Low neutrophil count is a condition called neutropenia, which is a low white blood cell count. A person with neutropenia has a greater risk of infection because the immune system is compromised. Neutropenia is a serious condition and precautions must be taken to prevent infection, according to UPMC.
In adults, neutropenia is defined as having less than 1,700 neutrophils per micro liter of blood, according to the Mayo Clinic. Cancer treatments are only one cause of a low neutrophil count. Other common causes are HIV/AIDS, an over active thyroid, Hepatitis A B or C, some medications, autoimmune disorders, malaria, and infectious or parasitic diseases, according to the Mayo Clinic.