Infectious keratoconjunctivitis in semi-domesticated reindeer (Rangifer tarandus tarandus): a questionnaire-based study among reindeer herders in Norway and Sweden.

BACKGROUND: The effects of climate change, loss of pastureland to other land usage and presence of large carnivores are the main reasons for the increase in supplementary feeding of semi-domesticated reindeer (Rangifer tarandus tarandus) in Fennoscandia over the last decades. Feeding might expose reindeer to stress and increased animal-to-animal contact, leading to an increased risk of infectious disease transmission, such as infectious keratoconjunctivitis (IKC). As it can develop rapidly and be very painful, IKC is described as an important animal welfare concern and a potential source of economic loss. The aim of this study was to investigate the current presence of IKC and potential associations between IKC and supplementary feeding through an online questionnaire survey, distributed among reindeer herders in Norway and Sweden in 2021. RESULTS: Seventy-six reindeer herders (33 from Norway and 43 from Sweden) responded to the questionnaire, representing 6% and 4% of the registered reindeer herding groups in Norway and Sweden, respectively. Infectious keratoconjunctivitis was common, with 54 (71%) of the 76 herders that responded having observed clinical signs during the past 10 years. These signs were mainly observed as increased lacrimation, causing "wet cheeks", but also as keratitis and conjunctivitis. Autumn and winter were the seasons in which IKC was observed most. The herders reported several measures, such as slaughter and isolation of affected reindeer, to counteract the spread of disease. The herding year 2019/2020 was associated with reports of outbreaks of IKC in herds as well as being the herding year where most herders (80%) had performed supplementary feeding. A significant association was found between IKC and feeding performed in an enclosure (odds ratio = 15.20), while feeding on free-range areas had a non-significant, negative, relationship with the appearance of IKC outbreaks (odds ratio = 0.29). Finally, there was a trend in the data suggesting that IKC affected calves especially. CONCLUSIONS: Infectious keratoconjunctivitis is a common disease, mainly observed in winter and autumn. It usually has mild to moderately severe clinical signs. Our results imply that IKC is associated with stress and feeding situations and that calves might be more susceptible than adults, however, this needs to be confirmed with further studies, preferably at an individual animal level.

Investigation of the pathogens contributing to naturally occurring outbreaks of infectious bovine keratoconjunctivitis (pinkeye) using Next Generation Sequencing.

Infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, has a marked negative impact on the economy of the cattle industry. Moraxella species, including Mor. bovis and Mor. bovoculi, which have been associated with this disease, colonize clinically healthy eyes as well, suggesting that there are intrinsic changes that may occur to the ocular microbiota or the involvement of additional unrecognized organisms that contribute to IBK. To evaluate this, 104 ocular swabs collected from eyes with IBK or clinically healthy eyes from 16 different cattle herds were subjected to 16 S rRNA gene PCR and next generation sequencing (NGS) analysis. Organisms detected were similar across the herds and there was no difference in the total number of bacterial groups detected among IBK cases and controls. However, the percentages of the different organisms detected varied between the two groups, including Moraxella spp., with more Moraxella spp. in eyes with IBK than controls. Further, using culture and whole genome NGS, a new species of Moraxella (suggested name Mor. oculobovii) was detected from the eyes of cattle from two farms. This strain is non-hemolytic on blood agar, is missing the RTX operon, and is likely a non-pathogenic strain of the bovine ocular microbiome. Alteration of the ocular microbiota composition may have a predisposing role, enhancing bacterial infection and the occurrence of clinical IBK. Future studies are required to evaluate if these changes are permanent or if there is a shift in the microbiome following recovery from the infection and how antibiotics might affect the microbiome.

A randomised control trial to evaluate the effectiveness of a commercial vaccine for pinkeye in Australian beef cattle.

Pinkeye (a generic term to describe infectious bovine keratoconjunctivitis) is a significant disease of cattle worldwide, impacting productivity and animal welfare. One commercial pinkeye vaccine, a systematically administered Moraxella bovis bacterin, has been available in Australia since 2007. This is the first field trial of the effectiveness of this vaccine for the prevention of naturally occurring disease in Australia. Extensively run beef herds in southwest Queensland that regularly experienced pinkeye were enrolled in the trial and animals were randomly allocated to vaccinated and control groups in different proportions in each herd. The subsequent incidence of clinical pinkeye between the two groups was compared for animals less than one-year-old. Data were analysed from 649 cattle from five herds over two pinkeye seasons: three herds of 390 calves from 1st November 2019 to 20th January 2020 and two herds of 259 calves from 23rd September 2020 to 21st April 2021. Pinkeye was common with 24% of all calves (156/649) contracting the disease during the trial. Univariable and multivariable binary logistic mixed-effect models were fitted to account for clustered data and potential residual confounding due to sex, weight, breed, coat colour, and periocular pigmentation. The incidence of pinkeye was not significantly different between vaccinated and control groups, both alone (p = 0.67) and after adjusting for sex and weight differences (p = 0.69). The vaccine was not protective against naturally occurring pinkeye under the field conditions.

Bacteria associated with infectious keratoconjunctivitis outbreak in confined lambs.

Introduction. Infectious keratoconjunctivitis is a significant ocular disease found in confined sheep. Little information about the aetiological agents and their antimicrobial susceptibility is available.Gap Statement. There is limited information on the aetiological agents involved in keratoconjunctivitis outbreaks in sheep.Aim. The present research aimed to determine the bacterial aetiological factors involved in an outbreak of infectious keratoconjunctivitis in confined lambs.Methodology. Ocular swabs were collected from 23 randomly selected lambs, which were classified into three groups according to the severity of the lesion: group I (N=6; no ocular involvement), group II (N=8; less severe injuries) and group III (N=9; more severe injuries). Isolation of aerobic bacteria and antimicrobial susceptibility tests were carried out. Molecular detection of Mollicutes was performed, and positive samples were tested to confirm the presence of the following species: Mycoplasma conjunctivae, Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri.Results. Moraxella sp. and Mollicutes were detected in all groups, but we inferred that Moraxella sp. are only significant in the early stages of the disease. M. conjunctivae was detected in all tested groups, while M. agalactiae was detected in samples of group III only. One strain of Moraxella sp. was resistant to erythromycin and showed intermedite resistance to tetracycline.Conclusion. The presence of these species confirms their importance in the aetiology of this disease, and the low resistance profile observed in the studied farm suggested an increased cure success rate.

A Review of Global Prevalence and Economic Impacts of Infectious Bovine Keratoconjunctivitis.

A summary of available literature on the prevalence and estimated economic impacts of infectious bovine keratoconjunctivitis (IBK) from around the world is made. Country-level prevalence of IBK has been reported only for the United States, Australia, and New Zealand. We provide an estimate of IBK prevalence rate by geographic climate and region accounting for cattle sub-species and age. Estimated prevalence worldwide is 2.78%. Historical economic impact assessments are available only for the United States, Australia, and United Kingdom. Rarely do assessments capture the full economic cost of the disease. Better data on prevalence and how treatment and prevention decisions modify disease impacts is required to estimate the global economic impact.

Current incidence, treatment costs and seasonality of pinkeye in Australian cattle estimated from sales of three popular medications.

Pinkeye is an economically important ocular disease occurring in all cattle producing areas of Australia. This study was undertaken to estimate the frequency of occurrence of the disease in Australia and treatment costs of the disease to the cattle industry using the sales of popular pinkeye medications as a surrogate indicator. Monthly sales data for Orbenin® Eye Ointment, Opticlox® Eye Ointment and Terramycin® Pinkeye Aerosol were analysed. We first estimated the number of cattle that can be treated with a syringe or a can and then using the data of sales of these pinkeye medications and the total cattle population of Australia, estimated the incidence of pinkeye. Probability distributions were used to include uncertainty around the estimates. Costs to producers were estimated based on retail prices of these medications. The results indicated that 732,864 syringes of Orbenin® Eye Ointment, 134,800 syringes of Opticlox® Eye Ointment and 27,755 cans of Terramycin® Pinkeye Aerosol are sold in Australia per year. Based on some assumptions of the number of cases treated by these drugs and number of cases left untreated, the number of cattle affected by pinkeye each year in Australia was estimated to be 2.80 million (95 % PI: 1.76, 4.65) or 10.25 % (95 % PI: 6.43, 16.97) of the entire Australian cattle herd. The cattle industry is expected to lose AU$ 9.67 million (95 % PI: 8.56, 13.11) each year just considering the cost of these three drugs. The results suggest that losses due to pinkeye in the Australian cattle industry are considerably higher than previously thought and should be used to inform the development of disease prevention and control policies.

Mycoplasma conjunctivae-Associated Keratoconjunctivitis in Norwegian Muskox (Ovibos moschatus).

In late summer 2014, an outbreak of ocular disease occurred in the Norwegian muskox (Ovibos moschatus) population. Animals showed rings of pus around their eyes and one euthanized animal was diagnosed with acute keratoconjunctivitis. The DNA sequence analysis of eye-swab samples from this animal revealed a high abundance of Mycoplasma conjunctivae.

Swimming Pool-Associated Vittaforma-Like Microsporidia Linked to Microsporidial Keratoconjunctivitis Outbreak, Taiwan.

We analyzed 2 batches of environmental samples after a microsporidial keratoconjunctivitis outbreak in Taiwan. Results indicated a transmission route from a parking lot to a foot washing pool to a swimming pool and suggested that accumulation of mud in the foot washing pool during the rainy season might be a risk factor.

Mycoplasma conjunctivae in insect vectors and anatomic locations related to transmission and persistence.

Mycoplasma conjunctivae is an obligate microparasite that causes Infectious Keratoconjunctivitis (IKC) in Caprinae species. IKC is a long-recognised disease, but little attention has been paid to the mechanisms of transmission of the mycoplasma and its occurrence in locations other than the eyes. In this study, the presence of M. conjunctivae is assessed in the eyes, external ear canals (EEC), nasal cavity, and vagina of host species as well as in potential vectors, which may be involved in the transmission and persistence of infection within the host. M. conjunctivae was detected by qPCR in 7.2 % (CI 95% 4.7-11.0) of the ear swabs and 9.5 % (CI 95% 6.4-13.9) of the nasal swabs from Pyrenean chamois, Iberian ibex, domestic sheep and mouflon without statistical differences between species. Mycoplasma detection in nasal swabs was mostly associated with ocular infection (95.6%), but this was not the case for EEC (52.6%). Among the eye-positive ruminants, 27.3% were positive in ear swabs and 64.7% in nasal swabs, and the threshold cycle values of the qPCR were correlated only between eye and nasal swabs (p < 0.01; r2 = 0.56). M. conjunctivae was detected in 1.7% - 7.1 % of Musca spp. captured during an IKC outbreak in Iberian ibex and in one out of three endemic sheep flocks. The results indicate that the transmission of M. conjunctivae may occur by direct contact with eye or nasal secretions and/or indirectly through flies. The M. conjunctivae DNA detection in EEC suggests that it can colonise the auditory tract, but the significance for its persistence within the host should be further assessed.

Infectious keratoconjunctivitis in free-ranging mule deer in Wyoming: a retrospective study and identification of a novel alphaherpesvirus.

We describe the clinicopathologic findings, relative prevalence, and pathogens associated with infectious keratoconjunctivitis in mule deer ( Odocoileus hemionus) in Wyoming. Seventeen cases with ocular lesions were identified among 1,036 mule deer postmortem submissions (1.6%) in an ~16 y period. Sixteen cases were observed in winter and most were in male (15 cases) and juvenile (13 cases) deer. Blindness was the most commonly reported clinical sign (10 cases). A herpesvirus was detected only in the 4 cases of bilateral necrotizing bulbar conjunctivitis. Phylogenetic analysis of glycoprotein amino acid sequences consistently identified this virus as a novel alphaherpesvirus. In 2 of these herpesvirus-positive cases, Actinomyces sp. and Moraxella ovis were also identified. Trueperella pyogenes was identified in 4 cases of unilateral ulcerative keratitis, keratoconjunctivitis, and panophthalmitis. M. ovis was cultured from 3 cases of bilateral conjunctivitis and keratoconjunctivitis. In the remaining cases, isolates included Moraxella bovis (1 case), Staphylococcus sp. and Streptococcus sp. (2), Flavobacterium sp. and Pseudomonas sp. (2), Escherichia coli and Enterobacter sp. (1), and bovine viral diarrhea virus 1 (1). No pathogens were identified in 2 cases. The relative prevalence of keratoconjunctivitis in mule deer in Wyoming appears to be low, and this disease is most commonly associated with infection by a novel alphaherpesvirus, T. pyogenes, and M. ovis.

Recombinant type Human mastadenovirus D85 associated with epidemic keratoconjunctivitis since 2015 in Japan.

The aim of this study was to report the emergence of a recombinant human mastadenovirus (HAdV) type 85 (HAdV-85) and to describe its genomic and clinical characteristics. The strains were detected and identified in Japan in cases of adenoviral conjunctivitis including epidemic keratoconjunctivitis (EKC). The type was designated as HAdV-85 based on the novel combination of penton base (P = HAdV-37), hexon (H = HAdV-19), and fiber (F = HAdV-8). The whole genome sequence determined for HAdV-85 was compared against sequences of other types in the same species. The results of the phylogenetic analysis suggested a recombinant origin between HAdV-53 and HAdV-64, which have been two major causes of adenoviral EKC in Japan over the past decade. During the period between 2008 and 2016 in Kumamoto city, southwest of Japan, 311 cases diagnosed with conjunctivitis were diagnosed as being the consequence of adenoviral infections. Among them, 11 cases were determined to have been caused by HAdV-85 since 2015. Thus, HAdV-85 could be an emerging causative agent of adenoviral conjunctivitis.

[What about tropical endemic vernal keratoconjunctivitis? Which relationship with intestinal parasites?] / Que savons-nous de la limboconjonctivite endémique des tropiques ? Et quel rapport avec les parasites intestinaux ?

Given the causative parasite hypothesis for tropical endemic limbo-conjunctivitis (TELC), we conducted an analytical case-control study of all children with tropical endemic limbo-conjunctivitis seen in the ophthalmology department of Laquintinie hospital in Douala during the period from January 2nd to April 30, 2015. RESULTS: We identified 64 cases of tropical endemic limbo-conjunctivitis out of 550 children seen; a hospital prevalence of 11.6%; thirteen cases (eight boys and five girls) did not meet inclusion criteria, and 51 cases were included, 31 boys (60.8%) and 20 girls (39.2%) with a male/female (M/F) sex-ratio of 1.41. For controls, we included 28 males (54.9%) and 23 girls (45.1%) for a M/F sex-ratio of 1.22. The prevalence of tropical endemic limbo-conjunctivitis in boys was 12.1%, and for girls it was 7.1% in the case group. Stage II was the most frequent at 29 cases (56.9%), as well as the mixed form at 31 cases (60.8%). The frequency of intestinal parasites was 14 cases (27.5%) in the group of tropical endemic limbo-conjunctivitis patients and 6 cases (11.8%) in the control group (P=0.08). Entamoeba histolytica in its cystic form was the most intestinal parasite found in both groups, 10 cases for tropical endemic limbo-conjunctivitis (19.6%) and 6 cases in the control groups (11.8%). The mean serum IgE among cases was 81.2 IU/ml, while in the controls it was 15.6 IU/ml (P=0.001) CONCLUSION: There is no relationship between intestinal parasitic infection and the occurrence of tropical endemic limbo-conjunctivitis.

Adenovirus-related epidemic keratoconjunctivitis outbreak at a hospital-affiliated ophthalmology clinic.

Adenovirus-associated epidemic keratoconjunctivitis (A-EKC) is a cause of large and prolonged outbreaks in ophthalmology clinics and can result in substantial morbidity. A-EKC outbreaks are often the result of contaminated ophthalmologic equipment, surfaces, or hands. Contaminated multidose eye drops are also a likely culprit, but few prior studies provide clear epidemiologic evidence that adenovirus transmission resulted from contamination of eye drops. We describe an A-EKC outbreak at a large, hospital-affiliated eye clinic that affected 44 patients. The unique epidemiology of the outbreak provides strong evidence that contaminated multidose dilating eye drops resulted in adenovirus transmission. Removal of multidose eye medication from the clinic, combined with case finding, enhanced infection control and enhanced environmental cleaning, led to rapid control of the outbreak.

The basic reproductive number estimated from a Mycoplasma conjunctivae outbreak in a dairy goat farm.

Clinicians can evaluate the relevance of an outbreak based on its basic reproductive number (R0). So far there has been no report on the R0 of Mycoplasma conjunctivae which is a major cause of goats' conjunctivitis in Taiwan. The present study sought to investigate an outbreak of infectious keratoconjunctivitis (IKC) by Mycoplasma conjunctivae (MC) in an indoor dairy goat barn. The epidemiological curve was recorded to build a susceptible-infected-recovered model and to estimate the R0 by three methods In the investigated goat barn, 60% (31/55) goats showed degrees of IKC signs. The number of infected animals increased quickly after 15days, but slowed down after 41days. The sick goats began to recover after 30days. The epidemic fully stopped after 81days. The estimated R0 ranged from 1.35 to 4.46. In summary, this is the first MC report in Taiwan, and the first one to estimate the R0 of MC.

Analysis on the treatment and prevention of epidemic conjunctivitis in 108 cases.

To explore the treatment method and preventive measures on epidemic keratoconjunctivitis. 108 patients with epidemic keratoconjunctivitis who received treatment in our hospital from January, 2015 to September, 2015.were selected. These patients were treated with interferon eye drops, Ganciclovir ophthalmic gel, and alternating eye treatment of tobramycin-dexamethasone eye drops and diclofenac sodium eye drops. Meanwhile, health education was also performed among patients, so as to promote the recovery of the disease as soon as possible and to prevent the spread of the disease Among the 108 patients, there were 101 patients recovered. 7 patients had cornea remained sub epithelial round hoary haze, including 2 patients with evident cornea remained sub epithelial round hoary haze due to the occurrence of glucocorticoid-induced intraocular pressure and the tobramycin and dexamethasone eye drops were suspend. The clinical cure rate was 91.79%. There was no pathophoresis to health patients among the 108 patients. Active treatment of epidemic keratoconjunctivitis, combined with health education and publicity could increase the clinical cure rate and control the transmit of the disease spread.

Infectious keratoconjunctivitis and occurrence of Mycoplasma conjunctivae and Chlamydiaceae in small domestic ruminants from Central Karakoram, Pakistan.

Infectious keratoconjunctivitis (IKC) is a contagious eye disease primarily caused by Mycoplasma conjunctivae in domestic and wild Caprinae. Chlamydophila species have also been detected in ruminants with IKC. The objectives of this study are to investigate the ocular infection of M. conjunctivae and Chlamydiaceae and assess its interaction in relation to IKC in sheep and goats from remote communities around the Central Karakoram National Park in Pakistan, performing a combination of cross-sectional and case-control study design. Mostly asymptomatic and endemic infections of M. conjunctivae and Chlamydiaceae were found in sheep (19.3 per cent and 4.5 per cent, respectively) and goats (9.5 per cent and 1.9 per cent, respectively) from all communities, assessed by qPCR. Prevalence significantly differed between species only for M. conjunctivae (P=0.0184), which was also more prevalent in younger sheep (P<0.01). Chlamydophila pecorum was identified by sequencing and was related with IKC only when coinfection with M. conjunctivae occurred, which suggest a synergic interaction. Cluster analysis of M. conjunctivae strains revealed higher diversity of strains than expected, evidenced interspecific transmission and suggested a higher local livestock trade than previously assumed. These results highlight the widespread occurrence of M conjunctivae in sheep worldwide and its implications for wildlife should be assessed from a conservation perspective.

Randomized blinded controlled trial to assess the association between a commercial vaccine against Moraxella bovis and the cumulative incidence of infectious bovine keratoconjunctivitis in beef calves.

OBJECTIVE To assess the association between a commercially available vaccine against Moraxella bovis and cumulative incidence of infectious bovine keratoconjunctivitis (IBK) from processing to weaning (primary objective) and body weight at weaning (secondary objective). DESIGN Randomized blinded controlled trial. ANIMALS 214 calves (≥ 2 months of age) born in the spring of 2015 at an Iowa State University cow-calf research unit with no visible lesions or scars on either eye. PROCEDURES Calves were randomly allocated to receive SC administration of a single dose of a commercial vaccine against M bovis (112 enrolled and 110 analyzed) or saline (0.9% NaCl) solution (111 enrolled and 104 analyzed). Calves were monitored for signs of IBK from treatment to weaning, and body weight at weaning was recorded. People involved in calf enrollment and outcome assessment were blinded to treatment group assignment. Cumulative incidence of IBK and weaning weight were compared between vaccinated and unvaccinated calves; the effect measure was the risk ratio and mean difference, respectively. RESULTS IBK was detected in 65 (59.1%) vaccinated calves and 62 (59.6%) unvaccinated calves (unadjusted risk ratio, 0.99; 95% confidence interval, 0.79 to 1.24) during the study period. No significant difference in weaning weights was identified between vaccinated and unvaccinated calves (unadjusted effect size, 4.40 kg [9.68 lb]; 95% confidence interval, -3.46 to 12.25 kg [-7.61 to 26.95 lb]). CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the commercially available M bovis vaccine was not effective in reducing the cumulative incidence of IBK or increasing weaning weight in beef calves.

Infectious keratoconjunctivitis in wild Caprinae: merging field observations and molecular analyses sheds light on factors shaping outbreak dynamics.

BACKGROUND: Infectious keratoconjunctivitis (IKC) is an ocular infectious disease caused by Mycoplasma conjunctivae which affects small domestic and wild mountain ruminants. Domestic sheep maintain the pathogen but the detection of healthy carriers in wildlife has raised the question as to whether M. conjunctivae may also persist in the wild. Furthermore, the factors shaping the dynamics of IKC outbreaks in wildlife have remained largely unknown. The aims of this study were (1) to verify the etiological role of M. conjunctivae in IKC outbreaks recorded between 2002 and 2010 at four study sites in different regions of France (Pyrenees and Alps, samples from 159 Alpine ibex Capra ibex, Alpine chamois Rupicapra rupicapra and Pyrenean chamois Rupicapra pyrenaica); (2) to establish whether there existed any epidemiological links between the different regions through a cluster analysis of the detected strains (from 80 out of the 159 animals tested); (3) to explore selected pathogen, host and environmental factors potentially influencing the dynamics of IKC in wildlife, by joining results obtained by molecular analyses and by field observations (16,609 animal observations). All of the samples were tested for M. conjunctivae by qPCR, and cluster analysis was based on a highly variable part of the lppS gene. RESULTS: We documented infections with M. conjunctivae in epidemic and endemic situations, both in symptomatic and asymptomatic animals. The identified M. conjunctivae strains were site-specific and persisted in the local wild population for at least 6 years. In epidemic situations, peaks of cases and disease resurgence were associated with the emergence of new similar strains in a given area. Social interactions, seasonal movements and the landscape structure such as natural and anthropogenic barriers influenced the spatio-temporal spread of IKC. Adults were more affected than young animals and host susceptibility differed depending on the involved strain. CONCLUSION: Our study indicates that IKC is a multifactorial disease and that M. conjunctivae can persist in wildlife populations. The disease course in individual animals and populations is influenced by both host and mycoplasma characteristics, and the disease spread within and among populations is shaped by host behavior and landscape structure.

Lacrimal Duct Occlusion Is Associated with Infectious Keratitis.

Background: To explore the prevalence of lacrimal duct obstruction in patients with infectious keratitis, and the necessity of lacrimal duct dredge in the treatment of human infectious keratitis. Methodology/Principle Findings: The design is prospective, non-control case series. Thirty-one eyes from twenty-eight continuous patients with infectious keratitis were included in this study. The presence/absence of lacrimal duct obstruction was determined by the lacrimal duct irrigation test. The diagnosis of infectious keratitis was made based on clinical manifestations, cornea scraping microscopic examination and bacterial/fungus culture. Diagnosis of viral keratitis was set up based on the recurrent history, deep neovascularization and typical outlook of the cornea scar. The treatment of keratitis included drugs, eye drops or surgery, while treatment of chronic dacryocystitis was lacrimal duct dredging with supporting tube implantation surgery. In the thirty-one eyes with infectious keratitis, fifteen suffered from fungal keratitis (48%), two bacterial keratitis (6%), and fourteen viral keratitis (45%). Eleven eyes (35%) from ten patients with infectious keratitis also suffered from lacrimal duct obstruction. In those cases, six eyes also suffered from lower canalicular obstruction, three nasolacrimal duct obstruction and chronic dacryocystitis, one a combination of upper and lower canalicular obstruction, one upper canalicular obstruction. After local and systemic applications of anti-bacterial, anti-viral, anti-fungal and anti-inflammatory drugs, twenty-eight eyes (90%) recovered within three weeks, while the ulceration of three patients required the lacrimal duct dredging and supporting tube implantation surgery for the healing. Conclusions: Herein, we first report that the prevalence of infectious keratitis is closely correlated to the occurrence of lacrimal duct obstruction. When both confirmed, simultaneous treatment of keratitis and lacrimal duct obstruction promptly is required. Further evaluation of mechanism, prevention and control of the diseases are warranted.

Clinical and corneal microbial profile of infectious keratitis in a high HIV prevalence setting in rural South Africa.

The purpose of this investigation was to determine the clinical and corneal microbial profile of infectious keratitis in a high human immunodeficiency virus (HIV) prevalence setting in rural South Africa. Data in this cross-sectional study were collected from patients presenting with symptoms of infectious keratitis (n = 46) at the ophthalmology outpatient department of three hospitals in rural South Africa. Corneal swabs were tested for herpes simplex virus type 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV) and adenovirus DNA by real-time polymerase chain reaction (PCR) and for bacteria and fungi by culture. Based on clinical history, disease characteristics and laboratory results, 29 (63 %) patients were diagnosed as viral keratitis, including 14 (48 %) viral keratitis cases complicated by bacterial superinfection, and 17 (37 %) as bacterial keratitis. VZV and HSV-1 DNA was detected in 11 (24 %) and 5 (11 %) corneal swabs, respectively. Among clinically defined viral keratitis cases, a negative viral swab was predominantly (93 %) observed in cases with subepithelial inflammation and was significantly associated with an increased duration of symptoms (p = 0.003). The majority of bacteria cultured were Gram-positive (24/35), including Staphylococcus epidermidis and S. aureus. Viral aetiology was significantly associated with a history of herpes zoster ophthalmicus (p < 0.001) and a trend was observed between viral aetiology and HIV infection (p = 0.06). Twenty-one (47 %) keratitis cases were complicated by anterior uveitis, of which 18 (86 %) were HIV-infected cases with viral keratitis. The data implicate a high prevalence of herpetic keratitis, in part complicated by bacterial superinfection and/or uveitis, in HIV-infected individuals presenting with infectious keratitis in rural South Africa.