"Demodicosis" Mimicking PreSeptal Cellulitis: Severe Periocular and Facial Inflammation Caused by "Normal" Skin Flora.

Due to their relatively high prevalence and commensalism, the pathogenicity of Demodex mites has been debated. Recent data, however, show Demodex to be associated with skin and ocular surface diseases such as rosacea, blepharitis, and keratitis. Here the authors report the first known case, to the best of the their knowledge, of Demodex infestation mimicking preseptal cellulitis in an adult human. A 29-year-old male bilaterally blind from advanced retinopathy of prematurity presented with a 2-month history of right-greater-than-left upper eyelid and periocular/cheek swelling, redness, and ocular discharge that did not resolve with oral antibiotics or oral steroids. Based on MRI findings, biopsies of the right lacrimal gland, right orbital fat, and right upper eyelid preseptal skin were obtained which revealed marked intrafollicular Demodex mite density and budding yeasts in the upper eyelid skin. This case serves to alert clinicians to this entity that may not otherwise be usually considered in ophthalmic clinical practice.

Periorbital necrotizing sweet syndrome: A report of two cases mimicking necrotizing soft tissue infections.

Purpose: Two cases are described of necrotizing Sweet syndrome (nSS), a rare variant of acute febrile neutrophilic dermatosis that mimics necrotizing soft tissue infections. Observation: A 74-year-old female with myelodysplastic syndrome (MDS) presented with isolated periorbital nSS that closely mimicked necrotizing fasciitis (NF); she displayed pathergy to debridement, was exquisitely responsive to corticosteroids, and underwent successful first-stage reconstruction of the eyelid with full-thickness skin grafting. A second 40-year-old female patient with relapsed acute myelogenous leukemia (AML) presented with multifocal nSS most prominently involving the eyelid. Positive herpes zoster virus (HSV) PCR and bacterial superinfection complicated the diagnosis. She improved with chemotherapy for AML and corticosteroid therapy. Conclusion: nSS is rare and a high level of clinical suspicion as well as an understanding of its distinguishing features is necessary to avoid undue morbidity. Identification of pathergy, histopathology, microbiology, and clinical context are critical to avoid misdiagnosis of infection.

Antibiotic utilization in endoscopic dacryocystorhinostomy: a multi-institutional study and review of the literature.

PURPOSE: Utilization of antibiotics for endoscopic dacryocystorhinostomy (endo-DCR) is largely dependent on individual surgeon preference. This study aimed to investigate prescribing practices of pre-, peri-, and postoperative antibiotics and effects on postoperative infection rates in patients who underwent endo-DCR. METHODS: A retrospective chart review of institutional data at two academic centers of endo-DCR cases from 2015-2020 was performed. Postoperative infection rates for patients who received pre-, peri-, and postoperative antibiotics, individually or in combination, and those who did not, were compared via odds ratio and ANOVA linear regression. RESULTS: 331 endo-DCR cases were included; 22 cases (6.6%) had a postoperative infection. There was no significant difference in the infection rates between patients without an active preoperative dacryocystitis who received different permutations of peri- and postoperative antibiotics. Patients who received preoperative antibiotics within two weeks of surgery for preexisting acute dacryocystitis, but did not receive peri- or postoperative antibiotics, had a higher rate of postoperative infections (p = 008). CONCLUSIONS: Our data suggest antibiotics may be beneficial only when patients have a recent or active dacryocystitis prior to surgery. Otherwise, our data do not support the routine use of antibiotic prophylaxis in endo-DCR.

Perceived change in age after functional upper blepharoplasty.

PURPOSE: To evaluate the perceived age of patients before and after functional upper blepharoplasty. METHODS: Retrospective chart review of patients who underwent upper blepharoplasty by a single surgeon at an academic center. The inclusion criterion was having external photographs before and after blepharoplasty. Exclusion criteria included any other concurrent eyelid or facial surgery. Primary endpoint: perceived change in age after surgery as judged by the American Society of Ophthalmic Plastic & Reconstructive Surgery (ASOPRS) surgeons. RESULTS: Sixty-seven patients (14 men, 53 women) were included. Mean pre-operative age was 66.9 years (range 37.8-89.4) and mean post-operative age was 67.4 years (range 38.6-89). The mean perceived age pre-operatively was 68.9 years, and the mean perceived age post-operatively was 67.1 years, a change of 1.8 years (p = 0.0001 by two-tailed paired T-test). Inter-rater reliability of the observers was measured by intraclass correlation coefficient of 0.77 for pre-operative and 0.75 for post-operative photos. The decreased perceived age was 1.9 years for women, 1.4 years for men, 0.3 years for Asians, 1.2 years for Hispanics, and 2.1 years for whites. DISCUSSION: Functional upper blepharoplasty by an experienced ASOPRS surgeon was shown to reduce the perceived age of a patient by an average of 1.8 years.

A Rapidly Expanding Hemorrhagic BRAF-Mutant Orbital Atypical Glomus Tumor.

A healthy 32-year-old woman presented with the acute onset of left sided eye pain, upper eyelid fullness, and binocular diplopia during light weightlifting. Examination elevated intraocular pressure, proptosis, upper eyelid ptosis, and motility deficits. CT demonstrated a well-circumscribed, homogeneous-appearing extraconal mass in the superior left orbit. The patient underwent an urgent orbitotomy with the excision of a hemorrhagic mass. Histopathology showed a glomus tumor with atypical features and hemorrhagic infarction, best classified as having uncertain malignant potential. A B-Raf proto-oncogene V600E mutation was detected with immunohistochemistry, which suggests a more aggressive tumor behavior yet presents an opportunity for targeted primary or adjunctive therapy. This is the first reported case of a B-Raf proto-oncogene-mutant atypical glomus tumor arising in the orbit.

The Effect of Microcystis on the Monitoring of Faecal Indicator Bacteria.

The survival of Escherichia coli (E. coli) bacteria, the most common faecal indicator bacteria (FIB), may be significantly affected by cyanobacteria present during a harmful algal bloom (HAB). Therefore, the effect of Microcystis on the survival of FIB E.coli and coliforms was investigated. Microcosms containing two species of Microcystis (M. aeruginosa and M. smithii) were established and then inoculated with four reference strains of E. coli (ATCC 25922, 8739, 51813, and 11775) to explore the cyanobacteria-bacteria dynamics at a laboratory setting. Monitoring over several days showed normal growth of Microcystis, with or without the presence of E. coli. However, Microcystis was shown to dramatically decrease the survival of E. coli over time. Analysis of microcystin production by Microcystis was found to correlate with loss of E. coli, suggesting a toxic effect of microcystins on E. coli bacteria. This phenomenon was also demonstrated for a natural consortium of E. coli and coliform bacteria by inoculating with contaminated lake water. The results indicate that the use of E. coli as FIB may be greatly compromised in the presence of Microcystis spp. such as during a HAB when associated toxins are produced.

Silicone Granulomas of the Eyelids-A Case Series Illustrating a Distant Migratory Phenomenon.

PURPOSE: Exogenous silicone has been reported to migrate to anatomic sights far from an initial injection or implantation site; this phenomenon has been rarely described in the ocular adnexa, especially in the eyelids. We document 3 additional cases of distant migration of silicone implanted elsewhere in the body to the eyelids and review the prior literature on this uncommon event. METHODS: A retrospective chart review of 3 patients was conducted along with analysis of diagnostic histopathology. A comprehensive review of the literature regarding dissemination or migration of silicone to the eyelids in patients with either silicone breast implants or silicone facial filler use was performed. RESULTS: Cases of silicone migrating to the eyelids from silicone breast implants and silicone-based facial filler are outlined in Tables 1 and 2, respectively. There are 4 total reports of women with silicone breast implants, including the 2 described here, with evidence of migration of silicone to the eyelid. Similarly, 5 cases of silicone-based facial filler with resultant migration of filler to the eyelids were identified, including 2 of the cases presented in this report (1 patient had both silicone breast implants and silicone facial filler). CONCLUSION: Silicone is chemically inert, but is known to travel throughout the body, causing a resultant foreign body response in tissue that can adversely affect even the eyelids. Silicone has a relatively characteristic histologic appearance and diagnosis of silicone granuloma highlights the importance of obtaining a thorough clinical history, particularly regarding prior cosmetic injections or breast enhancement surgery. Foreign material/foreign body granuloma is important to consider in patients with deep eyelid nodules of unclear etiology.

Optic Perineuritis Associated With Cryptococcal Meningitis Presenting With a "Hot Orbit" in a Patient With Chronic Lymphocytic Leukemia.

ABSTRACT: A 75-year-old man presented with 3 days of progressive left retro-orbital pain, eyelid swelling, tearing, and pain with extraocular movement. His medical history was significant for type II diabetes mellitus and chronic lymphocytic leukemia, stable on no therapy since diagnosis 8 years prior. The initial examination was significant for diffuse restriction of left ocular motility, marked lid edema, and mild dyschromatopsia. Computed tomography demonstrated asymmetric left periorbital soft tissue swelling and intraconal fat stranding with an irregular left optic nerve sheath complex and clear paranasal sinuses. He was hospitalized for orbital cellulitis and treated empirically with broad-spectrum intravenous antibiotics, but his visual acuity declined over the ensuing 2 days. Subsequent MRI demonstrated left-greater-than-right circumferential optic nerve sheath enhancement, and leptomeningeal enhancement. An orbital biopsy demonstrated monoclonal B-cell lymphocyte aggregation, whereas a lumbar puncture was positive for Cryptococcus antigen with subsequent demonstration of abundant Cryptococcus by Papanicolaou stain. The final diagnosis was optic perineuritis secondary to cryptococcal meningitis presenting with orbital inflammation. Although his clinical course was complicated by immune reconstitution inflammatory syndrome, symptoms and signs of optic neuropathy ultimately resolved after 1 month of intensive antifungal therapy.

ARHGEF-10 gene mutation presenting as orbital inflammatory syndrome.

Rho guanine nucleotide exchange factor 10 (ARHGEF-10) is a RHO GTPase that has a role for neural morphogenesis, however its effect on the eyes remains unknown. Here, we report a 44-year-old man who presented with eyelid swelling along with a history of bilateral hand contractures, high-arched feet and muscle wasting, who was found to have an ARHGEF-10 mutation. Neuroimaging was significant for numerous nerve-based cystic abnormalities in the bilateral orbits and throughout the neuraxis, and an orbital biopsy revealed S-100 and SOX-10 positive lesion consistent with pseudocysts. While the role of ARHGEF-10 remains unclear, further research is warranted to further describe its clinical manifestations.

Lower eyelid malposition following repair of complex orbitofacial trauma.

PURPOSE: To compare the incidence of lower eyelid malposition following repair of isolated orbital floor fractures with that of complex orbitofacial fractures (defined as multi-wall fractures or prior orbital fracture repairs requiring revision) by oculofacial plastic surgeons via a transconjunctival or swinging eyelid approach. METHODS: Retrospective review of 175 patients who underwent surgical repair of orbital fractures at our institution. The primary outcomes were the occurrence of lower eyelid malposition (ectropion, entropion, and eyelid retraction) and the need for subsequent surgical correction. RESULTS: Of 95 patients with isolated orbital floor fractures, 4 developed eyelid malposition (4.2%), 1 of which required surgical repair (1.1%). Of 80 patients with complex orbitofacial fractures (48 multi-wall fractures, 32 secondary revisions), 10 had pre-operative eyelid malposition and were excluded from further analysis. Fourteen of the remaining 70 patients developed postoperative eyelid malposition (20%), 3 of which required surgical repair (4.3%). The difference in the occurrence of eyelid malposition between groups was statistically significant (p = .001), but the difference in rates of those requiring subsequent repair was not (p = .182). There was no statistically significant difference in the occurrence of eyelid malposition when considering other surgical factors including lateral canthotomy, conjunctival closure, implant material, or anterior rim screws. CONCLUSIONS: The incidence of lower eyelid malposition following orbital fracture repair via a fornix-based approach was significantly higher for the repair of complex orbitofacial fractures than for isolated floor fractures. However, very few patients in either group required surgical repair for eyelid malposition. Surgical factors including implant material did not affect outcomes.

In vivo analysis of endocanalicular light pipe transillumination in endoscopic dacryocystorhinostomy: Anatomic considerations and cautions for the transitioning.

PURPOSE: Localization of the lacrimal sac is a critical step during endoscopic dacryocystorhinostomy (endo-DCR). A "light pipe" can be used to transilluminate the lacrimal sac endonasally. We hypothesized that this may misguide the surgeon learning endo-DCR to create an osteotomy mostly posterior to the maxillary line if only the bone overlying the transillumination was to be removed, as the thinner lacrimal bone will transmit light more readily than the thicker maxillary bone of the frontal process of the maxilla that forms the anterior lacrimal sac fossa. METHODS: The charts of 32 patients with primary acquired nasolacrimal duct obstruction in whom a lighted system was used during endo-DCR at Massachusetts Eye and Ear from April 2015 through October 2016 were reviewed. Patients with prior history of lacrimal surgery or trauma directly to the lacrimal sac fossa were excluded. Location of the maximal point of transillumination in relation to the maxillary line was observed and noted intraoperatively. RESULTS: Of a total of 39 endo-DCR surgeries performed, the intraoperative transillumination point was entirely posterior to the maxillary line in 32 instances (82%). CONCLUSIONS: Use of an endocanalicular light pipe preferentially illuminates posterior to the maxillary line endonasally. The anterior lacrimal sac fossa (maxillary line and anterior as visualized endonasally) is rarely transilluminated, likely due to thicker bone in that region. Surgeons learning how to perform endo-DCR using a light pipe should be aware of this phenomenon.

Medical comorbidities and orbital implant exposure.

PURPOSE: To investigate medical conditions and systemic therapies associated with orbital implant exposure in patients with anophthalmic sockets. METHODS: Retrospective review of patients who underwent enucleation or evisceration at a single centre between January 1, 2008 and March 1, 2018. Medical comorbidities, including peripheral or coronary artery disease, rheumatologic conditions, diabetes, malignancy and history of smoking were recorded. Use of immunomodulatory and anticoagulation therapy at the time of eye removal was noted. Patients were divided into two groups-those with implant exposure and those without. Univariate and multivariate analysis was used to compare groups. RESULTS: Two hundred and twenty-nine patients underwent eye removal surgery over a ten-year period. Implant exposure was seen in 20 (8.7%) patients. Univariate analysis revealed a statistically significant difference between groups in rates of smoking, malignancy, and immunomodulatory therapy at the time of surgery. A history of smoking (HR = 11.72; 95% CI: 2.95, 46.53; p = 0.0001) and immunomodulatory therapy (HR = 8.02; 95% CI: 1.96, 32.87; p = 0.004) were independent predictors of exposure. The probability of exposure was 81.2% when all three risk factors were present versus 4.4% when none were present (c-index = 0.737, 95% CI: 0.608, 0.865; p < 0.001). The model was a good fit to the data (Hosmer-Lemeshow goodness-of-fit test p = 0.475). CONCLUSIONS: Smoking and immunomodulatory therapy were associated with orbital implant exposure in patients with anophthalmic sockets. This is the first report examining medical comorbidities in patients with orbital implant exposure. Understanding the pathophysiology of implant exposure is crucial to preoperative planning and postoperative care.

Depth-Dependent Spatiotemporal Dynamics of Overwintering Pelagic Microcystis in a Temperate Water Body.

Cyanobacteria in the genus Microcystis are dominant components of many harmful algal blooms worldwide. Their pelagic-benthic life cycle helps them survive periods of adverse conditions and contributes greatly to their ecological success. Many studies on Microcystis overwintering have focused on benthic colonies and suggest that sediment serves as the major inoculum for subsequent summer blooms. However, the contemporaneous overwintering pelagic population may be important as well but is understudied. In this study, we investigated near-surface and near-bottom pelagic population dynamics of both microcystin-producing Microcystis and total Microcystis over six weeks in winter at Dog Lake (South Frontenac, ON, Canada). We quantified relative Microcystis concentrations using real-time PCR. Our results showed that the spatiotemporal distribution of overwintering pelagic Microcystis was depth dependent. The abundance of near-bottom pelagic Microcystis declined with increased depth with no influence of depth on near-surface Microcystis abundance. In the shallow region of the lake (<10 m), most pelagic Microcystis was found near the lake bottom (>90%). However, the proportion of near-surface Microcystis rose sharply to over 60% as the depth increased to approximately 18 m. The depth-dependent distribution pattern was found to be similar in both microcystin-producing Microcystis and total Microcystis. Our results suggest the top of the water column may be a more significant contributor of Microcystis recruitment inoculum than previously thought and merits more attention in early CHAB characterization and remediation.

Adult-onset asthma and periocular xanthogranuloma - A rare infiltrative disease of the orbit and eyelid.

PURPOSE: To present a case of adult onset asthma with periocular xanthogranuloma (AAPOX), and discuss existing literature on adult orbital xanthogranulomatous diseases (AOXGDs) and their treatment. OBSERVATIONS: A 63 year old male presented with progressive bilateral eyelid swelling with overlying yellow plaques associated with asthma. CT scan showed periorbital swelling with enlargement of the superior and lateral rectus muscles bilaterally. Biopsy demonstrated orbital xanthogranulomatous disease with increased IgG4 plasma cells. The patient was treated with intralesional triamcinolone, oral prednisone, and cyclophosphamide without significant improvement. Surgical debulking was eventually performed which improved his external symptoms until he was lost to follow up 15 months later. CONCLUSIONS AND IMPORTANCE: AOXGDs are a group of rare infiltrative diseases of the eyelids and orbit that can be associated with significant systemic morbidities. While they all have similar underlying histopathologic features, appreciating the clinical difference between these diseases is important in understanding patient prognosis and ensuring appropriate clinical monitoring. There is also growing research demonstrating that AAPOX, along with other AOXGDs, may represent part of a continuum of IgG4 related disease, similar to what is seen in this case. There is currently no reliably effective treatment for AOXGDs, and additional research into the management of these diseases is necessary.

Orbital Involvement by Biphenotypic Sinonasal Sarcoma With a Literature Review.

PURPOSE: To document a case of a biphenotypic sinonasal sarcoma that impinged on the orbit via a tumor-induced mucocele and review the previous literature devoted to this condition. METHODS: A clinicopathologic case report with detailed histopathologic, immunohistochemical, and radiological studies with tabulations of previously reported cases and immunohistochemical stains for ruling out mimicking lesions. RESULTS: A biphenotypic sinonasal sarcoma arose from the ethmoid sinus in a middle-aged man. The tumor induced a mucocele that bowed the medial orbital lamina papyracea into the orbit and caused diplopia and mild proptosis. The biopsy's dual positivity for S100 and smooth muscle actin together with positive paired box 3 immunohistochemical staining established the diagnosis of biphenotypic sinonasal sarcoma. CONCLUSION: Biphenotypic sinonasal sarcoma, which can involve the orbit in 25% of cases, is a rare head and neck malignancy that has only recently been described. Biphenotypic sinonasal sarcoma is a low-grade, locally aggressive, nonmetastasizing sarcoma displaying both neural and muscle differentiation. It is further characterized by rearrangements of the PAX3 gene with multiple fusion partners, most commonly MAML3 (Mastermind like transcriptional coactivator 3). It occurs predominantly in middle-aged women and exclusively in the sinonasal tract. However, it can spread throughout the central facial structures to invade the brain if not detected early. Ophthalmologists should be aware of this new entity to avoid delays in diagnosis and treatment. The previous literature devoted to this condition was reviewed and analyzed for clinical, radiological, histopathological, and immunohistochemical features. In circumstances where molecular testing is not available, paired box 3 immunohistochemical staining can be used as an alternative diagnostic marker. The current case is most unusual because the orbital findings were induced by a mucocele caused by the tumor that obstructed the sinus ostium. This produced diplopia without direct tumor invasion into the orbital fat.

Sclerosing Signet Ring Cell Carcinoma of the Lacrimal Gland: A Potentially New Primary Entity.

An 88-year-old man presented with diplopia, limitation of extraocular movements, and a firm palpable mass in the superolateral orbit. Biopsy revealed a sclerosing signet ring cell carcinoma with histopathologic features mimicking those of a primary signet ring cell (histiocytoid) carcinoma of the eyelid of eccrine or apocrine gland origin, a metastasis from an invasive lobular breast carcinoma or a metastatic diffuse-type gastric carcinoma. An extensive panel of immunohistochemical stains and molecular genetic analyses unequivocally failed to establish a precise diagnosis. Electron microscopy demonstrated features of a primary lacrimal gland lesion with intracytoplasmic lumens and zymogen granules typical of lacrimal secretory pyramidal cells. A thorough initial systemic work-up failed to reveal a primary visceral malignancy. Fifteen months of follow-up have failed to detect the emergence of another primary malignancy. To the best of our knowledge, a tumor with the morphology of the current lesion has not been previously described in the major or accessory lacrimal glands.

Fatty Acid Profiles from Routine Milk Recording as a Decision Tool for Body Weight Change of Dairy Cows after Calving.

Cows mobilize body reserves during early lactation, which is reflected in the milk fatty acid (FA) profile. Milk FA can be routinely predicted by Fourier-transform infrared (FTIR) spectroscopy, and be, thus, used to develop an early indicator for bodyweight change (BWC) in early lactating cows in commercial dairy farms. Cow records from 165 herds in Denmark between 2015 and 2017 were used with bodyweight (BW) records at each milking from floor scales in automatic milking systems. Milk FA in monthly test-day samples was predicted by FTIR. Predictions of BWC were based on a random forest model and included parity, stage of lactation, and test day milk production and components (fat, protein, and FA). Bodyweight loss was mainly explained by decreased short-chain FA (C4:0-C10:0) and increased C18:0 FA. The root mean square error (RMSE) of prediction after cross-validation was 1.79 g/kg of BW (R2 of 0.94). Model evaluation with previously unseen BWC records resulted in reduced prediction performance (RMSE of 2.33 g/kg of BW; R2 of 0.31). An early warning system may be implemented for cows with a large BW loss during early lactation based on milk FA profiles, but model performance should be improved, ideally by using the full FTIR milk spectra.

Development of a Benchmarking Tool for Dairy Herd Management Using Routinely Collected Herd Records.

Continuous assessment of the herd status is important in order to monitor and adjust to changes in the welfare and health status but can be time consuming and expensive. In this study, herd status indicators from routinely collected dairy herd improvement (DHI) records were used to develop a remote herd assessment tool with the aim to help producers and advisors benchmark the herd status and identify herd management issues affecting welfare and health. Thirteen DHI indicators were selected from an initial set of 72 potential indicators collected on 4324 dairy herds in Eastern Canada. Data were normalized to percentile ranks and aggregated to a composite herd status index (HSI) with equal weights among indicators. Robustness analyses indicated little fluctuation for herds with a small HSI (low status) or large HSI (high status), suggesting that herds in need of support could be prioritized and effectively monitored over time, limiting the need for time-consuming farm visits. This tool allows evaluating herds relative to their peers through the composite index and highlighting specific areas with opportunities for improvements through the individual indicators. This procedure could be applied to similar multidimensional livestock farming issues, such as environmental and socio-economic studies.

Evaluation of the new differential somatic cell count parameter as a rapid and inexpensive supplementary tool for udder health management through regular milk recording.

Mastitis, particularly in its subclinical form, is the costliest disease in milk production causing substantial financial losses to the dairy industry, impairing animal welfare, and one of the main reasons for treating dairy cows with antimicrobials. Somatic cell count (SCC) is broadly used as an indicator for mastitis or intramammary infection (IMI) and is the basis for udder health management programmes, e.g., through monthly dairy herd improvement (DHI) testing. While SCC shows the total number of cells in milk, the new Differential SCC (DSCC) shows also the combined proportion of polymorphonuclear neutrophils (PMN) and lymphocytes as a percentage of the total SCC. In this study, we investigated the test characteristics of DSCC as a new supplementary indicator for mastitis screening. We collaborated with 11 herds totalling 969 dairy cows and collected metered DHI samples once a month over four months. The IMI status was assessed through analysis of aseptic composite hand-stripped samples using culture and followed by species identification using MALDI-ToF. The pathogens detected were categorised as 'no', 'minor', 'major', or 'other' pathogens. The results of our study showed that the DSCC parameter was significantly associated with the IMI status and the cow's parity but not with days in milk or test-day milk weight. On the other hand, SCC was associated with all these four factors. DSCC counts were significantly higher in samples of cows with IMI caused by major pathogens as compared to cows with no IMI or IMI by minor or other pathogens. SCC alone, DSCC alone, and the combination of DSCC and SCC were further compared based on test characteristics using exemplary cut-offs. For example, working with a cut-off of 200,000 cells/ for SCC alone compared to working with the combination of DSCC of 65 % and/or 200,000 cells/mL to classify cows as infected by major pathogens, the sensitivity increased from 78 % to 92 % and the specificity decreased from 87 % to 66 %. With the combination, the positive predictive value changed from 52 % to 34 %, and the negative predictive value stayed at the same level (96 % vs 98 %). In summary, our study provides first insights on test characteristics of the DSCC parameter used in combination with the well-established SCC for monitoring udder health using DHI testing. This combination opens up the possibility to further improve udder health monitoring programmes (e.g., improved identification of IMI caused by major pathogens) but more work on the subject is needed.