Herpetic keratitis in Tanzania: association with malaria

INCIDENCE OF HERPES SIMPLEX VIRUS KERATITIS AND OTHER OCULAR DISEASE: GLOBAL REVIEW AND ESTIMATES

Purpose: We aimed to review available data on the incidence of herpes simplex virus (HSV) keratitis and other HSV ocular disease and to estimate the global burden of HSV ocular disease. Methods: We searched Medline and Embase databases to October 2020 for studies reporting on the incidence of HSV ocular disease. Study quality was evaluated using a four-point checklist. Pooled estimates were applied to 2016 population data to estimate global HSV ocular disease burden. Numbers with uniocular vision impairment (any visual acuity <6/12) were estimated by applying published risks to case numbers. Results: Fourteen studies had incidence data; seven met our quality criteria. In 2016, an estimated 1.7 (95% confidence interval, 95% CI 1.0–3.0) million people had HSV keratitis, based on a pooled incidence of 24.0 (95% CI 14.0–41.0; N = 2; I² = 97.7%) per 100,000 person-years. The majority had epithelial keratitis (pooled incidence 16.1 per 100,000; 95% CI 11.6–22.3; N = 3; I² = 92.6%). Available studies were few and limited to the USA and Europe. Data were even more limited for HSV uveitis and retinitis, although these conditions may collectively contribute a further >0.1 million cases. Based on global incidence, some 230,000 people may have newly acquired uniocular vision impairment associated with HSV keratitis in 2016. Conclusion: Over 1.8 million people may have herpetic eye disease annually. Preventing HSV infection could therefore have an important impact on eye health. Herpetic eye disease burden is likely to have been underestimated, as many settings outside of the USA and Europe have higher HSV-1 prevalence and poorer access to treatment.

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.

Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis

BACKGROUND

Eye disease due to herpes simplex virus (HSV) commonly presents as epithelial keratitis which, though usually self-limiting, may persist or progress without treatment.

OBJECTIVES

To compare the relative effectiveness of antiviral agents, interferon, and corneal debridement in the treatment of HSV epithelial keratitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 12), PubMed (January 1946 to 31 December 2014), EMBASE (January 1980 to 31 December 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to 31 December 2014), System for Information on Grey Literature in Europe (OpenGrey) (January 1995 to 31 December 2014), BIOSIS (January 1926 to 5 May 2014), Scopus (January 1966 to 31 December 2014), Japan Science and Technology Institute (J-Global) (January 1975 to 31 December 2014), China National Knowledge Infrastructure (CNKI) (January 1979 to 31 December 2014), British Library's Electronic Table of Contents (Zetoc) (January 1993 to 7 May 2014). We looked for trials listed on the the metaRegister of Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), Chinese Clinical Trial Registry, the U.S. Food and Drug Administration (FDA) (www.fda.gov/), National Institute for Health and Clinical Excellence (NICE) (www.

EVIDENCE

nhs.uk) and the European Medicines Agency (EMA) (www.ema.europa.eu/ema/) as of 31 December 2014. There were no language or date restrictions in the search for trials. We also culled literature digests and conference proceedings as of 15 April 2014. There were no language or date restrictions in the search for trials.

SELECTION CRITERIA

Randomised and quasi-randomised trials of HSV dendritic or geographic epithelial keratitis were included that reported the proportion of eyes healed at one week, two weeks, or both after enrolment.

DATA COLLECTION AND ANALYSIS

We tabulated data on study characteristics, risk of bias, and outcomes and used direct comparisons to estimate a risk ratio (RR) and, when feasible, a hazard ratio (HR) with a 95% confidence interval (CI). Heterogeneity was assessed by an inconsistency index. A multiple treatment comparison meta-analysis consolidated direct and indirect comparisons of relative healing at 14 days.

MAIN RESULTS

One hundred thirty-seven studies involving 8333 eyes met the inclusion criteria. Placebo-controlled studies were heterogeneous in comparison with idoxuridine (RR 1.74; 95% CI 1.03 to 2.91) and few in number for vidarabine (RR 1.81; 95% CI 1.09 to 3.01), interferon (RR 1.32; 95% CI 1.06 to 1.64), and debridement. Vidarabine (RR 1.13; 95% CI 1.02 to 1.25), trifluridine (RR 1.30; 95% CI 1.18 to 1.43), acyclovir (RR 1.23; 95% CI 1.14 to 1.34), and brivudine (RR 1.34; 95% CI 1.18 to 1.51) were more effective than idoxuridine. Trifluridine (RR 1.17; 95% CI 1.03 to 1.32) and acyclovir (RR 1.11; 95% CI 1.03 to 1.19) were more effective than vidarabine. No significant differences in healing emerged among trifluridine, acyclovir, brivudine, and foscarnet although few studies compared brivudine or foscarnet with other antivirals. Any potential advantage of ganciclovir compared to acyclovir was mitigated by study heterogeneity and possible publication bias. Only one study evaluated the joint use of two topical antivirals. In a limited number of studies, oral acyclovir (RR 0.92; 95% CI 0.79 to 1.07) or the combination of oral acyclovir with a topical antiviral (RR 1.36; 95% CI 0.68 to 2.74) appeared as effective as a single topical antiviral agent. Compared to topical antiviral monotherapy, the combination of an antiviral with either interferon or debridement had inconsistent effects on expediting healing and improving outcome.

AUTHORS' CONCLUSIONS

Placebo-controlled studies of HSV epithelial keratitis are limited to superseded interventions. Trifluridine and acyclovir are more effective than idoxuridine or vidarabine and similar in therapeutic effectiveness. Brivudine and foscarnet do not substantially differ in effectiveness from trifluridine or acyclovir. Ganciclovir is at least as effective as acyclovir. The addition of interferon to a nucleoside antiviral agent and the combination of debridement with antiviral treatment need to be further assessed to substantiate any possible advantage in healing.

Ocular infections in sub-Saharan Africa in the context of high HIV prevalence

Healthy eyes and good vision are important determinants of populations' health across the globe. Sub-Saharan Africa is affected by simultaneous epidemics of ocular infections and human immunodeficiency virus (HIV). Ocular infection and its complications, along with cataract and ocular trauma, are common conditions in this region with great impact on daily life. In this review, we discuss the epidemiology, clinical manifestations and microbial aetiology of the most important infectious ocular conditions in sub-Saharan Africa: conjunctivitis, keratitis and uveitis. We focus specifically on the potential association of these infections with HIV infection, including immune recovery uveitis. Finally, challenges and opportunities for clinical management are discussed, and recommendations made to improve care in this neglected but very important clinical field.

Herpes simplex epithelial and stromal keratitis: an epidemiologic update

Herpes simplex virus (HSV) is associated with a variety of ocular diseases, including epithelial and stromal keratitis. HSV can cause stromal opacification and is believed to be the leading cause of infectious blindness in the developed world. An improved understanding of the global burden of HSV keratitis, including the incidence of severe vision loss, could have a significant effect on prevention and treatment and place it in perspective among causes of corneal ulceration. We found that the global incidence of HSV keratitis is roughly 1.5 million, including 40,000 new cases of severe monocular visual impairment or blindness each year. We also discuss relevant epidemiologic issues regarding HSV epithelial and stromal disease.

The Eye Disease of Jefferson Davis (1808–1889)

The only Confederate president, Jefferson Davis, led a long and eventful life. He was a Mississippi planter, a husband, a father, West Point graduate, war hero, congressman, senator, secretary of war, and finally President of the Confederate States of America. In many ways he was a study of contrast with his northern counterpart, Abraham Lincoln. Davis was personally courageous and a rich, educated, southern aristocrat who did not deeply understand the political process or have the refined personal skills necessary to work well with others. Prior to his Presidency he served with distinction in two wars, but as a result of his confederate activity and pro-slavery philosophy he is one of the least discussed famous Americans. Davis's health was a constant problem and he suffered an almost fatal attack of "malaria" in 1836. In the winter of 1857-1858 he again was seriously ill and by the end of February 1858 a chronic, relapsing, ocular inflammatory condition began. Using historical evidence from multiple sources, this paper will propose a diagnosis of the Confederate President's ocular condition and consider how this could have influenced his military and political decisions.

Causes of blindness in Northern Tanzania: a hospital and rural health centre based study

OBJECTIVE

To identify the main causes of blindness in Northern Tanzania.

METHODS

Ophthalmic patients at the Kilimanjaro Christian Medical Centre and on outreach clinics in the Kilimanjaro region of Northern Tanzania were examined. The cause of blindness was documented for any eye seeing less than 3/60 Snellen. If more than one factor contributed to the visual loss, the single factor deemed to be the most visually disabling was documented.

RESULTS

1045 blind eyes of 781 patients were examined. 264 patients were bilaterally blind. The main cause of bilateral blindness was cataract [39%]. The other chief causes of blindness were glaucoma, trauma and corneal scarring. The most important cause of corneal scarring, approximately half the cases, was microbial keratitis. Refractive error alone was responsible for 4.2% of bilateral blindness, of which 2.7% was uncorrected post-cataract surgery aphakia.

CONCLUSIONS

Treatable causes of blindness, including cataract and refractive error account for over a third of all blindness in Northern Tanzania. Trauma, glaucoma and microbial keratitis are other important causes of blindness in the region.

Penetrating keratoplasty in Africa: graft survival and visual outcome

AIM

To study the survival and visual outcome of penetrating keratoplasty in an African setting.

METHODS

A retrospective analysis of 216 corneal grafts, performed on 203 eyes of 186 patients, at Kikuyu Hospital, Kenya over a 5 year period.

RESULTS

Half of the transplants were carried out for keratoconus with only 5% of the grafts being undertaken for corneal scarring caused by trachoma or measles. The average follow up was 27.3 months. The probability of graft survival at 2 years was 87.4% (95% CI 80.6%-94.3%) for keratoconus and 64.7% (95% CI 54.8%-74.6%) for other corneal pathologies. Forty seven grafts (21.8%) in 36 patients (17.7%) are known to have become opaque. The commonest causes of graft opacification were bacterial keratitis (6.0%), endothelial failure (6.0%), and graft rejection (5.1%). Preoperatively 55% of keratoconus eyes and 75.7% of non-keratoconus eyes were blind. Postoperatively, 5% of keratoconus eyes and 41.7% of the non-keratoconus eyes were blind. Normal vision was achieved in 53.7% of operated eyes. Grafts carried out for keratoconus had a better visual outcome than grafts performed for other corneal pathologies. Preoperatively, 12.4% of keratoconus and 48.5% of non-keratoconus patients were blind in their better eye. Postoperatively, 1.1% of keratoconus patients and 25.7% of non-keratoconus patients were blind. The number of patients with normal vision in the better eye increased from 32 (17.2%) to 106 (57.0%). Sight was restored to 34 blind patients, but two patients with severe visual impairment preoperatively were blind at their last follow up. There was therefore a net reduction of 32 in the number of blind patients after 216 keratoplasties.

CONCLUSIONS

Penetrating keratoplasty can be successful in Africa, particularly for keratoconus and other corneal dystrophies. However, penetrating keratoplasty has a limited role in the treatment of blindness from corneal scarring due to trachoma, measles, and vitamin A deficiency for which community based preventive measures must remain the priority.

Malaria and macrophage function in Africans: a possible link with autoimmune disease?

Systemic lupus erythematosus and sarcoidosis, both diseases in which immune responses are aberrant, are not found in Africans in West Africa, but their prevalence in people of West African descent in the USA and UK is higher than that for white people. It is argued here that malaria both prevents these diseases in West Africa by its effects on macrophage function, and has also selected for a predisposition to them.

Herpetic corneal ulcers in Malawi

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Calcification-like echographic patterns in uveal melanomas treated with brachytherapy

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