In people infected with HIV, bacterial pneumonia is one of the commonest and most serious infections occurring.
A metanalysis of cohort and case control studies published in BioMed Central's open access journal BMC Medicine
finds that current smokers with HIV were at double the risk of bacterial pneumonia than non-smoking counterparts, but that when people stopped smoking their risk was reduced.
The metanalysis reanalysed the data of several thousand participants with HIV, from 14 studies based in USA, Europe and South Africa. Overall it appeared that current smoking was associated with a 70-100% increase in risk of bacterial pneumonia, compared to non-smokers, but that stopping smoking decreased this by about a third. This was independent of CD4 count or antiretroviral therapy.
Prof Paul Aveyard, from University of Oxford who led the study explained that, "Antiretroviral treatment means that people with HIV can have a normal life expectancy. However they still have substantially increased health risks compared to the general population, including risk of pneumonia. Our results show that smokers with HIV have twice the risk of bacterial pneumonia, but that stopping smoking can reduce this risk. In order to prevent this potentially life threatening lung disease we believe that smoking cessation programs should be promoted as part of HIV treatment."