McDonald’s recently confirmed that all of the chicken it serves in the U.S. now comes from birds raised without antibiotics that are medically important to humans, but what about all the beef and pork menu items — not to mention the cheese and other dairy items? And what about McDonald’s eateries in other countries?

A newly launched email campaign is calling on people from around the world to pressure McDonald’s CEO Steve Easterbrook to address the antibiotics issue with regard to all meats, in all countries.

Overuse of antibiotics has been linked to the development of drug-resistant bacteria that make it more difficult to treat infections and can render existing treatments useless. While a significant number of physicians are still over-prescribing antibiotics in cases where they aren’t necessary, the overwhelming majority of antibiotics (at least 70%) sold in the U.S. are going into livestock animals.

The drugs are generally not given to treat any diseases, but are often administered under the vague umbrella category of “disease prevention.” However, research has shown that this low-dose, prophylactic approach to antibiotics use only serves to encourage drug resistance.

In the U.S. alone, food-borne pathogens account for upwards of 1-in-4 of the more than 2 million drug-resistant infections that hit Americans each year.

Antibiotics use in livestock is lower in Europe, but a 2015 estimate from researchers at the U.S. National Academy of Sciences predicts that global consumption of antibiotics in agriculture will increase by 67% by 2030.

Leading that charge will be the BRICS countries (Brazil, Russia, India, China, South Africa) that are emerging as world financial powers. The increased demand for poultry, beef, and pork in these and other developing regions could result in a 99% increase in antibiotic use in these countries over the next fifteen years, according to a recent report commissioned by UK Prime Minister David Cameron.

In an effort to pressure McDonald’s into doing its part as the world’s largest and most recognizable fast food brand, UK-based charity ShareAction has launched a letter-writing campaign asking Easterbrook to “make a meaningful commitment to phase out the routine prophylactic use of medically important antibiotics across the whole of your global livestock supply chains.”

Continues the letter, “I want to feel confident that the food I purchase has been responsibly sourced, and isn’t contributing to this rising threat to public health.”

Specifically, the email campaign calls for the fast food giant to commit to a timeline to fully phase out the non-medical use of antibiotics in McDonald’s global supply chain.

In a response to Reuters, McDonald’s would only point to earlier comments it has made about it being too premature to provide a timeline on getting to the drug-free point in non-chicken animals.

Chickens only require weeks to reach sufficient size, meaning it’s easier to make a large scale change in how the birds are raised. Cows and pigs take significantly longer to reach maturity and are sometimes moved around from owner to owner several times during the course of their lives.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.