Pulmonary tuberculosis in the adult in a low prevalence area: is the radiological presentation changing?

Abstract

Setting: Pulmonary division of a university hospital in Belgium, an area with a relatively low tuberculosis incidence (14.9 per 100 000 population in 1993).

Objective: To evaluate whether 'unusual' radiographic presentations of pulmonary tuberculosis (PTB) have increased in recent years, especially in elderly and non-indigenous patients.

Design: Retrospective study of chest X-rays of 219 patients aged over 18 years with bacteriologically proven PTB in the period 1981-1990, including 92 elderly (> or =65 years) and 17 non-indigenous patients. 'Unusual' presentations consisted of solitary pleural effusion, isolated hilar or mediastinal lymphadenopathies, normal chest X-ray, lower lung field TB, nodular lesions, diffuse infiltrations and atelectasis.

Results: There was an increase in 'unusual' presentations, from 24% in 1981-1985 to 35% in 1986-1990, yet this was not statistically significant (P = 0.08). This increase tended to be more pronounced in the elderly age group, i.e., from 24% to 42% compared to 23% to 31% in the younger age group. The proportion of elderly patients in the group with 'unusual' findings was 44% in 1981-1985 and 48% in 1986-1990. In the non-indigenous group, the percentage of 'unusual' findings did not change between the two periods (40% versus 41%). The proportion of non-indigenous patients in the group with 'unusual' findings increased from 7% in 1981-1985 to 13% in 1986-1990; however, this difference was not significant.

Conclusions: In an area with low TB incidence, adult PTB still presents with the classical pattern of reactivation disease. Although not statistically significant, there is a trend towards a relative increase in the frequency of unusual presentations in recent years, which is most pronounced in the elderly and in non-indigenous adults.