Figure 1From: Report of a pertussis outbreak in a low coverage booster vaccination group of otherwise healthy children in Italy Number of reported cases of pertussis disease during the outbreak. Puglia (Italy), April-May 2009. Legend: (■) Index case; (Green square symbol) Adults; (Blue square symbol) Cousin of index cas, student of middle school; (Yellow square symbol) Catechismate of index case; (Purple square symbol) Elementary school; (Red square symbol) Middle school.Back to article page