Clinical and laboratory predictors of influenza infection among individuals with influenza-like illness presenting to an urban Thai hospital over a five-year period
Fig 1
Temporal distribution of ILI cases testing positive for influenza infection (RED) and negative for influenza infection (BLUE).
Solid circles indicate months identified as experiencing influenza outbreaks (defined as months wherein > = 25% of ILI specimens tested positive for influenza infection by RT-PCR).