A doctor in Papua New Guinea says easy access to medication from local markets means bugs are becoming more resistant.
The Medical Coordinator for Doctors Without Borders in PNG, Dr Marieke Broekhoff, says people sometimes buy drugs without a prescription.
She says even when people do see a doctor, a lack of laboratory testing can lead to overuse of medication, which results in drug-resistant and stronger bugs.
"When you take antibiotics, antimalarial, anti TB, any drug that is supposed to kill a bug and you don't take it for the full course and the full dose, you start creating stronger bugs because you don't kill them all. You give them a chance to get to know the drug and to get stronger."
Dr Broekhoff says she is even seeing people in the remote Highlands with infections that are proving difficult to treat.
Yesterday was World Health Day and the WHO is says antimicrobial resistance is threatening lives and increasing health costs globally.