The contagious pertussis has continued spreading in the Philippines, where it has caused at least 40 deaths, after a province near the capital region reported an outbreak of the disease.

In a social media post on Wednesday night, the Cavite government posted a resolution declaring the province under a state of calamity "due to the outbreak of pertussis" after logging 36 cases and six deaths as of March 25.

Cavite province, southwest of Manila, is the fourth to declare a pertussis outbreak. Iloilo City in central Philippines, Quezon City and Pasig City in the capital region have also reported pertussis outbreaks in days.

On Wednesday, the Philippines' Department of Health (DOH) reported that 40 children have died of pertussis since the beginning of this year. It recorded 568 cases from January 1 to March 16, while the number was only 26 during the same period in 2023.

Pertussis, or whooping cough, is a highly contagious disease caused by the bacterium Bordetella pertussis. It spreads quickly from person to person, mainly through droplets produced by coughing or sneezing.

The disease can cause complications and even threaten lives, especially for babies. The best way to prevent pertussis is through immunization.

The DOH has urged parents to have their infants as young as six weeks old vaccinated.