Antibiotic resistance poses fatal threat

Shan Juan

( China Daily)

Updated: 2016-07-26

Experts warn that excessive use of drugs designed to kill bacteria could result in millions ofdeaths every year. Shan Juan reports.

As the use of antibiotics at China's healthcare facilities comes under increasingly strictcontrol, public health experts at home and abroad are turning their attention to agriculture andcalling for enhanced management to prevent potential overuse in the sector.

Every year, 50 percent of the antibiotics employed in the world are used in China, with 52percent of them used to treat animals bred for food, according to the latest report oninternational antibiotic use, led by Jim O'Neill, former chief economist at Goldman Sachs whowas an adviser to David Cameron, the former prime minster of the United Kingdom.

The report, called the Global Review on AMR (antimicrobial resistance), warns that by 2005,antimicrobial resistance could be responsible for killing 10 million people across the worldevery year, the equivalent of one person every 3 seconds - higher than the annual globaldeath toll from cancer.

It also estimates that by 2050, AMR could result in 1 million premature deaths every year inChina.

AMR occurs when microbes evolve to become increasingly, or fully, resistant to previouslyeffective antibiotics. The term also covers antibiotic resistance, which applies to bacteria andantibiotics.

"China could suffer an enormous loss of GDP because of that," O'Neill wrote in an emailexchange with China Daily.

He added that the government recognizes the issue as one of crucial importance and hasmade efforts to curb excessive antibiotic use, particularly for medical purposes.

Statistics from the National Health and Family Planning Commission show that antibiotic usein China's hospitals has fallen by 40 percent since 2012, when the commission imposedmeasures - including stricter controls, prescription-only access and health education - to curblong-term excess use.

However, the report notes that the lack of stringent supervision in the agricultural sector mustalso be corrected.

Xiao Yonghong, a professor at the Institute of Clinical Pharmacology at Peking University anda member of the commission's rational drug use committee, echoed those concerns, sayingthat while the abuse of antibiotics has almost been eliminated at large hospitals in cities, alack of surveillance data means it's difficult to assess the scale of the problem at grassroots-level clinics.

"Antibiotic abuse in animal farming is still widespread in China," Xiao said, adding that thecountry has no maximum residue limits for antibiotics detected in animal products, such asmeat and milk.

Unscreened residue

"The antibiotic residue is not screened before animal products hit the market," Xiao said,pointing out that regulations on the correct use of antibiotics in animal feed are not enforcedstrictly enough.

Su Jiufu, a duck farmer in Pucheng county, Weinan city, in the northwestern province ofShaanxi, said he doesn't think there is a problem: "I often eat the meat and eggs of the duckson my farm."

He generally sells his produce to grocery stores in the local township. "Storekeepers havenever asked me about antibiotic use," he said.

As an experienced farmer, Su acknowledged that antibiotic use is relatively common at duckfarms because the birds are prone to diseases.

The most commonly used antibiotics are Ciprofloxacin and Jinsaiwei, which are regularlyadded to the ducks' food, he said.

"That's not only for treatment, but prevention. Otherwise ducks can easily contract viralhepatitis, duck plague and fowl cholera, which spreads quickly, causing deaths and a loss ofincome for the farmers," he added.

Zeng Xiaoxiang, who owns a chicken farm in Meizhou, Guangdong province, sells about100,000 fowls a year. She said white-feathered breeds of chickens commonly seen on marketstalls need to be given antibiotics almost every day to treat and prevent diseases such asbronchitis and enteritidis, a type of salmonella.

"The drugs, mainly antibiotics, such as penicillin and amoxycillin, and vaccines cost 150,000yuan ($22,400) every year," she said. "The doses are usually increased during winter, whenchickens are at greater risk of disease."

Resistance gene

Excessive antibiotic use has already taken a toll. In 2011, researchers detected the MCR-1resistance gene - which renders colistin, a so-called last-line antibiotic, ineffective - in 5percent of chicken and pork samples collected from markets around the country.

However, by the end of 2014, the proportion had risen to 25 percent. Late last year, a studyled by Liu Yiyun, a professor at South China Agriculture University in Guangzhou, Guangdongprovince, was published in the renowned UK medical journal Lancet Infectious Diseases. Thestudy found that the MCR-1 resistance gene had been identified in a number of samplesprovided by hospital patients in the province.

"The gene can pass around among certain types of bacteria that exist in both animals andhumans," said Huang Liuyu, director of the Institute for Disease Prevention and Control withthe People's Liberation Army.

According to Huang, excessive antibiotic residue in animal products could be transmitted tohumans via the consumption of meat, eggs and milk, increasing the possibility of increasedresistance to antibiotics.

Also, the problem may "travel" and contaminate people in other parts of the world as a resultof increasing international travel and interpersonal exchanges, he said.

Globally, antimicrobial drugs are becoming less effective and the world is not developingenough new antibiotics to replace those that are now almost redundant, according to the UKreport.

O'Neill, the leader of the UK study, emphasized the need for measures to tackle the problem. "It's a serious global challenge, and thus it needs a global solution," he said.

Contact the writer at shanjuan@chinadaily.com.cn