Many people with tuberculosis stay in the latent infection stage, but some develop the active disease. Both stages are treatable. Tuberculosis (TB) is a bacterial infection that usually affects the ...

Syphilis is a sexually transmitted infection. Without treatment, the stages of syphilis include symptoms that worsen over time. They can lead to severe or possibly fatal complications. Syphilis is a ...

The human immunodeficiency virus (HIV) is a virus that attacks the body's immune system. If not treated, it can lead to the autoimmune deficiency syndrome (AIDS). As happens with other viruses, when a ...

Scientists have long believed that a newborn’s immune system was an immature version of an adult’s, but research from Cornell University shows that newborns’ T cells—white blood cells that protect ...