Acta Tropica 115 (2010) 77–83 Contents lists available at ScienceDirect Acta Tropica journal homepage: www.elsevier.com/locate/actatropica Molecular characterization of Cryptosporidium isolates from humans in Ethiopia Haileeyesus Adamu a , Beyene Petros a , Asrat Hailu b , Franz Petry c,∗ a Department of Biology, Biomedical Sciences Stream, Addis Ababa University, PO Box 42524, Addis Ababa, Ethiopia b Department of Microbiology, Immunology & Parasitology, Addis Ababa University, PO Box 28017/1000, Addis Ababa, Ethiopia c Institute of Medical Microbiology & Hygiene, University Medical Center Mainz, Augustusplatz/Hochhaus, D-55131 Mainz, Germany article info Article history: Available online 4 March 2010 Keywords: Cryptosporidium Epidemiology Genotyping Sequencing Ethiopia abstract In this study, 1034 faecal samples from patients with diarrhoea were screened for Cryptosporidium oocysts. Samples were collected from nine different regions in Ethiopia. Of these, 79 samples (7.6%) were positive for Cryptosporidium by modified Ziehl-Neelson staining. From all positive samples DNA was extracted and PCR amplification of the COWP, SSU-rRNA and GP60 gene fragments was performed. A total of 41 samples (52%) were positive in any of the three typing methods. The majority of isolates (39 of 41) was identified as Cryptosporidium parvum, with one Cryptosporidium hominis and one mixed infection. Sequencing of the GP60 gene fragments of 13 isolates resulted in three different subgenotypes of C. parvum, all belonging to the zoonotic subtype family IIa and one subtype of C. hominis (Ib). These data identify C. parvum as the major cause of human cryptosporidiosis in Ethiopia and suggest a zoonotic transmission of the disease in contrast to reports from other developing countries. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Cryptosporidiosis is caused by protozoan coccidial parasites of the genus Cryptosporidium and it is reported in more than 40 countries in the world (Dillingham et al., 2002). Cryptosporidium infection continues to be a significant health problem in both devel- oped and developing countries (Harp, 2003), where it is recognized as an important cause of diarrhoea in both immunocompromised and immunocompetent people. The diarrhoea can become chronic and life-threatening in immunocompromised persons and children younger than 5 years of age. Persistent diarrhoea is the leading cause of death in children under 5 years of age in developing coun- tries, where it accounts for 30–50% of child mortality (Ochoa et al., 2004). Among the five common Cryptosporidium species in humans, Cryptosporidium parvum and Cryptosporidium hominis are respon- sible for more than 90% of human cases of cryptosporidiosis in most areas (Xiao and Ryan, 2004). C. parvum infects cattle and other mammals in addition to humans, while C. hominis infects primar- ily humans. Geographic differences in the human incidence of C. parvum and C. hominis have been identified. In the United Kingdom, other parts of Europe, and New Zealand, C. parvum is responsible for slightly more infections than C. hominis (Guyot et al., 2001; Alves et al., 2003; Hajdusek et al., 2004; Learmonth et al., 2004; Leoni et al., 2006). In contrast, C. hominis is responsible for far more infections ∗ Corresponding author. Tel.: +49 6131 3933139; fax: +49 6131 3933439. E-mail address: fpetry@uni-mainz.de (F. Petry). than C. parvum in the United States, Australia, and several develop- ing countries (Leav et al., 2002; Tiangtip and Jongwutiwes, 2002; Cama et al., 2003; Peng et al., 2003; Tumwine et al., 2005; Chalmers et al., 2005; Gatei et al., 2006; Bushen et al., 2007; Muthusamy et al., 2006; Xiao and Ryan, 2008). Genetic polymorphism within Cryptosporidium species is being detected at a continuously growing rate, owing to the widespread use of modern molecular techniques. The anthroponotic and zoonotic cycles of cryptosporidiosis transmission previously iden- tified is simplification of the complexity of cryptosporidiosis epidemiology (Peng et al., 1997). Increasing evidence suggests that, anthroponotic and zoonotic transmission of C. parvum can be a per- sistent circulation of C. parvum in humans. According to Plutzer and Karanis (2009) 20 Cryptosporidium species have been rec- ognized and about 61 Cryptosporidium genotypes with uncertain species status have been found based on SSU-rRNA sequences to this date. The GP60 gene showed a high degree of sequence poly- morphism among isolates of Cryptosporidium species and several subtype groups and subgenotypes have been identified, of which the C. parvum IIa and IId subtype groups were found to be zoonotic (Xiao and Ryan, 2008; Plutzer and Karanis, 2009). Cryptosporidiosis is endemic in Ethiopia. It is probably because of the low standards of hygiene (Kloos and Yohanes, 1993), contam- inated source of drinking water (Fikrie et al., 2008), close contact with cattle, living in overcrowded situations with many family members coupled with poor personal hygiene (Ayalew et al., 2008). The prevalence has been reported to range from 8.1% in children younger than 5 years to 25.9% in adult AIDS patients (Fisseha et al., 1999; Adamu et al., 2006). However, no studies have molecularly 0001-706X/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.actatropica.2010.02.003