LOS ANGELES (AP) — Public health officials are warning that the coronavirus poses new risks to parts of the Midwest and South. That word comes as enhanced federal aid that helped avert financial ruin for millions of unemployed Americans is set to expire. If it runs out, many of the jobless will have to rely on threadbare safety nets offered by individual states. Early in the pandemic, the federal government added $600 to weekly unemployment checks. That increase ends this week. With Congress still haggling over next steps, most states will not be able to offer nearly as much while they wrestle with diminishing unemployment trust funds.