Some pharmacists in Africa say that they are compelled to buy from the cheapest but not necessarily the safest suppliers to compete with illegal street traders.

As much as one in 10 drugs sold in developing countries are counterfeited, and likely responsible for deaths of ten thousands of African children given ineffective treatments for diseases like malaria, The World Health Organization has stated.

With pharmaceutical sales in such countries running at nearly $300 billion a year, this implies that trade in fake medicines is a $30 billion business.

In the U.N. health agency’s first attempt to assess the problem, experts reviewed 100 studies involving more than 48,000 medicines. Drugs for treating malaria and bacterial infections accounted for nearly 65% of fake medicines.

“Imagine a mother who gives up food or other basic needs to pay for her child’s treatment, unaware that the medicines are substandard or falsified, and then that treatment causes her child to die,” WHO chief Tedros Adhanom Ghebreyesus said in a statement. “This is unacceptable.”

Counterfeit medicine may be contaminated or contain the wrong, or no active ingredient. They could have the right active ingredient, but at the wrong dose, according to the FDA. 

Since 2013, the WHO has recevied 1,500 reports of fake and low-quality products, with antimalarials and antibiotics the most commonly reported categories. However, the problem extends to everything from cancer drugs to contraceptive pills, Reuters reports.