Figure 4.

ARI reports from SLP, Mexico, winter seasons of (a) 2000-2001, $\widehat{\beta }=\mathrm{0.22}$, ${\widehat{R}}_{\mathrm{0}}=\mathrm{1.57}$, outbreak detected at epidemiological week 8, and (b) 2003-2004, $\widehat{\beta }=\mathrm{0.19}$, ${\widehat{R}}_{\mathrm{0}}=\mathrm{1.37}$, outbreak detected at epidemiological week 8.