A pharmacist in Cangzhou Central Hospital, Hebei Province, prepares medicine for patients (XINHUA)
Du, a Beijing resident in her 60s, believes that an antibiotic is a panacea for the maladies of her now 6-year-old granddaughter Guoguo.
Du began to take care of her granddaughter since the child was merely 2 months old, for the girl's parents were busy. She is comfortable with her caretaker duties except when the girl runs high fevers. Then, the anxious grandma will feed the girl antibiotics or take her to a private child clinic nearby for intravenous infusion.
The transfusion room in the clinic is chronically full of patients suffering from symptoms like fevers and coughing.
In China, many people take antibiotics as a quick cure-all. A report recently released by researchers at the Guangzhou Institute of Geochemistry revealed that China used approximately 162,000 tons of antibiotics in 2013, accounting for half of the world's total usage.
The report, titled Comprehensive Evaluation of Antibiotics Emission and Fate in the River Basins of China: Source Analysis, Multimedia Modeling, and Linkage to Bacterial Resistance, was published this May in the U.S.-based journal Environmental Science and Technology.
About 48 percent of the antibiotics were consumed by humans, whereas the rest were fed to farm animals, the report said.
The report was based on the findings of a research team headed by Ying Guangguo, a professor with the State Key Laboratory of Organic Geochemistry under the Guangzhou Institute of Geochemistry.
The research team studied national consumption, discharge and the presence of 36 frequently detected antibiotics in water and soil.
Antibiotics are not only used in hospitals but also in livestock farms. "Some pig farms, especially those with more than 10,000 pigs, add several antibiotics to fodder and drinking water for pigs. Once, we detected dozens of antibiotics in one type of fodder," said Ying.
Their survey showed that in 2013, a total of 92,700 tons of antibiotics were consumed, an estimated 54,000 tons of which were excreted by humans and animals; and eventually 53,800 tons of those entered into the receiving environment.
The report showed that amoxicillin, a penicillin-based antibiotic often used to treat infections and stomach ulcers, was the most frequently used antibiotic by both humans and animals.
By analyzing the data collected over a 10-year period with multimedia fugacity models, the research team predicted the environmental concentrations of antibiotics in all 58 river basins of China.
They visualized the discharged quantity of antibiotics and the concentration of antibiotics in water samples collected across the country respectively in two maps. Their maps suggest that among China's rivers, the Haihe River and the Pearl River had the highest concentration of antibiotic pollution, with an average of 79.3 kg of antibiotic per square km per year, dozens of times that of rivers located in western China. Whereas in terms of total antibiotic discharge, the Dongting Lake, the Yellow River, the Huaihe River and the Yangtze River basins had the highest levels in the country.
According to the report, about half the antibiotics released into the environment ended up in water, while the other half have found their way into soil. Antibiotics in the environment can enter into the human food chain.
The amount of antibiotics entering into human body with food is trivial compared with those used in medical therapy, so antibiotic residues in human body will not cause direct harm, said Ying. Nonetheless, he said that antibiotic abuse and pollution can pose a hazard by making bacteria more resistant to antibiotics.
Not long after scientist Alexander Fleming accidentally discovered the antibiotic he later named penicillin did he realize that bacteria can develop a resistance to antibiotics whenever too little an antibiotic was used or when it was used for too short a period. Antibiotics can kill bacteria, but harmful bacteria that survive an antibiotic dose can develop a resistance to the antibiotic, making it hard to treat for that particular bacteria in the future. More than half a century ago, he cautioned not to use penicillin unless medically necessary, and if it was necessary, to use it properly.
"Bacteria resistance to quinolones, broad-spectrum antibacterial pharmaceuticals, is quite commonplace," said Xu Jiangping, a professor with Guangzhou-based Southern Medical University.
He said that now the first generation of quinolones is no longer able to treat diarrhea caused by a bacterial infection, and their effect in treating infections in the respiratory and urinary systems is gradually diminishing, which is a sign of the bacteria's resistance to antibiotics.
According to Guangzhou-based Southern Weekend, in 2013, eight Chinese and American scientists found 149 unique resistance genes in the manure from three large Chinese pig farms. Their findings were published in the U.S.-based journal Proceedings of the National Academy of Sciences.
The research team led by Ying also compared the environmental concentration and antibiotics usage data with bacterial resistance rates in hospitals and aquatic environments, and found them to be correlated.
Collecting and analyzing
Because of a dearth of existing information on discharge and the antibiotics' presence in the environment, Ying's team painstakingly collected their own data. The team, initially staffed by Ying and his students and later joined by several more researchers and students, started gathering data nationwide in 2006.
In the past decade, team members have traversed major rivers and lakes to collect water samples. Because of seasonal and annual variation in water volume and the pollution concentration of a single river, multiple samples were taken from every river at various times, Ying said.
Data collection is a costly effort. To collect water samples, they rented boats, and to process and store samples, they often leased laboratories and bought refrigerators.
To learn about the presence of antibiotics in fish, researchers had to catch fish or buy them from local fishermen.
The research team also gathered data from urban and rural waste water treatment plants and livestock farms. As the plant and farms were reluctant to provide data, researchers had to creatively obtain such samples.
Researchers also bought sales data from 237 large pharmaceutical companies producing antibiotics.
In addition to collecting data, researchers also built a mathematical model to predict the environmental concentration of antibiotics. The task was challenging because waste water was treated to different degrees across regions, while antibiotics, with various physical and chemical properties, also decompose differently in the environment, Ying said.
Antibiotics can save lives, yet their misuse can cause grave consequences.
Xiao Yonghong, a professor with the First Affiliated Hospital of Zhejiang University, said that bacteria's resistance to antibiotics is a pressing global public health issue.
Citing studies conducted in the UK, he said if the situation cannot be improved, by 2050, China will lose 1 million people to infection caused by drug-resistant bacteria.
A policy report released by the Infectious Disease Society of America in April 2013 expressed serious concern over the growing ability of bacteria to develop resistance to antibiotics and lack of new antibiotics. The report said that since 2009, only two new antibiotics had been approved in the United States.
In China, the use of antibiotics in humans is managed by the public health authority, whereas that in livestock is managed by the agricultural authority.
China's public health authority has tightened control on the use of antibiotics in humans in recent years.
In 2005, the health authority set up a nationwide anti-bacterial surveillance system and an antimicrobial resistance surveillance system to monitor the use of antibiotics and drug-resistance of bacteria in the hopes of illuminating policy making in this regard.
In 2012, the health authority issued a circular on managing the clinical use of antibiotics, which went into force on August 1 of the same year. Doctors violating the rules may receive punishment such as suspension or revocation of license and even criminal punishment.
Progress has been made. In February, the National Health and Family Planning Commission (NHFPC) announced that the antibiotics usage for inpatients dropped by 41 percent in 2014, and that for outpatients has dropped to 10 percent, reported the Beijing-based Global Times.
The agricultural authority has also published several lists of banned agricultural antibiotics.
In addition to regulating doctors' prescriptions of antibiotics, the public should also be educated about the proper usage of antibiotics.
Li Zhongshi, a medical expert with the NHFPC, said that the overuse of antibiotics is caused by both the general public's misconception about the effectiveness of antibiotics and doctors' misdiagnosis or even profit-seeking behaviors.
Li Yingtao, a pharmacist with the Pharmacy Department of Peking Union Medical College Hospital, said that antibiotics are not effective for upper respiratory infection, fevers, coughs or sore throats caused by viral infections. She suggested parents follow doctors' advice, and even if antibiotics are necessary, they should first be administered orally, then through muscular injection and at last through intravenous infusion.
Copyedited by Kylee McIntyre
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