 of 101 (7.9%) infants from HIV+ mothers and in 13 of 33 (39.4%) infants from HIV- mothers (p < 0.00001). Most infants (93.9%) from HIV- mothers and only 5.9% of infants from HIV+ mothers were breastfed. CONCLUSIONS: CMV coinfection in mothers without advanced HIV disease from a CMV-immune population does not enhance the likelihood of congenital CMV infection. Perinatal CMV transmission from HIV-infected mothers may be decreased by avoiding breastfeeding. Further studies on mothers with late-stage HIV infection are needed.

Cytomegalovirus Infections↗

PubMed1998

Identification of Brazilian flaviviruses by a simplified reverse transcription-polymerase chain reaction method using Flavivirus universal primers.

We report a simplified reverse transcription-polymerase chain reaction (RT-PCR) method for identification of Brazilian flaviviruses based on the patterns of electrophoretic separation of the amplicons. The RT-PCR was done on the culture fluids of Aedes albopictus C6/36 cells infected with Brazilian flaviviruses, without previous extraction of viral RNA, using Flavivirus universal primers that anneal to highly conserved sequences within the nonstructural protein 5 and 3'- non translated region of the virus genome. Genomes of 13 Brazilian Flavivirus isolates were amplified. It was not possible to amplify the genome of Bussuquara virus. Analysis of the RT-PCR products gave reproducible results and three distinct amplicon patterns were observed. Cacipacoré (800-850 basepairs [bp]) and yellow fever viruses (600 bp) yielded a single amplicon; dengue virus types 1 and 2 (650 and 550 bp), dengue virus type 4 (550 and 450 bp), Iguape (650-600 bp and 750-700 bp), St. Louis encephalitis (700 and 650-600 bp), and Rocio viruses (600 and 500-550 bp) yielded two amplicons; and Ilheus virus yielded five amplicons, two larger than 1,000 bp, one 650-700 bp, one 550-600 bp, and one 450-500 bp. The analysis of amplicon DNA sequences of six viruses showed homology with the 3'- nontranslated region of Flavivirus genome. The use of the Flavivirus universal primers in this simple RT-PCR technique is suitable as a screening test for the genus Flavivirus, with the exception of Bussuquara virus, in Brazilian isolates in tissue culture fluid.

Aedes↗

PubMed1996

Culture conditions affect cytotoxin production by Serratia marcescens.

Cytotoxins have been implicated in the pathogenesis of bacterial infections. In this study, the influence of different culture conditions was evaluated on cytotoxin production of Serratia marcescens. Parameters such as culture media, incubation temperature, starting pH of culture medium, aeration, anaerobiosis, carbon sources, iron concentration in he culture media, and release of cell-bond toxin by polymyxin B were investigated. The data suggest that this cytotoxin is predominantly extracellular and is not induced by iron limitation. Aerobic culture with shaking resulted in higher cytotoxicity than static aerobic or anaerobic culture. Bacteria grown in glucose, sucrose or galactose were more cytotoxic than those grown in inositol or maltose. The culture conditions that were identified as optimal for cytotoxin production by Serratia marcescens were incubation temperature ranging from 30 to 37 degrees C, in medium adjusted pH 8.5, with shaking. This work will contribute to further studies on the identification of this cytotoxic activity.

Bacterial Toxins↗

PubMed1996

[Dengue and its vectors in Brazil].

History of dengue in Brazil is covered from the first citations in the XIXth century to the great outbreaks of the last ten years. DEN-1 and DEN-4 viruses have been isolated for the first time in 1982 during an epidemic in Boa Vista, Roraima State. In 1986-1987, epidemics of dengue type 1 covered an extended area from Rio de Janeiro/Sào Paulo States to the North East States of Brazil. During 1990-1991, dengue type 2 epidemics have been notified in the South East (Rio de Janeiro/São Paulo) and in some States of the interior of the country (Mato Grosso do Sul, Tocantins). DEN-1 virus was also circulating the same year in São Paulo and Minas Gerais States. Recently (1994), an important outbreak has been studied in Ceará State, where DEN-2 and DEN-1 viruses have been isolated. In Rio de Janeiro and Ceara (1990 and 1994, respectively), it is probably the succession of infections by DEN-1 and DEN-2 viruses which has caused many DHF/DSS cases. The urban vector has always been the mosquito Aedes aegypti, from which 4, 7 and 16 strains of DEN-4, DEN-1 and DEN-2 have been isolated, respectively. In Brazil, transovarial transmission of dengue viruses by this species has not yet been shown to occur in nature.

Aedes↗

PubMed1995

Dengue serologic survey in Ribeirão Preto, São Paulo, Brazil.

The city of Ribeirão Preto suffered a dengue 1 epidemic that began in November 1990 and ended in March 1991. A serologic survey designed to detect IgG antibodies to the four dengue serotypes and other flaviviruses was carried out in Ribeirão Preto during September and October of 1992. Dengue 1 antibodies were detected in 5.4% of the survey participants. Significantly higher seropositivity (9.3%) was found among subjects residing in the Northwest Sector of Ribeirão Preto than among those living in the city's other three sectors. The Northwest Sector also exhibited relatively high levels of breeding sites used by the Aedes aegypti vector, the highest number of reported dengue cases of any sector, and relatively poor socioeconomic conditions. The fact that the epidemic was limited mainly to the Northwest Sector probably resulted mainly from intense vector control and educational measures undertaken in response to the outbreak. As of the 1992 survey, most of the city's population remained vulnerable to dengue 1 infection; however, an estimated 23,000 with dengue 1 antibodies appeared to be at relatively high risk of developing dengue hemorrhagic fever/dengue shock syndrome in the event of infection with dengue 2. Both of these considerations indicate an ongoing need to maintain dengue education and vector control measures.

Adolescent↗

PubMed1994

Donated organs as a source of cytomegalovirus (CMV) in renal transplant patients.

Two patients receiving the same cadaver kidney graft were investigated prospectively for cytomegalovirus (CMV) infection using the polymerase chain reaction (PCR) and serologic tests (ELISA and IFI). The data indicate that a strain of CMV was probably transmitted from the same donor to both kidney recipients including one who was seropositive for CMV.

Adolescent↗

PubMed1993

[Comparison of two neutralization tests, used in vesiculovirus Piry serodiagnosis].

A serological survey of Piry was undertaken of the sera of inhabitants of Catolância-Bahia State, Brazil. Serum results obtained by a vesiculovirus neutralization test of C6/36 cells read by ELISA are compared with those obtained by the classic technique, carried out on newborn mice. The agreement between the results was as high as 98.7% of the 204 sera tested and the neutralization test of C6/36 cells was chosen as the most suitable technique for the sero-survey testing.

Animals↗

PubMed1991

[Dengue epidemic in Ribeirão Preto, SP, Brazil: a preliminary note].

A preliminary note on an outbreak of dengue which occurred in the city of Ribeirão Preto, State of S. Paulo, Brazil, from November 1990 to March 1991, is given. One case of Level II Dengue Hemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS) and two deaths associated with dengue related shock are described. Clinicians and epidemiologists are alerted to the possibility of sporadic DHF/DSS cases during outbreaks of classical dengue in formerly free areas.

Brazil↗

PubMed1990

Dengue serologic survey of schoolchildren in Rio de Janeiro, Brazil, in 1986 and 1987.

Two major epidemic waves of dengue 1 occurred in Rio de Janeiro, Brazil, in 1986 and 1987. This article reports the results of a survey of Rio schoolchildren who were tested serologically for antibodies to dengue 1 before and after the second major epidemic wave. The highest percentages of positive subjects were found in districts with relatively poor socioeconomic conditions and mosquito control problems. It also appears likely that the estimated number of dengue cases occurring in 1986-1987 was substantially below the number that actually occurred. In addition, because of this exposure to dengue 1, Rio de Janeiro now runs the risk of dengue hemorrhagic fever/dengue shock syndrome occurring should another dengue serotype be introduced within the next few years.

Adolescent↗