Throughout 2024, Indiana dealt with the usual wave of respiratory viruses (flu, COVID-19, and RSV) alongside a sharp rise in norovirus, a national surge in whooping cough, scattered measles cases, and seasonal mosquito-borne illness. Here’s a breakdown of what circulated, how severe it was, and what you can do to protect yourself.
Respiratory Viruses: Flu, COVID-19, and RSV
The big three respiratory viruses followed their typical seasonal pattern in Indiana, peaking during the colder months. Influenza, COVID-19, and RSV all co-circulated during the fall and winter of 2024, creating what health officials sometimes call a “tripledemic” effect on hospitals and urgent care clinics. If you or someone around you came down with fever, cough, body aches, and fatigue, one of these three was the most likely culprit.
Flu and COVID-19 can look nearly identical in the first few days. Both cause fever, sore throat, congestion, and muscle pain. RSV tends to hit harder in young children and older adults, often showing up as wheezing and difficulty breathing. Rapid combination tests that check for all three at once became widely available in pharmacies and clinics throughout the year.
Vaccination coverage in Indiana remained below the national average. Only about 39.5% of Indiana adults reported receiving a seasonal flu shot in 2024, ranking the state 31st nationally. That leaves a large portion of the population relying on natural immunity alone heading into each respiratory season.
Norovirus Surged Statewide
Stomach bugs hit Indiana harder than usual. The state saw a notable increase in norovirus activity during the 2024-25 season, and it wasn’t just a local phenomenon. Among the 14 states that participate in the CDC’s NoroSTAT reporting system, norovirus cases nearly doubled between August 2024 and January 2025 compared to the same window the previous season.
Norovirus spreads fast in close quarters: schools, daycares, nursing homes, cruise ships, and restaurants. Symptoms come on suddenly, usually 12 to 48 hours after exposure, and include intense nausea, vomiting, diarrhea, and stomach cramps. Most people recover within one to three days, but dehydration is a real risk for young children and older adults. The virus is notoriously tough to kill on surfaces. Alcohol-based hand sanitizers don’t work well against it, so thorough handwashing with soap and water is the most reliable defense.
Whooping Cough Made a Comeback
Indiana recorded 468 cases of pertussis (whooping cough) in 2024, translating to a rate of about 6.85 cases per 100,000 residents. That’s a significant jump from recent years and part of a broader national resurgence. Whooping cough tends to cycle, with larger outbreaks every few years, but declining vaccination rates have amplified the pattern.
In adults and teens, whooping cough often starts like a mild cold before developing into prolonged coughing fits that can last for weeks. The “whoop” sound, a gasping inhale after a coughing spell, is more common in children. For infants who haven’t completed their vaccine series, pertussis can be dangerous, sometimes requiring hospitalization. If you’ve had a persistent cough lasting more than two weeks, especially one that worsens at night or triggers vomiting, it’s worth getting tested.
Measles Cases Appeared
Indiana was among 32 U.S. jurisdictions that reported measles cases in 2024. The state confirmed 1 case during the year, a small number compared to hotspots like Illinois (67 cases) or Minnesota (65 cases), but notable because measles had been effectively eliminated in the U.S. for years. Nationally, 285 measles cases were confirmed across 2024, with 69% of those linked to 16 distinct outbreaks.
Measles is one of the most contagious viruses known. It lingers in the air for up to two hours after an infected person leaves a room. Symptoms include high fever, cough, runny nose, red eyes, and a distinctive rash that spreads from the face downward. Two doses of the MMR vaccine provide about 97% protection. The 2025 data already shows Indiana’s count rising to 10 cases, suggesting the trend is accelerating rather than fading.
West Nile Virus During Mosquito Season
During the warmer months, West Nile virus was the primary mosquito-borne concern. By mid-August 2024, St. Joseph County alone had identified 38 positive mosquito pools, and at least 3 human cases had been documented across other Indiana counties by that point in the season. Local health departments issued public advisories urging residents to take precautions.
Most people infected with West Nile never develop symptoms. About 1 in 5 gets a fever with body aches and headache. Roughly 1 in 150 develops a severe neurological illness. The practical steps are straightforward: use EPA-registered insect repellent, wear long sleeves during dawn and dusk when mosquitoes are most active, and eliminate standing water around your home where mosquitoes breed. Window screens without holes also make a meaningful difference.
How to Protect Yourself
With multiple illnesses circulating simultaneously, the basics matter more than any single intervention. Wash your hands frequently with soap and water, especially before eating and after using the restroom. This is your best tool against norovirus in particular, since hand sanitizer falls short against it. For respiratory viruses, staying home when you’re symptomatic and improving ventilation in indoor spaces reduces transmission to the people around you.
Updated vaccines for flu, COVID-19, and RSV (for eligible groups) were all available throughout 2024. Given that fewer than 4 in 10 Indiana adults got a flu shot last year, there’s a large gap between what’s available and what’s being used. If you’re behind on routine vaccinations, the pertussis booster (included in the Tdap shot) and MMR vaccine are worth checking on, particularly if you’re around infants or planning travel.