Antibiotics Use In Poultry Farming: Resistant bacteria raises health alarm
"The resistant bacteria found in poultry is a matter of great concern -- just like the concern we feel when we get resistant pathogens in humans. Because, it is transmissible across all species,"
Antibiotic overuse in poultry farming in Bangladesh is breeding the rise of "superbugs" that cannot be managed with traditional treatments, say multiple studies -- raising the stakes for the government to rein in the use of the drug considered the crown jewel of modern medicine.
A study by the Bangladesh Livestock Research Institute (BLRI) found three serotypes of Salmonella bacteria that were resistant to 17 antibiotics in different percentages in chicken samples collected from 29 wet markets in Dhaka. The resistance ranged from 6.7 to 100 percent.
"This is extremely alarming as it poses a big threat to public health," Mohammed Abdus Samad, lead researcher and head of the AMR Surveillance Laboratory at BLRI, told The Daily Star.
Studies suggest that bacteria that evolve in the guts of poultry and livestock can be passed to humans.
Samad's comment comes on the heels of a recent surveillance study by the Institute of Epidemiology, Disease Control and Research, which found almost all clinically important and widely used antibiotics have lost their effectiveness by more than 50 percent. The study also found five of the most critical medicines listed by the World Health Organisation.
Salmonella is one of the four key global causes of diarrheal diseases in humans, according to the WHO.
The overall prevalence of multiple types of Salmonella was the highest in broiler chickens (8.6 percent), followed by Sonali chickens (6.9 percent) and native chickens (3.1 percent), found the study, whose sample collection took place between February and December 2019.
Of those, 29 bacteria were multidrug-resistant (MDR), 15 were resistant to seven antibiotics, four to eight antibiotics and one to 10 antibiotics.
The 17 antibiotics tested include Ciprofloxacin, Streptomycin, Tetracycline, Gentamicin, Nalidixic Acid and Ampicillin, Meropenem, Ceftazidime, Ceftriaxone, and Cefotaxime and Aztreonam.
The BLRI researchers concluded in their study, which was released in April, that antibiotics were used the most in broiler chicken production, followed by Sonali chicken production.
And a study by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) validates their findings.
The study, which involved 768 poultry farms spread across 20 upazilas, found antibiotic usage was the highest in farms that reared broiler chickens: about 98 percent.
About 88 percent of the surveyed farms that raised Sonali chickens administered antibiotics in the previous 14 days of the farm visit by the icddr,b researchers and 72 percent of the layer chicken farms.
The study, which is yet to be made public, found farmers begin using antibiotics on day-old chicks and continue to feed them doses until they are sold to the market.
Up to 55 percent of the farmers administered antibiotics on the day-old chicks without reason. As a preventative measure, 3-5 percent of the farmers gave antibiotics on the day of selling, according to the study.
And the poultry farms' rationale for administering routine, preventative doses of antibiotics to healthy chickens is to keep illnesses from spreading among the flock that live in close quarters as well as to enhance growth.
More than eight in every 10 farmers administered antibiotics when chickens become sick.
The use of antibiotics for treatment was the highest in Sonali chicken farms (about 30 percent), followed by broiler farms (25 percent) and layer farms (20 percent).
"The amount of antibiotic use as a preventive measure is very significant," Sukanta Chowdhury, lead investigator of the study and an associate scientist at the icddr,b's programme for emerging infections, infectious diseases division, told The Daily Star.
The majority of the farmers were recommended antibiotic use by the veterinary practitioners and the feed dealers. However, the feed dealers have no right to make such recommendations.
The antibiotics used include tetracycline, fluoroquinolones, macrolides, aminoglycosides, penicillin and polymyxins, which are from both access and reserve groups.
The access group antibiotics are prescribed for a wide range of primary level infections, while the watch group ones are for higher resistance bacteria, according to the WHO.
The excessive use will ultimately lead to antimicrobial resistance (AMR), which is the ineffectiveness of antibiotics to kill microorganisms like bacteria, viruses and parasites.
So, there is a need for promotion of good farming practices, Chowdhury said.
Besides, the excessive use of antibiotics ultimately increases the production cost, so good farming practices would bring the poultry farms' outlay in check.
A robust campaign is needed to make the industry stakeholders aware that excessive use of antibiotics does not help; it is rather detrimental for human health and adds to the costs, Chowdhury added.
"The resistant bacteria found in poultry is a matter of great concern -- just like the concern we feel when we get resistant pathogens in humans," Nitish Chandra Debnath, One Health Bangladesh's national coordinator, told The Daily Star.
Any resistant bacteria, no matter whether it originated from humans or animals or the environment, is a matter of concern as it is transmissible across all species."
To tackle the AMR, all health management -- human, animal and nature -- have to be brought under the "One Health" approach, said Debnath, one of the 26 members of the UN-led One Health high-level expert panel.
One health recognises that human health is closely connected to the health of animals and the shared environment.