Economic analysis of new workplace technology including productivity and injury: The case of needle-less injection in swine.

Increasing intensification in swine production has led to new and specialized technologies, but the occupational health and safety impacts are rarely quantified in the business plans for adoption. Needle-less injection has potential to increase productivity and eliminate needle stick injury in workers, but it is not clear whether these benefits offset high capital investment and potential increases in musculoskeletal loads. This economic evaluation employed probabilistic scenario analysis using injury, cost, and production data gathered from interviews with swine producers in Manitoba and Saskatchewan. After adoption of needle-less injection, rates of needle-stick injury went down with no measureable effect on upper limb musculoskeletal disorders, resulting in lower health and safety costs for needle-less injectors. Needle-less injection duration was 40% faster once workers acclimatized, but large start-up costs mean economic benefits are realized only after the first year. The incremental benefit cost ratio promoted adoption of needle-less injectors over conventional needles for the base case of a 1200 sow barn; the conventional method is beneficial for barns with 600 sows or less. Findings indicate that well-designed technologies have the potential to achieve the dual ergonomics goals of enhancing human wellbeing and system performance. We anticipate that the economic and decision models developed in this study can be applied to other new technologies in agriculture and animal production.

Incidence and severity of Arcanobacterium pyogenes injection site abscesses with needle or needle-free injection.

Nursery-age pigs (n=198) were used to evaluate the difference in abscess formation at needle-free jet and conventional needle-and-syringe injection sites. Needle-free jet injection was used to administer injections in the neck and ham on one side of the animal whereas needle-and-syringe was used for neck and ham injections on the opposite side. Immediately prior to injection, the injection site surfaces were contaminated with an inoculum of Arcanobacterium pyogenes. Each pig was humanely euthanized 27 or 28 days after injections. Histopathological results showed that needle-free jet injection was associated with more abscesses than needle-and-syringe injection at both neck (P=0.0625) and ham (P=0.0313) injection sites. Out of 792 injection sites, only 13 abscesses were observed, with 12 of those present at needle-free jet injection sites. Needle-free jet injection may increase the occurrence of injection site abscesses that necessitate carcass trimming at pork processing plants.

Comparison of iatrogenic transmission of Anaplasma marginale in Holstein steers via needle and needle-free injection techniques.

OBJECTIVE: To compare iatrogenic transmission of Anaplasma marginale during sham vaccination between needle and needle-free injection techniques. ANIMALS: 26 Holstein steers confirmed negative for anaplasmosis by use of a competitive ELISA (cELISA) and an A marginale-specific reverse transcription (RT)-PCR assay. PROCEDURES: An isolate of A marginale was propagated to a circulating parasitemia of 2.0% in a splenectomized steer. Sham vaccination was performed in the left cervical muscles of the splenectomized parasitemic steer with a hypodermic needle fitted to a multiple-dose syringe. The same needle and syringe were used to sham vaccinate a naïve steer. This 2-step procedure was repeated until 10 naïve steers (group ND) were injected. Similarly, sham vaccination of the left cervical muscles of the splenectomized parasitemic steer and another group of 10 naïve steers (group NF) was performed by use of a needle-free injection system. Five control steers were not injected. Disease status was evaluated twice weekly for 61 days by use of light microscopy, a cELISA, and an A marginale-specific RT-PCR assay. RESULTS: Iatrogenic transmission was detected in 6 of 10 steers in group ND. Disease status did not change in the NF or control steers. Sensitivity of light microscopy, cELISA, and RT-PCR assay was 100% on days 41, 41, and 20 after sham vaccination, respectively; however, only cELISA and RT-PCR assay sustained a sensitivity of 100% thereafter. CONCLUSIONS AND CLINICAL RELEVANCE: Needle-free injection was superior to needle injection for the control of iatrogenic transmission of A marginale.

Ampicillin pharmacokinetics in swine following needle-free, intramuscular, and intravenous administration.

A cross-over study design was used to determine the pharmacokinetics of ampicillin in swine. Each of eight pigs was subjected to all of the following three treatments: (1) intramuscular (i.m.) injection of 17.6 mg/kg of ampicillin trihydrate; (2) injection of a mean dose of 17.6 mg/kg of ampicillin trihydrate using a needle-free (NF) injection device; and (3) intravenous injection of 17.6 mg/kg of sodium ampicillin administered as a bolus. Ampicillin trihydrate administered by NF injection in this study was not statistically different from i.m. injection as measured by AUC(0-infinity), MRT, MAT, or Cmax. However, the 90% confidence limits about the difference in NF to i.m. mean Cmax and AUC(0-infinity) values, expressed relative to the i.m. treatment mean, exceeded the traditional bioequivalence limits of +/-20%. In part, failure to demonstrate bioequivalence was attributable to small study size and the large within-subject variability associated with this drug. Therefore the power of this study was not sufficient to definitively prove or disprove bioequivalence and additional studies to describe appropriate dosage regimens for ampicillin trihydrate when administered by NF injection to pigs are warranted.