There are more reasons for low white blood cells. If it is accompanied by a fever, it is possible that the infection is present. Repeated high fever that does not go away can be a result of such an infection that is not under control. It is possible that some serious infections, such as bacterial infections, can cause low white blood cells if they are more severe and lead to a large consumption of leukemia in the sterilization process. Recurrent high fever, even high fever that does not go away, can also occur because of bacterial causing bloodstream infections. In the case of viral infections, the fever can also be high and unrelenting in more severe cases, and the white blood cell count can likewise be low. Therefore, it is important to look for the cause of the fever, and to determine which pathogenic infection is involved, taking into account the manifestations of the fever, as well as the corresponding changes in clinical symptoms and ancillary tests. This condition may be bacterial or viral, and the cause should be identified and treated accordingly. In addition, do not ignore the blood system diseases, such as aplastic anemia can also cause leukemia reduction with fever, bone aspiration or bone marrow biopsy can be clear.