2. Viruses
Some viral infections interfere with white blood cell development. HIV is one such virus. It infects and destroys white blood cells. This compromises the immune system and makes it difficult for the body to get rid of other viral and bacterial invaders. Once the immune system is compromised, other bacteria and viruses can enter the bone marrow and cause additional depletion and damage.
3. Congenital Disorders
Birth defects, which are also called congenital disorders, last for a person’s whole life. Several of these disorders may cause a low white blood cell count. Kostmann syndrome is a type of congenital neutropenia. It lowers the number of neutrophils, which are a type of white blood cell. Leukopenia, which is a reduced circulation of white blood cells, can result from myelokathexis.