Influenza in refugees on the Thailand-Myanmar border, May-October 2009.

We describe the epidemiology of influenza virus infections in refugees in a camp in rural Southeast Asia during May-October 2009, the first 6 months after identification of pandemic (H1N1) 2009 in Thailand. Influenza A viruses were detected in 20% of patients who had influenza-like illness and in 23% of those who had clinical pneumonia. Seasonal influenza A (H1N1) was the predominant virus circulating during weeks 26-33 (June 25-August 29) and was subsequently replaced by the pandemic strain. A review of passive surveillance for acute respiratory infection did not show an increase in acute respiratory tract infection incidence associated with the arrival of pandemic (H1N1) 2009 in the camp.

A prospective evaluation of diagnostic methodologies for the acute diagnosis of dengue virus infection on the Thailand-Myanmar border.

Clinically useful diagnostic tests of dengue virus infection are lacking. We prospectively evaluated the performance of real-time reverse transcriptase (rRT)-PCR, NS-1 antigen and IgM antibody tests to confirm dengue virus infection in acute blood specimens from 162 patients presenting with undifferentiated febrile illness compatible with dengue infection. rRT-PCR was the most sensitive test (89%) and potentially could be used as a single test for confirmation of dengue infection. NS-1 antigen and IgM antibody were not sufficiently sensitive to be used as a single confirmatory test with sensitivities of 54% and 17% respectively. The specificities of rRT-PCR, NS-1 antigen and IgM antibody tests were 96%, 100% and 88% respectively. Combining NS-1 and rRT-PCR or the combination of all three tests resulted in the highest sensitivity (93%) but specificities dropped to 96% and 83% respectively. We conclude that at least the combination of two tests, either agent detection (rRT-PCR) or antigen detection (NS-1) plus IgM antibody detection should be used for laboratory confirmation of dengue infection.