Down’s syndrome (DS) or trisomy 21 is the most frequently identified cause of mental disability [1,2]. Individuals with DS differ considerably in language and communication skills. Down’s syndrome is often associated with some impairment of cognitive ability, physical growth and a typical facial appearance [1-3]. The trisomy is a risk factor for several diseases such as congenital heart disease and leukemia, premature aging and recurrent infections, especially pulmonary infections, because of impaired cellular immunity [3-6]. Immunological investigation of a small number of DS patients with tuberculosis (TB) has shown no consistent defect [7]. The immune cellular status in children with DS is similar to that of the normal population as far as white blood cell, lymphocyte, CD4(+), CD8(+), natural killer and immunoglobulins are concerned [8], and maturation of T lymphocytes may be impaired in healthy young individuals with DS [9]. Although common, illness in people with intellectual disabilities may be under diagnosed and poorly managed [10]. The life expectancy for people with DS has increased substantially so that it is now common for a person with DS to live to age 50 years and beyond [1,3].

Tuberculosis is an infectious, treatable, and potentially lethal disease caused by the Mycobacterium tuberculosis (M. tuberculosis, M. bovis and M. africanum) complex. It usually affects lungs, but TB bacilli can spread to other sites, leading to extrapulmonary TB, especially in immune deficient persons. Few cases of TB in patients with DS have been reported but all reflected extrapulmonary disease with rare or severe complications [11-14]. The greatest single risk factor for developing active TB in an infected person is concurrent infection with human immune deficiency virus (HIV) [15,16]. Sputum smear microscopy can document Mycobacteria and a positive culture result for M. tuberculosis is the golden diagnostic standard in TB. Isolation of the bacillus makes it possible to perform drug resistance testing.

Case Report. A 37-year-old woman with DS was admitted to the Pulmonology Department. Despite antibiotic therapy, she had a subfebrile temperature of 2-month duration, and nodular and patchy shadows over the right pulmonary base (Figure 1). She had a history of recurrent upper and lower respiratory tract infections and no history of TB. She received the BCG (bacille Calmette Guerin) vaccination at birth.

She was without cough, pale, asthenic, of sub-average height, upset, frightened, uncommunicative and with signs of dementia. She had a speech disability and looked like a person with accelerated aging. The erythrocyte sedimentation rate was 80mm/first hour. She was mildly anemic and HIV-seronegative. The lungs were clear to auscultation. Besides nodular and patchy shadows on the right lower pulmonary lobe, the chest X-ray showed calcification in bronchopulmonary lymph nodes bilaterally, especially in the right pulmonary hilar region, and a calcified 7  4 mm density in the right axillary lymph nodes (Figure 1). The latter suggested a previous hematogenous dissemination that occurred most probably during primary TB. The tuberculin skin test (TST) PPD₃ was negative.

It was not possible to obtain a sputum sample for bacteriological examination. Apart from the standard bacteriological analysis, an oral brushing sample was taken for acid fast bacilli (the result was negative) and the material was cultured on Lowenstein-Jenssen medium.

Before the culture result confirmed M. tuberculosis, we established a diagnosis of TB on the basis of: 1) the patient’s history, 2) clinical features, 3) radiographic changes suggestive to previous (disseminated) TB, 4) the presence of TB risk factors such as stress and malnutrition, and 5) belonging to a risk group for developing TB from home in an intermediate TB incidence country [17,18]. Treatment was initiated following a standardized anti-tuberculosis drug regimen. She became afebrile very soon and started to gain weight. Positive culture results of oral mucosa brushing for M. tuberculosis confirmed the diagnosis of TB. The bacillus was sensitive to all the first-line anti-tuberculosis drugs tested.