Asian Pac J Trop Biomed 2013; 3(11): 916-924 916 Contents lists available at ScienceDirect Asian Pacific Journal of Tropical Biomedicine journal homepage: www.elsevier.com/locate/apjtb Document heading doi: 10.1016/S2221-1691(13)60179-3 2013 by the Asian Pacific Journal of Tropical Biomedicine. All rights reserved. 襃 Cryptosporidiosis as threatening health problem: A review Nurul Fariza Rossle*, Baha Latif Faculty of Medicine, Universiti Teknologi MARA, Jalan Hospital, 47000 Sungai Buloh, Selangor, Malaysia PEER REVIEW ABSTRACT Peer reviewer Cryptosporidium The protozoa under the genus is a zoonotic apicomplexan oCryptosporidiumbligate intracellular Dr. Xue-jie Yu, Professor, University parasite. Cryptosporidiosis, the term used to designate infection caused by sp., of Texas Medical Branch, Galveston, is considered as one of the most common food and waterborne diseases with worldwide spread, 409 772 1786 - , USA. Professor and Dean, Cryptosporidiumacting as a common cause of diarrhoea in animals and man. In immunocompetent individuals, School of Public Health, Shandong typically induces self-limiting diarrhoea, which may resolve on its own after 2-3 University, Jinan, China. d. However, cryptosporidiosis may turn life-threatening and subsequently lead to death in small E AIDS -mail: [email protected] chilCryptosporidiumdren, the elderly and immunocompromised person, especially in patient. The diagnosis Comments for infection is uμsually carried out through examination of stool for the presence of oocysts which measured 4-6 m with spherical appearance. Morphometric identification is This is a nice review article that often difficult because of thCryptosporidiume diminutive size and obscure internal structure of the protozoa. has summarized information on Often, the identification of is realised through the combination of methods cryptosporidiosis including classic incorporating data from morphometrics, molecular techniques, and host specificity. However, microbiology, epidemiology, clinical limitations to some of these techniques still exist whether because of cost, duration, expertise, or manifestations, diagnosis and reliability. Drugs combination is implemented in treatmen tStreptomyces of cryptosporidiosis. The efficiency treatments based on articles published of paromomycin, an aminocyclitol antibiotic isolated from , can be effective when from 1907 to 2013. Information in this 12 combined use with proteaCryptosporidiumse inhibitors or recombinant IL- . Since there is no drug that achieves article will give physicians and young the complete removal of from the host, supportive therapy was preferred in both scientists a comprehensive overview human and domestic animals. on cryptosporidiosis and this article will be helpful in controlling and KEYWORDS prevention of cryptosporidiosis. Cryptosporidium Details on Page 920 , Prevalence, Taxonomy, Outbreak, Diagnosis 1. Introduction [7] human casesCryptosporidium of cryptosporidiosis . Initially, sp. was reported by Tyzzer as C [8] ryptosporidiosis is a zoonotic proCryptosporidiumtozoal disease infective in mice , and then was pushed to the background caused by coccidial species of the genus until the first human case noted in 1976[9,10]. Afterwards, and which is reported in more than 40 countries in the more concerns over cryptosporidiosis have arisen since [1] I AIDS [11] world . n stool surveys of pCryptosporidiumatients with gastroenteritis, it was determined to cause death in one patient . the reported prevalence of is 1%-4% Mainly, cryptosporidiosis is responsible for acute self- in Europe and North America and 1%-37% in Africa, limiting diarrhoea in immunocompetent persons and life- A A S C A [2-6] sia, ustralia,Cryptosporidium and outh and entral merica . threatening diarrhoea in immunocompromised persons, In most cases, infection results in particularly in persons receiving immunosuppressive drugs AIDS [12] gastrointestinal problems such as severe diarrhoea in both and patients . C. hominis A A ( immunocompromiseCryptosporidiumd and immunocompetent people. mong mong all iC.de nparvumtified species, previously I) tCryptosporidiumhe five commo nparvum C. parvum specCryptosporidiumies in humans, known as the C. parvum genotype almost exclusiveC.ly ( ) ( hominis C. hominis and parvuminfects humans. previously known as the ( ) are responsible for more than 90% of genotype II) has a wide range of hosts including *Corresponding author: Nurul Fariza Rossle, Institute of Medical Molecular Article history: Biotechnology, Faculty of Medicine, Universiti Teknologi MARA, Jalan Hospital, 47000 Received 20 Aug 2013 Sungai Buloh, Selangor, Malaysia. Received in revised form 27 Aug, 2nd revised form 5 Sep, 3rd revised form 10 Sep 2013 Tel: +603 6126 7396 Accepted 20 Oct 2013 Fax: +603 6126 7073 Available online 28 Nov 2013 E-mail: [email protected] Foundation Project: This study was part of the project funded by MARA University of Technology Excellence Fund [Grant No. 600-RMI/ST/DANA 5/3/Dst (334/2011)]. Nurul Fariza Rossle and Baha Latif/Asian Pac J Trop Biomed 2013; 3(11): 916-924 917 II I humans and animals and has Cryptosporidiumbeen considere dcanis, as a into type meront or complete another cycle of type zoonotic species. Furthermore, meronts[25]. Type II meronts produce four merozoites which Cryptosporidium meleagridis, Cryptosporidium felis, [24,26] Cryptosporidium andersoni, Cryptosporidium muris become microgamonts or macrogamonts . F Cryptosporidium suis , ertilization between gamonts results in formation and have also been isolated from of a zygote which develops into oocyst containing four immunocompetent humans[13-15]. sporozoites[24,27]. Two types of oocysts are produced, thick- Cryptosporidiosis has a higher incidence in developing walled oocysts which are excreted in the faeces and thin- countries, especially in children, institutionalized patients, walled oocysts which re-circulate in the intestinal tract (AIDS) [11,24,26] T malnCryptosporidiumourished, and immunocompromised individuals causing autoinfection . his phenomenon may explain [16]. mostly infects children less than five the mechanism of persistent infection in AIDS patients in the years old and peaks for children less than two years old[17]. absence of subsequent oocyst exposure[2]. In industrialised countries, cryptosporidiosis also occurs [7,18] in adults due to foodborne or waterborne outbreaks . 3. Taxonomy Currently, nitazoxanide (Alinia) is approved for treatment of cryptosporidiosis in children and immunocompetent adults USA H I 1907 T in the . owever, nitazoxanide is not effective without an Cryptosporidium n , yzzer was the first to discover the genus appropriate immune response and is therefore ineffective who described it as a coccidian- [19] against immunocompromised individuals . lCryptosporidiumike organism in thmurise stomach of mice, which he named [8,28]. Later, Tyzzer discovered 2. Morphology and life cycle a second isCryptosporidiumolate in the sma lparvuml intestine of mice, which [29] H he named Cryptosporidium. ence, species Cryptosporidium nomenclature within the genus was initially O 4 6 60 μ ocysts of sp. are small, measuring - based on host occurrence, which led to more than [20] T [24] T m in diameCryptosporidiumter and are spherical-to-ovoid in shape . he species being described . he claCryptosporidiumssification based only on life cycle of is completed in a single host. It morphology has been difficult as species T involves both asexual and sexual stages. here are six major are morphologicaCryptosporidiumlly identical. developmental stages as described by Tzipori and Ward[2], Until recently, was classified as belonging which are excystation, merogony, gametogony, fertilization to the family Cryptosporidiidae, suborder Eimeriorina and E [30] and zygote development, formation of environmentally oToxoplasma,rder ucocc iCyclospora,diorida , w Isosporahich also inclSarcocystisudes in its ranks resistant oocyst wall, and sporogony (Figure 1)[21]. and [31]. To b S Cryptosporidium j Thick-walled porozoite c Trophozoite T I M a Ocyst d ype eront e date, over 20 species and 60 genotypes of oocyst (spourlated) exits host have been classified with invalidation of somCryptosporidiume old ones and introduction of new others[15,32]. Of these, Auto-infection parvum Cryptosporidium hominis Asexual Cycel k and are the most common Thin-walled [33] oogyst species causing the disease in human (Table 1). (sporulated) Eerozoite Table 1 Microgamont Cryptosporidium Microgametes f Recognized species in the genus . Undifferentiated g Gamont Type II Meront Species Host Reference C. hominis Merozoites Human [34] Macrogamont Sexual Cycle C. parvum [35] h Cattle, human i C. andersoni Cattle [36] Figure 1. Cryptosporidium C. muris Life cycle of sp. consisting of asexual and sexual Rodent [37] C. suis stages. Pig [38,39] C. felis Infection starts with the ingestion of the oocysts by Cat [40] C. canis the host. Oocyst is the exogenous stage, containing four Dog [41] C. wrairi Guinea pig [42] sporozoites within a tough two-layered wall excreted in C. baileyi [22] O Poultry [43] the faeces . ocyst stage is environmentally stable, able C. meleagridis Turkey, human, zoo birds [13,40,44-45] to survive through routine wastewater treatment and is C. bovis Cattle, sheep [46] resistant to inactivation by commonly used drinking water C. galli [23] Finches, chicken [47] disinfectants . C. serpentis Reptile [48] After oocysts are ingested via contaminated food or water, C. saurophilum Lizard, snake [14,49] from fomites,