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92 Possibility of Local Intervention in Preventing Seroconversion after Accidental Retrovirus Inoculation
F. Robicsek*, A. Fokin, and T. Masters
Carolinas Med. Ctr., Heineman Res. Labs, Charlotte, NC, USA
Background: About 1 million needle stick and sharp object injuries occur each year in health provider and research environments in the US. The chance of seroconversion for HIV is about 0.3%. Needle stick injuries occur usually at the subcutaneous level; thus, the lymphatic pathway is mainly involved. There is also a quantum dependency in the development of AIDS as an infectious disease. Local interventions may reduce the quantity and spread of viruses, thus enhancing systemic treatment.
Methods: In the feline model, seroconversion was monitored after a needle stick or cut with feline immunodeficiency virus-contaminated instruments. Betadine injection at the site of injury was used as an urgent local antiviral treatment. In the canine model, subcutaneous (SQ), intralymphatic, and intravenous injections of radioactive particles equal in size to a retrovirus (100(200 nm) were performed. Blood and lymph samples were collected for 45 minutes and evaluated by gamma counting. Flow rates, particle arrival time, concentration, flux, and accumulation were compared. A tourniquet was used to slow dissemination.
Results: Immediate infiltration of the injury site with Betadine prevented viremia in cats after needle stick, but not knife cut. After subcutaneous injection in dogs, particles arrived first in the blood and then in the lymph. Lymphoscintigraphy confirmed that 90% of the inoculum remained at the site for 45 minutes, with gradual release into circulation. The tourniquet delayed the arrival of particles in blood by 3 times and in lymph by 6 times. Concentration of particles in lymph was up to 103 times higher than in blood. Flux values in lymph and blood were comparable, but accumulation patterns were different. After direct injection into a lymphatic vessel at the paw, particles arrived in venous blood within 4 seconds, thus confirming functional lymphatico-venous communications at the peripheral level.
Conclusions: There is a physiological basis for immediate local treatment after accidental injuries with retrovirus contaminated instruments. Tourniquet application and infiltration of the site with an antiviral agent may slow the dissemination, decrease the amount of the spreading virus, and make systemic treatment more efficient.
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