Manifestaciones oftalmológicas del dengue, el zika y el chikungunya / Ophthalmic manifestations of dengue, zika and chikungunya

Las infecciones por arbovirus constituyen un reto significativo para los sistemas de salud. Cada vez se incrementa el reconocimiento de complicaciones del sistema nervioso central secundarias a ellas, lo que puede ser un dilema para su diagnóstico y tratamiento. Los arbovirus pueden alterar los mecanismos de inmunidad innatos del ojo al dañar las barreras óculo-hemáticas. En esta revisión nos propusimos caracterizar los principales hallazgos oftalmológicos de las enfermedades transmitidas por mosquito, como el dengue, el zika y el chikungunya, y su posible fisiopatología. Se realizó una búsqueda de la literatura sobre el tema en la base de datos de PubMED. En los pacientes con zika y chikungunya se reconocieron frecuentemente la conjuntivitis no purulenta y la queratitis. En los casos de dengue el edema macular y las hemorragias retinianas maculares fueron frecuentes; causaron disminución de la visión y defectos campimétricos; la vasculitis y coriorretinitis periférica podía ser asintomática si la mácula no estaba comprometida. Estuvieron implicados la trombocitopenia y otros procesos fisiopatológicos. En las enfermedades estudiadas se reportaron casos raros con parálisis de nervios oculomotores o neuritis óptica como respuesta autoinmune tardía. Recientemente se reportó el síndrome de zika congénito que incluyó múltiples anomalías del desarrollo. En los neonatos afectados se describió la atrofia macular, así como la pigmentación macular bilateral, la hipoplasia del nervio óptico, la catarata, entre otros. Existen diversas lesiones oculares secundarias a infecciones por dengue, zika y chikungunya que merecen reconocimiento, pues deterioran la función visual temporal o permanentemente(AU)

Arbovirus infections pose a significant challenge to health systems. Awareness of the secondary central nervous system complications caused by these infections is on the increase, which may be a dilemma for their diagnosis and treatment. Arboviruses may alter the innate immunity mechanisms of the eye by damaging blood-retinal barriers. The objective of this review was to characterize the main ophthalmological findings of mosquito-borne diseases, such as dengue, zika and chikungunya, and their possible physiopathology. A bibliographic search about the topic was conducted in the database PubMed. Non-purulent conjunctivitis and keratitis were frequently found in zika and chikungunya patients. Dengue cases often presented macular edema and macular retinal hemorrhage, which caused vision reduction, as well as campimetric defects. Vasculitis and peripheral chorioretinitis could be asymptomatic if the macula was not involved. Thrombocytopenia and other physiopathological processes were also present. Oculomotor nerve palsy and optic neuritis as a late autoimmune response were rarely reported in the diseases studied. Recent reports refer to congenital zika syndrome, which causes multiple developmental abnormalities. Macular atrophy, bilateral macular pigmentation, optic nerve hypoplasia and cataract, among other disorders, were described in affected neonates. A variety of ocular lesions secondary to dengue, zika and chikungunya infection deserve recognition, for they damage visual function either temporarily or permanently(AU)

Tick-Borne Diseases in the United States.

BACKGROUND: Tick-borne diseases are an important cause of human morbidity and mortality in the United States. The past several decades have witnessed an increase in both the number of recognized tick-borne pathogens and the number of tick-borne disease cases, whereas tick surveys have revealed substantial geographic expansions of tick populations throughout the country. Multiple laboratory testing options exist for diagnosis of tick-borne diseases, including serology, microscopy, and molecular-based methods. The preferred approach varies by the specific disease, locally available test options, and the stage of illness at patient presentation. Accurate and timely detection of tick-borne illness is of utmost importance, as prompt treatment is strongly linked to better outcomes. CONTENT: This review covers the clinical manifestations and preferred diagnostic approaches for important bacterial, viral, and parasitic tick-borne diseases in the United States, including Lyme disease, tick-borne relapsing fever, anaplasmosis, ehrlichiosis, spotted fever rickettsioses, and babesiosis. Infection with emerging pathogens such as Borrelia miyamotoi, Powassan virus, Heartland virus, Colorado tick fever virus, and Bourbon virus are also covered. SUMMARY: Our understanding of tick-borne diseases in the United States continues to improve with the detection of novel pathogens and development of new diagnostic modalities. While conventional diagnostic methods, including serology and microscopy, will play an ongoing role in the diagnosis of tick-borne diseases, implementation of advanced molecular diagnostics will further broaden our understanding of these diseases by facilitating detection of emerging pathogens and providing more accurate and timely diagnosis.

Emerging arboviruses and implications for pediatric transplantation: A review.

Recent years have brought a rise in newly emergent viral infections, primarily in the form of previously known arthropod-transmitted viruses that have increased significantly in both incidence and geographical range. Of particular note are DENV, CHIKV, and ZIKV, which are transmitted mostly by Aedes species of mosquitoes that exhibit a wide and increasing global distribution. Being important pathogens for the general population, these viruses have the potential to be devastating in the international transplant community, with graft rejection and death as possible outcomes of infection. In this review, we discuss the current state of knowledge for these viruses as well as repercussions of infection in the solid organ and HSCT population, with a focus, when possible, on pediatric patients.

Climate change and skin disease.

Despite commanding essentially universal scientific consensus, climate change remains a divisive and poorly understood topic in the United States. Familiarity with this subject is not just for climate scientists. The impact of climate change on human morbidity and mortality may be considerable; thus, physicians also should be knowledgeable in this realm. Climate change science can seem opaque and inferential, creating fertile ground for political polemics and undoubtedly contributing to confusion among the general public. This puts physicians in a pivotal position to facilitate a practical understanding of climate change in the public sphere by discussing changes in disease patterns and their possible relationship to a changing climate. This article provides a background on climate change for dermatologists and highlights how climate change may impact the management of skin disease across the United States.

A retrospective chart review study to describe selected zoonotic and arboviral etiologies in hospitalized febrile patients in the Republic of Armenia.

BACKGROUND: Scant information is available on the infectious causes of febrile illnesses in Armenia. The goal of this study was to describe the most common causes, with a focus on zoonotic and arboviral infections and related epidemiological and clinical patterns for hospitalized patients with febrile illnesses of infectious origin admitted to Nork Infectious Diseases Clinical Hospital, the referral center for infectious diseases in the capital city, Yerevan. METHOD: A chart review study was conducted in 2014. Data were abstracted from medical charts of adults (≥18 years) with a fever (≥38 °C), who were hospitalized (for ≥24 h) in 2010-2012. RESULTS: Of the 600 patients whose charts were analyzed, 76 % were from Yerevan and 51 % were male; the mean age (± standard deviation) was 35.5 (±16) years. Livestock exposure was recorded in 5 % of charts. Consumption of undercooked meat and unpasteurized dairy products were reported in 11 and 8 % of charts, respectively. Intestinal infections (51 %) were the most frequently reported final medical diagnoses, followed by diseases of the respiratory system (11 %), infectious mononucleosis (9.5 %), chickenpox (8.3 %), brucellosis (8.3 %), viral hepatitis (3.2 %), and erysipelas (1.5 %). Reviewed medical charts included two cases of fever of unknown origin (FUO), two cutaneous anthrax cases, two leptospirosis cases, three imported malaria cases, one case of rickettsiosis, and one case of rabies. Engagement in agricultural activities, exposure to animals, consumption of raw or unpasteurized milk, and male gender were significantly associated with brucellosis. CONCLUSION: Our analysis indicated that brucellosis was the most frequently reported zoonotic disease among hospitalized febrile patients. Overall, these study results suggest that zoonotic and arboviral infections were not common etiologies among febrile adult patients admitted to the Nork Infectious Diseases Clinical Hospital in Armenia.

Arthropod-borne viruses transmitted by Phlebotomine sandflies in Europe: a review.

Phlebotomine sandflies are known to transmit leishmaniases, bacteria and viruses that affect humans and animals in many countries worldwide. These sandfly-borne viruses are mainly the Phlebovirus, the Vesiculovirus and the Orbivirus. Some of these viruses are associated with outbreaks or human cases in the Mediterranean Europe. In this paper, the viruses transmitted by Phlebotomine sandflies in Europe (Toscana virus, Sicilian virus, sandfly fever Naples virus) are reviewed and their medical importance, geographical distribution, epidemiology and potential spreading discussed. Data on vertebrate reservoirs is sparse for sandfly fever viruses. The factor currently known to limit the spread of diseases is mainly the distribution areas of potential vectors. The distribution areas of the disease may not be restricted to the areas where they have been recorded but could be as wide as those of their vectors, that is to say Larroussius and P. papatasi mainly but not exclusively. Consequently, field work in form of viral isolation from sandflies and possible reservoirs as well as laboratory work to establish vectorial competence of colonised sandflies need to be encouraged in a near future, and epidemiological surveillance should be undertaken throughout the European Union.

Arboviruses and their vectors in the Pacific--status report.

Three arboviruses have already caused epidemics in various Pacific Island countries and territories, and currently represent a direct threat to public health. The diseases concerned are all mosquito-borne and should be kept under careful surveillance. Dengue fever, which is a worldwide major public health problem, is mainly transmitted in the Pacific by the Aedes aegypti vector but also by other mosquitoes of this genus with varying ranges. Epidemic polyarthritis due to the Ross River virus is endemic in Australia. At least one major epidemic has occurred in the Pacific where various vector mosquito species occur. Japanese encephalitis is a zoonosis that can be transmitted to humans by mosquitoes of the genus Culex. Its area of distribution in Asia is expanding and the possibility of fresh incursions into the region should be borne in mind. This paper reviews the situation regarding these diseases in the Pacific and provides information on the way they are transmitted as well as on the biology of the mosquito vectors.

Transmission cycles, host range, evolution and emergence of arboviral disease.

Many pandemics have been attributed to the ability of some RNA viruses to change their host range to include humans. Here, we review the mechanisms of disease emergence that are related to the host-range specificity of selected mosquito-borne alphaviruses and flaviviruses. We discuss viruses of medical importance, including Venezuelan equine and Japanese encephalitis viruses, dengue viruses and West Nile viruses.

Queenslanders' use of personal strategies to minimise risk of mosquito-borne disease.

OBJECTIVE: To describe Queenslanders' awareness, knowledge and attitudes towards mosquito-borne diseases and their transmission, and to determine which factors influence the adoption of effective individual prevention strategies. METHODS: In 1995-6, cross-sectional surveys of adult residents in the western suburbs of Brisbane and registered voters in Cairns were conducted. Forced entry logistic regression was used to predict use of personal protection and elimination of domestic breeding sites in the two cities. RESULTS: Final sample sizes were 347 in Cairns and 165 in Brisbane with response rates of approximately 70%. RRVD awareness was nearly universal in both cities. A majority of residents (60% in Brisbane and 65% in Cairns) report they are careful to avoid being bitten by mosquitoes. 25% of Cairns residents and 18% of Brisbane residents report always using some method of personal protection. Cairns residents are also more likely to say that they actively prevent mosquitoes from breeding in their yards (76% in Brisbane and 87% in Cairns). Knowledge of mosquitoes and disease transmission was slightly higher in Cairns. In Brisbane, dislike of mosquitoes and being regularly bitten were significant in the multivariate model predicting personal protection, whereas concern for disease and being female were significant in Cairns. Concern about disease was a significant predictor of eliminating breeding sites in both cities. CONCLUSIONS: Raising concern about mosquito-borne disease can increase use of personal prevention strategies. However, providing information on prevention strategies may not be effective. The most effective strategies are not practiced or seen by the public to be related to minimising risk of disease. IMPLICATIONS: Greater emphasis in health promotion campaigns should be placed on encouraging permanent alterations to the domestic environment rather than temporary methods that are difficult to sustain and not effective against the common vectors for mosquito-borne diseases in Queensland. Educational messages should explicitly link preventive behaviours with the reduction in the likelihood of contracting a serious disease.

Langerhans cells migrate to local lymph nodes following cutaneous infection with an arbovirus.

Whereas there has been recent interest in interactions between dendritic cells and pathogenic viruses, the role of dendritic cells in the initiation of protective immunity to such organisms has not been elucidated. The aim of this study was to examine whether a resident dendritic cell population in the skin, Langerhans cells, respond to cutaneous viral infections which are effectively cleared by the immune system. We therefore characterized the ability of Langerhans cells to migrate to local draining lymph nodes following infection with the arthropod-borne viruses, West Nile virus or Semliki Forest virus. The data show that major histocompatibility complex class II+/NLDC145+/E-cadherin+ Langerhans cell numbers are increased in the draining lymph nodes of infected mice and this increase is accompanied by a concomitant decrease in the Langerhans cell density in the epidermis. Langerhans cell migration is associated with an accumulation of leukocytes in the lymph node, which is one of the earliest events in the initiation of an immune response. Both the migratory response and the draining lymph node leukocyte accumulation were abrogated if ultraviolet-inactivated instead of live viruses were used, suggesting the activation and subsequent migration of Langerhans cells requires a live, replicating antigen. Our findings are likely to have wider implications for the development of epidermally delivered vaccines and suggest that mobilization of dendritic cells may be involved in the development of immune responses to arthropod-borne viruses.

Mosquito-borne viruses in western Europe: a review.

Several mosquito-borne arboviruses belonging to the genera Alphavirus, Flavivirus, and Bunyavirus have been reported to occur in mosquitoes and to infect humans and other vertebrates in western Europe. These zoonotic viruses circulate in nature either in an Aedes-mammal, Anopheles-mammal, or Culex-bird transmission cycle. Infected humans normally do not contribute to the virus circulation. West Nile virus (Flavivirus) caused an outbreak of fever, malaise, pain in eyes and muscles, and headache and encephalitis in southern France during 1962-1965, and an outbreak of encephalitis with a high case-fatality rate in Romania during 1996. West Nile virus has been isolated from birds, horses, and mosquitoes in Portugal, France, the former Czechoslovakia, and Romania. These data, together with reports of antibodies to West Nile virus in birds, domestic mammals, and humans in several other countries, show virus activity in southern and central Europe. Sindbis virus (Alphavirus) caused outbreaks of fever, rash, and arthralgia in northern Europe during 1981-1982, 1988, and 1995. Two California group viruses (Bunyavirus), Tahyna virus and Inkoo virus, have been identified in western Europe. Tahyna virus causes fever and respiratory symptoms and sometimes also central nervous system involvement. It occurs in most countries of central and southern Europe, and is most common in central Europe. Inkoo virus has not been associated with disease in humans in western Europe although Russian studies indicated that it can cause encephalitis. Inkoo virus occurs in northern Europe, especially in the far north. Batai virus of the Bunyamwera-group (Bunyavirus) occurs in southern, central, and northern Europe, most frequently in central Europe. The antibody prevalence in humans generally is very low, indicating that the potential of this virus as a human pathogen is probably low in Europe. The Lednice virus (Bunyavirus) has been reported only from the former Czechoslovakia and Romania, and apparently is not transmitted to humans. In addition to the six mosquito-borne viruses documented in western Europe, there is serological evidence of infection with a Semliki Forest complex virus (Alphavirus) in central and southern Europe. Although mosquito-borne viruses presently are not considered to be the cause of major health problems in western Europe, the morbidity caused by Sindbis virus, and the morbidity and mortality caused by West Nile virus, merit further studies on the ecology, epidemiology, and medical importance of these viruses. The California group of viruses and a virus of the Semliki Forest complex may be the cause of unrecognized health problems in western Europe. Specific sampling of potential vectors for virus isolation, detailed characterization of virus strains, and the use of fully characterized strains for serological diagnosis will help to elucidate the present and future potential of mosquito-borne viruses as human pathogens in Europe.

The isolation of Akabane virus (Iriki strain) from calves in Taiwan.

Nonsuppurative encephalitis in calves aged 4-12 months, cow abortion and fetal deformities were endemic in dairy farms in Taiwan in recent years. A virological investigation emphasizing on Arthpodborn virus (Arbovirus) was conducted. Total of 11 strains of Akabane virus were isolated from endemic districts between June and July of 1992. Among them, seven viruses were isolated from blood samples of 15 calves showing nervous signs. Another 4 Akabane viruses were isolated from clinically healthy calves from three of six dairy farms investigated. All the six investigated farms had a recent history of abortion and fetal deformities. The isolates caused prominent cytopathic effects in HmLu-1 cells and could reach a high virus titers (5 x 10(6) TCID50/ml). As demonstrated by a cross neutralization test, the isolates had identical antigenicity to Iriki strain of Akabane virus, but were antigenically more distant to JaGar-39 and OBE-1 strain of Akabane virus. This is the first report on the isolation of Akabane virus in Taiwan, and also the second report on the isolation of Iriki virus in the world.

Encefalite por Arbovirus Rocio / Encephalitis by arbovirus

Aborda a encefalite por arbovírus Rocio sob aspectos da etiologia, patologia, quadro clínico, exames laboratoriais, epidemiologia e profilaxia. (MC)

Arboviruses and the central nervous system.

Arboviruses cause encephalitis by infecting neurons of the host. Virus infection per se may cause death or dysfunction of neurons. The severity of the virus effect is dependent on the virulence of the virus and the maturity of the infected neuron. Neurons do not directly interact with T cells since they do not express MHC class I or class II antigens in vivo. Other cells such as microglia and perivascular macrophages probably present viral antigen to activated T cells coming to the brain from lymphoid organs. Infection elicits a local immune response that is characterized by mononuclear cell infiltration and local production of cytokines and antiviral antibody. The cytokines are primarily characteristic of type 2 T cells providing B cell help and macrophage deactivation. Control of virus replication is effected by antibody which does not eliminate infected cells. Therefore, viral RNA persists in the CNS, requiring continuous intraparenchymal production of antiviral antibody.

[Dhori virus--a causative agent of human disease. 5 cases of laboratory infection]. / Virus Dkhori--vozbuditel' zabolevaniia cheloveka. Piat' sluchaev laboratornoi infektsii.

The materials presented in the paper are first indications of the pathogenicity of Dhori virus for man and prove the role of this agent in the occurrence of 5 cases of the disease in laboratory workers accidentally infected during the preparation of cultural agents. Clinically, Dhori infection was characterized by an acute course with marked general toxicity and a febrile period of 2 to 4 days. Two out of 5 patients had changes on the part of the nervous system of the type of encephalitic reaction predominantly with subcortical symptoms and mild involvement of the pyramidal system or in the form of encephalopolyradiculoneuritis with paresthesia and sensitivity disorders.