Health Alert: South Carolina Doctors Warn of Spike in ‘100-Day Cough’ Cases Across These Counties

The South Carolina Department of Public Health (DPH) has issued new advisories this week as the state faces one of its most complex respiratory viral seasons in years.

While hospitals in the Upstate are currently managing a highly publicized Measles outbreak, doctors in the Midlands and Lowcountry are urging families not to ignore a different threat: a sharp rise in Pertussis (Whooping Cough).

Known as the “100-Day Cough,” this bacterial infection is currently surging in counties where vaccination rates have lagged, creating a “double whammy” for parents trying to navigate sick symptoms in January.

The Hotspots: Where is it Spreading?

Health officials are currently tracking two distinct “danger zones” in the state:

• The Upstate (Spartanburg & Greenville Counties): This region is the epicenter of the 2026 Measles outbreak, but urgent care centers are also reporting high rates of Pertussis. Doctors warn that the early symptoms (cough, runny nose) are identical, leading to dangerous confusion.
• The Lowcountry (Charleston & Beaufort): Without the measles focus, the primary threat here is Pertussis. Schools in Mount Pleasant and Hilton Head have reported increased absenteeism due to students with lingering, violent coughs.
• The Midlands (Lexington County): A cluster of “100-Day Cough” cases has been identified in the suburbs west of Columbia, specifically affecting middle school-aged children.

Is it Measles, Flu, or the ‘100-Day Cough’?

Because the Upstate is dealing with Measles (which starts with a cough), diagnosis is trickier than usual. Here is how to distinguish the “100-Day Cough” from other threats:

• The Cough Type: Pertussis causes violent, rapid coughing fits that may end with a “whoop” sound or vomiting. Measles typically includes a cough plus a high fever and watery red eyes (conjunctivitis) before the rash appears.
• Duration: The flu or measles acute phase lasts about a week. Pertussis is the “marathon” illness—it can plague a patient for 10 to 12 weeks.
• Key Sign: With Pertussis, you often feel fine between coughing fits. With Measles or Flu, you feel incredibly sick, feverish, and lethargic constantly.

Warning for Parents: If you live in Spartanburg or Greenville, do not guess. If your child has a fever and cough, seek medical attention immediately due to the active Measles spread.

Why is This Happening Now?

South Carolina health experts point to “immunity gaps” as the primary driver.

• Waning Protection: The Tdap vaccine (for Pertussis) fades after 10 years.
• The “Outbreak Fatigue”: With so much news focused on the Measles surge in the Upstate, many adults in other parts of the state have delayed getting their flu or Tdap boosters, leaving the door open for the “100-Day Cough.”

The Action Plan: What to Do Today

1. Check Your Records: If it has been more than 10 years since your last Tdap shot, you are vulnerable. Pharmacies like CVS, Walgreens, and Publix across the state have stock.
2. The “Vomit” Test: If you or your child coughs so hard that it causes gagging or vomiting, it is likely Pertussis. Ask your doctor for a PCR test, not just a flu swab.
3. Cocoon the Vulnerable: If you have a newborn (too young for vaccines), ensure everyone who visits them is boosted. This is critical as infant hospitalizations are rising in the Charleston area.

Stay safe, South Carolina. Share this alert with neighbors in the Upstate and Low country to help stop the spread.