Bird flu has been found in a backyard poultry flock in northeastern Indiana, and it's the first time the specific strain in question has been detected in the central U.S., animal health officials said Monday.

The H5N8 virus found in Whitley County is different from the H5N2 virus that has led to the loss of more than 30 million chickens, turkeys and other birds since March in 13 states, including Minnesota and Wisconsin, the U.S. Department of Agriculture said.

Some birds in the Whitley County flock of 77 ducks, geese, chickens, turkeys and other species have died, the agency said. The remaining birds were removed, the Indiana State Board of Animal Health said.

The board said it was checking with nearby poultry owners to see if the disease has spread. The board said it is coordinating with the USDA, the Indiana State Poultry Association and the Indiana Animal Disease Diagnostic Laboratory in responding to the disease.

Indiana is a leading poultry-producing state, nationally ranked first in the production of ducks and fourth in turkeys.

The board encourages backyard poultry owners to watch for signs of and report illnesses and deaths to the U.S. Department of Agriculture. Signs include sudden death, lack of energy or appetite, decreased and misshapen egg production; nasal discharge, coughing, sneezing and diarrhea.

Bird flu doesn't affect the safety of eating eggs or and poses little risk to humans. No human infections with the virus have been detected, the USDA said.

Bird flu can be carried by free-flying waterfowl such as ducks, geese and shorebirds. The occurrence in Whitley County west of Fort Wayne is the first time the H5N8 strain has been detected in the Mississippi flyway for migrating birds over the central U.S. The H5N8 strain previously had only been confirmed in the Pacific flyway after being detected in Oregon and Washington.