[Epidemiology of spondylarthritides]

Epidemiologic studies on spondyloarttritides (SpA) encompass mode descriptions on disease appearance within the population, levels of disease frequency: incidence and prevalence, comorbidity, mortality, geographical distribution and clinical features, as well as risk factors for disease appearance. Ethnical, genetic, environmental performers are linked with appearance and expression of the disease. Clear distinction among SpA subgroups, especially in their early phases might not always be possible due to clinical picture overlapping, thus within the initial phase of the disease, the diagnosis of certain SpA diseases might be underestimated. SpA prevalence with various different populations varies between 0.21% up to 1.9% worldwide, and it varies between 1% up to 2% within Europe. With Eskimo population on Alaska and population of Siberia, prevalence rates appear to be from 2% up to 3.4%. SpA are rare with African and Japanese populations. Differences between ethnical groups might be explained by different criteria for selection of a target population, but with differences in HLA-B27 frequency as well. HLA-B27 subtypes distribution plays significant impact on AS prevalence with different race/ethnical groups. Challenges that aggravate the exact evaluation of the SpA diseases with the population, include comprise heterogeneity of population, lack of application feasibility of valid criteria (like testing on HLA-B27 antigen, pelvis radiography and MR), but also transition issue of certain SpA symptoms (eg. peripheral arthritis, enthesitis). Spondyloarthtritis (SpA) present a serious health, social and economical problem everywhere in the world. Uniform data for all populations are significant for making a proper picture on this disease group arduousness, and for epidemiological studies such data, because of their mutual overlapping, should be united within one single group.