Acute follicular conjunctivitis of epizootic origin. Feline pneumontis

Zoonotic transmission of Chlamydia felis from domestic cats; A case series of chronic follicular conjunctivitis in humans

We present three cases of chronic follicular conjunctivitis resulting from the zoonotic transmission of Chlamydia felis from domestic cats. Our objective is to raise awareness regarding the potential zoonotic transmission of Chlamydia felis from domestic cats and describe the methodology for definitive pathogen identification using Polymerase Chain Reaction (PCR) and subsequent sequence analysis, a useful tool in the identification of these rare pathogens. We discuss the factors that could be contributing to the potential under-diagnosis of zoonotic C. felis infections and propose a treatment regime for cases of C. felis-related conjunctivitis.

Chlamydia pecorum Associated With an Outbreak of Infectious Keratoconjunctivitis in Semi-domesticated Reindeer in Sweden

Infectious keratoconjunctivitis (IKC), the most common ocular disease in ruminants worldwide, has affected semi-domesticated Eurasian reindeer (Rangifer tarandus tarandus) for over 100 years, both as individual cases and in outbreaks affecting tens to hundreds of animals. Recurrent IKC outbreaks have been affecting a semi-domesticated reindeer herd in Östra Kikkejaure (Norrbotten county, Sweden) from 2014. The latest episode of these recurrent outbreaks, in winter 2016/2017, was investigated in this study. Clinical findings were in line with previous reports of IKC in semi-domesticated reindeer and the clinical signs displayed by the affected animals (n = 30) included increased lacrimation, follicular conjunctivitis, purulent secretions around the affected eyes and corneal edema. Laboratory analyses of the samples revealed the presence of Chlamydiaceae in most samples obtained from the clinically affected animals (98.3%, n = 60), but also a high seroprevalence of cervid herpesvirus 2 (CvHV2) antibodies (56.6%, n = 53). Moraxella bovoculi was isolated from nine IKC-affected animals during the outbreak (45.0%, n = 20). All affected animals were treated with long-acting antibiotics and recovered from the disease, testing negative for the presence of Chlamydiaceae DNA by PCR 16 days and 3 months after the initial treatment. For the first time, Chlamydia pecorum was identified in semi-domesticated reindeer, and the involvement of Chlamydiaceae in a clinical outbreak of IKC is reported. The CvHV2 seroprevalence (56.6%) and the data obtained from a previous outbreak in 2014 also suggest the involvement of the reindeer alphaherpesvirus in the recurrent outbreaks.

Follicular Conjunctivitis due to Chlamydia felis-Case Report, Review of the Literature and Improved Molecular Diagnostics

A 29-year-old woman presented with unilateral, chronic follicular conjunctivitis since 6 weeks. While the conjunctival swab taken from the patient’s eye was negative in a Chlamydia (C.) trachomatis-specific PCR, C. felis was identified as etiological agent using a pan-Chlamydia TaqMan-PCR followed by sequence analysis. A pet kitten of the patient was found to be the source of infection, as its conjunctival and pharyngeal swabs were also positive for C. felis. The patient was successfully treated with systemic doxycycline. This report, which presents one of the few documented cases of human C. felis infection, illustrates that standard PCR tests are designed to detect the most frequently seen species of a bacterial genus but might fail to be reactive with less common species. We developed a modified pan-Chlamydia/C. felis duplex TaqMan-PCR assay that detects C. felis without the need of subsequent sequencing. The role of chlamydiae-specific serum antibody titers for the diagnosis of follicular conjunctivitis is discussed.

Detection of Chlamydophila pneumoniae in cats with conjunctivitis

OBJECTIVE

To determine the presence of chlamydial species including recently described chlamydial agents as well as the human pathogen Chlamydophila pneumoniae in feline conjunctivitis.

ANIMAL STUDIED

Twenty five cats without and 49 cats with conjunctivitis were tested for chlamydia using a Chlamydiaceae real time (RT) PCR (targeting the 23S rRNA gene sequence), a Chlamydiales PCR (targeting the 16S rRNA gene sequence), and cell culture. The PCR products of all positive samples were sequenced and subsequently analyzed using a basic local alignment search tool search.

RESULTS

Chlamydiaceae RT PCR and subsequent sequence analyses identified C. pneumoniae in five cats in the conjunctivitis group. The presence of Chlamydophila felis was shown in two cats with conjunctivitis. Chlamydiae related to uncultured members of Chlamydiales were detected in three conjunctivitis cases and in one cat without clinical symptoms.

CONCLUSION

This study detects for the first time, the known human pathogen C. pneumoniae in feline conjunctivitis cases using Chlamydiaceae RT PCR and sequence analyses.

Zoonotic potential of Chlamydophila

The purpose of this article is to present the diseases induced in humans and animals by the different species of Chlamydophila, after providing an overview on the history of these infectious agents and their taxonomy. The route of transmission and the available methods for prevention and control in the different animal species are reviewed.

Is Chlamydophila felis a significant zoonotic pathogen?

PROBLEM

Chlamydophila felis is a common cause of conjunctivitis in cats and in some textbooks is listed as an important zoonotic pathogen. However, there are no published comprehensive reviews assessing the evidence supporting this. SEARCH AND ANALYSIS: Bibliographic databases and bibliographies of papers and textbooks were searched for all published cases of zoonotic disease associated with chlamydiosis in cats. All published case reports were reviewed to establish the quality of the evidence supporting the association between C. felis and zoonotic disease.

RESULTS

There are only seven case reports, most of which were published before the development of assays capable of distinguishing C. felis from other chlamydial species, implicating this organism in zoonotic disease. None of the three cases of pneumonia and systemic disease described, two of which occurred in immunocompromised patients, can be unambiguously attributed to C. felis. Of the four cases of follicular keratoconjunctivitis described, only one, in an immunocompromised patient, could be unambiguously attributed to C. felis.

CONCLUSION

While there is evidence that C. felis may occasionally cause keratoconjunctivitis in humans, there is little evidence to suggest it can cause serious systemic disease or pneumonia.

Feline chlamydia and calicivirus infections

Feline conjunctivitis is common and often presents a clinical challenge to the veterinarian. Chlamydia psittaci is an important pathogen and should always be considered when evaluating cats with conjunctivitis. FCV is an infrequent cause of conjunctivitis and only causes the disease in conjunction with other clinical signs of this infection, such as oral mucosal ulcers and upper respiratory tract disease.

Feline infectious pneumonia: a short literature review and a retrospective immunohistological study on the involvement of Chlamydia spp. and distemper virus

A short literature review of feline infectious pneumonia, feline Chlamydia and Paramyxoviridae is presented. In a retrospective study (from 1987 to 1996) 245 cases of feline pneumonia or conjunctivitis/rhinitis were investigated: histological diagnoses and aetiologies were compared; all lungs were examined immunohistologically for the occurrence of chlamydia and of canine distemper virus (CDV), but neither pathogen could be demonstrated. The results confirm previous reports indicating that feline chlamydia is not a primarily pulmonary pathogen and that CDV is not a causative agent of pneumonia in cats as it is in large felids. The review provides a summary of the known causes and pathology of infectious pneumonia in cats (in order of frequency), although some remain aetiologically uncertain. It focuses on chlamydia and distemper virus - a recognized and as yet unknown cause of feline pneumonia. The role and especially the frequency of chlamydia as a cause of feline pneumonia are controversial but distemper virus, known to cause pneumonia in dogs and large felids, has not as yet been demonstrated in cats. The aims of the retrospective study were to determine the occurrence of chlamydia in 245 cases of feline pneumonia or conjunctivitis/rhinitis, and to investigate the presence of CDV in these lungs.

Differentiating conjunctivitis of diverse origins

While symptoms can be very distressing, patients with conjunctivitis general maintain good vision and recover completely without permanent sequelae. The great majority of cases of conjunctivitis are infectious or allergic in origin. Seen with increasing frequency are external eye diseases related to contact lens wear or prolonged use of ophthalmic medications. The various forms of conjunctivitis are often not associated with pathognomonic features. A thorough history and ophthalmic examination often permit a presumptive diagnosis and initiation of empiric therapy. For example, a chronic bilateral conjunctivitis, characterized by itching and papillary hypertrophy, suggests an ocular allergy, most frequently the result of exposure to airborne allergens. However, a number of causes, including infections and hypersensitivity reactions, have the potential to threaten vision or produce marked conjunctival scarring which must be identified by the use of appropriate laboratory techniques, followed by specific therapy. Most bacterial and viral conjunctivitis are self-limited, but antimicrobial therapy for the former is advocated to shorten the course, improve patient comfort, prevent recurrence, avoid complications and limit spread to other individuals.

Chlamydial infections of the heart

Chlamydiae are common human pathogens, causing a broad spectrum of infectious diseases. Chlamydial infections involving the heart have been described in numerous previous reports. These organisms are documented to cause endocarditis, myocarditis and pericarditis. Furthermore, Chlamydia pneumoniae, the recently discovered respiratory pathogen, has also been implicated in coronary artery disease. For the first time the literature on involvement of the heart in chlamydial infections is reviewed. Information on the discovery of Chlamydia species is also included and the problem of the species determination of Chlamydia in interpretation of the older literature is mentioned.

Acute conjunctivitis caused by an atypical chlamydial strain: Chlamydia IOL 207

A case of acute conjunctivitis in man caused by Chlamydia IOL 207 is described. Chlamydiae were isolated from the eye, and rising titres of type-specific antibodies to C. IOL 207, in serum and tears demonstrated an aetiological role for this agent. C. IOL 207 is an atypical chlamydial strain which serological studies suggest is widespread in some communities.

Infective endocarditis with glomerulonephritis associated with cat chlamydia (C. psittaci) infection

A patient with glomerulonephritis and endocarditis is described who had evidence of feline Chlamydia psittaci infection. Treatment with antichlamydial drugs resulted in resolution of the glomerulonephritis and the endocarditis. It is recommended that screening for chlamydia is included in the investigation of patients with suspected or obscure endocarditis.

Isolation of Chlamydia psittaci from a patient with interstitial keratitis and uveitis associated with otological and cardiovascular lesions

A case history of a 15-year-old schoolgirl with fluctuating bilateral uveitis, bilateral stromal keratitis with vascularisation, and bilateral deafness associated with tinnitus and balance disturbance is described. Three years from the onset of her clinical signs she died of a sudden cardiac arrest caused by endocarditis associated with valvular and arterial lesions. Chlamydia psittaci was isolated from her conjunctiva. In her blood type-specific antichlamydial antibody at a level of 1/64 against her own isolate was detected. The clinical findings in this patient were suggestive of a Cogan's syndrome. It is highly probable that the chlamydia isolated from the eyes was responsible for her various lesions.