Genetic variations and relationship among dengue virus type 3 strains isolated from patients with mild or severe form of dengue disease in Indonesia and Thailand.

Sequence analysis was conducted on structural and non-structural genes of 7 strains of dengue virus type-3 (DENV-3 virus) isolated in Indonesia and Thailand in the year 1973, 1994, and 1998 from patients with different clinical manifestations. In general, sequence similarity among isolates was greater than 93%, indicating that the mutation rate of DENV-3 circulating in this region was not more than 7% in the last 3 decades and suggesting that sequences that may responsible for viral architectures and/or biological function were strictly conserved. Mutations unique to viral strains associated with specific clinical manifestations were not found. Alignment of PrM/M and E nucleic acid sequences followed by parsimony analysis of sequences obtained in this study and published elsewhere allowed generation of phylogenetic trees, demonstrating that DENV-3 strains isolated in Indonesia in 1998 belonged to a separate cluster (subtype 2) from those isolated between 1973-1985 (subtype 1).

Enhancing knowledge and awareness of dengue during a prospective study of dengue fever.

In 1992, the Indonesian CDC implemented strategies to control and prevent dengue fever (DF) by including community involvement to reduce larva breeding sites and a mass health education program. To contribute to this effort, we incorporated an educational component into a prospective study of DF conducted at two textile factories in Bandung. This education provided: a lecture on the signs and symptoms of dengue and ways to prevent the disease, posters in the health clinic at each factory and handouts given to each volunteer with an explanation of symptoms. Upon enrollment, each participant completed a questionnaire to gather demographic information. Additionally they were given a brief (non-standardized) test (PRE-test) of their dengue knowledge, which was verbally administered by the study physicians. Five questions (15 point system) were designed to assess the participant's ability to recognize and describe aspects of dengue in lay terms. The subject material included: the symptoms of acute DF, transmission of dengue virus, and basic steps for disease prevention. The same questionnaire was re-administered 18 months later (POST-test), and the results were compared. A total of 2,340 participants completed both the PRE- and POST-tests; there were 1,373 males and 967 females, median age 36 years (range 18-59). Only 0.3% of participants scored EXCELLENT (15-14 points) on the PRE-test whereas 8.4% scored EXCELLENT on the POST-test. Fewer participants scored VERY BAD (2-0 points) on the POST-test compared to the PRE-test (1.4% vs 4.0%). The average raw scores for the PRE- and POST-tests were 7.8 and 10.1, respectively. Improvement of individual scores correlated highly with educational level. No significant correlation was identified for gender, age, factory location or a diagnosis of dengue during the study. These findings demonstrate that our prospective study enhanced knowledge and awareness of dengue in the volunteers.

A serological study of Chikungunya virus transmission in Yogyakarta, Indonesia: evidence for the first outbreak since 1982.

A study of epidemic transmission of Chikungunya virus (CHIK) was initiated in April 1999 in Yogyakarta, Indonesia. Three hundred seventeen volunteers from three kelurahans (sub-districts) were recruited. Anti-CHIK IgG antibodies were detected in 68% to 74% of cases and 28% to 32% of controls. In the kelurahan with no reported CHIK illness, 29% of cases and 28% of controls had anti-CHIK IgG antibodies. None of these cases demonstrated anti-CHIK IgM antibodies. In the two kelurahans with disease activity, anti-CHIK IgM antibodies were detected in 3% to 36% of cases, with the highest percentage from the kelurahan with recently reported cases. Ten percent of controls from Gowok had anti-CHIK IgM detected in their serum. Twelve acutely ill volunteers were later included from the kelurahan Pilahan for virus identification. Samples from two volunteers were culture- and RT-PCR-positive for CHIK. This is the first documentation of epidemic transmission of CHIK in Indonesia since 1982.