Smoking 'could increase TB risk' (Research)

[Drkheyre]

Source: Irinnews
www.irinnews.org.

Smoking cigarettes may increase the risk of developing tuberculosis, a study has suggested. A team from Stellenbosch University, in South Africa, studied 2,400 people living in Cape Town. Some 82% of those who smoked, or who had done previously for at least a year, tested positive for TB, compared with 70% in the non-smokers' group. Writing in Thorax, the researchers say smoking might reduce the ability of the lungs to fight off infections.

"Smoking damages macrophages in the lungs, which are the first line of defence against infections" Professor Peter ramrod, British Thoracic Society All those who took part in the study were asked about their smoking habits and given a tuberculin skin test to check if they were infected with TB. People were defined as smokers if they had ever smoked for at least a year. Smokers were also asked the average number of cigarettes they had smoked each day.

Basic information such as age, sex, education level, body mass index, and income was also taken into account. Behaviour of 1,309 current smokers or ex-smokers, 1,070 (82%) had a positive skin test, compared with 70% (762) of the 1092 people who had never smoked. The more cigarettes someone had smoked over his life, the higher the risk was that they would have a positive test.

The researchers, TB Centre at Stellenbosch University, said the reason for the link was not confirmed. But they said smoking could reduce the lungs' ability to fight off infections, including TB. They stress further evidence is needed to investigate the association. And they said they could not discount the possibility that the link between TB infection and smoking was merely down to socio-economic and behavioural differences. "People who smoked would therefore be more at risk of acquiring TB."