THE WARTHIN-STARRY STAIN IN THE DIAGNOSIS OF SMALL-INTESTINAL MICROSPORIDIOSIS IN HIV-INFECTED PATIENTS

A protocol for the handling of small intestinal biopsies from HIV-infe cted patients is presented. This protocol includes the Warthin-Starry stain for the detection of microsporidia. This stain has proved a reli able and sensitive diagnostic technique for micro-sporidial sporidial infections as it stains both Enterocytozoon bieneusi and Septata intes tinalis in duodenal enterocytes. Because the stain demonstrates Septat a intestinalis in lamina propria macrophages as well as enterocytes, i t allows for the practical differentiation of these two microsporidial infections. The Warthin-Starry stain has also demonstrated Septata in testinalis in nasal and colonic biopsies in some of these patients. Si nce the completion of an earlier study, a further 40 cases of Enterocy tozoon bieneusi and three cases of Septata intestinalis have been diag nosed in just over 240 consecutive duodenal biopsies from HIV positive patients presenting with diarrhoea and other gastrointestinal complai nts. Other opportunistic infections include cytomegalovirus in four ca ses, mycobacteria in eight cases, cryptosporidia in nine cases, giardi a in four cases and Isospora belli in one case. Since the ratio of the se opportunistic infections has remained much the same as in the previ ous study of 180 consecutive duodenal biopsies, we suggest that these rates may reflect the actual prevalence of microsporidial infections i n AIDS patients in Sydney, Australia.