Some 26 of 62 poultry samples taken from Bangkok markets and stores have tested positive for two antibiotics, according to a survey by the Foundation for Consumers (FFC).
The samples -- 32 chicken breasts and 30 livers -- were collected from supermarkets in shopping malls and local fresh markets across Bangkok and its surrounding area from June 9-15.
"Antibiotics are increasingly being prescribed to treat diseases so we have had a chance to absorb these drugs and even risk ingesting dangerous doses if we consume food that has been contaminated with them, too," Niyada Kiatying-Angsulee, director of the Drug System Monitoring & Development Centre, said Thursday.
"Their increased usage can make people drug-resistant and force patients to take stronger antibiotics until it gets to the point where no drugs will be able to cure them," added the pharmacist.
The survey focused on three antibiotics: Doxycycline, a broad-spectrum drug that is part of the tetracycline group; amoxicillin, which is penicillin-based and part of the beta-lactum family; and enrofloxacin, a fluoroquinolone.
Enrofloxacin was detected in five of the samples and traces of doxycycline in 21 samples.
The others were all declared free of antibiotics, which some farmers feed to their chickens to make them grow fatter with more meat to sell.
According to the Food and Drug Administration (FDA), the use of enrofloxacin is allowed in the livestock industry provided no residue remains in the meat when it heads to market.
Regarding the 21 samples where doxycycline was detected, they remain in compliance with a "safe" level stipulated by the FDA.
Antibiotics can cause harmful effects such as allergies, rashes, yeast infections, digestive issues and a host of unpleasant symptoms.
Doxycycline can also cause tooth staining, mostly in children, while enrofloxacin can lead to vomiting and diarrhea.