Outbreak Of Keratoconjunctivitis Research Articles

Cervid Herpesvirus 2, the Primary Agent in an Outbreak of Infectious Keratoconjunctivitis in Semidomesticated Reindeer

An outbreak of infectious keratoconjunctivitis (IKC) occurred in semidomesticated reindeer (Rangifer tarandus tarandus) in Troms County, Norway, in February 2009. Twenty-eight animals with clinical symptoms and 12 apparently healthy animals were investigated. They ranged in age from calves of the year to 4-year-old animals (mean, 1.9 years; standard deviation, +/-0.9). The seroprevalence of antibodies against cervid herpesvirus 2 (CvHV2) was 86% in animals with IKC and 42% in unaffected animals. For the 28 clinically affected animals, CvHV2 was detected by PCR in swabs obtained from the eye (82%), nose (64%), and vagina (24%), and CvHV2 was isolated from eye swabs from 8 animals. Virus was not isolated from clinically unaffected animals but was detected by PCR in eye swab samples from five of them. The viral activity, assessed by the ability to cause a cytopathic effect in cell culture, increased with the severity of clinical symptoms, but in severe clinical cases, virus was absent and secondary bacterial infections were dominant. Moraxella sp. isolates were obtained from seven animals, and those from two animals were identified as Moraxella bovoculi. Staphylococcus aureus, Streptococcus sp., and Arcanobacterium pyogenes were also isolated. It is concluded that CvHV2, which is endemic in reindeer, can cause IKC, probably most commonly as a primary infection of calves. This can be a very painful and devastating disease of economic importance for reindeer herders. This is the first report of CvHV2 as the primary agent of IKC in reindeer. This is also the first isolation of this virus in reindeer under natural herding conditions.

First Report of Mycoplasma conjunctivae from Wild Caprinae with Infectious Keratoconjunctivitis in the Pyrenees (NE Spain)

Frequent outbreaks of infectious keratoconjunctivitis have been reported in wild Caprinae in Europe. While etiologic studies in the Alps indicate that the main etiologic agent is Mycoplasma conjunctivae, there are few reports from other mountain areas, such as the Pyrenees, where M. conjunctivae has never been reported. In 2006 and 2007, five adult Pyrenean chamois (Rupicapra pyrenaica; two males and three females) and one adult male European mouflon (Ovis orientalis musimon) were studied; they exhibited clinical symptoms of infectious keratoconjunctivitis such as blindness, corneal opacity, and ulceration. In three of the five chamois tested, and in the mouflon, Mycoplasma conjunctivae was identified from conjunctival swabs by means of a TaqMan(R) polymerase chain reaction based on the lipoprotein gene lppS. Cluster analysis indicated that the three southern chamois isolates form a cluster that is distinct from the mouflon isolate. This is the first report of M. conjunctivae in Pyrenean chamois, and it supports the hypothesis that M. conjunctivae also could be the main cause of infectious keratoconjunctivitis in areas other than the Alps, such as the Pyrenees.

Preliminary Studies on the Etiology of Keratoconjunctivitis in Reindeer (Rangifer tarandus tarandus) Calves in Alaska

Keratoconjunctivitis outbreaks occur each summer in reindeer (Rangifer tarandus tarandus) herds in western Alaska, USA. This condition has not been well characterized nor has a definitive primary etiologic agent been identified. We evaluated the eyes of 660 calves near Nome, Alaska, between 29 June and 14 July 2005. Clinical signs of keratoconjunctivitis were observed in 26/660 calves (3.9%). Samples were collected from the conjunctival sac of both affected (n=22) and unaffected (n=24) animals for bacterial culture, enzyme-linked immunosorbent assay testing for Chlamydophila psittaci, and for polymerase chain reaction assays for Mycoplasma and Moraxella spp. No primary bacterial or viral etiologic agent(s) were isolated or identified. The cause of keratoconjunctivitis among reindeer calves was not determined, but it could involve an anaerobic bacteria, a difficult-to-isolate viral agent, stress associated with repeated handling, ocular foreign bodies, exposure to corral dust or arthropods, or a combination.

Serologic cross‐reactivity of AustralianMoraxella bovisto vaccinal bacterin strains as determined by competitive ELISA

To conduct a serologic survey and define pili antigenic variability via the serologic cross-reactivity of Moraxella bovis isolates from naturally occurring infectious bovine keratoconjunctivitis (IBK) outbreaks in Australia. This project applies to the development of an M bovis pili-based vaccine targeting Australian strains originating from intensive cattle producing regions. Ocular swabs were collected from cattle affected with clinical signs of IBK from 25 veterinary practices. Standard criteria were used to identify 70 M bovis. Pure, piliated isolates were evaluated with a modified competitive enzyme-linked immunosorbent assay (ELISA) for cell-bound M bovis pili to determine their serologic cross-reactivity with pili of vaccinal bacterin strains EPP63, FLA64, and SAH 38. Sixty-four percent (45/70) of M bovis isolates demonstrated homologous pili antigens to a vaccinal strain. M bovis isolates homologous to one of the three vaccinal strains were obtained in 77% (34/44) of IBK outbreaks sampled. No IBK outbreak had isolates homologous to more than one vaccinal strain; however, 29% (10/34) of outbreaks with a cross-reacting strain had non-cross-reacting strains as well. The similar prevalence of pilus antigen homology to strain FLA64 was observed with isolates derived from NSW, Tasmania, and Victoria, compared with results of prior smaller serologic studies, suggests that the common pilus antigens in M bovis within Australia have been relatively stable over the last 20 years. The prevalence of a limited number of pilus antigens in M bovis suggest that the application of a vaccine containing the bacterial strains EPP63, FLA64, and SAH38 may provide a useful management tool for reducing production losses associated with IBK in Australia.

Nosocomial outbreak of epidemic keratoconjunctivitis accompanying environmental contamination with adenoviruses

An outbreak of acute keratoconjunctivitis involving 27 patients occurred in the Department of Ophthalmology, Kurume University Hospital. Adenoviral DNA was detected in four inpatients, one outpatient and one healthcare worker. Sequence-based typing of adenoviral DNA indicated serotype 3 from one inpatient, the rest being serotype 37. At a later stage of the outbreak adenoviral DNA types 37 and/or 3 were also detected from almost all environmental instruments and commonly used eye drops, despite thorough disinfection of the environment and enforcement of various infection control measures. The detection rate of adenoviral DNA in environmental swabs was 81%. A further second disinfection of the environment reduced the detection rate of adenoviral DNA to 38%. The outbreak ceased after closing the ophthalmology ward and outpatient consulting room, accompanied by enhanced cleaning of environmental instruments and the introduction of disposable eye drops for individual patients.

Molecular detection of adenovirus type 8 epidemic keratoconjunctivitis in Hungary

Both infectious and non-infectious forms of acute conjunctivitis are known. Viruses, especially different types of adenoviruses are the etiological agents of infectious epidemic conjunctivitis (conjunctivitis epidemica). The author's aims were to describe an outbreak of keratoconjunctivitis and to detect the viral agent by molecular methods in Hungary. Classical epidemiological methods were used for investigation. Polymerase chain reaction (PCR) followed by sequencing were used for the detection of adenoviral hexon region from freshly collected conjunctival swabs. Between 9 October and 18 December 2006, a total of 60 patients became ill with keratoconjunctivitis in 7 settlements in Southwest Hungary. Mean age was 51,2 years. Conjunctivitis (100%), lacrimation (94%), foreign body sensation (83%), and dim vision (76%) were the main clinical symptoms. Both eyes were affected in half of the cases. Direct contact was the main transmission route including nosocomial spread associated with ophthalmology practices. Five (62.5%) of 8 conjunctival swabs were PCR-positive for adenovirus type 8 (HAdV8/Baranya/2006/HUN; EF210714) which was genetically identical to adenovirus strain detected in Austria in 2004 (DQ149614). The outbreak of keratoconjunctivitis was partially associated with nosocomial infection caused by type 8 adenovirus. Both the recognition of the clinical illness, laboratory diagnosis and public health measures are necessary for the prevention of keratoconjunctivitis infection and epidemic.

Adenovirus Transmission in a Nursing Home: Analysis of an Epidemic Outbreak of Keratoconjunctivitis

Background: An epidemic outbreak of keratoconjunctivitis occurred in a nursing home in Madrid from August to December 2005. Objective: This article reports the outbreak, the infection control measures taken, and risk factors for keratoconjunctivitis. Methods: A cohort study was conducted on the nursing home staff and residents. Specific attack rates and relative risks with their 95% confidence intervals were estimated. A multivariate analysis (logistic regression) was performed proving odds ratios (OR) of becoming ill. Conjunctival swab samples were taken and tested for viral infection. More stringent infection control measures were implemented following the occurrence of the initial cases. Results: Forty-six cases were identified in the nursing home (infection rates of 30.5% in residents and 8.3% in workers). Total duration of the outbreak was 120 days. Corneal ulcer occurred in 3 cases. The factors appearing as independent risk factors were age (OR = 5.7 in people aged ≧90 years compared to those aged <80 years), cognitive impairment (OR = 2.64) and nursing home floor (OR = 2.74 for the first floor, where the outbreak started). Adenoviral DNA was amplified in 10 samples, and 8 of them could be typed as adenovirus serotype 8. Conclusions: Early adoption of adequate hygiene measures is essential to control these outbreaks. In nursing homes with a high number of people with cognitive impairment, an additional effort should be made when the first cases occur to provide such people an increased and improved care and monitoring.

Brote nosocomial de queratoconjuntivitis epidémica en una Unidad de Cuidados Intensivos Neonatal

To describe an epidemic nosocomial outbreak of keratoconjunctivitis affecting at least 43 people in a Neonatal Intensive Care Unit in Madrid, between May and October 2002, perform epidemiologic research and determine preventive measures to prevent new outbreaks. Description of the outbreak, clinical case definition, microbiologic and epidemiologic research through the use of questionnaires. Analysis of the incidence of subepithelial infiltrates 1 year after infection and the use of topical corticosteroid therapy. The epidemic began in the Neonatal Service, with a pair of twins being found as the initial focus. Dissemination occurred to about 24 workers of the unit, and 19 workers from other services. The microbiologic diagnosis confirmed adenovirus in 10 conjunctival smears and one serologically, with the remainder obeying clinical and epidemiological criteria of such infection. Infected patients using topical corticosteroids had a higher incidence of infiltrates 12 months later than those not using such agents (p=0.003 in Fisher test). Epidemic keratoconjunctivitis occurs frequently, is highly contagious and has possible long-term sequelae, necessitating the use of preventive measures to avoid spread and new outbreaks.

An Outbreak of Epidemic Keratoconjunctivitis Caused by a New Intermediate Adenovirus 22/H8 Identified by Molecular Typing

In a 4-week period, 12 patients contracted adenoviral keratoconjunctivitis. Eight of these patients had visited the same ophthalmologist's practice before onset of symptoms. Adenovirus was detected in swab specimens obtained from 9 patients. Sequence-based typing of 2 isolates revealed type 22/H8. This is, to our knowledge, the first report of a keratoconjunctivitis outbreak caused by an intermediate adenovirus type 22/H8.

Outbreaks of infectious keratoconjunctivitis in alpine chamois and ibex in Switzerland between 2001 and 2003

Five outbreaks of infectious keratoconjunctivitis (IKC) affecting alpine chamois and ibex in the western and central Swiss Alps were recorded in 2001 to 2003. Mycoplasma conjunctivae was identified from conjunctival...

Molecular epidemiology of adenovirus strains isolated from patients with ocular disease in the area of Thessaloniki, Greece (1998-2002)

Thirty strains of adenovirus (Ads) associated with ocular disease have been isolated over a period of 4 years in Thessaloniki, Northern Greece. Eleven strains were isolated from sporadic patients with conjunctivitis or keratoconjunctivitis in Thessaloniki city between 1998 and 2000. Nineteen strains were isolated from patients with keratoconjunctivitis during an outbreak of Ads in the area of Thessaloniki (Thessaloniki and Serres cities) in 2002. PCR-sequence method using primers targeted against the hypervariable regions (HVRs) of hexon gene, as well as the neutralization test were used for typing the Ad isolates and assessing a possible relation among these strains, and their genetic variability. Ad4 with very close homology to variant Z-G 95-873 was the most frequent genotype causing sporadic conjunctivitis over a period of 4 years. Two other strains, one Ad2, and one Ad3 were similar to the prototype ones, and a third one shows close homology to the variant of prototype Ad15, the Morrison strain. The genome typing of twenty two Ad8 isolates showed very close homology in their amino acid and nucleotide sequences to the variant of Ad8, strain 1127 (accession no. X74663). Four were isolated from patients with keratoconjunctivitis in 1998, 1999, 2000 and 18 during the outbreak in 2002. As far as strain 1127 is concerned, all the Ad8 isolates showed the same changes in the HVR 1 and HVR 2 except one isolate in 1998, which showed some changes outside the HVRs. During the outbreak of Ad8 keratoconjunctivitis, it was not possible to identify the exact source of infection (nosocomial or/and outpatients). Finally, Ad4 variant Z-G 95-873 and Ad8 which is closely related to the strain 1127, were found to be the predominant adenoviruses circulating in Northern Greece during 1998-2002.

Serological and genetic characterisation of a unique strain of adenovirus involved in an outbreak of epidemic keratoconjunctivitis

Aims: To characterise a novel strain of adenovirus (Ad) type Ad8 (genome type Ad8I) involved in an epidemic keratoconjunctivitis (EKC) outbreak in Hiroshima city using serological testing and sequence analysis...

Bacteriological Investigation of Infectious Keratoconjunctivitis in Norwegian Sheep

Contagious keratoconjunctivitis is a rather common disease in Norwegian sheep. Since the knowledge of its aetiology is limited, the present study was performed to determine the microorganisms involved. Local veterinarians throughout the country collected conjunctival swabs from both sick (n = 43) and healthy (n = 42) sheep on 15 farms with outbreaks of ovine keratoconjunctivitis, and further from healthy sheep (n = 50) on 17 farms not showing any signs of conjunctival disease. All samples were cultivated for bacteria and mycoplasma.Listeria monocytogenes was isolated from 3 cases (1%) in one single herd. Staphylococcus aureus (5%), Corynebacterium spp. (2%) and Escherichia coli (4%) were isolated only in herds with keratoconjunctivitis, but from both sick and healthy animals. Moraxella (Branhamella) ovis was isolated from 28% of sampled animals in affected herds and from 10% of sampled animals in healthy herds. The corresponding numbers for Moraxella spp. were 9%/12%, for Pseudomonas spp. 7%/8%, for Staphylococcus spp. 22%/22%, for Bacillus spp. 12%/14%, for Micrococcus spp. 6%/2% and for Streptococcus/Enterococcus spp. 2%/2%. Mycoplasma conjunctivae was isolated from 16 animals with keratoconjunctivitis (37%) and from 3 animals without clinical signs (7%) in farms with keratoconjunctivitis. In farms without clinical signs of keratoconjunctivitis, M. conjunctivae was isolated in 4 animals (8%).To our knowledge, this is the first time M. conjunctivae has been isolated in Norway. Other predisposing agents found were Moraxella (Branhamella) ovis and Listeria monocytogenes. The etiological importance of different microorganisms in ovine keratoconjunctivitis seems to vary; some are probably only present as secondary invaders. Other possible causes of ovine keratoconjunctivitis in Norway, such as Chlamydia psittaci, remain to be investigated.

The change of etiological agents and clinical signs of epidemic viral conjunctivitis over an 18-year period in southern Taiwan.

Epidemic viral conjunctivitis is a highly contagious eye disease that occurs worldwide and is caused mainly by adenoviruses and enteroviruses. An 18-year analysis of the changes of pathogens and clinical signs in a subtropical and densely populated island presents certain special features. We retrospectively analyzed the clinical information and laboratory records of the conjunctivitis patients with positive conjunctival swabs from 1980 to 1997. The positive rate of laboratory diagnosis of epidemic conjunctivitis was 50.0% (1,233/2,467). From 1980 to 1994, the predominant causative agent of adenoviral keratoconjunctivitis was adenovirus type 8 (Ad8), with six genotypes being evolved. Three of the new Ad8 genotypes each caused a new epidemic. After 1995 the predominant adenoviral pathogens shifted to Ad37 and Ad19, and no more Ad8 was isolated. Enterovirus type 70 (EV70) was isolated from four outbreaks of acute hemorrhagic conjunctivitis (AHC) from 1980 to 1984, but rarely in later years. Coxsackievirus A type 24 variant (CA24v), which first appeared in 1985, appeared later as the causes of four major epidemics of AHC from 1985 to 1994. The overall clinical symptoms of viral conjunctivitis were more severe in the 1990s than in the 1980s. In southern Taiwan, outbreaks of adenoviral keratoconjunctivitis caused by new genomic variants could be associated with the long-term endemic co-circulation of Ad8, Ad19, and Ad37, while epidemics of CA24v AHC were caused mainly by introduction of new viral strains from neighboring countries. The aggravation of host symptoms in the 1990s needs further investigation and close follow-up.

Epidemic kerato-conjunctivitis—do outbreaks have to be epidemic?

To study: the epidemiology of an outbreak of adenoviral keratoconjunctivitis in a UK teaching hospital; disease presentation and its effect on clinical diagnostic efficiency; patterns of viral transmission between staff and patients; the effectiveness of infection control procedures in minimising outbreaks. Prospective/retrospective clinical audit and retrospective audit of virological culture results: all viral culture swabs taken during an outbreak of adenoviral keratoconjunctivitis were analysed. The case records of patients whose viral swabs were positive for adenoviral culture were traced. The time for viral cultures to become positive (culture positive time) was calculated. Analysis of the case notes was performed to elucidate (1) the source of infection and (2) the risk factors for acquisition of the infection. Retrospective clinical audit was performed to evaluate the effectiveness of infection control procedures. Adenovirus isolates underwent serotyping. During the 3-month period of study, there were 38 confirmed cases of adenoviral keratoconjunctivitis. This represented a 217% increase in the number of new cases per 3-month period. The case notes for five patients were untraceable. Of the remaining 33 patients, 21 (63%) had acquired their infection either directly or indirectly from the eye department and 22 (67%) had presented with unilateral disease. The rate of misdiagnosis was higher (9/22=42%) in patients presenting with unilateral disease than those presenting with bilateral disease (2/11=18%). Intradepartmental acquisition of infection was associated with invasive procedures, for example use of diagnostic/therapeutic contact lenses. Culture positive times ranged from 3 to 29 days. The introduction of infection control procedures was associated with a dramatic decrease in the incidence of departmentally acquired cases with no new cases after 2 weeks. Multiple serotypes of adenovirus were involved. Outbreaks of adenoviral keratoconjunctivitis are a serious public health issue concerning ophthalmic departments. This audit study illustrates several important points: (1) how hospital-acquired infection can account for a significant proportion of the cases seen, (2) how multiple types of adenovirus can be involved in a single outbreak, (3) that severe unilateral disease is associated with a higher rate of misdiagnosis; and (4) how standard viral culture techniques may not be satisfactory in confirming/disproving infection when the diagnosis is in doubt. The potential benefit of infection control procedures in minimising this outbreak could not be proven within this audit.

Direct costs associated with a nosocomial outbreak of adenoviral conjunctivitis infection in a long-term care institution

Background: In October 2000, 41 people were infected during an outbreak of adenoviral keratoconjunctivitis. Such nosocomial outbreaks are frequently reported in long-term care institutions, even though simple measures to prevent or limit such occurrences are well documented. This study describes the significant direct costs incurred as a result of this nosocomial outbreak that involved patients and staff. Methods: The costs measured in this study were grouped into the following 4 categories: medical, investigative, preventive, and lost productivity. Information about costs incurred by the hospital was gathered from a number of sources. Results: The outbreak cost the hospital US $29,527 ($1085 for medical costs, $8210 for investigative costs, $3048 for preventive measures, and $17,184 for lost productivity). Conclusion: This study demonstrates the substantial expense incurred by 1 hospital as a result of an outbreak of a preventable disease. The measures necessary to prevent such a costly outbreak are simple and, therefore, cost-effective. (Am J Infect Control 2002;30:407-10.)

Identification of the hexon region of an adenovirus involved in a new outbreak of keratoconjunctivitis.

We tested 15 adenovirus (Ad)-positive patients involved in a case of nosocomial spread of keratoconjunctivitis. A neutralization test, PCR-restriction fragment length polymorphism analysis, and sequencing of the hypervariable regions of the hexons were performed in order to identify the type of Ad involved. The serotype of the Ad was not identical to any published Ad sequence by either method.

Epidemiological and microbiological study of an outbreak of infectious keratoconjunctivitis in sheep

After several thousand sheep had been imported from Australia and New Zealand to Croatia during 1995, many native sheep that had been in contact with the imported animals acquired a...

Epidemic keratoconjunctivitis outbreak at a tertiary referral eye care clinic

An outbreak of epidemic keratoconjunctivitis (EKC) occurred at a tertiary referral eye care clinic between late September and mid-November 1995. Before the outbreak, instruments were cleaned with 70% isopropyl alcohol and handwashing between patients was not routine. Infection control measures were implemented when the outbreak was recognized in mid-October. Control measures included triaging suspected cases to a separate waiting area, cohorting cases to a specific examining room, endorsing the use of gloves and handwashing during examinations of patients, and cleaning instruments with a buffered bleach solution. Thirty-six cases were diagnosed before the infection control measures were taken, and 3 cases were seen after the control measures were taken. Also, numerous secondary cases occurred in the community. No additional cases were diagnosed from December to February 25, 1996. Acquisition of the infection was linked to visits to 4 of 20 physicians in the eye clinic with 61% of cases associated with visits to 1 of those 4 physicians. The use of diagnostic lenses applied directly to the eye was associated with infection (odds ratio = 2.83, 95% confidence interval = 0.79 to 10.4), although this did not reach statistical significance. The use of tonometers, ophthalmic solutions, or laser therapy was not associated with infection, and all environmental cultures were negative. This outbreak emphasizes the need for implementation of routine infection control guidelines to prevent nosocomial transmission of epidemic keratoconjunctivitis and stresses the need for appropriate disinfection of instruments. (AJIC Am J Infect Control 1998;26:399-405)

Echovirus keratoconjunctivitis

To investigate an outbreak of echovirus-related keratoconjunctivitis. We undertook a retrospective study of recent cases of echovirus infection with recall and further evaluation of conjunctivitis patients. All patients from whom an echovirus was isolated in Liverpool during 1995 were included. The natural course of ocular echovirus disease was studied, including the likelihood of echovirus keratoconjunctivitis being linked with meningitis and the risk of long-term carriage of the virus in the conjunctiva. Of 10 unrelated patients with echovirus conjunctivitis, six also had a mild keratitis. None of these patients developed meningitis, and no cases of long-term carriage in the conjunctiva were encountered. There was no link between cases of echovirus meningitis and conjunctivitis. There was no corresponding increase in other ocular viral isolates. Echovirus is a relatively unrecognized cause of keratoconjunctivitis. Echoviral keratoconjunctivitis appears to be an independent ocular event unassociated with systemic sequelae. Long-term carriage in the conjunctiva does not appear to occur.