TB or not TB?



"Tuberculosis, MTB, or TB (short for tubercle bacillus) is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis.^[1] Tuberculosis typically attacks the lungs but can also affect other parts of the body. It is spread through the air when people who have an active TB infection cough, sneeze, or otherwise transmit their saliva through the air.^[2] Most infections are asymptomatic and latent, but about one in ten latent infections eventually progresses to active disease which, if left untreated, kills more than 50% of those so infected. Diagnosis of latent TB relies on the tuberculin skin test.

One third of the world's population is thought to have been infected with M. tuberculosis,^[3] with new infections occurring at a rate of about one per second.^[3] In 2007, there were an estimated 13.7 million chronic active cases globally,^[4] while in 2010 there were an estimated 8.8 million new cases and 1.5 million associated deaths, mostly occurring in developing countries.^[5] The distribution of tuberculosis is not uniform across the globe; about 80% of the population in many Asian and African countries test positive in tuberculin tests. This is a particular problem in sub-Saharan Africa, where rates of HIV are high.^[30][31] Tuberculosis is closely linked to both overcrowding and malnutrition, making it one of the principal diseases of poverty." (Source: Wikipedia)

Mercy Ships takes the risk of tuberculosis very seriously and all long term crew and day workers are required to have a tuberculosis skin test annually. One of my duties as the crew clinic administrative assistant is to call crew in to have this test and to assist with the paperwork that accompanies it. Recently the Engineering Department needed more day workers to help with some extra duties. Before they could be declared fit for work they all had to have their TB skin test. The test is a needle that can cause a reaction if the individual is positive for the presence of TB, whether latent (dormant) or actual. If the test, read 48 hours after it is administered, is positive a chest x-ray is performed to determine the presence of TB. Below are all the guys lined up outside the crew clinic ready to have their TB skin tests read.

Waiting inside the clinic.

Even if a test shows a reaction, it may not be positive. Any swelling or "induration" under 10mm is declared negative and 10mm or over is positive. Above the crew nurse Lynne shows a day worker his measurement.

Lynne and I had quite the system going. Lynne read each of the tests while I recorded the results on cards for the day workers to keep. For any who were positive I filled out an x-ray form for the Crew Physician to order a chest x-ray.

And this is what a strong positive test looks like-yes it is me three days post test! I had my TB skin test in April 2011 and, as I tested positive, I no longer need to have a TB skin test ever again. (Thank goodness-it was very painful!!). I had a chest x-ray which showed no evidence of TB. When we returned to Australia I had a special blood test to find out if I had latent TB. Fortunately the test came back negative. Below day four post test.

What we are doing is just a drop in the ocean as far as preventing the spread of this terrible disease. However if a case of active TB occurred on the ship it could be disastrous. Prevention and early detection is most definitely better that the cure!