The Centers for Disease Control and Prevention is investigating hepatitis A outbreaks in multiple states among people reporting drug use and/or homelessness and their contacts, the agency said in an advisory today. California, Indiana, Kentucky, Michigan, Utah and West Virginia have reported a total of more than 2,500 infections spread through person-to-person contact since January 2017, the largest outbreak since vaccination was recommended for at-risk populations in 1996 and the first large outbreak among homeless Americans, CDC said. Health care providers should consider hepatitis A in anyone with jaundice and clinically compatible symptoms; encourage vaccination for at-risk populations or within two weeks of exposure to the virus; and report all diagnosed hepatitis A cases to their public health department, the agency said. CDC said it continues to monitor demand for the adult vaccine, which has experienced some supply constraints during the outbreak but is more readily available now.