Blood.
Other fluids also carry HIV, but in trace amounts. Saliva will not freely spread HIV. (I've heard that you could drink two gallons [four liters] of saliva from an infected individual and still have just a small percentage of risk.) Sweat is even less potent. This is why universal precautions (i.e. gloves) are a must for every single run you go on. It only takes a drop of blood to land on or near a break in your skin for you to run the risk of infection.
Endocrine cardiac
intestinal fluid
Airfield repair
Airfield Damage Repair
This is most likely your coolant.
The pink fluid is most likely transmission fluid.
brain
water
In a hypoosmotic state, such as one that occurs with water intoxication, edema is most likely to result as intracellular fluid increases.
They don't get "inside" They bury their head parts in the surface of the skin. You can take precautions to minimise the risk, the most obvious being not to expose parts of the body in areas where tick infestation is likely.
Camera's can most likely expose everything.. especially when they are hidden properly to capture something.
Most likely blisters.