A large outbreak of probable rotavirus in Nusa Tenggara Timur, Indonesia.

An outbreak of acute diarrheal disease was reported in Kupang, Nusa Tenggara, Indonesia, in August 2002. An investigative team carried out a retrospective historical review of records, and a case-control study involving data and specimen collections. Etiologic determination involving stool specimens was based on an enzyme-linked immunosorbent assay, with a reverse transcriptase-polymerase chain reaction performed for serotyping purposes. Two thousand six hundred probable cases were identified from hospital records during the outbreak months of June, July, August, and September 2002. Previous enteric outbreaks were recognized from the same months in the preceding years and all annual outbreak episodes following a period of prolonged, low rainfall. In contrast to previous outbreaks discerned from trend analysis, the overwhelming burden of disease fell upon the pediatric population versus the young and old in previous outbreak instances. Rotavirus was found to be the causative etiology, with serotype 1 predominating.

Tracking the re-emergence of epidemic chikungunya virus in Indonesia.

Twenty-four distinct outbreaks of probable chikungunya (CHIK) etiology were identified throughout Indonesia from September 2001 to March 2003, after a near 20-year hiatus of epidemic CHIK activity in the country. Thirteen outbreak reports were based on clinical observations alone, and 11 confirmed by serological/virological methods. Detailed epidemiological profiles of two investigated outbreaks in Bogor and Bekasi are presented. Human sera were screened using an ELISA for IgM and IgG anti-CHIK antibodies. Additionally, reverse transcriptase PCR and virus isolation were attempted for virus identification. The mean age of cases was 37 +/- 18 years in Bogor and 33 +/- 20 years in Bekasi. There was no outstanding case-clustering, although outbreak-affected households were observed to be geographically grouped within villages. The attack rates in Bogor and Bekasi were 2.8/1000 and 6.7/1000 inhabitants respectively. Both outbreaks started in the rainy season following increased Aedes aegypti and A. albopictus densities.

Transmission of epidemic dengue hemorrhagic fever in easternmost Indonesia.

In April 2001, a second suspected outbreak of dengue hemorrhagic fever in the easternmost region of Indonesia was investigated in Merauke, a town located in the southeastern corner of Papua, by the Indonesian Ministry of Health and the U.S. Naval Medical Research Unit No. 2. Principal case criteria of hemorrhagic disease provided for a study enrollment of 15 clinically acute and 37 convalescing subjects. Additionally, 32 comparable age/sex controls were selected from neighboring households. Laboratory diagnosis involved three testing methodologies: virus isolation by cell culture, a reverse transcriptase-polymerase chain reaction (RT-PCR) assay, and serologic assays. Antibody (IgM) to dengue virus was detected in 27% of the acute clinical cases, 30% of the convalescing cases, and only 3% of the matched controls. Dengue 3 was the only viral serotype detected from acute serum samples by the RT-PCR. The mean +/- SD age of the acute and convalescing cases was 7.8 +/- 5.4 years. Overall hospital records accounted for 172 suspected outbreak cases, all urban residents of Merauke with no recent travel history outside the area. The estimated outbreak-associated case fatality rate among all suspected dengue cases was 1.2%. A seven-year retrospective review of hospital records in Merauke showed negligible disease reporting involving hemorrhagic disease prior to the outbreak.