Cryptosporidium oocysts were searched by Heine 's method in stools of nine cal/s with cryptoporidiosis after stool treatment with two disinfectants, 10% paraformaldehyde solution and 14,5% sodium hypochlorite solution. After 30 minutes exposition to sodium hypochlorite solution oocysts became non refractile and acquired a reddish tinge, making their Identification difficult. No morphological alterations occured in oocysts after paraformaldehyde treatment. We recommend paraformaldehyde at 10% concentration as means of human immunodeficiency virus (HIV) inactivation for routine use in stool examinations and therefore making safer those type of procedures for laboratory personnel, when using Heine 's method.
Cryptosporidiosis; Heine's method; Disinfectants; Human immunodeficiency virus (HIV) inactivation