Experimental transmission of Cryptosporidium parvum isolates from wild rodents and calves to laboratory bred common voles (Microtus arvalis)

摘要

The oocysts of Cryptosporidium parvum isolated from Microtus arvalis, Clethrionomys glareolus and calves were used in laboratory experiments carried out on 35 M. arvalis. Oocysts were detected in 43% of 14 voles infected with C. parvum derived from calves and in 54% of 13 voles infected with C parvum isolates from C. glareolus. All voles inoculated with oocysts from M. arvalis (MA-voles) developed infection. There were observed differences in courses of infection between the three groups of voles with MA-voles demonstrating the most typical curve with an acute phase of infection in the first 4 weeks and a 2-week-long phase of self-curing. The infections with 'heterologous' C. parvum isolates (C. glareolus and calf isolates) transformed into chronic infections with lower oocyst productions. A strong host age effect was observed on prevalence of C. parvum among voles of different ages. Eight-month-old voles did not become infected and in older animals the infections were milder. The successful cross-transmission of two C. parvum isolates to M arvalis suggests that this species should be considered as reservoir host for this important parasite of humans and animals.