Objective: We investigated the propagation of viral-size particles by lymph and blood after subcutaneous injection.
Methods: In the canine model, transport of [99mTc] sulfur colloid particles of different sizes was studied in different settings in venous blood and lymph for 45 minutes after inoculation.
Results: The mean arrival time of particles in the blood was 2.10+/-0.46 minutes and 8.87+/-1.72 minutes in the lymph. Lymph flow in the canine leg was 28.79 +/-2.09) microl/min and was increased by leg massage. The particle concentration was 1000 times higher in the lymph fluid than in blood. Particle flux values were comparable in blood and lymph. The accumulation of particles in blood initially rose faster than in lymph. Accumulation in lymph rises slower but continues longer and reaches higher values. Ninety percent of the inoculum remains at the injection site for at least 45 minutes. Particle size matters more in blood distribution. Leg massage enhances particle transport by lymph.
Conclusions: After subcutaneous injection, viral-size particles initially arrive in the blood and later in the lymph. Accumulation in lymph and blood increases for a prolonged time after inoculation. Results suggest possibilities for limiting the spread of infectious matter by early local antiviral treatment.