National Outbreak of Acanthamoeba Keratitis Associated with Use of a Contact Lens Solution, United States

An outbreak of Acanthamoeba keratitis, a rare, potentially blinding, corneal infection, was detected in the United States in 2007; cases had been increasing since 2004. A case–control study was conducted to investigate the outbreak. We interviewed 105 case-patients from 30 states and 184 controls matched geographically and by contact lens use. Available contact lenses, cases, solutions, and corneal specimens from case-patients were cultured and tested by molecular methods. In multivariate analyses, case-patients had significantly greater odds of having used Advanced Medical Optics Complete Moisture Plus (AMOCMP) solution (odds ratio 16.9, 95% confidence interval 4.8–59.5). AMOCMP manufacturing lot information was available for 22 case-patients, but none of the lots were identical. Three unopened bottles of AMOCMP tested negative for Acanthamoeba spp. Our findings suggest that the solution was not intrinsically contaminated and that its anti-Acanthamoeba efficacy was insufficient. Premarket standardized testing of contact lens solutions for activity against Acanthamoeba spp. is warranted.     

聚合酶链反应技术对棘阿米巴角膜炎诊断的临床应用

目的 探讨聚合酶链反应(PCR)技术临床应用于棘阿米巴角膜炎诊断的可行性及优越性。方法 以一段特异性通用引物并配合热启动聚合酶链反应技术来检测临床标本中的棘阿米巴原虫。结果 在门诊初诊为棘阿米巴角膜炎的13例(13只眼)中，通过PCR检测法有11只眼证实为棘阿米巴原虫感染，同时角膜刮片染色后镜检有5例发现了棘阿米巴包裹。结论 聚合酶链反应技术对棘阿米巴角膜炎的诊断有重要的临床应用价值。     

鸟苷类药物抗鼠单纯疱疹病毒三叉神经节潜伏感染的实验研究

应用细胞培养病毒分离技术,对国产鸟苷类药物无环鸟苷(ACV)、脱氧无环鸟苷(D-CV)、丙氧鸟苷(DHPG)抗鼠单纯疱疹病毒三叉神经节潜伏感染全身用药疗效进行了观察.结果表明:治疗组与对照组比较差异有显著意义(P<0.01),以DHPG疗效最好,DCV次之.灌胃10d组与腹腔注射7d组疗效相当,二者与5d组比较差异显著(P<0.01),提示全身用药疗程不宜过短.     

IN VITRO CULTURE OF VARIOUS SPECIES OF MICROSPORIDIA CAUSING KERATITIS: EVALUATION OF THREE IMMORTALIZED CELL LINES

Being intracellular parasites, microsporidia can only be propagated in cell culture systems. This study evaluated three cell lines to determine the most suitable host-parasite In vitro system. Confluent monolayers of vero, SIRC, and HeLa cell lines, grown in 24-well tissue culture plates, were inoculated with varying concentrations (1 × 10⁴to 1 × 10⁸ spores/ mL) of Vittaforma corneae, Encephalitozoon hellem, Encephalitozoon cuniculi, and Encephalitozoon intestinalis spores. Growth was compared quantitatively at weekly intervals. Encephalitozoon species showed the highest amount of growth when cultured in vero cell line, while there was no significant difference in their growth in SIRC and HeLa cell lines. In comparison, V. corneae showed the highest growth in SIRC cells, followed by vero cells. The analytical sensitivity was found to be 1 × 10⁴ spores/mL for vero cell line compared to 1 × 10⁵spores/mL for SIRC cell line and 1 × 10⁷ spores/ mL for HeLa cell line. HeLa cells also showed rapid disruption of cells, and the spores could not be easily distinguished from cell debris. This is the first report of the comparison of vero, SIRC, and HeLa for the propagation of microsporidial spores. Vero cell line was found to be more sensitive than SIRC and HeLa cells, and we believe that the inclusion of vero cell line in the routine culture protocols of ocular parasitology laboratories would result in a significant increase in the diagnostic yield.     

Ocular injury by mustard gas

Sulfur mustard is a chemical warfare agent which was widely used during World War I and more recently in conflicts in the Middle East. This highly toxic compound causes severe dermal, gastrointestinal, respiratory and ocular injuries. It acts as an alkylating agent that induces structural changes and, hence, destruction of nucleic acids and proteins, impairing the cell's normal homeostasis and eventually causing its death. Sulfur mustard reacts rapidly with ocular tissues, and after a latent period of a few hours the patient starts suffering from severe eye pain, photophobia, excessive lacrimation and blindness. The injury, which is restricted to the anterior segment of the eye, may cause long-lasting incapacity in large numbers of casualties. Approximately 0.5% of the severely wounded victims may develop late complications which require prolonged ophthalmologic observation and therapy. In light of the ever-present threat of mustard chemical warfare against military and civilians, physicians worldwide should be aware of its grave effects and know how to care for its victims.     

Comparison of Topical 0.3% Ofloxacin to Fortified Tobramycin – Cefazolin in the Therapy of Bacterial Keratitis

Summary Background: In this study we compared topical ofloxacin with a combination of fortified tobramycin sulphate and cefazolin sodium solutions in the treatment of culture-proved bacterial keratitis. Methods: 30 eyes of culture-proved bacterial corneal ulcers of moderate severity were included in a prospective randomized, controlled, double-masked study for comparison. The cases were randomly allocated to treatment with 0.3% ofloxacin solution (Group I) and combination of fortified antibiotics (1.5% tobramycin and 5% cefazolin solutions – Group II as control) along with supportive cycloplegic, vitamins and antiglaucoma therapy. Time for healing of ulcer and subjective symptoms were main outcome measures. Student's t-test was used to compare the results. Results: Staphylococcus aureus and coagulase-negative staphylococci were the two most common organisms isolated. Resolution of the ulcer was achieved in 93% and 87% in the treated and the control group, respectively. The mean duration of symptomatic relief was 7.8 ± 1.54 days in the treated group and 8.33 ± 1.44 days in the control group; for epithelial healing it was 15.0 ± 3.86 days in the treated group and 15.46 ± 3.86 days in the control group. Post resolution the best corrected visual acuity of 20/200 or better was achieved in all but one eye each in both groups. Conclusions: Both ofloxycin 0.3% and combined fortified tobramycin 1.5% and cefazolin 5% topical drops were comparable for treating cases of bacterial corneal ulcer of moderate severity. However, considering the easy availability and cost effectiveness of ofloxacin, a monotherapy with ofloxacin may be preferred over the combined, fortified tobramycin and cefazolin therapy. Received: October 20, 1999 · Revision accepted: March 3, 2000     

The Role of Tissue Resident Memory CD4 T Cells in Herpes Simplex Viral and HIV Infection

Tissue-resident memory T cells (TRM) were first described in 2009. While initially the major focus was on CD8⁺ TRM, there has recently been increased interest in defining the phenotype and the role of CD4⁺ TRM in diseases. Circulating CD4⁺ T cells seed CD4⁺ TRM, but there also appears to be an equilibrium between CD4⁺ TRM and blood CD4⁺ T cells. CD4⁺ TRM are more mobile than CD8⁺ TRM, usually localized deeper within the dermis/lamina propria and yet may exhibit synergy with CD8⁺ TRM in disease control. This has been demonstrated in herpes simplex infections in mice. In human recurrent herpes infections, both CD4⁺ and CD8⁺ TRM persisting between lesions may control asymptomatic shedding through interferon-gamma secretion, although this has been more clearly shown for CD8⁺ T cells. The exact role of the CD4⁺/CD8⁺ TRM axis in the trigeminal ganglia and/or cornea in controlling recurrent herpetic keratitis is unknown. In HIV, CD4⁺ TRM have now been shown to be a major target for productive and latent infection in the cervix. In HSV and HIV co-infections, CD4⁺ TRM persisting in the dermis support HIV replication. Further understanding of the role of CD4⁺ TRM and their induction by vaccines may help control sexual transmission by both viruses.     

疏风清热法联合西药治疗上皮型单纯疱疹病毒性角膜炎疗效

目的：观察疏风清热法联合西药治疗上皮型单纯疱疹病毒性角膜炎的临床疗效。
　　方法：将75例上皮型单纯疱疹病毒性角膜炎患者随机分为治疗组38例38眼和对照组37例37眼。对照组局部给予更昔洛韦眼用凝胶点眼,并对症处理;治疗组在对照组治疗方案的基础上,同时服用以疏风清热为主的中药汤剂治疗。观察临床治疗效果并进行分析。
　　结果：治疗组的治愈率、总有效率分别为79%和95%,对照组的治愈率、总有效率分别为54%和78%,两组比较差异均有统计学意义(P<0.05);治疗后治疗组角膜病损面愈合指数优于对照组(P<0.05);治疗6mo时随访治疗组痊愈患者的复发率为10%,对照组痊愈患者的复发率为40%,两组比较差异有统计学意义(P<0.05);治疗组的治愈时间平均为14.74±8.58d,对照组的治愈时间平均为19.68±8.71d,两组比较差异有统计学意义(P<0.05)。
　　结论：疏风清热法联合西药治疗上皮型单纯疱疹病毒性角膜炎有较好的疗效。     

真菌性角膜炎的治疗进展

真菌性角膜炎(fungal keratitis,FK)是一种由致病真菌引起的、致盲率极高的感染性角膜病,随着现代医学的发展,早期患者或者对药物敏感的真菌感染患者,药物或手术治愈率较前有了明显的提高,但是晚期患者及对药物不敏感的致病真菌感染患者,药物难以控制、溃疡迁延不愈、病情进展恶化,目前仍旧是临床上角膜盲的主要病因之一。在文中我们将就真菌性角膜炎药物及手术治疗的近5a国内外的研究进展作一综述。