Seven people, most of them young children, have died from whooping cough or pertussis in Papua New Guinea's Madang province.
The Secretary for Health says there's an outbreak of the contagious disease in Bogia and the dead are mostly under five years old.
Dr Clement Malau says there's no further information about how many people are infected, but patrols have gone out to deal with the outbreak.
He says it's likely those who died weren't immunised.
"In Madang province we've got I guess pertussis coverage of 39 percent. The national average is 59 percent. So it's below on national average. In Bogia it's about 16 percent, pertussis immunisation coverage."
Dr Clement Malau says getting vaccines to people in the Bogia area is difficult and often the vaccines are weakened by not being kept at the right temperature.