COMPARISON BETWEEN THREE LABORATORY METHODS FOR THE DIAGNOSIS OF CRYPTOSPORIDIUM

Abstract

Introduction: Human cryptosporidiosis is caused by infection with apicomplexan protozoan of the genus Cryptosporidium (C. hominis and C. parvum). Cryptosporidium is widely recognised as a cause of acute gastroenteritis with diarrhoea, abdominal pain, nausea or vomiting. It mainly affects children but can presents as a potentially life-threatening disease in immunocompromised individuals. The aim of this study is to compare three different methods for the detection of Cryptosporidium: modified Ziehl-Neelsen acid-fast (MZN-AF) stain, ELISA Cryptosporidium Ag test and quick immunochromatographic test in the scope of their utility as diagnostic procedures in patients with diarrhoea. Materials and Methods: The three methods were used for laboratory testing of outpatient and hospitalized individuals with diarrhoea, abdominal pain and other unspecific symptoms of GI tract. Results and Discussion: MZN-AF staining is used to confirm the presence of Cryptosporidium oocysts in faecal smear. This method is very specific but less sensitive for the laboratory diagnosis and requires an experienced microscopist for interpretation of the results. ELISA Cryptosporidium Ag test is an enzyme immunoassay for the determination of Cryptosporidium parvum and Cryptosporidium hominis antigens in human stool samples and requires trained laboratory technician and specialised equipment for its execution. Cryptosporidium/Giardia Combi immunochromatographic test is quick and easily performed procedure for in vitro determination of Cryptosporidium and/or Giardia duodenalis antigens in stool samples. Both immunological tests have good sensitivity and specificity. Conclusions: MZN-AF staining stool concentration is the gold standard in clinical laboratories due to its specificity and affordability. Immunochromatographic test is the method of choice for quick identification of intestinal protozoan parasites as a cause of diarrheal infection in both outpatient and hospitalized patients for their proper and swift etiological treatment.