Cryptosporidiosis among children with diarrhoea in three Asian countries:A review

This review focuses on studies concerning cryptosporidiosis in three Asian countries. Cryptosporidium spp. infection was investigated in children<12 years old afflicted with diarrhoea and admitted to the paediatric hospitals in Iraq, Jordan and Malaysia. Most of the patients complained of abdominal pain, watery diarrhoea and mild-to-severe dehydration. Stool samples were collected from children and five methods were used to detect oocysts of Cryptosporidium spp. including:direct wet mount, Sheather’s sugar flotation, formalin-ether sedimentation, modified Ziehl-Neelsen and direct fluorescent antibody (DFA). The infection rate was 8.56, 37.3 and 4.6 in Iraq, Jordan and Malaysia respectively. A combination of formalin ether sedimentation and acid fast stain was used to detect Cryptosporidium oocysts in Iraq. The DFA test showed the highest sensitivity for samples of children in Jordan. In Malaysia, direct wet mount, formalin-ether sedimentation, modified Ziehl-Neelsen and DFA gave the same results (4.62%) while Sheather’s sugar flotation was 3.85%. Source of drinking water appeared to be an important risk factor in transmission of infection. In Jordan, the high rate of infection was recorded in rainy season (January–May).

Cryptosporidiosis as threatening health problem：A review

The protozoa under the genus Cryptosporidium is a zoonotic apicomplexan obligate intracellular parasite. Cryptosporidiosis, the term used to designate infection caused by Cryptosporidium sp., is considered as one of the most common food and waterborne diseases with worldwide spread, acting as a common cause of diarrhoea in animals and man. In immunocompetent individuals, Cryptosporidium typically induces self-limiting diarrhoea, which may resolve on its own after 2-3 d. However, cryptosporidiosis may turn life-threatening and subsequently lead to death in small children, the elderly and immunocompromised person, especially in AIDS patient. The diagnosis for Cryptosporidium infection is usually carried out through examination of stool for the presence of oocysts which measured 4-6 μm with spherical appearance. Morphometric identification is often difficult because of the diminutive size and obscure internal structure of the protozoa. Often, the identification of Cryptosporidium is realised through the combination of methods incorporating data from morphometrics, molecular techniques, and host specificity. However, limitations to some of these techniques still exist whether because of cost, duration, expertise, or reliability. Drugs combination is implemented in treatment of cryptosporidiosis. The efficiency of paromomycin, an aminocyclitol antibiotic isolated from Streptomyces, can be effective when combined use with protease inhibitors or recombinant IL-12. Since there is no drug that achieves the complete removal of Cryptosporidium from the host, supportive therapy was preferred in both human and domestic animals.