A multitude of dyes but unsatisfactory staining: Physico-chemical profile and factors associated with staining quality of Romanowsky-type stains used for malaria microscopy in Plateau State, Nigeria

Introduction There is paucity of studies done to assess the composition and staining quality of Romanosky-type stains used for malaria microscopy in Nigeria. Methods We conducted a cross-sectional study among 92 laboratory facilities and subjected them to UV-spectroscopy, HPLC, GC, ashing and pH measurement. We conducted multivariable binary logistic regression analysis at p<0.05. Result Of 94 stains, 38(40.4%) were Field, 36(38.3%) were Giemsa, and 20(21.3%) were Leishman stains. Overall, 23.7%, 33.3% and 25.0% of Field, Giemsa and Leishman stains respectively yielded satisfactory staining. Predictors of staining quality were proportion of Azure B>20% (aOR = 15.1, 95% CI = 2.62-115.00); Azure B to Eosin Y ratio >1.5 (aOR = 4.55, 95% CI = 1.03-25.10); and alcoholic solvent (aOR = 27.70, 95% CI = 2.43-462.00). Conclusion Romanowsky-type stains used for malaria microscopy in Plateau State were of variable composition and mostly lacked the RGE-relevant dyes required for good nuclear and cytoplasmic differentiation of malaria parasites.