Leukemia is a class of malignant clonal disorders of hematopoietic stem cells that develop with an organism’s susceptibility (e.g., chromosomal mutations or relatively weak, immune deficient) and environmental factors (viral, chemical, radiological, etc.). The cause of leukemia may be related to viral infections, ionizing radiation, long-term exposure to certain chemicals, and possibly to genetic factors. However, leukemia is not an infectious disease, and it is safe to say that leukemia does not develop because of infection.
- Susceptibility is a genetic factor and is not contagious;
- A variety of environmental factors that may produce corresponding organismal responses in other individuals in the same environment, especially viruses (e.g., HTLV-1, etc.).
So, leukemia is not currently considered to be contagious, but individuals with the same environmental background as the leukemia patient may develop similar disease characteristics once their own susceptibility increases.