Low neutrophil counts are often seen in viral infections, such as influenza virus, measles virus, hepatitis B virus, or varicella, rubella, or cytomegalovirus, which can occur in a range of viral infections. Low neutrophil counts can also occur in certain severe bacterial infections, such as cornual tuberculosis or septicemia, as well as in the elderly and infirm, chronic wasting disease, and advanced malignant tumors. Some radiation or radioactive nuclides, chemicals, and chemical drugs can cause low neutrophil counts, such as antithyroid drugs, methimazole or propylthiouracil, which can cause low neutrophil counts. In addition, low neutrophil counts can also occur when neutrophil destruction is increased in hypersplenism.