Effects of grinding surgical tissue specimens and smear staining methods on Buruli ulcer microscopic diagnosis

To optimize Buruli ulcer (BU) microscopic diagnosis, we compared two smear preparation methods from tissue specimens: smears made with tissue suspension after grinding and smears made directly with unground tissue. We also compared two smear staining methods: auramine and Ziehl-Neelsen (ZN). IS 2404-PCR was used as reference method. One hundred and thirty-one surgical tissue specimens from patients suspected of having BU were analyzed. Both smear preparation methods and both staining methods were equivalent in any combination. Thus we recommend ZN stained smears of unground tissue for peripheral treatment centres.