Sputum Conversion Among Patients With Smear Positive Pulmonary Tuberculosis

Introduction: In the patients with smear-positive pulmonary tuberculosis (TB) bacteriologic assessment of sputum for detection of acid bacilli (AFB) Has essential role. This evaluation is accomplished by direct sputum smear & sputum culture. These examinations must be done in regular and preferably monthly after beginning of treatment. These tests have two important aims, including, determining of treatment efficacy & duration of isolation."nMethods and Materials: Most of the studies have that classic six month regimen led to sputum smear conversion & negative sputum culture in 85% of patient. This treatment regimen has two phases, including, attack phase and maintenance phase. In the attack phase we use four drugs, including, Isoniazid (INH), Rifampin (RMP), Pyrazinamide (PZA) and Ethambutol (EMB) for the first 2 months and if necessary until the end of third month. In the maintenance phase we use INH and Rif for the remaining of treatment course. The main objectives of this study were to determine the time needed for smear conversion and assessment of probable factors which may influence the smear conversion until 4 months after beginning of therapy. The factors that were assessed, were, Age, nationality, sex, clinical symptoms, underlying diseases, chest radiography (number of cavities), smoking, drug abuse and concentration of AF13 in the sputum Generally, we did this cross sectional study on the patient's records, who had been observed in Imam Khomeni Hospital, west health service center and masih daneshvary hospital between."nResults: This study showed that from totally 218 patients, 138(74.6%) patients had sputum conversion at the first 2 months of treatment and until the end of 3rd & 4th month this rate reached to 83.3% respectively. So in the end of fourth month only 32(14.7%) patients did not show sputum smear conversion. On the other hand this study showed that two factors including presence of cavities in chest radiography & concentration of AFB in the sputum are influencing this rate strongly."nConclusion: Role of other factors such as age, nationality , Smoking, diabetes mellitus and weigh loss are controversial and another studies are necessary for confirming their roles. Other factors including sex, clinical symptoms has not been show to be important. Some factors such as drug abuse and immunosuppresive therapy has not been assessed in this study, because number of cases were not enough for statistical analysis.