Tetracycline and sulphonamide residues in farmed fish in Dar es Salaam, Tanzania and human health risk implications.

In Africa, antibiotic residue investigations in animal food have primarily been focused on meat, neglecting farmed fish. This cross-sectional study conducted in Dar es Salaam, Tanzania, aimed to assess sulphonamide and tetracycline residues in farmed fish, comparing levels with Codex Alimentarius Commission's acceptable daily intake (ADI) and maximum residue limits (MRLs). A total of 84 farmed fish were sampled and analysed in the presence of tetracycline and sulphonamide residues. All samples were positive for sulphonamide residues (100%; n = 84), and 2.4% (n = 2) were positive for tetracycline and consequently also positive for both compounds. Tetracycline levels were below ADI and MRL, 28.5% (n = 24) surpassed the ADI, and 6% (n = 5) of the samples exceeded the MRL for sulphonamide. Regular monitoring of antibiotic residues in aquaculture products is crucial to mitigate health risks and expanding assessments to include other commonly used compounds is warranted.

Determination of Sulphonamides and Tetracycline Residues in Liver Tissues of Broiler Chicken Sold in Kinondoni and Ilala Municipalities, Dar es Salaam, Tanzania.

In Tanzania, the increased demand for animal-derived foods, particularly eggs, meat, and milk, has resulted in the intensification of farming systems with the use of antimicrobials, particularly sulphonamides and tetracyclines. According to the FAO/WHO Codex Alimentarius commission, concentrations of antimicrobial residues in food exceeding the acceptable daily intake (ADI) and maximum residual limit (MRL) pose a health risk to consumers. This cross-sectional study determined the concentrations of sulphonamide and tetracycline residues in the liver tissues of commercial broiler chicken sold in Dar es Salaam, Tanzania, to find out whether the amounts of residues were within the legally permitted and acceptable limits in food. We conveniently sampled eighty-four liver tissue samples from broiler chicken sold in two out of six large markets in Dar es Salaam. The amounts of tetracycline and sulphonamide residues were determined using an ELISA kit (Shenzhen Lvshiyuan Biotechnology Company, Shenzhen, China). The results showed that all 100% (n = 84) samples contained tetracycline residues and 21.4% (n = 18) samples contained sulphonamide residues, while 21.4% (n = 18) contained both sulphonamide and tetracycline residues. The concentrations of sulphonamide residues were within the maximum residual limit (MRL). However, 90.5% (n = 76) of the samples had tetracycline levels that exceeded the acceptable daily intake (ADI) range 0-3 µg/kg and 13.1% (n = 11) of the samples had tetracycline levels that exceeded the maximum residue limit of 300 µg/kg. The observed presence of antibiotic residues in the poultry tissues poses a health risk to consumers, and may lead to antimicrobial resistance micro-organisms, which may spread to humans and animals via the environment. Vigorous surveillance and observation of the withdrawal periods should be advocated to ensure that the food from animals is safe with regard to the residues of veterinary medicines.