What is Primary Complex? Children exposed to Mycobacterium tuberculosis may sometimes develop a tuberculosis (TB) infection called Primary Complex. The most common route of infection is through inhalation. A person with active TB coughs up the germ and it is inhaled by a healthy child. The TB then travels to the lungs. The immune system kicks in and “quarantines” the germ at the local site and at the neighboring lymph nodes (this forms the “walled-in” complex).The child remains healthy and usually has no symptoms. They may remain symptom free until their immune system declines and the disease becomes active.
How do you diagnose Primary Complex? As most patients have no symptoms, they only find out they have Primary Complex through a tuberculin skin test (also called a Mantoux test or PPD test). A small amount of purified protein derivative (a.k.a. PPD) of the TB germ is injected superficially into the forearm. An itchy, raised, red reaction past a certain size (this changes depending on other conditions) is considered positive. In 20% of cases, a PPD test will be negative in patients with TB infection. Other times, children will have a falsely positive PPD test because they had the BCG BCG (Bacillus Calmette-Guerin) vaccine.
Should Primary Complex be treated? Yes. If primary complex is left untreated, it may eventually evolve into active tuberculosis. Drug treatment choices vary depending on the drug resistance to tuberculosis.
Is Primary Complex contagious? No. As the infection is “walled-in” it cannot be spread.
How do you prevent Primary Complex?
Avoid symptomatic (coughing) individuals that are high risk to have tuberculosis.
There is also a vaccine for TB that has mixed results as to whether it actually prevents the disease. It is known to prevent severe disseminated or dispersed TB infection.
Make sure to include household help as well when getting tested for Primary Complex.