Molecular Characterisation of Cryptosporidium spp. in Mozambican Children Younger than 5 Years Enrolled in a Matched Case-Control Study on the Aetiology of Diarrhoeal Disease.

Cryptosporidium is a leading cause of childhood diarrhoea and associated physical and cognitive impairment in low-resource settings. Cryptosporidium-positive faecal samples (n = 190) from children aged ≤ 5 years enrolled in the Global Enteric Multicenter Study (GEMS) in Mozambique detected by ELISA (11.5%, 430/3754) were successfully PCR-amplified and sequenced at the gp60 or ssu rRNA loci for species determination and genotyping. Three Cryptosporidium species including C. hominis (72.6%, 138/190), C. parvum (22.6%, 43/190), and C. meleagridis (4.2%, 8/190) were detected. Children ≤ 23 months were more exposed to Cryptosporidium spp. infections than older children. Both C. hominis and C. parvum were more prevalent among children with diarrhoeal disease compared to those children without it (47.6% vs. 33.3%, p = 0.007 and 23.7% vs. 11.8%, p = 0.014, respectively). A high intra-species genetic variability was observed within C. hominis (subtype families Ia, Ib, Id, Ie, and If) and C. parvum (subtype families IIb, IIc, IIe, and IIi) but not within C. meleagridis (subtype family IIIb). No association between Cryptosporidium species/genotypes and child's age was demonstrated. The predominance of C. hominis and C. parvum IIc suggests that most of the Cryptosporidium infections were anthroponotically transmitted, although zoonotic transmission events also occurred at an unknown rate. The role of livestock, poultry, and other domestic animal species as sources of environmental contamination and human cryptosporidiosis should be investigated in further molecular epidemiological studies in Mozambique.