Fig. 1.
Scatter plot of cycle threshold (Ct) in a real-time reverse transcription PCR for measles virus RNA in samples of PBMC (a), throat swab (b) and urine (c), Yamagata Prefecture, Japan, March–April 2017. Measles cases are classified into three groups: modified measles (M-Me), a prodromal stage of typical measles at the point of sample collection (P-Me) and typical measles (T-Me). Black circles represent super-spreaders. Bars represent median Ct. Asterisks denote statistical significance (P < 0.05).