Setting: Health services in Khartoum, Red Sea, Gadarif, Kassala, Bahr el Jebel, Gezira and North Kordofan States of Sudan.
Objective: To investigate the association of presenting symptoms and clinical history with grade of sputum smear positivity in tuberculosis patients.
Methods: The 5338 tuberculosis suspects aged 15 to 49 years who consulted between March 1998 and March 1999 underwent sputum smear microscopy, with smears graded by a standardised method. Patients who gave consent had a structured interview concerning the nature and duration of their symptoms and whether they had a sick relative at home. Statistical analysis determined the association of symptoms and home characteristics with the results of smear examination.
Results: A total of 514 suspects (9.6%) demonstrated acid-fast bacilli: 45 (8.8%) grade +1, 167 (32.5%) grade +2 and 302 (58.8%) grade +3. Most of the patients had a duration of symptoms of 6-9 weeks, while 100 had symptoms of more than one year's duration, many (n = 47) with other chronic respiratory diseases. Multiple chest symptoms were positively, and duration of symptoms negatively associated with grade of positivity (P = 0.018 and 0.028, respectively). A high grade of smear positivity (+3) and the longest duration of symptoms, among those reporting symptoms of less than one year's duration, were significant predictors of the presence of a sick household member (OR = 1.99, 95%CI 1.12-3.55; OR = 1.004, 95%CI 1.000-1.008).
Conclusion: This study demonstrates a relation between the grade of smear positivity and the clinical features of tuberculosis patients.