BATON ROUGE — Whooping cough cases are on the rise in Louisiana, mirroring national trends, the Louisiana Department of Health said Friday.

According to LDH, 164 cases were reported in the first four months of 2025 alone, compared to only 153 cases recorded in all of 2024.

Louisiana's whooping cough numbers are the highest they have been in at least 35 years, LDH said.

The significant spread of whooping cough is leading to a corresponding increase in reported hospitalizations and deaths, public health officials said. Since September 2024, 40 people in Louisiana have been hospitalized with whooping cough, with 70 percent of those hospitalizations being babies younger than one year old.

Two deaths have been reported among infants hospitalized with whooping cough, the first deaths reported in the state from the illness since 2018.

Whooping cough is a highly contagious respiratory illness caused by the bacterium Bordetella pertussis, LDH said. People with whooping cough commonly have severe coughing fits, causing them to take deep breaths right after breathing, hence the "whooping" sound.

Infected people can spread the bacteria from the start of symptoms through about three weeks after coughs start, with infants being the most vulnerable.