The World Health Organization (WHO) says one of every 10 medicines sold in developing countries is either fake or of poor quality.
In a report this week, WHO officials said fake or substandard drugs are to blame for tens of thousands of children dying. These deaths could be easily prevented, officials said.
Trying to understand the problem, experts looked at 100 studies, all of which were completed between 2007 and 2016. The studies examined use of more than 48,000 drugs.
The experts found that 10.5 percent of the drugs were not what they appeared to be.
Drugs for treating malaria and bacterial infections were responsible for nearly 65 percent of the fake medicines.
A statement from WHO chief Tedros Adhanom Ghebreyesus was released with the report. He asked people to imagine a mother who uses her money for medicine instead of food and then sees her child die because the medicine was of poor quality or falsified.
"This is unacceptable," he said.
Poor countries spend about $300 billion a year for medications. WHO officials said that means the fake drug industry is worth of an estimated $30 billion.
The London School of Hygiene and Tropical Medicine estimates that 116,000 people die each year from fake anti-malaria medication in African countries south of the Sahara Desert.
In 2013, WHO officials launched a worldwide system for following fake and compromised drugs. It has received reports about nearly 1,500 problematic medicines, including drugs for the heart, diabetes, fertility, mental health and cancer. WHO also noted problems with fake vaccines for diseases such as yellow fever.
WHO believes the examples of fake medicine it found are only "a small fraction" of the real problem because many fake drugs are not reported.
Officials credited the system with saving the lives of more than 20 children in Paraguay. Tests showed the children had swallowed a contaminated drug. The drug was in a cough medicine that had killed 60 people in Pakistan just a few months earlier.
I'm Susan Shand.
Susan Shand adapted this story for Learning English from an Associated Press story. George Grow was the editor.