Dengue viruses in the Caribbean. Twenty years of dengue virus isolates from the Caribbean Epidemiology Centre.

The first isolate of a dengue virus in the Americas was obtained in Trinidad and Tobago in 1953, and several dengue virus isolates were obtained in subsequent years. However, the systematic isolation and typing of dengue viruses in support of virus surveillance and outbreak investigations did not start until the creation of the Caribbean Epidemiology Centre (CAREC) in 1975. Since then, over two thousand viral isolates have been obtained and typed from many countries in the English and Dutch-speaking Caribbean.

Molecular diagnosis of dengue by reverse transcriptase-polymerase chain reaction.

The techniques of reverse transcriptase-polymerase chain reaction (RT-PCR) and subsequent PCR were employed in the analysis of serum samples from a range of patients from the Caribbean Epidemiology Centre (CAREC) member countries. Results were compared with those from viral isolation and immunofluorescence. In the second part of the study, ten serum samples were stored for one week under four sets of conditions: -20 degrees C, 4 degrees C, 25 degrees C, and thawed (20 degrees C) and frozen (-20 degrees C) daily.

Measurement of nucleoside diphosphate kinase-Nm23 activity by anion-exchange high-performance liquid chromatography.

A first-order assay to detect the activity of nucleoside diphosphate kinase (NDP-kinase; EC 2.7.4.

A highly conserved nucleotide string shared by all genomes of human papillomaviruses.

The nucleotide string TAAAACGAAAGT is the longest perfect homology shared by all sequenced human papillomavirus genomes. This nucleotide string, which was also found to be highly specific for human papillomavirus genomes, shares the same genomic position in all viral types (5' end of the E1 open reading frame) and putatively codes in every case for the same amino acids. One possible evolutionary model was used to estimate the probability of random occurrence of the nucleotide string in 10 human papillomavirus genomes.

Amplification of human papillomavirus DNA sequences by using conserved primers.

The polymerase chain reaction has potential for use in the detection of small amounts of human papillomavirus (HPV) viral nucleic acids present in clinical specimens. However, new HPV types for which no probes exist would remain undetected by using type-specific primers for the polymerase chain reaction before hybridization. Primers corresponding to highly conserved HPV sequences may be useful for detecting low amounts of known HPV DNA as well as new HPV types.