The Ministry of Health and Family Welfare issued a notification on July 19, 2019, prohibiting the manufacture, sale, and distribution of the drug colistin and its formulations for food-producing animals, poultry, aqua farming and animal feed supplements because such use is likely to involve risk to human beings. That means the drug also cannot be used as a veterinary medicine for farm animals. The ban is announced in a bid to preserve the drug’s efficacy in humans. The ban was imposed following a case in the Bombay High Court in which evidence gathered by the Bureau of Investigative Journalism about colistin use in Indian farming was used by a lawyer to call for a ban on antibiotics for livestock being sold over the country.
Colistin
Colistin is a valuable, ‘last-resort’ antibiotic that saves lives in critical care units. Colistin, also known as polymyxin E, is an antibiotic produced by certain strains of the bacteria Paenibacillus polymyxa. It is effective against most Gram-negative bacilli. It is a decades-old drug that fell out of favour in human medicine due to its kidney toxicity. According to WHO, colistin is a ‘reserve’ antibiotic used only in the most severe circumstances, when all other alternatives have failed. Colistin is also listed as a highest priority critically important antibiotic (HPCIA) in the WHO’s list of critically important antimicrobials for human medicine. But it is allowed to be used for non-therapeutic purposes in animals. This includes its use for growth promotion, e.g., fattening of broiler poultry in less time and with less feed, as well as for preventing disease in healthy animals. Being an HPCIA implies that the drug is the sole or one of the limited available therapies to treat serious bacterial infections in people. When colistin fails, doctors are left with the limited options of using fosfomycin that costs ` 24,000 per day. This is very expensive and hence would be unaffordable to many patients. Colistin resistance would lead to loss of lives.
The discovery of a colistin-resistant gene that can pass between bacteria, conferring resistance to bugs never exposed to the drug, sent shock waves through the medical world in 2015. Scientists believe that the gene originated in bacteria in Chinese livestock, but it has since been found across five continents. Antimicrobial resistance has been a serious cause of concern for some time now.
Use of Colistin
There is a strong and growing global push to restrict the use of colistin in food-animal production. Many countries in the world have banned colistin for animal use. In 2016, the drug was banned in China when mcr-1 gene was detected in food samples. This gene confers resistance to colistin. However, contrary to the practice in its own country, China exported nearly 100 metric tonnes of colistin-premixed animal feed, supplements, and additives in 2015 and 2016 to India. Other countries like Japan, Malaysia, and Australia do not permit colistin use in food-producing animals.
Countries like Bangladesh, Sri Lanka, Thailand, Indonesia, Vietnam, Singapore, and the European Union (EU), prohibit antibiotic use as growth promoters in animal feed, including colistin.
The EU is about to impose a ban on preventive mass medication in animals that will come into enforcement from 2022, which means that colistin would also not be used for disease prevention in animals, post 2022 in the EU.
The Interagency Coordination Group on Antimicrobial Resistance (IACG) in its April 2019 report to the secretary-general of the United Nations has recommended an urgent action from member states, which includes India, to phase out the use of antimicrobials for growth promotion in animals, starting with an immediate end to the use of HPCIAs that include colistin.
In India The use of colistin as a growth promoter in food-animal production, such as in the poultry sector in India, is a common practice. Nearly 95 per cent of colistin used in animal feed in India is imported from China. In 2014, the Centre for Science and Environment (CSE), a Delhi-based non-profit, had warned misuse of antibiotics in poultry in the country. Indiscriminate colistin use by several companies such as Venky’s for raising poultry in India was also reported by an international agency. In India, Venky’s supplies supermarkets and fast food outlets like KFC, McDonald, and Pizza Hut. Some other companies include Vetline which sells colistin-containing feeds under the brand names Coligro-100 and Progro-vet. A global study in 2017 on antibiotics use in farm animals projected the consumption of antibiotics through animal sources to nearly double during 2013–30 in India.
The study ranked India the fourth largest consumer of antibiotics in food animals globally after China, the United States, and Brazil.
This means that antimicrobial resistant (AMR) problem is expected to worsen due to the consumption of antibiotics through animal sources. Colistin resistance is being increasingly reported from Indian hospitals. The medical professionals are alarmed at the failure of efficacy of the trusted antibiotic. A number of patients have shown resistance to the drug. In 2018, researchers from the Apollo Cancer Hospital, Chennai, and the Christian Medical College, Vellore, claimed in a paper published in the Journal of Global Antimicrobial Resistance, that samples of raw food lifted from across Chennai had tested positive for colistin-resistant bacteria.
Ban in India
Released in 2017, the Indian National Action Plan on AMR, focused on limiting the use of last-resort and high-end antibiotics in food-animal production. In June 2017, the Indian Council of Medical Research (ICMR) agreed that food animals should not be treated with last-line antibiotics for humans such as colistin. In 2018, the Department of Animal Husbandry, Dairying and Fisheries (DADF) issued a letter to the Central Drugs Standards Control Organisation (CDSCO). The apex drug regulator of India recommended a ban on the growth-promotional use of colistin in animal feed as a premix or supplement. Accordingly, the Drug Technical Advisory Board (DTAB) recommended for a ban on colistin in its 81st meeting in Delhi in November 2018. DTAB is constituted to advise the government at the centre and states on technical matters arising out of the administration of the Drugs and Cosmetics Act.
Taking note of these factors and the last year’s research claim, a ban has been imposed on colistin for animals under provisions of section 26A of Drugs and Cosmetics Act, 1940. As per the notification issued by the Centre, it was brought to the notice of the central government that the use of colistin and its formulations for food-producing animals, poultry, aqua farming, and animal feed supplements was likely to involve risk to human beings. The Drug Technical Advisory Board (DTAB), government’s top advisory body on technical matters related to drugs in India, has considered the matter and recommended prohibiting colistin. The health ministry has also directed that manufacturers of colistin and its formulations shall affix a label on the container of the drug, reading ‘Not to be used in food-producing animals, poultry, aqua farming, and animal feed supplements’, on the package, its insert, and promotional literature.
In this direction, the state of Kerala has taken some positive steps, whose poultry market is growing because of poultry integration, a kind of contract farming.
Colistin can save human lives and its efficacy needs to be preserved. Its use as a growth promoter in food animals must not be allowed. If India is serious towards limiting antibiotic misuse in food-animal production sector, a strong action against colistin is the first and important step. The move is to ensure that arbitrary use of colistin in the food industry, particularly as growth supplements used in animals, poultry, and aqua farms, would likely reduce the antimicrobial resistance within the country. The ban shows an element of commitment by the central government, but the implementation challenges in state and local levels are yet to be seen.