Look for trophozoites during hematocytometry or in the Giemsa-Wright stain that is usually performed for the CSF cell count.
Examine a drop of fresh, *warmed* CSF under a cover slip for motile trophozoites—they may move fast or VERY slowly and may be confused with WBC. Take several minutes to review the slide. Gentle heating increases movement; a drop of distilled water also prompts flagellation & and increased motility.
Experts worry that expanding and longer warm seasons may worsen "heat-loving" infectious diseases. Our planet has been warming for several decades, and this is accelerating.
All unchlorinated, warm fresh water is an excellent environment for free-living amoebae, Legionella, Pseudomonas, and non-tuberculous Mycobacteria.
The beautiful spring-fed lake that Philip swam in 12 days before he sickened and died. (Google Earth)