The figure above is a bar chart showing selected notifiable disease reports for the United States with comparison of provisional 4-week totals through January 20, 2018, with historical data. Reports of acute hepatitis A and meningococcal disease increased with hepatitis A increasing beyond historical limits. Reports of giardiasis, acute hepatitis B, acute hepatitis C, legionellosis, measles, mumps and pertussis decreased with giardiasis and acute hepatitis B decreasing beyond historical limits.