Figure 4.

Probabilities of measles cases (A) occurrence, (B) ascertainment, and time–dependant effective reproduction number of (C) classic measles, (D) modified measles, Japan, 14 March–10 May 2018 (n=99)

^a Aged < 20.

The average number of secondary transmission were calculated from the dominant eigenvalue of age-dependent next-generation matrix.

Horizontal grey dashed line indicates the reproduction number at 1.0 for reference, below which the epidemic follows a declining trend.

Day 1 is 14 March 2018, the first day of the outbreak.