As Americans prepare for the Thanksgiving holiday this week, respiratory viruses are ramping up, creating hazardous infectious conditions for mass travel and multi-generational family gatherings.

Flu is on the rise in most of the country, with six Southern states and the District of Columbia already seeing high levels of influenza-like illnesses (ILI) activity. Louisiana has reached "very high" ILI activity, the Centers for Disease Control and Prevention reported in the latest flu surveillance update. The percentage of flu tests coming back positive is also increasing nationwide, with only one region, the Mid-Atlantic region, showing a stable week-over-week positivity rate. However, the CDC noted that its rate overall is trending upward.

This year's flu season is again starting early; the current flu activity levels are about four to six weeks ahead of when we usually see them. And with activity already at highs in many states, there's a good chance that we'll again see extremely high levels in some places—moving from red to the dreaded deep purple on CDC's scale, which we saw last year.

But this year's season is not quite as early as last year's remarkable season, which kicked off in the beginning of October. This could signal that flu is shifting back toward its pre-pandemic cycle.

As for the pandemic virus, which continues to circulate, the US remains in a relative lull. But the latest CDC data shows COVID activity is picking up in two regions: region 5 (Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin) and region 7 (Iowa, Kansas, Missouri, and Nebraska). The two regions are seeing sharp inclines in the number of emergency department patients with diagnosed COVID-19. The country's other eight regions are seeing plateauing or slightly declining numbers.

Overall, the country is seeing slight upticks in COVID-19 metrics relative to the previous week: test positivity (percent increase of 0.1 percent), emergency department visits (7.1 percent), hospital admissions (8.6 percent), and deaths (9.1 percent).

Meanwhile, the remaining respiratory viral menace, RSV, is at high transmission levels nationally. States in the South have the highest activity levels, but transmission is heading up in all regions.

For those planning to travel or attend gatherings for the holiday, health officials urge the standard precautions to prevent spreading or catching viruses, including being up to date on seasonal flu and COVID-19 vaccines. For older adults, there's also an RSV vaccine.

In an interview on Monday, CDC Director Mandy Cohen summed it up with: "Wash your hands. Stay home if you're sick. Masks do work, so wearing a mask if you're around a lot of other people. And don't forget ventilation—open a window," she said.

Lastly, on Monday, the CDC announced that every US household is eligible to order four additional free at-home COVID-19 tests (here).