A loss of $3.7 million in federal funds is forcing Georgia to reduce its workforce for HIV prevention.

After an inquiry by Georgia Health News, the Department of Public Health this week acknowledged that 20 people in state health districts have been notified they will probably lose their jobs in January, and that an unspecified number of staffers at the department level have received the same notification.

The statement said the reduction in funding ‘‘will have a substantial impact on the state’s HIV prevention work.’’ The agency said it is working to soften the blow as much as possible.

“Since those notifications [of job losses] were made, the department has identified funds in an effort to lessen the impact within the districts,’’ the statement said. “We now expect to preserve some positions beyond January 15, 2012.’’

A consumer advocacy organization Thursday decried the personnel cuts, saying they will have a major effect on the state’s already overwhelmed HIV prevention staff.

HIV is the virus that causes AIDS, and Georgia is sixth in the nation in reported AIDS diagnoses.

The job cuts would continue what experts call a decade-long fraying of the public health infrastructure in Georgia.

The recently created Department of Public Health, like other state agencies, has felt the squeeze from budget cuts ordered by Gov. Nathan Deal. The new agency was established by legislation that aimed to raise Public Health’s visibility and clout.

A national report this week said Georgia and 39 other states have reduced funding for public health services from fiscal year 2009-10 to 2010-11. Georgia’s funding declined by 15.7 percent, said the report from the Trust for America’s Health and the Robert Wood Johnson Foundation.

The report said local, state and federal cuts to public health budgets and staff are starting to erode a decade’s worth of progress on emergency preparedness, a crucial public health function.

After years of tight budgets, Georgia’s public health workforce has double-digit job vacancy and turnover rates, state officials recently reported.

The commissioner of Public Health, Dr. Brenda Fitzgerald, said recently that she is concerned about the budget crunch continuing to weaken the public health safety net.

The department budget, for example, eliminated funding for a program to prevent heart attack and strokes.

The state said in its statement on the job cuts that the decrease in HIV prevention funding from the Centers for Disease Control and Prevention ‘‘is not unlike similar cuts in other states as the CDC moves to redirect some funding to specific metropolitan areas.’’

After years of a nationwide economic slump, disputes over budgeting are going on at all levels of government.

District HIV prevention workers perform community education about the disease and track HIV contacts in their areas.

AID Atlanta, an advocacy organization, Thursday called the impending personnel losses at Public Health ‘‘very unfortunate.’’

The funding cuts will affect programs for testing, counseling and intervention, said Tracy Elliott, executive director of AID Atlanta, a nonprofit that seeks to reduce HIV infections and help improve the quality of life of people living with HIV.

HIV infections are increasing in the state, especially in the metro Atlanta area, he said.

“The department is already understaffed,’’ Elliott said. “This will make it even more difficult. The people there are very dedicated, but they’re overwhelmed.’’