Biomedical subjects

Lee W Riley

Publications and source records attributed to Lee W Riley.

57 records · Page 4Linked to original sources

PubMed2002

Complete nucleotide sequence analysis of a Brazilian dengue virus type 2 strain.

In the last decade, dengue fever (DF) in Brazil has been recognized as an important public health problem, and an increasing number of dengue haemorrhagic fever (DHF) cases have been reported since the introduction of dengue virus type 2 (DEN-2) into the country in 1990. In order to analyze the complete genome sequence of a DEN-2 Brazilian strain (BR64022/98), we designed primers to amplify contiguous segments of approximately 500 base pairs across the entire sequence of the viral genome. Twenty fragments amplified by reverse transcriptase-PCR were cloned, and the complete nucleotide and the deduced amino acid sequences were determined. This constitutes the first complete genetic characterization of a DEN-2 strain from Brazil. All amino acid changes differentiating strains related to the Asian/American-Asian genotype were observed in BR64022/98, indicating the Asiatic origin of the strain.

Amino Acid Sequence↗

PubMed2002

Population-based case-control investigation of risk factors for leptospirosis during an urban epidemic.

Between March and October 2000, 157 suspected cases of leptospirosis hospitalized with complications of Weil's syndrome and a mortality of 8% were identified in Salvador, Brazil. We conducted a population-based case-control study to identify risk factors for acquisition of leptospirosis in neighborhoods with high endemicity during the rainy season-associated urban epidemic. Sixty-six (65%) of 101 laboratory-confirmed cases and 125 age and sex-matched healthy neighborhood controls were interviewed. Residence in proximity to an open sewer (matched odds ratio [OR] = 5.15, 95% confidence interval [CI] = 1.80-14.74), peri-domiciliary sighting of rats (OR = 4.49, 95% CI = 1.57-12.83), sighting groups of five or more rats (OR = 3.90, 95% CI = 1.35-11.27), and workplace exposure to contaminated environmental sources (OR = 3.71, 95% CI = 1.35-10.17) were found to be independent risk factors for acquiring disease. Some of these risk factors are amenable to focused interventions, which include provision of closed drainage systems for sewage and reduction of rodent populations in the peri-domicilary environment. Environmental control of transmission may help to greatly reduce the incidence of severe leptospirosis.

Adolescent↗

PubMedDate not supplied

Molecular typing of dengue virus type 2 in Brazil.

Strain typing is a critical tool for molecular epidemiological analysis and can provide important information about the spread of dengue viruses. Here, we performed a molecular characterization of DEN-2 viruses isolated in Brazil during 1990-2000 from geographically and temporally distinct areas in order to investigate the genetic distribution of this serotype circulating in the country. Restriction site-specific polymerase chain reaction (RSS)-PCR presented the same pattern for all 52 Brazilian samples, showing the circulation of just one DEN-2 variant. Phylogenetic analysis using progressive pairwise alignments from 240-nucleotide sequences of the E/NS1 junction in 15 isolates showed that they belong to genotype III (Jamaica genotype).

Amino Acid Sequence↗