Extralabel use of penicillin in food animals.

Penicillin is one of the most commonly detected drug residues in tissues and milk, and is the antimicrobial for which information is most often sought through FARAD.

Current status of aquatic species biologics.

No vaccine is a substitute for good management and diligent biosecurity in an aquaculture facility. It is always important to ensure the best water quality possible, provide quality nutrition, avoid overcrowding of tanks and raceways, remove dead fish to prevent pathogen buildup and spread, and reduce or eliminate unnecessary stress on fish. Use of a preventive medicine vaccine program and improved management can help ensure good health in a fish population and reduce the industries' use of therapeutic agents.

Use of frozen semen to avoid human immunodeficiency virus type 1 transmission by donor insemination: a cost-effectiveness analysis.

OBJECTIVE: Reappraisal of current guidelines mandating frozen-thawed semen. DESIGN: Cost-effectiveness analysis comparing the use of frozen semen with the use of fresh semen from the same donors without a second antibody test. SETTING: A Markov model computer simulation. PATIENT(S): A theoretical cohort of 80000 women whose husbands are azoospermic. INTERVENTION(S): Simulation with calculation of costs and payoffs. MAIN OUTCOME MEASURE(S): Total lifetime direct health care costs, costs per live birth, life expectancy, quality adjusted life years (QALY), marginal cost effectiveness (dollar/QALY). RESULT(S): If all 80000 women who undergo donor insemination in the United States each year chose to use fresh semen from donors screened according to the current practice guidelines but without semen cryopreservation, there would be 8881 more births and the mean cost per live birth would be US dollars 15501 less. One recipient would become infected with HIV-1 every 5.1 years, during which time over 180000 noninfected children would be born. The average life expectancy of recipients would be reduced by 2 days, but their quality-adjusted life expectancy would increase by over 1 month. Medicolegal costs to physicians would need to exceed US dollars 780 million per infection to equalize the cost effectiveness of the fresh and frozen policies. CONCLUSION(S): The guidelines should be revised to allow the use of fresh semen by informed recipients.

Comparison of the use of regulatory assays and high-performance liquid chromatography for detection of residues of ceftiofur sodium metabolites in tissue specimens of culled dairy cattle.

OBJECTIVE: To compare the results of regulatory screening and confirmation assays with those of high-performance liquid chromatography (HPLC) in the detection of ceftiofur metabolites in the tissues of culled dairy cattle. ANIMALS: 17 lactating Holstein dairy cows. PROCEDURE: Daily IM injections of ceftiofur sodium were administered at a dose of 2.2 mg of ceftiofur equivalents/kg (n = 6) or 1.0 mg of ceftiofur equivalents/kg (10) for 5 days. Following withdrawal times of 12 hours (high-dose ceftiofur) and either 5 or 10 days (low-dose ceftiofur), cows were slaughtered and liver, kidney, and diaphragmatic muscle specimens were harvested and analyzed by HPLC and standard regulatory methods that included the following assays: the swab test on premises, the fast antimicrobial screen test, the calf antibiotic and sulfa test, and the 7-plate bioassay confirmation test. RESULTS: In all tissue specimens, residues of ceftiofur and desfuroylceftiofur-related metabolites, as measured by HPLC, were less than regulatory tolerance, as defined by the FDA. False-positive screening assay results were more likely for tissue specimens that had been frozen for shipment to a federal laboratory, compared with fresh tissue specimens that were assayed at the slaughter establishment (23% vs 3% false-positive results, respectively). CONCLUSIONS AND CLINICAL RELEVANCE: The observation that fresh tissues had negative results on screening assays, whereas subsets of the same tissue specimens had false-positive results on screening assays following freezing, suggests that freezing and thawing interferes with microbial inhibition-based regulatory screening assays.