Abdominal Tuberculosis in Children and Adolescents: to this Day a Diagnostic Challenge

Background

Infection with Mycobacterium tuberculosis (TB) affects mostly the lung, whereas about one eighth of cases are extra pulmonary infections. For extra pulmonary manifestations, the abdomen is affected in 11–16%, the intestine being involved in almost half of these cases (Khan R et al. World J Gastroenterol 2006; 12: 6371–6375). Possible routes of abdominal TB infection are: by reactivation of a silent focus acquired in the past or by infection spreading to the abdomen via swallowed (infectious) sputum, hematogenously or per continuitatem from an infected neighbouring organ. In developing countries, abdominal TB may also result from infection with Mycobacterium bovis by drinking infected cow milk or eating uncooked meat. As in many developing countries bovine TB is still endemic humans in these areas are at higher risk for TB due to infection with Mycobacterium bovis.

In the bowel, inflammation can result in ulcerative lesions with risk of bleeding, perforation, fistula or obstruction. Abdominal TB may pose a major challenge to the clinician (Chiappini E et al. J Pediatr Gastroenterol Nutr 2009; 49: 550–558). Many features of the disease can also occur in patients with inflammatory bowel disease (IBD), especially Crohn’s disease (Makharia GK et al. Am J Gastroenterol 2010; 105: 642–651), for example: fever, night sweats, weight loss, raised acute phase markers, anaemia, leucocytosis, thrombocytosis and symptoms of obstruction.

In developed countries the incidence of TB is much lower when compared to developing countries and even Eastern Europe, this is due to higher standards in hygiene, medical care and lower incidence rates for human immunodeficiency virus (HIV) infections in developed countries. Since 2002, a decreasing incidence rate of 1.3% per year is recognized worldwide, while the incidence rate (per 100 000 population) in 2010 was 128. The total number of infections is also decreasing, for 2010 worldwide 12 million TB infections were expected.

In Germany, a gradual decrease in TB total infection rates over the last years were observed as well. In 2010, 4 800 infections were registered (Tuberculosis country profiles: Germany. Available from: www.who.int/tb/country/data/profiles/en/index.html). The incidence rates differ between German domestic population and resident immigrants from high incidence areas: 4 per 100 000 persons and 20 per 100 000 persons, respectively (Robert Koch Institut 2011. See also: edoc.rki.de/series/rki-bericht-zur-epidemiologie-der-tuberkulose-in-deutschland/2009/PDF/2009.pdf). This difference in incidence is also seen in children: 0.9 vs. 6.4 per 100 000. For Germany, the rate of extra pulmonary TB alone was 19.8% in 2009 (mostly infection of lymph nodes).