Prevalence of Feline Chlamydia psittaci and Feline Herpesvirus 1 in Cats with Upper Respiratory Tract Disease

Abstract

The epidemiology of feline chlamydiosis and feline herpesvirus 1 (FHV1) infection in cats was determined using a duplex poly-merase chain reaction assay. In cats with upper respiratory tract disease (URTD), prevalences of 66 (14.3%) of 462 cats and 98 (21.2%) of 462 cats were found for Chlamydia psittaci and FHV1, respectively. In cats without URTD, prevalences were 1/87 (1.1%) for both pathogens. Younger cats, cats sampled in summer, and cats with conjunctivitis were more likely to be positive for C psittaci than were cats sampled in other seasons and cats without conjunctivitis. Cats with recent contact with cats outside the household, cats with acute disease, and sneezing cats were more likely to be positive for FHV1 than were cats that had not had recent contact with cats outside the household, cats with chronic disease, and cats that were not sneezing. Purebred cats were less likely to be positive for FHV1 than were mixed breed cats and prevalence varied with year of sampling. Coinfection with both pathogens was lower than would be expected from their respective prevalences. Vaccinated cats were equally likely to be positive for FHV1 as unvaccinated cats. In sneezing cats FHV1 was more likely to be detected than C psittaci, particularly in acute cases, and when sneezing was not accompanied by conjunctivitis. Cats with reproductive disease concurrent with URTD were more likely to be infected with FHV1 than with C psittaci. Thus, the factors that should be considered in clinical diagnoses of C psittaci infections are the presence of conjunctivitis, age, and season, whereas contact with other cats, acute disease, and sneezing should be considered in diagnoses of FHV1 infection.

Evaluation of different sampling methods and results of real‐time PCR for detection of feline herpes virus‐1,Chlamydophila felisandMycoplasma felisin cats

“…Because C. felis is a conjunctival pathogen and corneal samples are rarely positive, 7,12 the low detection rate in our study may be explained by the lack of conjunctival samples in 16 of 23 (70%) cats with clinical signs. In addition, earlier studies have shown a higher prevalence for C. felis in younger cats, whereas the mean age of the cats with clinically signs in our study was relatively high 13,14 …”

“…Sykes et al . showed that detection of FHV‐1 DNA was less common if disease had been present for longer than 1 week 13 . A third possible explanation could be a lower prevalence of FHV‐1 in the area of Sweden where samples in the present study were collected.…”

“…Previous studies have reported different prevalence of C. felis depending on population, country, and assay used. In Italy 14 of 70 (20%) samples were positive, in Britain 20 of 113 (18%) cats with ocular signs were positive, and in Australia 66 of 462 (14%) cats with ocular signs or rhinitis were positive 7,13,31 . In all of these studies, conjunctival swabs were collected and assessed by using conventional PCR.…”

“…Young cats are particularly susceptible to infection. Chlamydophila felis can become persistent in ocular or non‐ocular sites, but probably develops a shorter carrier state than does FHV‐1 7,12–14 …”

Role of Chlamydia in the Development of Ocular Adnexal Lymphoma

“…[77]. The association of OAL with C. psittaci has been reported mostly in subjects coming from rural areas, following a prolonged contact with household animals [8].…”