On Wednesday, Dr. Sarah Fortune of the Harvard School of Public Health presented a lecture on the evolution of drug resistant mycobacterium tuberculosis.

Prof. Lawrence Wangh (BIOL) introduced Fortune and presented a brief introduction on drug resistance in organisms, specifically bacteria.

Fortune began by discussing key facts of tuberculosis and its implications.

There are approximately 10 million cases of active tuberculosis annually and approximately two million deaths related to tuberculosis. About one third of the world's population is thought to be infected with latent tuberculosis, meaning that new infections occur at a rate of about one per second.

In an interview with the Justice, Fortune spoke of her interest in the early 1990 HIV epidemic in New York City. "I was at Colombia Presbyterian Hospital and we had floors of the hospital that were full of people dying of HIV and TB together. … People weren't focusing on TB the same way [as HIV], so I decided I would work on TB."

Fortune said in her lecture that tuberculosis is difficult to treat because it is an aerosol infection residing within the alveolar macrophages, and it uses the macrophages as a host but does not kill them. This means that the infection resides within the lungs and feeds off nutrients from the lungs, but does not kill the cells.

People in the developing world are more likely to contract tuberculosis because their immune systems are more likely to be compromised due to higher rates of HIV and AIDS, according to Fortune. Only about five to 10 percent of those infected with tuberculosis without HIV develop an active disease. In contrast, 30 percent of those co-infected with HIV develop tuberculosis.

Fortune said that the emergence of HIV has been consistently driving up the presence of multidrug-resistant, extensively drug-resistant and fully drug-resistant strains of TB, specifically in Sub-Saharan Africa.

The World Health Organization prescribes those with the active disease a daily regiment of four antibiotics for two months, followed by two antibiotics for four to six months. For those diagnosed with latent tuberculosis one antibiotic is administered daily over a period of nine months. The two antibiotics most commonly used are isoniazid and rifampicin, and treatment can be prolonged, according to Fortune.

Talk is now circulating among scientists, including Fortune, about the long-term reliability of using only one antibiotic for latent tuberculosis, especially with the increasing risk of drug resistance among tuberculosis. Fortune noted that "latent TB can most likely reactivate with only one antibiotic."

A newly discovered form of tuberculosis, the Beijing Strain, has been proven to be more drug-resistant than both the Euro-American Strain and the Indo-Oceanic Strain.

Even with multiple variants of rifampicin antibiotic treatment, this strain retains a fourfold higher resistance rate over the Euro-American strain.

While such variants as the Beijing Strain leave scientists with further questions, other issues of TB are becoming clearer, such as early treatment lowering risk of drug resistance. "Early, sensitive diagnostics are key to controlling TB and curtailing growth of drug-resistant TB," noted Fortune.

Fortune commented, "There is an enormously strong connection between HIV and TB, so HIV is fueling the TB epidemic. 

TB is the single largest cause of death in people with HIV."

Wangh agreed, noting that "the funding agencies, until recently, have funded ... the HIV people very well, and the TB people far less well, but rarely if ever, a combination. The first joint TB-HIV meeting [was only about two years ago], so the people weren't even talking to each other, which is extraordinary."

Fortune was impressed with the turnout and happy to have the opportunity to speak with interested students, Brandeis scientists and Professor Wangh, whose work ties in directly with her research. "[Wangh] is an expert on news type technologies for diagnostics, which I think are incredibly important for both limiting transmission and limiting the emergence of drug resistance."