The use of skin ulcer measurements to estimate immunity against tuberculosis in the guinea-pig

• Published in: Tubercle Vol. 40; no. 4; pp. 235 - 244
• Main Authors: Iland, C.N., Barker, Ruth M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.1959
• ISSN: 0041-3879
• DOI: 10.1016/S0041-3879(59)80111-2

Normal non-immune guinea-pigs after intradermal challenge with living vole bacilli develop ulcerated swellings which reach a maximum in about four weeks and then heal. Guinea-pigs vaccinated with BCG and then challenged with vole bacilli by the intradermal route also develop ulcerated swellings; but which are smaller, appear more rapidly and heal more quickly than in the non-immune animal. The speeds of development of hypersensitivity and immunity by the guinea-pig are reflected in the progress of these lesions and a comparison of their measurements in non-immune and vaccinated animals can be used for estimating the level of immunity. The comparison is more accurate if the effect of hypersensitivity is excluded and this was attempted by simultaneously challenging the animals in different sites with both killed and living vole bacilli. The measurements of the lesions produced by the ‘dead’ challenge were subtracted from those of the ‘living’ challenge and the resulting values were used in the assay. Using the technique described the method appears sensitive and precise. Statistically significant results can be obtained with a small number of animals and in a short time. The method therefore has advantages over mortality rate determinations.