Metagenomic analysis of the ocular toxoplasmosis in children uveitis from Fayoum governorate, Egypt.

Granulomatous anterior uveitis with single or numerous gelatinous nodules was found in children living in rural Egypt. All ocular diseases were originally thought to be water-born and related to digenic flukes. The current study sought to learn more about the causes of anterior granulomatous uveitis in Egyptian youngsters who used to swim in rural water canals. 50 children with eye lesions that had not responded to medical treatment were recruited. Four samples were surgically extracted and examined using real-time PCR, transmission electron microscopy (TEM), and shotgun metagenomic sequencing (SMS). Toxoplasma gondii was detected free within the syncytium's distal section, while the proximal part exhibited active synthesis of a presumably extra-polymeric material, possibly released by the microbial population. Toxoplasma gondii was found in 30 samples. Serologically, distinct anti-Toxoplasma antibodies were not found in 91.6% of patients. SMS showed that the T. gondii ME 49 strain had the greatest percentage (29-25%) in all samples within an Acinetobacter-containing microbial community. These findings suggested that these bacteria entered the body via the exterior route rather than the circulatory route. The lack of genetic evidence for subsequent parasite stages invalidates the prior findings about the assumed trematode stage.

Multiplex Solid-Phase Real-Time Polymerase Chain Reaction without DNA Extraction: A Rapid Intraoperative Diagnosis Using Microvolumes.

PURPOSE: Current polymerase chain reaction (PCR) methods for the diagnosis of infections are time consuming and require large sample volume and skilled technicians. We developed a novel, easy-to-use, and rapid (processing time, 1 minute; total time, 33 minutes) multiplex real-time PCR test (Direct Strip PCR) that did not require DNA extraction to detect 9 pathogens that could cause uveitis in 20-µl samples. DESIGN: Multicenter prospective evaluation of a diagnostic PCR test. PARTICIPANTS: A total of 511 participants (patients with infectious uveitis and controls) were examined at 18 institutes worldwide. METHODS: After validation, intraocular fluid samples were subjected to etiologic or exclusive diagnosis, including intraoperative rapid diagnosis. MAIN OUTCOME MEASURES: The concordance and correlations between Direct Strip PCR and quantitative PCR (qPCR) results. RESULTS: Direct Strip PCR exhibited rapid detection, good repeatability and specificity, long storage stability, and detection ability equal to that of qPCR. It also showed low interinstitutional variability compared with qPCR, even when PCR beginners used various real-time PCR machines. The Direct Strip PCR for 9 pathogens exhibited high concordance against the qPCR (positive concordance rate, 98.8%-100%; negative concordance rate, 99.8%-100%; κ coefficient, 0.969-1.000; P < 0.001-0.031). Additionally, results obtained using Direct Strip PCR and qPCR were highly correlated (ρ = 0.748; P < 0.001). This assay was used for rapid intraoperative diagnosis. CONCLUSIONS: The Direct Strip PCR test may improve the prognosis of various infectious diseases because it facilitates rapid etiologic evaluation at the first hospital visit and can be used for intraoperative diagnosis.

Encephalitozoon cuniculi infection in cats: European guidelines from the ABCD on prevention and management.

OVERVIEW: Encephalitozoon cuniculi is a common obligate intracellular microsporidian parasite of rabbits that is increasingly recognised as a pathogen of cats and other mammalian species. These guidelines aim to review the literature on feline E cuniculi infection and provide recommendations on prevention and management. INFECTION IN CATS: E cuniculi infection should be considered as a differential diagnosis in cases of feline uveitis and cataract formation. It is not significantly associated with either chronic kidney disease or meningoencephalitis. E cuniculi infection is more common in stray or feral cats than in pet cats. DIAGNOSIS AND TREATMENT: Serological tests for antibody detection in the blood are easy to perform and can be useful for diagnosis, but their specificity is low as antibodies have been found in apparently healthy cats. PCR appears to be more sensitive than histopathology for diagnosis, and is more sensitive when performed on cataractous lenses compared with aqueous humour, although ease of sampling is an obvious limitation. Treatment is with fenbendazole for 3 weeks and phacoemulsification to remove microsporidia from cataractous lenses. ZOONOTIC RISK: E cuniculi is a potential zoonotic agent, and there is a particular risk to immunocompromised humans posed by infected rabbits. Albeit infrequent, spore shedding has been identified in cats, so care should be taken around infected cats.

Usefulness of aqueous and vitreous humor analysis in infectious uveitis.

OBJECTIVE: To evaluate the role of intraocular fluid analysis as a diagnostic aid for uveitis. METHODS: Twenty-eight samples (27 patients including 3 HIV-infected patients) with active (n=24) or non-active (n=4) uveitis were submitted to aqueous (AH; n=12) or vitreous humor (VH) analysis (n=16). All samples were analyzed by quantitative PCR for herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and Toxoplasma gondii. RESULTS: The positivity of the PCR in AH was 41.7% (5/12), with 50% (2/4) in immunocompetent and 67% (2/3) in HIV+ patients. The positivity of the PCR in VH was 31.2% (5/16), with 13% (1/8) in immunocompetent and 50% (4/8) in immunosuppressed HIV negative patients. The analysis was a determinant in the diagnostic definition in 58% of HA and 50% of VH. CONCLUSION: Even in posterior uveitis, initial AH analysis may be helpful. A careful formulation of possible clinical diagnosis seems to increase the chance of intraocular sample analysis being meaningful.

Evaluation of a Multiplex Strip PCR Test for Infectious Uveitis: A Prospective Multicenter Study.

PURPOSE: A novel multiplex polymerase chain reaction (PCR) test (Strip PCR) for 24 common ocular infectious disease pathogens was established. Solid-phase techniques provide stable, prompt, and accurate results while using less sample amount with lower cost than conventional quantitative real-time PCR (qPCR). Strip PCR for infectious uveitis was optimized and evaluated using intraocular samples. DESIGN: Evaluation of diagnostic testing. METHODS: We examined 722 samples at 14 institutions. Genomic DNA from aqueous humor and vitreous fluid was analyzed by qPCR and Strip PCR. Clinical diagnosis was determined based on symptoms, clinical findings, and laboratory tests. MainOutcomeMeasures: The diagnostic parameters of the Strip PCR were based on qPCR results. RESULTS: Strip PCR showed low intra- and inter-institutional variability even when performed by technicians with various PCR skill levels. The targets of Strip PCR for infectious uveitis were optimized for 9 major pathogens (herpes simplex virus [HSV] 1, HSV2, varicella-zoster virus, human T-cell lymphotropic virus 1, human herpesvirus 6, Epstein-Barr virus, cytomegalovirus, Toxoplasma gondii, and Treponema pallidum) with 772 intraocular samples. The Strip PCR successfully detected pathogen DNA at concentrations ranging from 100 to 109 copies/mL in 252 of the 255 qPCR-positive samples. It yielded negative results for all the 191 qPCR-negative samples. Strip PCR had higher sensitivity (98.8%), specificity (98.5%), positive predictive value (98.8%), and negative predictive value (98.5%) than qPCR, with distinct primers. The Strip PCR results had strong correlation with that of the qPCR (r = 0.838) and they were consistent with the clinical diagnosis. CONCLUSIONS: Easy-to-use Strip PCR is recommended for rapid diagnosis of infectious uveitis, as its results are equivalent to that of conventional qPCR.

Usefulness of aqueous and vitreous humor analysis in infectious uveitis

OBJECTIVE: To evaluate the role of intraocular fluid analysis as a diagnostic aid for uveitis. METHODS: Twenty-eight samples (27 patients including 3 HIV-infected patients) with active (n=24) or non-active (n=4) uveitis were submitted to aqueous (AH; n=12) or vitreous humor (VH) analysis (n=16). All samples were analyzed by quantitative PCR for herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and Toxoplasma gondii. RESULTS: The positivity of the PCR in AH was 41.7% (5/12), with 50% (2/4) in immunocompetent and 67% (2/3) in HIV+ patients. The positivity of the PCR in VH was 31.2% (5/16), with 13% (1/8) in immunocompetent and 50% (4/8) in immunosuppressed HIV negative patients. The analysis was a determinant in the diagnostic definition in 58% of HA and 50% of VH. CONCLUSION: Even in posterior uveitis, initial AH analysis may be helpful. A careful formulation of possible clinical diagnosis seems to increase the chance of intraocular sample analysis being meaningful.

Human toxocariasis seroprevalence among patients with uveitis in Alborz Province, Iran.

INTRODUCTION AND OBJECTIVE: Toxocariasis, predominantly caused by Toxocara canis, is a common zoonotic parasitosis worldwide. Toxocara infection is a cause of vision impairment and blindness. The presented study investigates the frequency of antibodies against Toxocara among uveitis patients and the epidemiological factors associated with disease. MATERIAL AND METHODS: Fifty-four patients with uveitis and 59 healthy subjects were studied. Anti-Toxocara antibodies status was determined in all serum samples using enzyme linked immunosorbent assay (ELISA), and seropositive samples analyzed by Western blot (WB) technique. RESULTS: The frequency of Toxocara canis infection was found to be significantly higher in uveitis patients, compared to healthy controls by the use of ELISA test, being 14.8% and 1.7%, respectively. From 8 seropositive samples, 5 (62.5%) patients exhibited Toxocara immunoglobulin G (IgG) antibodies in response to Western blot, whereas in the control group, none were detected positive by Western blot. No significant difference was found between pet owners, nor between different places of residence. The seroprevalence to Toxocara among uveitis patients was significantly related to gender, age and medical diagnosis. The highest prevalence was found in patients with posterior uveitis (27.8%). CONCLUSIONS: Anti-Toxocara antibody titers are associated with the risk of vision impairment -uveitis. The risk factor associated with Toxocara exposure identified in this study warrants further investigation.

Patterns of Uveitis at Two University-Based Referral Centres in Cape Town, South Africa.

Purpose: To analyze the pattern of uveitis at two tertiary hospitals in South Africa which has a high prevalence of HIV, TB and syphilis. Methods: Data of 198 patients were obtained retrospectively between August 2014 and August 2016, including patient demographics, clinical examination, special investigations and final diagnosis. Results: Infectious uveitis was the most common aetiological category (47%), followed by idiopathic (34.8%) and non-infectious (18.2%). Syphilis was the most common identifiable cause (16.2%). Other important causes were toxoplasmosis, herpes viruses, tuberculosis and HLA-B27. HIV positive patients, who constituted 40% of the study population, were more likely to present with a posterior or panuveitis (relative risk 1.50, 95% CI 1.19-1.89) and more likely to have an infectious cause compared to HIV negative patients (relative risk 2.47, 95% CI 1.82-3.35). Conclusions: This study emphasizes the importance of HIV testing and investigations for infectious causes of uveitis, especially syphilis, in this population.

Diagnostic Value of Positive Findings of Toxoplasma gondii-Specific Immunoglobulin M Serum Antibody in Uveitis Patients to Confirm Ocular Toxoplasmosis.

Purpose: To assess the value of positive immunoglobulin (Ig) M serum antibody (Ab) findings in uveitis patients. Methods: We reviewed medical records of patients who had a positive serological test for Toxoplasma gondii-specific IgM Ab. Their clinical data, including history, demographic characteristics, laboratory findings, clinical findings, treatment outcomes, and recurrences, were reviewed retrospectively. Results: Of 2919 uveitis patients who underwent a serological test for suspected ocular toxoplasmosis (OT), 18 presented with positive Ig M results. All 18 patients (100.0% specificity) were clinically diagnosed with OT. None had any retinochoroidal scar at the initial visit, indicating the OT was a recent and primary infection. However, 15 patients (83.3%) had no history suspected to account for the Toxoplasma transmission. Conclusions: The T. gondii IgM serum Ab is a specific biomarker for diagnosis of primary OT. Epidemiological studies are warranted to investigate the non-classic transmission routes of T. gondii in OT.

Evaluation of Serological and Molecular Tests Used for the Identification of Toxoplasma gondii Infection in Patients Treated in an Ophthalmology Clinic of a Public Health Service in São Paulo State, Brazil.

Ocular toxoplasmosis is one of the most common complications caused by the infection with the parasite Toxoplasma gondii. The risk of developing eye lesions and impaired vision is considered higher in Brazil than other countries. The clinical diagnosis is difficult and the use of sensitive and specific laboratorial methods can aid to the correct diagnosis of this infection. We compared serological methods ELISA and ELFA, and molecular cPCR, Nested PCR and qPCR for the diagnosis of T. gondii infection in groups of patients clinically evaluated with ocular diseases non-toxoplasma related (G1 = 185) and with lesions caused by toxoplasmosis (G2 = 164) in an Ophthalmology clinic in Brazil. Results were compared by the Kappa index, and sensitivity (S), specificity (E), positive predictive value (PPV), and negative (NPV) were calculated. Serologic methods were in agreement with ELISA more sensitive and ELFA more specific to characterize the acute and chronic infections while molecular methods were discrepant where qPCR presented higher sensitivity, however, lower specificity when compared to cPCR and Nested PCR.

Management of presumed trematode induced granulomatous uveitis in pediatric patients.

PURPOSE: To outline the management of newly identified trematode induced uveitis in pediatric patients STUDY DESIGN: Prospective interventional case series METHODS: Patients with distinctive uveitis were recruited to either receive steroid monotherapy or undergo surgical excision of the inflammatory lesions based on a scoring system. Outcome measures included best corrected visual acuity (BCVA), intraocular inflammatory activity, and incidence of ophthalmic complications RESULTS: 170 patients (174 eyes) were recruited. Mean age was 11.1 years. Mean initial decimal BCVA (± SD) was 0.58 (± 0.31). Of 116 eyes with disease scores <5, 109 were treated effectively with steroids (93.97%). Surgical excision was offered to 58 patients and proved curative in the treated eyes. Protracted inflammation with persistence of the granulomas was noted in 5 patients refusing surgery. Mean follow up period was 21.5 months. Mean final BCVA was 0.69 (±0.27). A significant change in BCVA was noted (p=0.002). There has not been a need for retreatment in any of the study patients, who were also given instructions on evading exposure to fresh water habitats. Larger lesions, mixed disease morphology, older age at presentation were associated with higher rates of ophthalmic complications and vision loss CONCLUSION: A novel waterborne trematode inducing uveitis has been identified in Egypt. A favorable response to steroid monotherapy is demonstrated in low grade disease, while surgical excision was found to be curative in patients with larger lesions or those showing suboptimal response to medical treatment.

Detection and molecular characterization of Acanthamoeba spp. in stray cats from Madrid, Spain.

Acanthamoeba spp. is a widespread protozoan that has been isolated from air, dust, soil, water and biological samples. An opportunistic pathogen of humans and animals, it may cause ocular keratitis, encephalitis, and even multisystem disease. The frequency of Acanthamoeba in animals is unknown. The aim of present study was determine the presence of Acanthamoeba spp. in immunocompromised stray cats - animals possibly more likely to harbour the infection given their immunocompromised status and frequenting of contaminated environments. Of 307 cats examined, 55 were positive for feline immunodeficiency virus and/or feline leukaemia virus and therefore included in the study. Corneal scrapings were obtained to isolate Acanthamoeba spp. by culture and molecular detection by conventional and real time PCR. None of the samples examined directly by molecular methods were positive for Acanthamoeba spp. However, two (3.6%) cases of the cultured samples provided positive results, which were confirmed by subsequent molecular analysis. Sequencing assigned one isolate to genotype T4 and the other to T2. Since Acanthamoeba spp. may also infect animals and humans, the present findings may raise some public health and veterinary concerns.

Rapid Detection and Identification of Uveitis Pathogens by Qualitative Multiplex Real-Time PCR.

Purpose: Infectious uveitis is a serious sight-threatening infection commonly caused by herpesviruses and Toxoplasma gondii. Etiologic diagnosis based on the clinical evaluation is often challenging. We developed and validated a multiplex real-time PCR assay coupled with high-resolution melting (HRM) for rapid detection and identification of herpes simplex viruses 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), and T. gondii. Methods: The assay was designed to target pathogen genome regions that yield products with distinct melting temperatures. Analytical specificity, sensitivity, and precision of HRM identification were determined. Clinical validation was performed by testing 108 intraocular fluids collected from eyes suffering with infectious uveitis (n = 30) and controls (n = 78). Results: A nonoverlapping high-precision profile for each pathogen was generated following HRM (coefficient of variation 0%). The assay was highly sensitive, with a limit of detection of 20 genome copies for herpesviruses and 200 genome copies for T. gondii. The intra- and interassay variability of cycle threshold (Ct) measurement was ≤4% and ≤6%, respectively. Thirteen intraocular specimens collected from suspected cases of infectious uveitis were positive (mean Ct values varied from 19.4 to 27.7). Melting profiles of positive cases were consistent with HSV-2 (n = 5), VZV (n = 5), CMV (n = 2), and T. gondii (n = 1). Amplicon identities were confirmed by sequencing. Control intraocular samples from patients without a clinical diagnosis of infectious uveitis were all negative. Conclusions: This assay allows rapid, sensitive, and reliable detection and identification of the most common known causes of infectious uveitis, making early pathogen information-based intervention possible.

Development and evaluation of multiplex real-time PCR for diagnosis of HSV-1, VZV, CMV, and Toxoplasma gondii in patients with infectious uveitis.

Infectious uveitis is a vision threatening inflammatory ocular disease wherein early diagnosis may prevent the loss of vision. The purpose of this study was to develop a multiplex real-time PCR for the diagnosis of Herpes simplex virus-1, Varicella zoster virus, cytomegalovirus and Toxoplasma gondii in patients with suspected infectious uveitis. A total of 126 intraocular samples (aqueous and vitreous humor) were collected and subjected to multiplex real-time PCR. Overall 26.2% (33/126) patients were found to be positive for one or more of the pathogens tested. The overall positivity for VZV, HSV, CMV and T. gondii was found to be 16 (12.7%), 7 (5.6%), 5 (3.9%), and 9 (7.1%); with mean pathogen load of 5.07×105, 9.5×104, 1.08×104 and 394 (copies/µl) respectively. The development of highly sensitive and specific assay for early differentiation of pathogens is important for the early initiation of treatment thereby preventing irreversible damage to the ocular structures.

Evaluating the presence of Toxoplasma gondii in peripheral blood of patients with diverse forms of uveitis.

The purpose of this study was to evaluate the presence of Toxoplasmosis gondii in samples of peripheral blood from patients with varying etiologies of uveitis. Whole blood from patients with different forms of uveitis was tested for the presence of T. gondii using real-time PCR targeting the well-characterized 529 bp fragment. Extracted DNA was both frozen. Thirty-one patients were included in the current study and grouped as follows: acute toxoplasmosis (n = 10); toxoplasmic retinal scars (n = 9); non-infectious etiologies of uveitis (n = 6); and IgG negative for toxoplasmosis (n = 6). In total, only two patients were shown to have circulating T. gondii in peripheral blood; both of these patients were IgG positive for toxoplasmosis, were receiving immunosuppressive therapy for autoimmune uveitis, and had no clinical features of toxoplasmosis. T. gondii was identified in peripheral blood of some immunosuppressed patients. No other patients, including those with acute toxoplasmosis, had circulating parasites in peripheral blood.

Epidemiology of Uveitis, Caused by HTLV-1, Toxoplasmosis, and Tuberculosis; the Three Leading Causes of Endemic Infectious Uveitis in Japan.

Ethnicity, geography, and socioeconomic factors are among the aspects influencing the prevalence of uveitis in specific areas and countries. Human T-lymphotropic virus type 1-associated uveitis and ocular toxoplasmosis are endemic to Southern Kyushu, the southern-most region of Japan. Recent reports have postulated that the prevalence of intraocular tuberculosis is increasing in Tokyo. This review focuses on local factors that affect the three major vectors for infectious endemic uveitis in Japan, as well as their routes of transmission and factors for improving diagnoses. This information will facilitate the promotion of public health measures aimed at decreasing uveitis prevalence in Japan.

Aqueous humor polymerase chain reaction in uveitis - utility and safety.

BACKGROUND: To study the value and safety of aqueous humor polymerase chain reaction (PCR) analysis for Herpes simplex, varicella zoster, cytomegalovirus, Epstein-Barr virus and Toxoplasma gondii in patients with uveitis. METHODS: Records of 45 consecutive patients with anterior and posterior uveitis who underwent AC paracentesis with PCR were reviewed. The main outcome measure was frequency of PCR positivity. Secondary outcomes were alteration of treatment, safety of paracentesis, and correlation of keratitic precipitates with PCR positivity, RESULTS: The overall PCR positivity was 48.9 % (22/45). Therapy was changed because of the PCR results in 14/45 patients (37.7 %). One patient experienced a paracentesis related complication (1/45, 2.2 %) without long-term sequelae. CONCLUSION: Aqueous PCR altered the diagnosis and treatment in over a third of our patients and was relatively safe. Aqueous PCR should be considered for uveitis of atypical clinical appearance, recurrent severe uveitis of uncertain etiology, and therapy refractory cases.

Illuminating uveitis: metagenomic deep sequencing identifies common and rare pathogens.

BACKGROUND: Ocular infections remain a major cause of blindness and morbidity worldwide. While prognosis is dependent on the timing and accuracy of diagnosis, the etiology remains elusive in ~50 % of presumed infectious uveitis cases. The objective of this study is to determine if unbiased metagenomic deep sequencing (MDS) can accurately detect pathogens in intraocular fluid samples of patients with uveitis. METHODS: This is a proof-of-concept study, in which intraocular fluid samples were obtained from five subjects with known diagnoses, and one subject with bilateral chronic uveitis without a known etiology. Samples were subjected to MDS, and results were compared with those from conventional diagnostic tests. Pathogens were identified using a rapid computational pipeline to analyze the non-host sequences obtained from MDS. RESULTS: Unbiased MDS of intraocular fluid produced results concordant with known diagnoses in subjects with (n = 4) and without (n = 1) uveitis. Samples positive for Cryptococcus neoformans, Toxoplasma gondii, and herpes simplex virus 1 as tested by a Clinical Laboratory Improvement Amendments-certified laboratory were correctly identified with MDS. Rubella virus was identified in one case of chronic bilateral idiopathic uveitis. The subject's strain was most closely related to a German rubella virus strain isolated in 1992, one year before he developed a fever and rash while living in Germany. The pattern and the number of viral identified mutations present in the patient's strain were consistent with long-term viral replication in the eye. CONCLUSIONS: MDS can identify fungi, parasites, and DNA and RNA viruses in minute volumes of intraocular fluid samples. The identification of chronic intraocular rubella virus infection highlights the eye's role as a long-term pathogen reservoir, which has implications for virus eradication and emerging global epidemics.