Sites of feline coronavirus persistence in healthy cats

Abstract

Feline coronavirus (FCoV) is transmitted via the faecal-oral route and primarily infects enterocytes, but subsequently spreads by monocyte-associated viraemia. In some infected cats, virulent virus mutants induce feline infectious peritonitis (FIP), a fatal systemic disease that can develop in association with viraemia. Persistently infected, healthy carriers are believed to be important in the epidemiology of FIP, as they represent a constant source of FCoV, shed either persistently or intermittently in faeces. So far, the sites of virus persistence have not been determined definitely. The purpose of this study was to examine virus distribution and viral load in organs and gut compartments of specified-pathogen-free cats, orally infected with non-virulent type I FCoV, over different time periods and with or without detectable viraemia. The colon was identified as the major site of FCoV persistence and probable source for recurrent shedding, but the virus was shown also to persist in several other organs, mainly in tissue macrophages. These might represent additional sources for recurrent viraemia.

Levels of feline infectious peritonitis virus in blood, effusions, and various tissues and the role of lymphopenia in disease outcome following experimental infection

“…However, closer examination of these studies indicates that detection of feline coronavirus genomic RNA has not been as clear-cut as assumed, mainly because detection is often at or beyond the limits of reliability for the assay procedure. Three studies reported on the detection of feline coronavirus RNA in blood, but all were concerned with FECV rather than FIPV infection and detection was inconsistent (Meli et al, 2004;Kipar et al, 2010;Vogel et al, 2010). Kipar et al (2001Kipar et al ( , 2006 compared virus loads in various tissues, excluding blood, in naturally infected cats and indicated that virus loads were higher in FIPV than FECV infected cats.…”

“…The authors reported that this test was highly accurate in identifying cats with FIP. Shortly thereafter additional studies using the same assay demonstrated replicating forms of RNA in the blood of healthy cats infected with FECV (Can-Sahna et al, 2007;Kipar et al, 2010), casting doubts on the specificity of such tests. The ability of FECV to replicate in blood monocyte/macrophages was also reported by other groups (Vogel et al, 2010).…”

A retrospective clinical and epidemiological study on feline coronavirus (FCoV) in cats in Istanbul, Turkey

“…1016/j.prevetmed.2015.01.017 0167-5877/© 2015 Elsevier B.V. All rights reserved. Kipar et al, 2010). FCoVs primarily infect enterocytes and spread from the intestine by monocyte-associated viremia (Gunn-Moore et al, 1998;Kipar et al, 2005).…”

Coronaviruses as Encephalitis - Inducing Infectious Agents

“…The virulent form of FCoV, called FIPV, occurs following mutations acquired during a persistent infection (Brown et al, 2009;Rottier et al, 2005;Vennema et al, 1998) and neurologic involvement could occur in FIP disease Summers et al, 1995). The colon was identified as the major site of FCoV persistence; nevertheless the virus could also persist in tissue macrophages representing a source for viremia (Kipar et al, 2010). Infected macrophages disseminate systemically and trigger immunological responses resulting in microgranuloma formation, vasculitis, organ failure, and death (Pedersen and Boyle, 1980;Poland et al, 1996 andVennema et al, 1998).…”