As kids across the Tennessee Valley head back to school this week, health officials have a warning for parents. If you're child is showing any symptoms of the flu, keep them at home.

Tennessee and Georgia are among 43 states experiencing widespread flu activity. As of last week, Chattanooga ranked number one in the country for flu activity, according to a Walgreens flu index. 

With the high number of local cases, health officials say getting medicine to treat your symptoms may be hard to find. 

Many local pharmacies are now struggling to keep the drug, Tamiflu in stock. Local Walgreens pharmacists say right now, they're in good shape with weekly shipments holding steady but at this pace, it's unclear how long the prescription will hold out.

"This particular increase has been unusual it's hit hard and fast, just in the last week almost every prescription was for Tamiflu," said Pharmacist Curt Coley.

Coley tells Channel 3 Eyewitness news he is seeing prescriptions for Tamiflu by the hundreds. While his pharmacy has about 10 days worth of supply left, Coley says due to the high volume of cases some local pharmacies are either running low or completely out.

"We've seen quite an increase in the flu cases reported recently in the past two to three weeks," said Coley. "It's outstripped the demand in many places for Tamiflu."

According to weekly records from Erlanger Hospital, doctors started seeing positive flu cases in the emergency room as early as October. In the month of November, the number of adults and children treated jumped from 8 to 188, and records show in the first 3 weeks of December, flu cases grew from 133 a week to 212. 

Last week Erlanger saw 134 positive cases. Health officials say that slight decrease is most likely attributed to kids being home for the holidays. Doctors say they're expecting to see a "back to school" spike in the coming weeks. 

The number of cases are just as high at Parkridge Medical Center where doctors have seen 992 cases since October first.

Doctor Tom Voychehovski with Hamilton Pediatrics says he is diagnosing about 10 - 20 children with the flu each week. His important message for parents -'Don't send your child back to school unless they're completely well.

"No to going back to school, wait another 2 to 3 days until the fever and cough are gone and they're ready to learn," said Dr Voychehovski.

Doctors say the flu can be fatal if left untreated especially for at-risk groups like children under the age of 2, adults above the age of 65, pregnant women and anyone with a pre-existing medical condition like asthma or heart disease.

"Tamilflu doesn't work 48 hours after a fever starts so you have to do it right away, you have to start medication right away," said Dr. Voychehovski.

Doctors anticipate the flu season lasting until late March. Health Experts say the best way to stay healthy is to wash your hands, stay away from those who are sick, eat healthy, and get the flu shot. 

Even though this year's shot does not cover all of the active strands, doctors say it will lessen flu symptoms. 

Health Officials say this year's shot will also protect you from the H1N1 Swine Flu Virus. If you have any flu-like symptoms, you should seek medical help immediately.