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.

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.

Semliki forest virus: cause of a fatal case of human encephalitis.

A fatal case of human encephalitis has been observed for which our results indicate that Semliki Forest virus (SFV) was the etiologic agent. This is surprising in view of the fact that this virus, which has been widely studied, was believed to be one of the arboviruses nonpathogenic for man. Described are the clinical course, the virological examinations performed, and the histopathological findings in the central nervous system.

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.

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.

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)

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.

Oropouche virus. II. Epidemiological observations during an epidemic in Santarém, Pará, Brazil in 1975.

An epidemic of Oropouche fever occurred in Santarém, Pará, Brazil in 1975. In the first survey for Oropouche antibodies involving a random sample of an entire city, infection rates varied from 0-44%, depending on the specific area within the city. Women had higher infection rates than men, but this difference was statistically significant only for persons older than 10 years of age. An analysis of school data showed that pupils in the evening classes had a greater increase in absenteeism during the epidemic period than those attending morning or afternoon classes. These data are compatible with the concept that Culicoides paraensis rather than Culex pipiens quinquefasciatus is the main vector of Oropouche virus in Brazil.

Arbovirus infections among laboratory personnel in Ibadan, Nigeria.

Laboratory-acquired infections encountered between 1963 and 1977 among personnel of the Virus Research Laboratory, Ibadan, Nigeria, are reported. Two cases of chikungunya infection occurred and one each with Dugbe, Wesselsbron, and dengue viruses. In each case, virus was isolated or development of antibody demonstrated. Among virus and two each to chikungunya and Rift Valley fever viruses, without experiencing any clinically recognized disease.

Attempts to reproduce amyotrophic lateral sclerosis in laboratory animals by inoculation of Schu virus isolated from a patient with apparent amyotrophic lateral sclerosis.

A virus isolated from the CSF of a patient who had amyotrophic lateral sclerosis for 7 years, and prolonged pleocytosis in the CSF, was adapted to suckling mouse brain by subsequent serial blind passages. This Schu virus belongs to the tick-borne encephalitis complex of the genus Flavivirus (Togaviridae). Suckling mouse brain homogenate of the 13th passage was used for transmission experiments in various species of laboratory animals. Golden hamsters infected subcutaneously fell ill after a number of months, lost weight, and had paresis of the legs. Histologically they had petechial hemorrhages in different parts of the CNS and inflammatory changes in the gray substance of the spinal cord. Pilot studies with repeated inoculations of small doses of different flavivirus strains suggest a course of the disease in experimental animals which resembles slow-virus infections insofar as no encephalitis is produced and degenerative changes of the anterior horn cells prevail over inflammatory signs in the spinal cord. After intracerebral application of Schu virus, cynomolgus monkeys developed the typical lesions of togavirus panencephalitis with epileptic seizures, ataxia, and paresis. After subcutaneous application, the virus seems to spread along peripheral nerves to anterior spinal roots and spinal cord, where mainly motor neurons of the anterior horn are damaged, and from there to the brain. The histological findings are such that one may assume the disease of the patient was due to the infection with the virus isolated from his CSF. Therefore, the hypothesis may be advanced that at least some of the cases diagnosed as amyotrophic lateral sclerosis are due to a togavirus infection.

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.

Potentiation of keystone virus infection in cotton rats by glucocorticoid-induced stress.

Cotton rats (Sigmodon hispidus) were treated daily with corticosteroids and then inoculated with keystone virus. Viremia and neutralizing antibody profiles were determined in treated and untreated rats. Compared to untreated rats, the treated rats were substantially more susceptible to infection, and their viremia lasted much longer. This experimental model suggests that stress associated with excess glucocorticoid synthesis within a natural population could cause an increase in transmission of arboviruses. It also suggests that the effects of stress should be considered when experimental laboratory studies are designed.

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.

[Etiology of Karelia fever--a new arbovirus infection]. / Etiologiia karel'skoi likhoradki--novoi arbovirusnoi infektsii.

In August-September 1981, in some areas of Karelia (on the border of northern and middle taiga) there occurred diseases with signs of fever, rash, and arthralgia developing in some patients into a chronic condition. Examinations of paired sera from patients with the acute disease and from convalescents using a set of Toga- and Bunya-viruses showed the etiology of the disease to be associated with a virus from the Togaviridae family, genus Alphavirus, of the antigenic Sindbis complex.

[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.

Síndrome de Guillain-Barré en tiempos de arbovirosis / Guillain-Barré syndrome in times of arbovirosis

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