Monocytosis

Monocytosis is an increase in the number of monocytes circulating in the blood. Monocytes are white blood cells that give rise to macrophages and dendritic cells in the immune system.
In humans, monocytosis occurs when there is a sustained rise in monocyte counts greater than 800/mm³ to 1000/mm³.
Monocytosis has sometimes been called mononucleosis, but that name is usually reserved specifically for infectious mononucleosis.

Causes

Monocytosis often occurs during chronic inflammation. Diseases that produce such a chronic inflammatory state:

Infections: tuberculosis, brucellosis, listeriosis, subacute bacterial endocarditis, syphilis, and other viral infections and many protozoal and rickettsial infections.
Blood and immune causes: chronic neutropenia and myeloproliferative disorders.
Autoimmune diseases, immune diseases and vasculitis: systemic lupus erythematosus, rheumatoid arthritis and inflammatory bowel disease. Monocytosis can be a symptom of mast cell activation syndrome (MCAS).
Malignancies: Hodgkin's disease and certain leukaemias, such as chronic myelomonocytic leukaemia and monocytic leukemia.
Recovery phase of neutropenia or an acute infection.
Obesity
Miscellaneous causes: sarcoidosis, drug overdose, lipid storage disease and .

During these stages of extreme inflammation, monocytosis can damage tissues because it increases the activation of the immune response and prevents the inflammation from subsiding which is seen in cases where sepsis occurs.

Diagnosis

Blood Test
Blood test checking for monocytosis

Treatment

if there is typhoid fever and levofloxacin or moxifloxacin.
Gentamicin and doxycyclin if brucellosis.