Background: Iron is an essential micronutrient for bacteria, fungi, and humans; as
such, each has evolved specialized iron uptake systems to acquire iron from the extracellular environment.
Objective: To describe complex ‘tug of war’ for iron that has evolved between human hosts and
pathogenic microorganisms in the battle for this vital nutrient.
Methods: A review of current literature was performed, to assess current approaches and controversies
in iron therapy and chelation in humans.
Results: In humans, sequestration (hiding) of iron from invading pathogens is often successful;
however, many pathogens have evolved mechanisms to circumvent this approach.
Conclusion: Clinically, controversy continues whether iron overload or administration of iron
results in an increased risk of infection. The administration of iron chelating agents and siderophore-
conjugate drugs to infected hosts seems a biologically plausible approach as adjunctive
therapy in the treatment of infections caused by pathogens dependent on host iron supply (e.g.
tuberculosis, malaria, and many bacterial and fungal pathogens); however, thus far, studies in
humans have proved unsuccessful.