Higher level of Quinolones residue in poultry meat and eggs; an alarming public health issue in Nepal

Background: Antibiotics are widely used in poultry production to prevent disease, improve growth and productivity. However, their indiscriminate use has led to the presence of antibiotic residues in poultry meat and eggs, which threaten consumer health by causing allergies, toxicity, gut disruption, and antibiotic resistance, necessitating strict MRL enforcement and monitoring for food safety. Quinolones, classified as critically important drugs, pose a significant risk, as their residues in poultry products can facilitate the transfer of resistant zoonotic pathogens to humans. This study aimed to evaluate the qualitative and quantitative presence of quinolone residues in meat and eggs supplied to Kathmandu Valley, Nepal, assessing the associated risks to human health. Methods: A standardized questionnaire was used to analyze the antibiotic usage trends in the poultry industry, with data collected via the Epicollect+ Android application. A total of 120 meat and 120 egg samples were collected from five designated sectors. Antimicrobial residues were screened using Enzyme-Linked Immunosorbent Asssay (ELISA). Only samples exceeding the maximum residue limit (MRL) were further quantified using High-Performance Liquid Chromatography (HPLC). Results: About 88.33% of chicken meat and 80% egg samples tested positive for Quinolone residue. Among the meat samples, three from Kathmandu exceeded the maximum residue level (MRL), with one sample each from commercial and education sector containing Enrofloxacin residues, and one sample from the health sector containing residues of both Enrofloxacin and Ciprofloxacin. The egg samples of Kathmandu, Bhaktapur and Lalitpur district showed Quinolone residue prevalence of 83.9%, 76.9%, and 65%, respectively. Sector-wise analysis revealed the highest prevalence of Quinolone residue in eggs from the household sector (100%) and the lowest in the education sector (66.6%), with the difference being statistically significant (p = 0.005). Conclusion: A high level of Quinolone residue in the chicken meat and egg samples in the study indicates the imprudent and haphazard use of antibiotics in poultry production which is a leading cause of emergence of antimicrobial resistant poultry pathogens, posing a serious risk of resistance transfer to human pathogens and representing a significant public health concern.