World TB Day 2009

More tuberculosis, more research

Web and Media Technologies, eHealth Research and Innovation Platform

Sub-Saharan Africa is still experiencing an escalating number of tuberculosis (TB) incidents annually, although other parts of the world seem to more successful in controlling the epidemic.

The Interim Director of the Tuberculosis Epidemiology and Intervention Research Unit of the South African Medical Research Council (SAMRC), Dr Martie van der Walt, says that one of the reasons for the annual increase in TB incidents in the Sub-Saharan region is due to people being co-infected with HIV and TB. According to the World Health Organisation’s ‘Global Tuberculosis Control 2008’ report, South Africa diagnosed 184 000 new infections in 2006. In epidemiological terms this is also called incidence. “In 2006 [the latest TB figures] the total number of TB patients in South Africa amounted to more than 480 000 which after India, China and Indonesia is the 7th highest number of cases in the world,” said Dr van der Walt.

The HIV rate in South Africa is the main cause for the high tuberculosis rate in South Africa. According to Dr van der Walt these two diseases ‘go hand in hand’. “People living with HIV are more susceptible to acquiring a TB infection; and TB in return is the main reason for deaths amongst people living with HIV. A person with TB who is infected with HIV, also progresses to active TB much faster due to a weakened immune system,” van der Walt added.  The latest research in treating co-infected HIV and TB patients indicated that the two diseases can be treated at the same time and not as in the past when HIV treatment was suspended until after the TB infection was cleared. Dr van der Walt says it is, however, important for the health worker to be aware of the co-infection so that the correct medication can be prescribed.

Research by the Tuberculosis Epidemiology and Intervention Research Unit of the SAMRC, has shown that multi-drug resistant and extensively drug resistant TB is prevalent in all the provinces in South Africa. It also appears that certain TB strains are beyond the stage of being extensively drug resistant. According to Dr van der Walt people with ‘normal TB’ or drug sensitive TB could face a risk of multi-drug resistant TB if they do not complete their treatment. “Once TB has formed a resistance against four of the strongest TB drugs, extensively drug resistant or XDT-TB emerges. Treatment for this type of TB could last for more than 24 months to clear the infection,” says Dr van der Walt.

In an interview with the Web and Media Technologies Division of the SAMRC, Dr van der Walt stressed the importance of research in the field of TB. She motivated this statement by explaining in more detail the purpose of her unit’s state-of-the-art AIR facility which is based at a TB treatment hospital in Witbank, South Africa. “TB is transmitted via the air. The Airborne Infectious Research facility (AIR) aims to facilitate research in how TB is transmitted and how infections can be prevented or minimized in highly populated areas such as prisons,” Dr van der Walt added. The air of patients who are suffering from active TB is controlled and exposed to guinea-pigs. It is then researched how TB infections can be curbed.

Find out more about the AIR facility by listening to the podcast: Part 1, Part 2 and Part 3. These podcasts are also available in Afrikaans: Deel 1, Deel 2, Deel 3.

For the latest WHO report on tuberculosis, visit http://www.who.int/tb/publications/global_report/en/

Author: Janus Snyders
Article approved by: Dr Martie van der Walt
Interim Director
Tuberculosis Epidemiology and Intervention Research Unit
South African Medical Research Council
Email: vdwalt@mrc.ac.za