Marion County has seen a tenfold increase in the typical number of hepatitis A cases this year, with a marked recent rise, county health officials said Thursday.

Most years, Marion County has about two to four cases of the infectious disease. This year, 57 people have come down with the virus that affects the liver, according to the Marion County Public Health Department.

Marion County is not alone. Over the past year and a half year, multiple states and counties have seen their hepatitis A rates soar in the wake of an outbreak that has mostly affected homeless people and drug users and their close contacts, according to the Centers for Disease Control and Prevention.

Indiana has had more than 770 cases of hepatitis A associated with this outbreak and two deaths. Kentucky has seen more than 3,000 cases and 19 deaths.

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In Indiana, Wayne County, whose county seat is Richmond, has been particularly hard hit with 137 cases, according to the Indiana State Department of Health.

While hepatitis A is often transmitted by eating or drinking something that has been infected with the virus, in this instance common sources of food or drink do not appear to be spreading the disease, according to the CDC.

Typically the virus is transmitted by the fecal-oral route or by close contact, including sex.

Because the virus affects the liver, symptoms include jaundice, darkened urine and or clay colored stools, nausea and or vomiting, low appetite, and fatigue. In most instances, the virus runs its course in a few weeks, though it can be life-threatening for some.

Vaccination can prevent against the virus and a vaccine is available at doctor's offices, pharmacies, and health department's offices. The vaccine can prevent infection if it is administered within two weeks of exposure.

Thorough hand washing also helps prevent the spread of the virus.

At this point, the CDC sees no need for everyone living or traveling to states that have been affected to get the vaccine. They do recommend that people who use injection or non-injection drugs and the homeless be vaccinated as well as those who have regular close contact with them.

The agency recommends in general that those who engage in risky behavior, such as drug use, be vaccinated, along with those who have chronic liver disease.

Call IndyStar staff reporter Shari Rudavsky at 317-444-6354. Follow her on Facebook or on Twiter.