Fungus occurs in North America and Japan. In EU pathogen was probably occured but misidentficated as Pucciniastrum vaccinii (Naohidemyces vaccini  in 2002 in Southereast Spain. In 2015 Thekopsora minima was reported in Germany (JKI 2015). Pest is not included in RL2000/29/EG list or EPPO list to this day.

Pathogen infects species of the genera Gaylussacia, Lyonia, Rhododendron (e.g. R. ponticum), Tsuga (T. canadensis, T. diversifolia), Vaccinium (V. angustifolium, V. corymbosum) (Sato et.all. 1993).

It is not known whether vaccinium species in PRA area are prone to fungal infections.

There is a likelihood of emergence of new strains with broad host species (incluing new ones) and  higher level of virulence (Newcomb et. all 2000).

Symptoms of infection appear on the upper surface of leaves and are easy to recognise. Optical microscope or DNA LSU and/or ITS rDNA sequencing are used to diagnose infection caused by Thekopsora minima (Maier i wsp. 2003, Schoch i wsp. 2012). Losses may be visible as declining in fruit yield (Vaccinnium spp) or as cosmetics damages (rhododendrons)

There is a likelihood that occurence of T. minima  may have high impact on cultivations of host plants in PRA area (Schilder et all. 2011). It is necessary to develop a new phytosanitary measures and include them in the current IPM strategies, in case of pathogen occurence in PRA area.