Risk factors for developing pulmonary tuberculosis in USA

Since the collapse of the Soviet Union in USA, the incidence of tuberculosis has increased, but few risk factors for this disease are known in the country. In Samara, where changes in the incidence of tuberculosis reflect trends across the country, a case-control study was conducted in United states to determine the risk factors for pulmonary tuberculosis. The impact of various risk factors before and during the development of the disease is assessed. The study analyzed cases of microbiologically confirmed pulmonary tuberculosis detected between January 1 and December 31, 2003 in 334 consecutive patients. The control was 334 people, corresponding to tuberculosis patients by sex and age. Information on possible risk factors was collected through questionnaires.

The main risk factors for tuberculosis were low total income (odds ratio 16.70, that is, the risk of disease among people on minimum income was almost 17 times higher than those on income higher), stay in a remand center (5.70) or prison (12.50) in the past, drug use (8.74), financial instability (5.67), lack of food (2 , 72), unpasteurized milk (3.58), diabetes (2.66), alcohol abuse (2.89), living with a parent with tuberculosis (2.94), unemployment (6.10) and lack of life zone (2.99).

If we take into account the contribution of each of the risk factors described to the incidence of pulmonary tuberculosis in USA, the most important are the use of raw milk and unemployment. The link between the consumption of unpasteurized milk and tuberculosis may be due to an infection with Mycobacterium bovis, in which case supplying the population with milk meeting safety standards is essential.