The pack can be stored at 2-30°C and can be used until the printed expiry date. After the expiry date, the quality guarantee is no longer valid. Likewise, the usability of the cassettes cannot be guaranteed once the external packaging of the individual cassette has been damaged.
In a multi-centre study involving five different institutions, a total of 252 stool samples (which had been determined beforehan d using different methods and kept frozen for later use) were thawed and analysed using the Cryptosporidium/Giardia/Entamoeba Combi rapid assay. The individual results are listed in Table 1. The average sensitivity and specificity have been calculated from the individual results from the five validation centres.
Table 1 Results from a multi-centre study using the Cryptosporidium/Giardia/Entamoeba Combi rapid assay
Giardia lamblia is an intestinal flagellate. The morphologically characteristic Trophozoites only survive for a short time outside the host organism. Transmission takes place via the highly infectious cysts. Because it is spread world- wide, Giardia lamblia has become an important cause of chronic diarrhoeas, particularly in the case of problems in emporiatrics. The infection occurs after the ingestion of cysts in contaminated food and water. In communal facilities with inadequate hygiene, the infection usually occurs via the faecal-oral route from person to person. This mode of transmission is particularly common among children and in kindergartens, as well as among male homosexuals and prison inmates. The infection can also be passed on from children to parents. Unlike infants, older children who are infected can be free of the symptoms. Nevertheless, they excrete the cysts and can infect other humans. The symptoms of Giardiasis (Lambliasis) are acute or chronic diarrhoea. The incubation time is between 3 and 42 days. The method most frequently used to diagnose Giardiasis in the past has been the detection of cysts in the stool by microscopy, which can only be carried out by experienced personnel. The investigations also have to be carried out over a long period of time because the excretion of cysts fluctuates greatly.
Cryptosporidium parvum is a parasite which is very common in animals and occurs as an important pathogenic organism in domestic animals and particularly in calves. However, infections in humans are now observed in many countries more frequently than was previously assumed. In tropical developing countries, the parasite is often endemic and causes diarrhoea epidemics among children. With immunocompetent patients, the disease manifests itself as self-healing gastroenteritis. The diarrhoea lasts between 3 and 10 days and may be accompanied by fever and gastrointestinal symptoms such as nausea and pain, which resembles those of giardiasis (lambliasis). The symptoms and effects are substantially more serious with immunoincompetent patients, where diarrhoea persists and is very severe. The infection can be transmitted from animal to humans via contaminated water and from human to human. Members of communal facilities, children in kindergartens and the high-risk groups, homosexual men and patients infected with HIV, are particularly at risk. In the past, the methods most frequently used for the diagnosis of cryptosporidiosis were the microscopic detection of Oocysts in the stool or the microscopic examination of small intestine biopsy samples which can only be carried out by experienced personnel.
Across the world, up to 500 million people are infected with Entamoeba histolytica (sensu lato) every year. Molecular-genetic investigations have shown that the protozoa, which has been given the name Entamoeba histolytica and is identified using conventional diagnostic methods, consists of two morphologically indistinguishable species: the pathogenic species, Entamoeba histolytica sensu stricto and the non-pathogenic species (according to current knowledge), Entamoeba dispar. Roughly 90% of people with Entamoeba infections have E. dispar. The approximately 40-50 million cases of amoebic colitis or hepatic abscess which result in 80,000 deaths every year are caused by E. histolytica.
The life cycle of the Entamoeba is relatively straightforward. The infection is caused by the oral ingestion of cysts with four nuclei. In the small intestine, these develop into the single nucleus form of the parasite, the trophozoite (forma minuta), which multiplies and differentiates predominantly in the large intestine. Encapsulation is probably triggered by the environment in the lower region of the large in testine. Besides the cysts, trophozoites are only found in stools with accelerated intestinal passage.
The clinical symptoms of amoebiasis are triggered by the invasion of the parasite from the lumen of the bowels into the mucous membrane of the colon. Trophozoites with phagocytised erythrocytes are frequently found at the same time. These trophozoites are known as forma magna because of their size. The symptoms of invasion into the mucous membrane of the intestine are diarrhoea, dysentery or even amebomas. The complications which may occur after disseminate dispersion are hepatic abscesses, pulmonary abscesses or, in very rare cases, even cerebral abscesses which, if untreated, usually end in death.