Though the rodent reservoir of Chapare virus is unknown, similar arenaviruses are typically transmitted either through direct or indirect contact with the saliva, urine, and droppings of infected rodents. Examples of direct contact include bites and scratches by infected rodents. Examples of indirect contact include breathing in the virus when it is stirred into the air or ingestion of food contaminated with the urine, salvia, or droppings of infected rodents.
An infected person can then spread the illness to other people through contact with the patient’s body fluids, or during procedures in healthcare settings that can aerosolize (spray particles of) the infected person’s body fluids—such as during chest compressions, CPR, and intubation. Because there are very few documented cases of Chapare in humans, more research is needed to understand how the virus spreads and causes illness.