Epidemiology of dengue in Sri Lanka before and after the emergence of epidemic dengue hemorrhagic fever.

Before 1989, dengue epidemiology in Sri Lanka was characterized by frequent transmission of all four dengue serotypes but a low incidence of dengue hemorrhagic fever (DHF). After 1989, cases of DHF dramatically increased. Here we present the results of epidemiologic studies conducted in Colombo, Sri Lanka before and after epidemic emergence of DHF in 1989.

Antibodies to hepatitis C virus in patients who have had multiple transfusions in Sri Lanka.

Objective: To determine the prevalence of antibodies to hepatitis C virus (HCV) in patients who have had multiple transfusions in Sri Lanka.

Setting: University Medical Unit at the National Hospital, Colombo, the Cancer Institute, Maharagama, and the Lady Ridgeway Children's Hospital, Colombo.

Patients: One to 5 ml of blood for serology was collected from 200 multiply transfused patients (those who have received five or more blood transfusions).

NS 1 gene sequences from eight dengue-2 viruses and their evolutionary relationships with other dengue-2 viruses.

The nucleotide sequences of the NS 1 genes from five Thai and three Sri Lankan dengue-2 viruses were determined by sequencing the viral RNA using synthetic oligonucleotide primers. The results were shown to be similar to four published dengue-2 NS 1 sequences and the classification of these genes was compared with the one obtained for the envelope genes of the same viruses. The classification was similar and showed that the Thai isolates could be divided into two separate groups and that the Sri Lankan isolates were distinct.

Variation of the nucleotide and encoded amino acid sequences of the envelope gene from eight dengue-2 viruses.

The nucleotide sequences of the envelope genes from five Thai and three Sri Lankan dengue-2 viruses were determined by sequencing the viral RNA using synthetic oligonucleotide primers. The results were compared with the four published dengue-2 envelope sequences to obtain a classification of these viruses, which showed that the Thai isolates could be divided into two separate groups while the Sri Lankan isolates were distinct. There was no correlation between disease severity and envelope protein sequence, or between year of isolation and sequence.