Factors associated with case fatality of human H5N1 virus infections in Indonesia: a case series.

BACKGROUND: Indonesia has had the most human cases of highly pathogenic avian influenza A (H5N1) and one of the highest case-fatality rates worldwide. We described the factors associated with H5N1 case-fatality in Indonesia. METHODS: Between June, 2005, and February, 2008, there were 127 confirmed H5N1 infections. Investigation teams were deployed to investigate and manage each confirmed case; they obtained epidemiological and clinical data from case-investigation reports when possible and through interviews with patients, family members, and key individuals. FINDINGS: Of the 127 patients with confirmed H5N1 infections, 103 (81%) died. Median time to hospitalisation was 6 days (range 1-16). Of the 122 hospitalised patients for whom data were available, 121 (99%) had fever, 107 (88%) cough, and 103 (84%) dyspnoea on reaching hospital. However, for the first 2 days after onset, most had non-specific symptoms; only 31 had both fever and cough, and nine had fever and dyspnoea. Median time from onset to oseltamivir treatment was 7 days (range 0-21 days); treatment started within 2 days for one patient who survived, four (36.4%) of 11 receiving treatment within 2-4 days survived, six (37.5%) of 16 receiving treatment within 5-6 days survived, and ten (18.5%) of 44 receiving treatment at 7 days or later survived (p=0.03). Initiation of treatment within 2 days was associated with significantly lower mortality than was initiation at 5-6 days or later than 7 days (p<0.0001). Mortality was lower in clustered than unclustered cases (odds ratio 33.3, 95% CI 3.13-273). Treatment started at a median of 5 days (range 0-13 days) from onset in secondary cases in clusters compared with 8 days (range 4-16) for primary cases (p=0.04). INTERPRETATION: Development of better diagnostic methods and improved case management might improve identification of patients with H5N1 influenza, which could decrease mortality by allowing for earlier treatment with oseltamivir.

Three Indonesian clusters of H5N1 virus infection in 2005.

BACKGROUND: Since 2003, the widespread ongoing epizootic of avian influenza A (H5N1) among poultry and birds has resulted in human H5N1 cases in 10 countries. The first case of H5N1 virus infection in Indonesia was identified in July 2005. METHODS: We investigated three clusters of Indonesian cases with at least two ill persons hospitalized with laboratory evidence of H5N1 virus infection from June through October 2005. Epidemiologic, clinical, and virologic data on these patients were collected and analyzed. RESULTS: Severe disease occurred among all three clusters, including deaths in two clusters. Mild illness in children was documented in two clusters. The median age of the eight patients was 8.5 years (range, 1 to 38). Four patients required mechanical ventilation, and four of the eight patients (50%) died. In each cluster, patients with H5N1 virus infection were members of the same family, and most lived in the same home. In two clusters, the source of H5N1 virus infection in the index patient was not determined. Virus isolates were available for one patient in each of two clusters, and molecular sequence analyses determined that the isolates were clade 2 H5N1 viruses of avian origin. CONCLUSIONS: In 2005 in Indonesia, clusters of human infection with clade 2 H5N1 viruses included mild, severe, and fatal cases among family members.