Extrapulmonary TB: discrepancies in prevalence between the EU and individual countries

Extrapulmonary tuberculosis (TB) constitutes <6% of all TB cases in Poland. This number is much below the European Union average, which is about 22%. What might be the reasons for such a discrepancy, given that the prevalence of TB in Poland is about 18/100,000 and is significantly higher than in most EU countries? Could this mean that many cases of extrapulmonary TB are underdiagnosed in Poland?

Lori Whitehead: Underdiagnosis is always a possibility, and we know that extrapulmonary TB is much more difficult to diagnose than pulmonary TB, but I would doubt that that is the case in Poland. In most cases, extrapulmonary TB occurs about 30% of the time, and pulmonary TB 70% of the time. The things that will influence and cause a higher rate of extrapulmonary TB would be things like immunocompromised state, for example, with human immunodeficiency virus (HIV)-positive people and people with AIDS, it is 50/50 whether it is extrapulmonary or pulmonary TB. The other thing that increases the incidence, or the prevalence I should say, of extrapulmonary TB is if pulmonary TB starts, the diagnosis was missed, and then it disseminates.

I believe that health care in Poland is good, I believe that the public health measures are very solid, and I would state that probably you have a healthier population than some other countries. I think it probably speaks in favor of the fact that there is early detection and treatment of TB, rather than letting it ruin the lungs and go extrapulmonary. I would also hope that in your country there is more surveillance for people who are on biologic agents, people who have HIV positivity, people who are susceptible to go on and disseminate and get extrapulmonary TB; I would hope that there is more publicly controlled measures in place that detect this early and before it gets to that stage. It is a curious observation actually.