Cough aerosol production in patients with pulmonary tuberculosis with and without HIV infection
RATIONALE: Infectivity of patients with pulmonary tuberculosis who are HIV infected is not clear compared to those who are non-HIV infected. There is an association between cough aerosol production and T.B transmission with great variability in the amount of aerosol produced by infected patients; therefore aerosol production can be used as surrogate marker of infectivity OBJECTIVES: To evaluate the amount of cough aerosol produced in patients with pulmonary tuberculosis who are HIV infected compared to those who are non-HIV infected; and to evaluate the association between immunosuppression and aerosol production. METHODS: Data from two different cohorts with available information on the amount of cough aerosol produced and HIV status were merged to increase validity of the study Measurements and main results: Secondary data analysis performed on the merged data using the amount of mycobacterial tuberculosis colony forming unit produced in cough aerosol by patients with pulmonary tuberculosis as our outcome variable and compared HIV infected patients with non-HIV infected; thereafter in the HIV-subgroup we ran data analysis to evaluate the association between aerosol production and degree T-cell count. CONCLUSION: HIV infection is associated with decrease aerosol production in patients with pulmonary tuberculosis, other factor included degree of AFB smear the duration on TB treatment before aerosol collection modified this association. In HIV infected person the degree of immunosuppression dose not correlate with the amount of aerosol produced.