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 13, 2018, with historical data. Reports of acute hepatitis A increased beyond historical limits. Reports of giardiasis, acute hepatitis B, acute hepatitis C, legionellosis, measles, meningococcal disease, mumps and pertussis decreased with giardiasis and acute hepatitis B decreasing beyond historical limits.