If it's under a microscope slide cover then you're pretty safe - the fluid is sandwiched between the slide & the cover and isn't going to go anywhere.
(You don't normally try and image free standing droplets that could run off for a couple of reasons: Except for the clearest liquids they'd be too optically thick to see anything useful and you'd have problems focusing on objects that can move in the z direction as well as laterally with respect to the lens.)
Plus, malaria isn't transmitted via fecal-oral or respiratory route, so holding it up to your face isn't terribly risky. Taking the sample is much more risky, since there are sharps involved.
(You don't normally try and image free standing droplets that could run off for a couple of reasons: Except for the clearest liquids they'd be too optically thick to see anything useful and you'd have problems focusing on objects that can move in the z direction as well as laterally with respect to the lens.)