Editor—Campbell and Bah-Sow describe the varied patterns of abnormality in chest radiographs in patients with pulmonary tuberculosis, appearances often being less specific in immunocompromised patients.1 We agree that a high index of suspicion is necessary in such patients and highlight the inadequacy of a chest radiograph in excluding pulmonary tuberculosis.
Our hospital is in a major suburban town in Greater London and has an ethnically diverse and unusually mobile population. In the past 12 months, 16% of cases of pulmonary tuberculosis (excluding mediastinal lymphadenitis and pleural disease) had co-infection with HIV. In one such case the chest radiograph was completely normal while sputum was smear positive.
Figure 1.
Credit: CDC
This occurs more often than we expected: in 2004 a paper from Addis Ababa showed that 9.2% of patients with HIV and culture proved pulmonary tuberculosis had a normal chest radiograph.2 An earlier paper from Rome showed that 9% of patients who were HIV positive and sputum culture positive had a normal chest radiograph and were sputum smear negative. Although these patients were no different in demographic characteristics, degree of immunosuppression, or Mycobacterium tuberculosis drug susceptibility pattern, they had an increased risk of death and shorter median survival.3 In a series from New York, 14% of patients with coinfection (HIV or culture positive for tuberculosis) had a normal chest radiograph, and this rose to 21% when patients with low CD4 counts were considered (< 200).4
Competing interests: None declared.
References
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