Dr. Stephen Ash

U.K. Clinical Dean on the Fight Against Tuberculosis

Despite all the modern advances in medicine, tuberculosis (TB) is still a major global problem. One third of the world’s population is infected with TB and in 2015 alone there were more than 1.8 million deaths related to the disease.

AUC students who elect to do clinical rotations in the United Kingdom have the unique opportunity to see TB cases, especially at Ealing Hospital where Professor Ash is a physician and lead consultant in infectious disease and tropical medicine.

Professor Ash (left) using an ultrasound with AUC students at Ealing Hospital.

Ealing Hospital along with Central Middlesex and Northwick Park Hospitals, make up the London North West Healthcare NHS Trust, which has the largest TB service in the country (larger than any TB center in North America). Over 500 cases of active TB are treated at those sites each year. 

According to Professor Ash, most of the adult patients who present with TB come with a reactivation of latent TB. Often, their primary TB infection was acquired during childhood and in an an area where TB is endemic (e.g., India, China, Indonesia, Nigeria, South Africa, and Bangladesh). A reactivation later in life can be provoked by immunological deficiencies, such as HIV, chemotherapy, immunosuppressive drugs, or alcoholism. And then there's vitamin D deficiency.

TB-xray-2-(1).pngVitamin D deficiency is an under-appreciated factor in the reactivation of latent TB. Macrophages are a key cell group in defending the body against TB and they produce many cytokines in order to produce granulomas, which is an important process to contain the tubercle bacillus. However, the macrophage needs vitamin D to produce the most important cytokine: gamma interferon.

For Professor Ash, this poses the question: Can vitamin D supplements or increased sunlight exposure, reduce the chances of the reactivation of latent TB?

The chest X-ray image shown to the right is a patient of Professor Ash who suffered from severe pulmonary/miliary TB.

AUC students at Ealing and other UK hospitals are likely to see TB in other parts of the body, including lymph nodes, meninges, and the spine (Pott’s disease), among others. It's another example of the global health opportunities that AUC students can experience during their training and education. 

>>Learn more about AUC's UK clinical experience and our affiliated UK hospitals