Eye manifestations of intrauterine infections and their impact on childhood blindness

Causes of infectious pediatric uveitis: A review

Infectious pediatric uveitis is a rare disease that can cause severe ocular damage if not detected rapidly and treated properly. Additionally, early identification of an infection can protect the child from life-threatening systemic infection. Infectious uveitis can be congenital or acquired and may manifest as a primary ocular infection or as a reactivation. Nevertheless, publications on infectious paediatric uveitis are usually limited to a small number of patients or a case report. So far, most studies on uveitis in children have focused primarily on noninfectious uveitis, and a systematic study on infectious uveitis is lacking. In this review, we summarize the literature on infectious uveitis in pediatric populations and report on the epidemiology, pathophysiology, clinical signs, diagnostic tests, and treatment. We will describe the different possible pathogens causing uveitis in childhood by microbiological group (i.e. parasites, viruses, bacteria, and fungi). We aim to contribute to early diagnosis and management of infectious pediatric uveitis, which in turn might improve not only visual outcome, but also the general health outcome.

Bilateral optic atrophy in Wilson disease: A case report and literature review

Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. The clinical manifestations of WD are complex and variable, with Kayser-Fleischer ring (K-F ring) and the sunflower cataract being the most common ocular findings. Visual impairment is rare in patients with WD. We report the case of a 17-year-old female with bilateral optic atrophy associated with WD and summarize the clinical features of previously reported cases of optic neuropathy in WD, Clinicians should be aware that WD is a rare cause of optic neuropathy and that optic neuropathy in patients with WD may need to be recognized and screened.

Congenital Malformations of the Eye: A Pictorial Review and Clinico-Radiological Correlations

Congenital malformations of the eye represent a wide and heterogeneous spectrum of abnormalities that may be part of a complex syndrome or be isolated. Ocular malformation severity depends on the timing of the causative event during eye formation, ranging from the complete absence of the eye if injury occurs during the first weeks of gestation, to subtle abnormalities if the cause occurs later on. Knowledge of ocular malformations is crucial to performing a tailored imaging protocol and correctly reporting imaging findings. Together with the ophthalmologic evaluation, imaging may help frame ocular malformations and identify underlying genetic conditions. The purpose of this pictorial review is to describe the imaging features of the main ocular malformations and the related ophthalmologic findings in order to provide a clinico-radiological overview of these abnormalities to the clinical radiologist. Sight is a crucial sense for children to explore the world and relate with their parents from birth. Vision impairment or even blindness secondary to ocular malformations deeply affects children's growth and quality of life.

Ocular Involvement in Congenital Infections - TORCH

This review summarises the ophthalmological findings in congenital infections. Intrauterine infections are an important cause of childhood blindness. The most common infections are grouped under the acronym TORCH, which stands for Toxoplasma gondii, others, rubella, CMV, and herpes simplex. Overall, these infections are not very common in first-world countries during pregnancy, but are of particular importance because of the threat to vision. Diagnosis of infection or reactivation is a gynaecological challenge. However, ophthalmological examination of newborns can be appropriately targeted if the causative agent is known. The most important therapeutic agents used in the newborn are summarised.

Evaluation and monitoring of eye findings in children exposed to Zika virus during gestation: 3 years of follow-up

INTRODUCTION

Congenital Zika syndrome (CZS) is a recently described disease. Our main objective was to evaluate and monitor, over 3 years, the ophthalmoscopic findings in children exposed to zika virus (ZIKV) during gestation.

METHODS

This prospective observational study was conducted in Rio de Janeiro, Brazil, between April 2016 and May 2019. We evaluated two groups with exanthema serving as a proxy for viremia: (i) children whose mothers had exanthema during pregnancy and (ii) children who had microcephaly without maternal exanthema during pregnancy. We performed indirect ophthalmoscopy at recruitment and every 6 months thereafter. We also tested the association between ocular findings with maternal exanthema, microcephaly, CZS and maternal infection confirmed by reverse transcriptase quantitative polymerase chain reaction and gender.

RESULTS

Of the 72 children included, 16 (22.2%) had optic nerve and/or retinal lesions. All 16 had CZS and 15 (93.7%) had microcephaly (14 at birth and 1 postnatally). The child with postnatally acquired microcephaly was born to a mother without exanthema during pregnancy. Fifty-six (77.8%) of the 72 children were followed for a median time of 24 months and none exhibited differences between admission and follow-up examinations. After logistic regression, only microcephaly at birth was associated with eye abnormalities (odds ratio, 77.015; 95% confidence interval, 8.85-670.38; p < 0.001).

CONCLUSION

We observed that there was no progression of the lesions over the follow-up period. We also showed that the eye findings were associated only with microcephaly at birth. Attention should be paid to all children born during a ZIKV epidemic, regardless of maternal exanthema and/or microcephaly at birth.

The lens epithelium as a major determinant in the development, maintenance, and regeneration of the crystalline lens

The crystalline lens is a transparent and refractive biconvex structure formed by lens epithelial cells (LECs) and lens fibers. Lens opacity, also known as cataracts, is the leading cause of blindness in the world. LECs are the principal cells of lens throughout human life, exhibiting different physiological properties and functions. During the embryonic stage, LECs proliferate and differentiate into lens fibers, which form the crystalline lens. Genetics and environment are vital factors that influence normal lens development. During maturation, LECs help maintain lens homeostasis through material transport, synthesis and metabolism as well as mitosis and proliferation. If disturbed, this will result in loss of lens transparency. After cataract surgery, the repair potential of LECs is activated and the structure and transparency of the regenerative tissue depends on postoperative microenvironment. This review summarizes recent research advances on the role of LECs in lens development, homeostasis, and regeneration, with a particular focus on the role of cholesterol synthesis (eg., lanosterol synthase) in lens development and homeostasis maintenance, and how the regenerative potential of LECs can be harnessed to develop surgical strategies and improve the outcomes of cataract surgery (Fig. 1). These new insights suggest that LECs are a major determinant of the physiological and pathological state of the lens. Further studies on their molecular biology will offer possibility to explore new approaches for cataract prevention and treatment.

Lymphocytic choriomeningitis virus: An under-recognized congenital teratogen

BACKGROUND

Lymphocytic choriomeningitis virus (LCMV) is a neglected rodent-borne arenavirus associated with transplacental transmission and fetal infection.

AIM

To summarize the epidemiological, clinical, and diagnostic features of reported patients with congenital LCMV infection.

METHODS

A literature search was conducted in PubMed, Medline, Google Scholar, and ResearchGate. The keywords used were ‘congenital lymphocytic choriomeningitis virus,’ and 48 studies were included. In addition, we conducted a relevant search by Reference Citation Analysis (RCA) (https://www.referencecitationanalysis.com).

RESULTS

The results have shown 27 reports of congenital LCMV infection in 86 patients, with 52.73% of them being males. Patients presented with chorioretinitis (83.53%), hydrocephalus (54.12%), and psychomotor retardation or developmental delay (54.12%). Computed tomography and/or magnetic resonance imaging most often demonstrated ventriculomegaly (74.07%), periventricular calcifications (66.67%), and microcephaly (40%). Most mothers of congenitally infected infants were exposed to rodents during pregnancy, predominantly mice, with flu-like symptoms mainly occurring during the first two trimesters of gestation. Mortality in congenitally infected children was 16.47%. The diagnosis of congenital LCMV infection was confirmed serologically in most patients (86.67%).

CONCLUSION

LCMV is still an insufficiently recognized fetal teratogen that often leads to long-term neurologic sequelae. Clinicians need to be familiar with LCMV and its potential teratogenic effect and as well as to effectively differentiate LCMV from other TORCH (T: Toxoplasma gondii, O: Other pathogens, R: Rubella virus, C: Cytomegalovirus, H: Herpes simplex virus) pathogens.

Medical management and resolution of perinatal bilateral exophthalmia and secondary corneal ulcers in an Antillean manatee (Trichechus manatus manatus) neonate from Puerto Rico

OBJECTIVE

To present a novel case of perinatal bilateral exophthalmos and corneal ulcers in a neonate Antillean manatee and describe the medical treatment that led to the resolution of the observed clinical signs and vision restoration.

ANIMAL STUDIED

A manatee stranded alone in Puerto Rico on July 5, 2020.

RESULTS

The manatee was found in critical condition with pronounced exophthalmos, lagophthalmos, and corneal opacification of both eyes (OU). Vision impairment was evident due to the lack of ocular menace reflex and bumping into the tank's walls. Biomicroscopy revealed conjunctival hyperemia and chemosis, limited third eyelid movement, but had viscous tears present OU. Dense, full-thickness, white to cream-colored cellular infiltrates affected 70% of the cornea with peripheral active vascularization OU. Rubeosis iridis was also present OU. Treatment consisted of supportive medical management, including nutritional support and topical treatment for ulcerative keratitis. Resolution of the corneal ulcers and functional vision were achieved after 6 weeks of therapy. Currently, bilateral, mild, intermittent exophthalmos is observed with no adverse clinical signs, and the calf is in good health.

CONCLUSIONS

The extent of bilateral corneal disease on a neonatal calf may be a result of an intrauterine infection or possible trauma at or right after birth. While the latter may have led to exophthalmia and consequent corneal disease, the exact cause could not be determined. Supportive therapy and medical management of infectious keratitis were successful and led to vision recovery. This is the first report of ocular pathology in a neonatal manatee.

Possible association between viral infection and poor survival of the corneal graft after penetrating keratoplasty in patients with congenital corneal opacity: a cohort study

BACKGROUND

Congenital corneal opacity (CCO) is a rare disorder. Penetrating keratoplasty (PK) is the main surgical option for CCO, but many factors affect graft survival. Therefore, this study aimed to perform a virological examination of CCO specimens after PK to explore the relationship between virological factors and graft survival after PK.

METHODS

This prospective study included consecutive patients (<6 months of age) diagnosed with CCO and treated with PK at Beijing Tongren Hospital from August 2017 to January 2018. Next-generation sequencing was used to detect viral DNA in the CCO specimens. The survival of the primary graft was analysed using the Kaplan-Meier method.

RESULTS

Overall, 24 eyes of 24 infants were treated with PK during the study period. The mean age at surgery was 4.8±1.1 months. Epstein-Barr virus DNA was detected in two specimens, varicella-zoster virus DNA in one specimen, herpes simplex virus DNA in three specimens and cytomegalovirus DNA in one specimen. In the virus-positive group, only one (14.3%) graft remained clear during follow-up. In contrast, in the virus-negative group (n=17), 13 (76.5%) grafts were still clear at the last follow-up. The mean survival of the grafts in the virus-positive group was significantly shorter than in the virus-negative group (11.0±9.8 months vs 27.1±7.7, p<0.001).

CONCLUSION

The presence of viral DNA in CCO specimens might be associated with poor graft survival after PK.

Pediatric uveitis: Role of the pediatrician

The challenges of childhood uveitis lie in the varied spectrum of its clinical presentation, the often asymptomatic nature of disease, and the evolving nature of the phenotype alongside normal physiological development. These issues can lead to delayed diagnosis which can cause significant morbidity and severe visual impairment. The most common ocular complications include cataracts, band keratopathy, glaucoma, and macular oedema, and the various associated systemic disorders can also result in extra-ophthalmic morbidity. Pediatricians have an important role to play. Their awareness of the various presentations and etiologies of uveitis in children afford the opportunity of prompt diagnosis before complications arise. Juvenile Idiopathic Arthritis (JIA) is one of the most common associated disorders seen in childhood uveitis, but there is a need to recognize other causes. In this review, different causes of uveitis are explored, including infections, autoimmune and autoinflammatory disease. As treatment is often informed by etiology, pediatricians can ensure early ophthalmological referral for children with inflammatory disease at risk of uveitis and can support management decisions for children with uveitis and possible underling multi-system inflammatory disease, thus reducing the risk of the development of irreversible sequelae.

Pediatric liver diseases and ocular changes: What hepatologists and ophthalmologists should know and share with each other

Several rare pediatric liver disorders are accompanied by ophthalmic signs whose awareness and early identification may be of value in confirming/accelerating their diagnosis. Many of these signs are asymptomatic and can only be detected with an ophthalmological examination. Corneal signs are described in patients with Wilson's disease, Alagille's syndrome and some liver storage diseases. Cataract plays an important role to diagnose galactosemia. Retinal involvement is seen in some peroxisomal disorders (e.g. Zellweger's syndrome), in mucopolysaccharidoses (pigmentary retinopathy), and in Niemann-Pick disease (macular cherry red spot). In mucopolysaccharidoses optic nerve can be involved as optic atrophy secondary to pigmentary retinopathy or to chronic papilledema. Children with neonatal cholestasis due to hypopituitarism may present septo-optic dysplasia. Several infectious agents have an ophthalmological/hepatic involvement in the fetal life and/or thereafter. Some mitochondrial liver diseases, such as Pearson's syndrome, present pigmentary retinopathy and a chronic progressive external ophthalmoplegia. Finally, some drugs while protecting the liver may damage the ocular system as seen with long-term glucocorticoids and Nitisinone administration. This review provides a synopsis of those conditions that hepatologists and ophthalmologists should share among themselves to better take care of patients. Synoptic tables are presented to facilitate the mutual understanding of the issues.

Newborn Glaucoma: Do not Forget Infections

Intrauterine infections can affect various structures of the developing fetal eye. Rubella infection results in congenital cataracts, keratopathy, retinopathy and less commonly, glaucoma. Ophthalmic manifestations of intrauterine cytomegalovirus (CMV) infection have been reported to be chorioretinitis, optic nerve colobomas, and corneal opacities, but have not been implicated in congenital cataract or congenital glaucoma. Concurrent infection with both rubella and CMV virus has not been reported. We report concurrent rubella and CMV infection in a baby born with corneal opacification, severe congenital glaucoma, and congenital cataract. It is important to recognize these babies early and investigate for intrauterine infections rather than assume they are all primary congenital glaucoma. Involvement of the cornea, glaucoma, and cataract make management of these babies a major challenge requiring a multidisciplinary team approach.

Diagnosis of congenital/perinatal infections by neonatologists: a national survey

OBJECTIVE

To describe the clinical approach used by neonatologists for diagnosis of congenital/perinatal infections (CPI); no such data currently exist.

STUDY DESIGN

A national survey regarding the diagnosis of toxoplasma, syphilis, rubella, cytomegalovirus, and herpes simplex virus (HSV) infection in neonates.

RESULT

We received 553 (11%) responses. Central nervous system calcification or hydrocephalus was the commonest trigger to pursue a CPI diagnosis (98%); maternal history was the least frequent (67%). Four hundred twenty-two (76%) used general screening such as "TORCH titer screen" (57%) or total IgG or IgM (39%). Further evaluation targeted known clinical sequelae; but cerebrospinal fluid testing was used in only 65% of those suspected of having HSV or syphilis. Fifty-six percent chose a treponemal instead of a non-treponemal test for syphilis. Multivariable analyses did not identify factors associated with the clinical diagnostic approach.

CONCLUSION

We observed clinically important deviations from CPI diagnostic test recommendations in a national cohort of neonatologists.

Visual function in infants with antenatal Zika virus exposure

PURPOSE

To report the findings of a cross-sectional study of visual function in infants with confirmed or suspected antenatal Zika virus (ZIKV) infection seen at a single referral center in Rio de Janeiro.

METHODS

Infants were examined following the ZIKV outbreak period at Instituto Fernandes Figueira/FIOCRUZ. Visual function was considered abnormal if an infant could not fix and follow a standardized high-contrast target (10 cm) by 3-6 months of age. Visual function and associations with structural eye abnormalities, central nervous system (CNS) abnormalities, microcephaly, and nystagmus were assessed. Sensitivity and specificity of screening criteria for structural eye abnormalities was assessed.

RESULTS

A total of 173 infants met inclusion criteria. Abnormal visual function was found in 52 infants (30.0%) and was significantly associated with eye abnormalities (40/52; OR = 44.2; 95% CI, 16.6-117.6), CNS abnormalities (50/52; OR = 64.0; 95% CI, 14.7-277.6), microcephaly (44/52; OR = 31.5; 95% CI, 12.7-77.8), and nystagmus (26/52; OR = 120.0; 95% CI, 15.6-924.5). Using microcephaly as screening criteria for the detection of eye abnormalities provided a sensitivity of 88.9% (95% CI, 76.0-96.3) and specificity of 82.8% (95% CI, 75.1-88.9). Using both abnormal visual function and microcephaly increased sensitivity to 100% (95% CI, 92.1-100.0) and decreased specificity to 80.5% (95% CI, 72.5-86.9).

CONCLUSIONS

Infants with suspected antenatal ZIKV infection and reduced visual function should be referred to an ophthalmologist. Visual function assessments are helpful in screening for antenatal ZIKV exposure in resource-limited settings and can identify infants who may benefit from visual habilitation.

ZIKA virus infection causes persistent chorioretinal lesions

Zika-infected patients can have eye involvement ranging from mild conjunctivitis to severe chorioretinal lesions, however the possible long-term sequelae of infection and timeline to recovery remain unknown. Here we describe the partial recovery of chorioretinal lesions in an immunocompetent patient diagnosed with bilateral posterior uveitis associated with Zika infection and show that some lesions resolved with focal atrophy evident as pigmentary changes on funduscopy. To better understand the progression of the lesions and correlate the changes in fundus imaging with local viral load, immune responses, and retinal damage, we developed a symptomatic mouse model of ocular Zika virus infection. Imaging of the fundus revealed multiple hypopigmentary patches indicative of chorioretinal degeneration as well as thinning of the retina that mirror the lesions in patients. Microscopically, the virus primarily infected the optic nerve, retinal ganglion cells, and inner nuclear layer cells, showing thinning of the outer plexiform layer. During acute infection, the eyes showed retinal layer disorganization, retinitis, vitritis, and focal choroiditis, with mild cellular infiltration and increased expression of tumor necrosis factor, interferon-γ, granzyme B, and perforin. Focal areas of gliosis and retinal degeneration persisted 60 dpi. The model recapitulates features of ZIKA infections in patients and should help elucidate the mechanisms underlying the damage to the eyes and aid in the development of effective therapeutics.

Congenital lymphocytic choriomeningitis virus-an underdiagnosed fetal teratogen

Congenital lymphocytic choriomeningitis virus (LCMV) infection is associated with high mortality and morbidity. Although the number of cases reported in the literature has been increasing, it might still be clinically an underdiagnosed human fetal teratogen. We report 2 more cases of serologically proven congenital LCMV infection. One case presented with Aicardi-like syndrome features. Since congenital LCMV infection may mimic Aicardi syndrome, serologic testing should be considered in the workup of patients with Aicardi syndrome to rule out LCMV infection.

Ocular effects of Zika virus-a review

Zika virus was considered an innocent pathogen while restricted to the African and Asian population; however, after reaching the Americas in March 2015, it became a global threat. Despite usually causing mild or no symptoms in infected adults, Zika virus displays a different behavior toward fetuses. When infected during gestation, fetuses have their immature neural cells killed by the virus and consequently have devastating findings at birth. In the past year the drastic effects of Zika virus infection in newborns include neurological, ophthalmological, audiological, and skeletal abnormalities. These findings represent a new entity called congenital Zika syndrome. We summarize the ocular findings of congenital Zika Syndrome, as well as the current understanding of the illness, systemic manifestations, laboratory investigation, differential diagnosis, prophylaxis, and treatment for this disorder.

Characterizing the Pattern of Anomalies in Congenital Zika Syndrome for Pediatric Clinicians

Importance

Zika virus infection can be prenatally passed from a pregnant woman to her fetus. There is sufficient evidence to conclude that intrauterine Zika virus infection is a cause of microcephaly and serious brain anomalies, but the full spectrum of anomalies has not been delineated. To inform pediatric clinicians who may be called on to evaluate and treat affected infants and children, we review the most recent evidence to better characterize congenital Zika syndrome.

Observations

We reviewed published reports of congenital anomalies occurring in fetuses or infants with presumed or laboratory-confirmed intrauterine Zika virus infection. We conducted a comprehensive search of the English literature using Medline and EMBASE for Zika from inception through September 30, 2016. Congenital anomalies were considered in the context of the presumed pathogenetic mechanism related to the neurotropic properties of the virus. We conclude that congenital Zika syndrome is a recognizable pattern of structural anomalies and functional disabilities secondary to central and, perhaps, peripheral nervous system damage. Although many of the components of this syndrome, such as cognitive, sensory, and motor disabilities, are shared by other congenital infections, there are 5 features that are rarely seen with other congenital infections or are unique to congenital Zika virus infection: (1) severe microcephaly with partially collapsed skull; (2) thin cerebral cortices with subcortical calcifications; (3) macular scarring and focal pigmentary retinal mottling; (4) congenital contractures; and (5) marked early hypertonia and symptoms of extrapyramidal involvement.

Conclusions and Relevance

Although the full spectrum of adverse reproductive outcomes caused by Zika virus infection is not yet determined, a distinctive phenotype-the congenital Zika syndrome-has emerged. Recognition of this phenotype by clinicians for infants and children can help ensure appropriate etiologic evaluation and comprehensive clinical investigation to define the range of anomalies in an affected infant as well as determine essential follow-up and ongoing care.

Lymphocytic choriomeningitis, Ljungan and orthopoxvirus seroconversions in patients hospitalized due to acute Puumala hantavirus infection

BACKGROUND

The emergence and re-emergence of zoonotic and vector-borne diseases are increasing in Europe. Prominent rodent-borne zoonotic viruses include Puumala hantavirus (PUUV; the causative agent of nephropathia epidemica, NE), lymphocytic choriomeningitis virus (LCMV), and orthopoxviruses (OPV). In addition, Ljungan virus (LV) is considered a potentially zoonotic virus.

OBJECTIVE

The aim of this study was to compare clinical picture between acute PUUV patients with and without additional rodent-borne viral infections, to investigate if concurrent infections influence disease severity.

STUDY DESIGN

We evaluated seroprevalence of and seroconversions to LCMV, LV and OPV in 116 patients hospitalized for NE. Clinical and laboratory variables were closely monitored during hospital care.

RESULTS

A total of five LCMV, 15 LV, and one OPV seroconversions occurred. NE patients with LCMV seroconversions were younger, and had lower plasma creatinine concentrations and platelet counts than patients without LCMV seroconversions. No differences occurred in clinical or laboratory findings between patients with and without seroconversions to LV and OPV. We report, for the first time, LCMV seroprevalence in Finland, with 8.5% of NE patients seropositive for this virus. Seroprevalences for LV and OPV were 47.8% and 32.4%, respectively.

CONCLUSION

Cases with LCMV seroconversions were statistically younger, had milder acute kidney injury and more severe thrombocytopenia than patients without LCMV. However, the low number of seroconversion cases precludes firm conclusions. Concurrent LV or OPV infections do not appear to influence clinical picture for NE patients.

Zika Virus-Associated Microcephaly and Eye Lesions in the Newborn

On February 1, 2016, Zika virus (ZIKV) was designated as a Public Health Emergency of International Concern by the director of the World Health Organization. Zika virus has spread to numerous countries throughout the Americas, affecting up to an estimated 1.3 million people since the first reports from Brazil in early 2015. Although ZIKV infections are self-limiting, fetal microcephaly and ophthalmic anomalies have been associated with ZIKV infection as a possible result of perinatal transmission. The causal link between maternal ZIKV infection and newborn microcephaly and eye lesions has not been proven beyond doubt and is currently debated. We discuss the possibility of causality by ZIKV using Koch's postulates and the more appropriate Bradford Hill criteria. In this review, we summarize and consolidate the current literature on newborn microcephaly and eye lesions associated with ZIKV infection and discuss current perspectives and controversies.

Emerging Role of Zika Virus in Adverse Fetal and Neonatal Outcomes

The rapid spread of the Zika virus (ZIKV) in the Americas and its potential association with thousands of suspected cases of microcephaly in Brazil and higher rates of Guillain-Barré syndrome meet the conditions for a Public Health Emergency of International Concern, as stated by the World Health Organization in February 2016. Two months later, the Centers for Disease Control and Prevention (CDC) announced that the current available evidence supports the existence of a causal relationship between prenatal Zika virus infection and microcephaly and other serious brain anomalies. Microcephaly can be caused by several factors, and its clinical course and prognosis are difficult to predict. Other pathogens with proven teratogenicity have been identified long before the current ZIKV epidemic. Despite the growing number of cases with maternal signs of infection and/or presence of ZIKV in tissues of affected newborns or fetuses, it is currently difficult to assess the magnitude of increase of microcephaly prevalence in Brazil, as well as the role of other factors in the development of congenital neurological conditions. Meanwhile, health agencies and medical organizations have issued cautious guidelines advising health care practitioners and expectant couples traveling to, returning from, or living in affected areas. Analogous to dengue virus (DENV) epidemics, ZIKV has the potential to become endemic in all countries infested by Aedes mosquitoes, while new mutations could impact viral replication in humans, leading to increased virulence and consequently heightened chances of viral transmission to additional naive mosquito vectors. Studies are urgently needed to answer the questions surrounding ZIKV and its role in congenital neurological conditions.

Causes of Severe Visual Impairment and Blindness: Comparative Data From Bhutanese and Laotian Schools for the Blind

PURPOSE

To determine and compare the major causes of childhood blindness and severe visual impairment in Bhutan and Laos.

DESIGN

Independent cross-sectional surveys.

METHODS

This survey consists of 2 cross-sectional observational studies. The Bhutanese component was undertaken at the National Institute for Vision Impairment, the only dedicated school for the blind in Bhutan. The Laotian study was conducted at the National Ophthalmology Centre and Vientiane School for the Blind. Children younger than age 16 were invited to participate. A detailed history and examination were performed consistent with the World Health Organization Prevention of Blindness Eye Examination Record.

RESULTS

Of the 53 children examined in both studies, 30 were from Bhutan and 23 were from Laos. Forty percent of Bhutanese and 87.1% of Laotian children assessed were blind, with 26.7% and 4.3%, respectively, being severely visually impaired. Congenital causes of blindness were the most common, representing 45% and 43.5% of the Bhutanese and Laotian children, respectively. Anatomically, the primary site of blinding pathology differed between the cohorts. In Bhutan, the lens comprised 25%, with whole globe at 20% and retina at 15%, but in Laos, whole globe and cornea equally contributed at 30.4%, followed by retina at 17.4%. There was an observable difference in the rates of blindness/severe visual impairment due to measles, with no cases observed in the Bhutanese children but 20.7% of the total pathologies in the Laotian children attributable to congenital measles infection.

CONCLUSIONS

Consistent with other studies, there is a high rate of blinding disease, which may be prevented, treated, or ameliorated.

Recurrent headaches may be caused by cerebral toxoplasmosis

AIM

To establish seroprevalence and provide characteristics of Toxoplasma gondii (TG) infection in children with recurrent headaches.

METHODS

The study was performed in 178 children aged 7-17 years admitted consecutively to the Department of Pediatric Neurology from November 2009 to July 2011. The children were surveyed with a questionnaire with the help and assistance of their parents and blood samples taken on admission were studied for the presence of specific anti-TG IgM, IgG antibodies and IgG avidity using enzyme immunoassay Platelia Toxo IgM, IgG.

RESULTS

The study showed that 19 children (8 boys, 11 girls; 8-17 years old, mean age 14.36 years) had high serum anti-TG IgG antibody levels (range: 32.2 > 240 UI/mL, mean 120.18 UI/mL; positive value for IgG was ≥ 9 UI/mL). The avidity index (AI) ranged from 0.202 to 0.925 (scale: ≥ 0.5 high AI). The results for IgM antibodies were all negative and the obtained results ranged from 0.113 to 0.25 U/mL (mean = 0.191 IU/mL) and all values below 0.8 IU/mL were considered negative. The most frequent complaints found in the seropositive patients were headaches that affected the frontal (13 children), occipital (4) and parietal areas (5). Headaches usually had a pulsating (in 7 patients) and squeezing (6) character and rarely were piercing, dull or expanding. Interestingly, 8 children did not feel discomfort during the headaches, probably because they did not have sufficiently increased intracranial pressure yet. The headaches usually appeared 1-2 times/mo, lasted for 2-6 h, and had a mean intensity of 5.5 points in a 10 point subjective scale. The comorbidities included epilepsy (5 patients), various infections in 3 children (chronic eustachitis, chronic rhinitis, chronic purulent tonsillitis, streptococcal pharyngitis, meningitis, allergic diseases), disturbances of behavior, deficits of attention, and ocular and motor concentration disorders in 1 child. The electroencephalographic and neuroimaging studies performed in our patients had a very limited value in establishing cerebral toxoplasmosis.

CONCLUSION

Ten point six seven percent of the studied children had markedly increased serum anti-TG IgG antibodies and high AI indicated chronic infestation. It is suggested that tests for TG infection should be introduced to routine diagnostics in patients with recurrent headaches.

Toxoplasmosis

Toxoplasma gondii, an Apicomplexan, is a pathogic protozoan that can infect the central nervous system. Infection during pregnancy can result in a congenial infection with severe neurological sequelae. In immunocompromised individuals reactivation of latent neurological foci can result in encephalitis. Immunocompetent individuals infected with T. gondii are typically asymptomatic and maintain this infection for life. However, recent studies suggest that these asymptomatic infections may have effects on behavior and other physiological processes. Toxoplasma gondii infects approximately one-third of the world population, making it one of the most successful parasitic organisms. Cats and other felidae serve as the definite host producing oocysts, an environmentally resistant life cycle stage found in cat feces, which can transmit the infection when ingested orally. A wide variety of warm-blooded animals, including humans, can serve as the intermediate host in which tissue cysts (containing bradyzoites) develop. Transmission also occurs due to ingestion of the tissue cysts. There are three predominant clonal lineages, termed Types I, II and III, and an association with higher pathogenicity with the Type I strains in humans has emerged. This chapter presents a review of the biology of this infection including the life cycle, transmission, epidemiology, parasite strains, and the host immune response. The major clinical outcomes of congenital infection, chorioretinitis and encephalitis, and the possible association of infection of toxoplasmosis with neuropsychiatric disorders such as schizophrenia, are reviewed.

Ophthalmological findings in congenital cytomegalovirus infection: when to screen, when to treat?

Cytomegalovirus (CMV) is the leading cause of known congenital viral infections. Approximately 90% of congenitally infected newborns exhibit no clinical abnormalities at birth. In 5% to 15%, a wide spectrum of clinical signs is present at birth. Ophthalmological signs are seen in a large percentage of symptomatic patients but rarely in otherwise asymptomatic infants. Chorioretinitis, optic atrophy, and cortical visual impairment are the most frequent causes of visual problems in congenitally infected infants. There is no clear consensus in the literature on screening or treatment modalities concerning the ophthalmological aspects of congenital CMV. Further prospective studies are needed to set up guidelines for ophthalmological screening and treatment of infants with congenital CMV.

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 in virology

This article outlines the ocular complications of viral infection. The emphasis is on the most common viruses encountered by the physician, and their clinical features and treatment are discussed while demonstrating the variation and often significant sequelae of ocular viral infection.

Review for disease of the year: differential diagnosis of ocular toxoplasmosis

The diagnosis of ocular toxoplasmosis is mainly clinical, based in the presence of focal necrotizing retinochoroiditis often associated with a preexistent chorioretinal scar, and variable involvement of the vitreous, retinal blood vessels, optic nerve, and anterior segment of the eye. Recognition of this clinical spectrum of toxoplasmic retinochoroiditis is crucial, but other infectious, noninfectious, and neoplastic entities should also be considered in the differential diagnosis. Investigations such as serological tests, polymerase chain reaction of ocular fluids, and assessment of intraocular antibody synthesis are helpful in uncertain cases. This article provides an overview of the differential diagnosis of ocular toxoplasmosis, focusing on the most important entities to be considered and emphasizing distinctive features of each one of them in the clinical setting. Ocular toxoplasmosis has multiple clinical manifestations, which partially overlap with those of other entities and these should be carefully considered when making the differential diagnosis, particularly in less typical cases.

Rubella virus as a possible etiological agent of Fuchs heterochromic iridocyclitis

BACKGROUND

To determine whether rubella virus is involved in the pathogenesis of Fuchs heterochromic iridocyclitis (FHI).

METHODS

Fourteen patients (14 eyes) diagnosed with FHI based on characteristic ocular manifestations and eight control subjects were studied. Aqueous humor (AH) samples from 14 FHI patients and one vitreous sample from a FHI patient were analyzed for intraocular antibody production against rubella virus by calculation of the Goldmann-Witmer coefficient (GWC). Viral detection by nested polymerase chain reaction and isolation by culture in RK-13 cells were conducted in nine FHI patients. In addition to laboratory examinations, medical history of rubella virus vaccination was also obtained.

RESULTS

Ten patients with FHI examined showed intraocular synthesis of rubella virus antibodies (GWC > 3). A high index of rubella virus antibody production was also found in the vitreous sample (GWC = 30.6). GWC in all control subjects were below detectable level. The rubella genome was detected in two of nine patients, and rubella virus was isolated from one of nine patients with FHI. None of the patients with FHI had been vaccinated against rubella.

CONCLUSIONS

Our laboratory data strongly suggest a relationship between FHI and rubella virus.

Quantitation of RNA decay in dried blood spots during 20 years of storage

BACKGROUND

Diseases with an onset during childhood or adult life can have their origin during fetal life or at birth. Neonatal blood dried on filter paper (Guthrie cards) collected for screening purposes is routinely stored for decades. In addition to clinical use, these filters in combination with patient registers constitute an invaluable resource for epidemiological and pathophysiological research. Although RNA has been successfully recovered from such filters even after decades of storage, the potential decay of RNA over time has not previously been investigated using quantitative methods.

METHODS

Filter papers (n=5) with dried blood spots from the Swedish National PKU register, stored for 1, 5, 10, 15 or 20 years were randomly selected. RNA was isolated from each sample, quantitated by spectrophotometry and reverse transcribed following DNase I treatment. Amplifiable cDNA was subsequently detected by real-time PCR using primers specific for transcripts encoding beta-actin.

RESULTS

Transcripts encoding beta-actin were detected in all 25 samples analyzed at a mean threshold cycle (Ct) of 25 (SD 1.9). A one-way ANOVA indicated no significant effect of storage time on Ct values.

CONCLUSIONS

The lack of significant decay of RNA in dried blood filters stored for up to 20 years suggests that such filters are useful for studies of RNA determinants of diseases with an onset in childhood as well as adult life.

Neonatal Care and Data

Neonatology encompasses the care of all infants: from term newborns to extremely premature infants, from healthy infants to those suffering from severe infections or genetic disorders. While the management of infants can vary greatly, there are essential core data and knowledge that is needed to care for them.