Genetic diversity of Cryptosporidium isolates from young children and livestock in eastern Ethiopia

Abstract

Cryptosporidiosis is a leading cause of morbidity and mortality due to diarrhoea during early childhood in low-income countries, including Ethiopia. Human Cryptosporidium infections can be anthroponotically or zoonotically transmitted. This study assesses the diversity and frequency of Cryptosporidium species and genotypes circulating in children and young livestock in eastern Ethiopia, with the aim of tracing the sources of infection. Cryptosporidium isolates from young children (n = 152), calves (n = 8), lambs (n = 4), goat kids (n = 4), and camels (n = 11) were subjected to PCR targeting the SSU rRNA and gp60 loci. Species and subtypes were determined by Sanger sequencing. Two Cryptosporidium species were found in children: C. hominis (75.3%, 67/89) and C. parvum (24.7%, 22/89). Three gp60 subtype families, Ia (30.0%, 9/30), Ib (10.0%, 3/30), and Id (60.0%, 18/30), were identified within C. hominis whereas gp60 subtype families IIe (55.6%, 10/18) and IIc (44.4%, 8/18) were identified within C. parvum. The predominant subtypes were C. hominis IdA15 and C. parvum IIeA10G1. Among livestock, C. ubiquitum was found in two camels and a goat kid, C. xiaoi in a lamb and goat kid, and C. ryanae in a calf. We did not identify any C. parvum among the animal samples. The goat isolate of C. xiaoi was characterised as subtype XXIIIg. Human cryptosporidiosis cases in eastern Ethiopia are primarily caused by anthroponotically transmitted Cryptosporidium species and subtypes, whereas zoonotic transmission events seem infrequent.