Antibiotic resistance is on the rise in China, fueled by over-prescription of the microbe-killing drugs, their use in livestock, and the pollution of the country's waterways, experts have warned.
China consumed an estimated 162,000 tons of antibiotics in 2013 alone, accounting for half of the global total, according to a recent report from researchers at the Guangzhou Institute of Geochemistry.
Based on 10 years of field research into antibiotics in China's major rivers, the report found that human consumption accounted for about 48 percent, while the rest were fed to domestic animals to prevent disease.
According to some estimates, China sees one million deaths a year from antibiotic-resistant infections, which occur when the microbes adapt to the antibiotics when there is not enough dosage to kill them.
The report in the May edition of the U.S. journal Environmental Science and Technology focused on 36 commonly detected antibiotics, 92,700 tons of which were consumed in 2013, and some 53,800 tons of which ended up in China's rivers after excretion by animals and humans.
One of the worst-hit bodies of water was the iconic Dongting Lake in central China, where researchers found some 3,440 tons of the substances.
The Yellow River, Huaihe River, and Yangtze River downstream basins all absorbed more than 3,000 tons of antibiotics in 2013.
The most commonly used antibiotic in China in both humans and animals was amoxicillin, with florfenicol, lincomycin, penicillin, and norfloxacin also commonly found, the report said.
Drugs overprescribed
The massive amount of antibiotics found in China's waterways is likely linked to overprescription in China, where they account for around half of all drugs prescribed by hospitals, compared with just 10 percent in hospitals in developed countries.
However, the figures for developed countries didn't include antibiotic prescriptions in primary health-care facilities, and many Chinese go to hospitals to seek primary care.
U.S.-based primary care physician Zhang Youmei said the overuse of antibiotics is already giving rise to multi-drug resistant "superbugs" worldwide.
But he said there are psychological reasons behind overprescription, particularly in China.
"Respiratory tract infections are self-limiting, and they often get better by themselves in a few weeks," Zhang said. "But patients in mainland China who get a cold or flu demand antibiotics from their doctor."
"A lot of doctors in China satisfy those demands, and that is something that needs to change."
U.S.-based doctor Wan Yanhai, who fled the country after he blew the whistle on the spread of the HIV/AIDS epidemic through rural blood-selling schemes in poverty-stricken Henan province, agreed.
"Patients in China have a whole set of superstitions around prescriptions, and they insist on having a prescription whenever they see the doctor," Wan said.
"Otherwise, they don't see the point of going to the doctor."
Economic incentives
Wan said doctors are often paid commissions for prescribing drugs, so every prescription boosts their income.
"This is one of the reasons behind the misuse of antibiotics," he said. "Doctors will satisfy unreasonable demands from patients in an unprincipled manner, because they have an economic incentive to do so."
"If the patient asks for antibiotics, they will prescribe them."
He said the government is fully aware of the problem, and has previously tried to step up controls over antibiotics used in poultry farms, and also to break the link between doctors' incomes and pharmaceutical companies, but to no avail.
"Corruption is pretty serious in all of China's government departments, and there are close ties between government and business," Wan said.
"This leads to a situation where we have laws, but they're not obeyed."
According to report lead author Ying Guangguo, a professor in environmental chemistry and ecotoxicology, the same antibiotics that end up in rivers and fields through wastewater then return to human bodies through aquatic and agricultural products, forming a "vicious circle."
"We covered the length of every major river in the country, taking water samples, carrying out monitoring and collecting pollution data," Ying was quoted as saying by the Guangzhou-based Southern Weekend newspaper.
He said that livestock farmers all denied regular use of antibiotics, when questioned by the research team.
But tests found a range of antibiotics in the fodder and manure at nearly all large farms, the paper said in an article translated by the environmental website chinadialogue.net.
Children at risk
In April, a study by Shanghai's prestigious Fudan University found that Chinese children are frequently exposed to antibiotics found in their environment and food, state media reported.
In that study, researchers tested 1,064 children aged eight to 11 in Shanghai and neighboring Jiangsu and Zhejiang provinces for 18 antibiotics, and found them present in the urine samples of 60 percent of the children, Xinhua news agency reported.
In 2014, the World Health Organization (WHO), identified antibiotic resistance as a major threat to public health, leading to longer periods of sickness and higher mortality rates from disease.
Meanwhile, the Global Times newspaper quoted pharmaceutical expert Zhou Xiaoqing as saying that 300,000 children in China have become deaf through overuse of antibiotics.
But the paper said antibiotics aren't included in tests of drinking water quality, despite widespread evidence of environmental contamination.
In February, China's National Health and Family Planning Commission rolled out management guidelines for antibiotics to all local medical institutions and private clinics, to be implemented by the end of the year, it said.
Reported by Gao Shan for RFA's Mandarin Service. Translated and written in English by Luisetta Mudie.