Cytauxzoon sp. infection in the first endemic focus described in domestic cats in Europe

Information about epidemiological and clinicopathological aspects of domestic cat infection by species of Cytauxzoon other than Cytauxzoon felis is limited and it has rarely been reported. Following the detection of clinical cytauxzoonosis in three cats from Trieste (Italy), an epidemiological study was carried out in colony (n = 63) and owned (n = 52) cats from the same city to investigate the presence of Cytauxzoon sp. infection and to assess clinicopathological findings and variables associated with this infection. Cytauxzoon sp. infection was detected by 18S rRNA gene PCR in 23% (27/118) and by blood smear examination in 15% (18/118) of domestic cats. The 18S rRNA gene sequences obtained were 99% identical to the Cytauxzoon sp. sequences deposited in GenBank® from Spanish, French and Mongolian wild and domestic cats. Erythroparasitemia was observed mainly in apparently healthy cats. Cytauxzoon sp. infection was statistically associated with the colony group and the outdoor life style. No statistical association was found between positivity by PCR and breed, gender, age, presence of ticks and/or fleas, clinical status, laboratory findings such as anemia, FIV and/or FeLV status and mortality rate. Persistence of the infection was monitored and documented in four clinical cases. We reported the first clinicopathological description of naturally occurring Cytauxzoon sp. infection in domestic cats living in Italy. The predominance of subclinical erythroparasitemia and the evidence of persistent infection support the hypothesis that the domestic cat might serve as a reservoir host for this infection.