Algaemia is a secondary term that refers to the emerging condition in which green algae enter the bloodstream.
Prototheca and Chlorella, which is extremely rare, are the only two known algae genera capable of inflicting disease on mammals, including humans, through invasion of host tissue.
Symptoms include but are not limited to: numbness in the extremities, olecranon bursitis or general inflammation, cutaneous infections in the hair, skin or fingernails, skin lesions, difficulty breathing, respiratory failure, multiple organ failure, and can result in death if not treated in the early stages of infection.
It is believed that this genus of algae began with photosynthetic ability but over time transitioned to a parasitic form.
[3] Two groups within Prototheca have been identified: those typically associated with cattle (P. ciferrii and P. bovis), and those considered human-associated (P. wickerhamii, P. zopfii, and P. miyajii).
The algal cells have been identified in samples from sewage, fresh and saltwater, animal feces, and some foods.