Measles virus (MV)-infected persons have been found to be at a greatly increased risk of developing respiratory infections caused mainly by Staphylococcus aureus and Mycobacterium tuberculosis. Secondary microbial infections have been implicated as important causes of morbidity and mortality in patients with measles. Polymorphonuclear leukocytes (PMNL), the first cells of the immune system to migrate to the site of microbial invasion, are the principal cells involved in the immune response to invasion of the host by microbes, particularly bacteria and fungi.
