Evaluation of peer-mediated systems navigation for ageing families of individuals with developmental disabilities

BACKGROUND

As individuals with intellectual and developmental disabilities (I/DD) age, services often diminish, with many family caregivers experiencing challenges finding and navigating services. The purpose of this study was to examine the benefits of a state-wide family support project for ageing caregivers (50+) of adults with I/DD in accessing and using services.

METHOD

A one-group pre-test-post-test design was used to determine if participation in the MI-OCEAN intervention grounded in the Family Quality of Life (FQOL) theory reduced ageing caregivers' (n = 82) perceptions of barriers to accessing, using and needing formal services.

RESULTS

After participating in the study, there was a reduction in reported barriers to accessing services. There was also greater use and reduced need for 10 of the 23 listed formal services.

CONCLUSIONS

Findings indicate that a peer-mediated intervention grounded in FQOL theory can be beneficial in empowering ageing caregivers by reducing perceived barriers to accessing services and increasing their use of advocacy and support services.

Neuroimaging Correlates of Post-Traumatic Stress Disorder in Traumatic Brain Injury: A Systematic Review of the Literature

Introduction

Neuroimaging has been a highly utilized technique for studying traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) independently of one another, however, neuroimaging has increasingly been identified as a useful tool in better understanding TBI-related psychiatric conditions, such as PTSD.

Objectives

To complete a systematic review of the literature examining neuroimaging findings in TBI-related PTSD and to highlight the current literature’s limitations in order to strengthen future research.

Methods

A PRISMA compliant literature search was conducted in PubMed (MEDLINE), PsychINFO, EMBASE, and Scopus databases prior to May of 2019. The initial database query yielded 4388 unique articles, which were narrowed down based on specified inclusion criteria (e.g., clear TBI definition, clinician-diagnosed PTSD, statistically analyzed relationship between neuroimaging and PTSD, quantified time interval between TBI and neuroimaging).

Results

A final cohort of 10 articles met inclusion criteria, comprising the findings of 482 participants with TBI. Key neuroanatomical findings among the included articles suggest that PTSD is associated with significant changes in whole-brain networks of resting state connectivity and disruptions in bilateral frontal and temporal white matter tracts, fronto-limbic pathways, the internal capsule, and the uncinate fasciculus (Figure 1). Figure 1a:

Traumatic brain injury alters presentation of mild behavioral impairment domains across progression of all-cause dementia

Introduction

Traumatic brain injury (TBI) may alter dementia progression, although co-occurring neuropsychiatric symptoms (NPS) have received less attention. The mild behavioral impairment (MBI) construct relates NPS to underlying neural circuit disruptions, representing an important area of inquiry regarding TBI and dementia.

Objectives

(1) to examine the influence of prior TBI history (preceding study enrollment) on MBI incidence in all-cause dementia (prior to dementia diagnosis, i.e. MBI’s original definition) and (2) to utilize MBI domains as a construct for examining the influence of TBI on related NPS across the course of dementia onset and progression.

Methods

Using National Alzheimer’s Coordinating Center data, individuals progressing from normal cognition to all-cause dementia over 7.6±3.0 years were studied to estimate MBI incidence and symptom domains in 124 participants with prior TBI history compared to 822 without.

Results

Moderate-severe TBI was associated with the social inappropriateness MBI domain (OR_adj.=4.034; p=0.024) prior to dementia onset, and the abnormal perception/thought content domain looking across dementia progression (HR_adj.=3.703, p=0.005). TBI (all severities) was associated with the decreased motivation domain looking throughout dementia progression (HR_adj.=1.546, p=0.014).

Conclusions

TBI history is associated with particular MBI domains prior to onset and throughout progression of dementia. Understanding TBI’s impact on inter-related NPS may help elucidate underlying neuropathology.

Disclosure

No significant relationships.

Polysomnography Following Traumatic Brain Injury: A Systematic Review and Meta-Analysis

Introduction

Sleep disturbances are common following traumatic brain injury (TBI) worsening morbidity and other neuropsychiatric symptoms. Post-TBI alterations in sleep architecture require further study.

Objectives

(1) To evaluate polysomnographic measures of sleep architecture in participants with history of TBI compared to controls and as meta-analyses of pooled means. (2) To evaluate effects of timing and severity of TBI on polysomnographic outcomes.

Methods

PRISMA compliant systematic review was conducted of MEDLINE, PsycINFO, EMBASE and Scopus. Inclusion criteria: 1) reporting polysomnography in the context of TBI and 2) operationalizing TBI using clear/formalized criteria. Data were pooled in random-effects meta-analyses with outcomes expressed as mean differences (MD).

Results

In participants with TBI, sleep was comprised of 19.39% REM sleep, 8.13% N1, 51.18% N2, and 17.53% N3, as determined by meta-analyses of single means. Total sleep time was reduced in chronic (>6 months) TBI compared to acute-intermediate TBI (<6 months) (p=0.01). Compared to controls, participants with TBI differed with increased N1 sleep (MD=0.64%; 95%CI=0.02,1.25; p=0.04), reduced sleep efficiency (MD=-1.65%; 95%CI=-3.18,-0.12; p=0.03), and reduced sleep latency on the multiple sleep latency test (MD=-5.90mins; 95%CI=-10.09,-1.72; p<0.01). On sub-group analyses, participants with mild TBI differed from controls with reduced total sleep time (MD=-29.22mins, 95%CI=-54.16,-4.27; p=0.02). Similarly, participants with acute-intermediate TBI exhibited increased sleep latency compared to controls (MD=8.96mins; 95%CI=4.07,13.85; p<0.01) and differed significantly from participants with chronic TBI (X2(1,N=608)=6.54; p=0.01).

Conclusions

Sleep architecture is altered following TBI with potential implications regarding functional outcomes and recovery. These alterations appear to differ based on severity of injury and time since injury.

Disclosure

No significant relationships.

Deceased donors as nondirected donors in kidney paired donation

As proof of concept, we simulate a revised kidney allocation system that includes deceased donor (DD) kidneys as chain-initiating kidneys (DD-CIK) in a kidney paired donation pool (KPDP), and estimate potential increases in number of transplants. We consider chains of length 2 in which the DD-CIK gives to a candidate in the KPDP, and that candidate's incompatible donor donates to theDD waitlist. In simulations, we vary initial pool size, arrival rates of candidate/donor pairs and (living) nondirected donors (NDDs), and delay time from entry to the KPDP until a candidate is eligible to receive a DD-CIK. Using data on candidate/donor pairs and NDDs from the Alliance for Paired Kidney Donation, and the actual DDs from the Scientific Registry of Transplant Recipients (SRTR) data, simulations extend over 2 years. With an initial pool of 400, respective candidate and NDD arrival rates of 2 per day and 3 per month, and delay times for access to DD-CIK of 6 months or less, including DD-CIKs increases the number of transplants by at least 447 over 2 years, and greatly reduces waiting times of KPDP candidates. Potential effects on waitlist candidates are discussed as are policy and ethical issues.

GSK2245035, a TLR7 agonist, Does Not Increase Pregnancy Loss in Cynomolgus Monkeys

GSK2245035, a small molecule Toll-like Receptor 7 (TLR7) agonist developed for immunomodulatory treatment for allergic airways disease, aimed to reduce Th2 and enhance Th1/Treg responses to aeroallergens via the local induction of type I interferons (IFNs). GSK2245035 demonstrated selectivity for potent release of type I IFNs compared to TNF-α and IL-6, with dose dependent increases in the interferon inducible chemokine, IP-10, in the nasal compartment. Implantation and parturition require pro-inflammatory processes including IFNs, Interferon Stimulated Genes, TNFα and IP-10 while pregnancy requires immune regulation to maintain maternal fetal immune tolerance, and recombinant type I IFNs induced abortions in monkeys. Due to its mechanism of action, GSK2245035 was studied at pharmacologically and clinically relevant doses in a monkey pregnancy model. Monkeys received 0, 3 or 30 ng/kg/week GSK2245035 intranasally once weekly, from Day 20 postcoitum through Day 63 postpartum. Although systemic IFN-α and IP-10 levels were approximately 14.8 or 40 -fold (respectively) above predose levels at 3 or 30 ng/kg/week, respectively, there were no effects on pregnancy and infant outcome. Non-adverse effects included increased incidence of nasal discharge, increased maternal body temperature at 30 ng/kg/week and dose-dependent increases in maternal IP-10 and IFN-α and decreased infant anti-KLH IgM and IgG titers following KLH immunization at ≥3 ng/kg/week, relative to controls. Potentially, lower IFN-α and IP-10 levels as well as once-weekly intranasal dosing vs daily subcutaneous or intramuscular dosing with recombinant type I IFNs could explain the lack of pregnancy effects; however, there was an undesired impact on offspring immune function.

Antiviral Therapy of Haemorrhagic Fevers and Arbovirus Infections

RNA viruses of the families Arena-, Bunya-, Filo-, Flavi-and Togaviridae cause illness in humans ranging from mild, non-specific febrile syndromes to fulminant, lethal haemorrhagic fever. They are transmitted from animals to humans and from human to human by arthropods, aerosols or contact with body fluids. Antiviral compounds, convalescent plasma and interferon inhibit many of these agents in vitro and in virus-infected animals. Drug or plasma treatment is now in use for several human diseases, and would probably be beneficial for a number of others for which there is only limited treatment experience. Success is linked to early diagnosis and initiation of therapy. Ribavirin is used to treat Lassa fever and haemorrhagic fever with renal syndrome, and would probably be effective for Crimean-Congo haemorrhagic fever and for all New World arenavirus diseases. The value of ribavirin in the early treatment of hantavirus pulmonary syndrome is under evaluation. Convalescent plasma is the therapy of choice for Argentine haemorrhagic fever, and would also probably be effective for other New World arenaviruses and some other infections if a safe supply of plasma could be maintained. Ribavirin and interferon-α have both shown protective efficacy in non-human primates infected with Rift Valley fever virus. No effective therapy has yet been identified for filovirus infections, but results in animal models are encouraging. More clinical research is urgently needed. Even if placebo-controlled drug trials cannot be performed, conscientious reports of the results of therapy in limited numbers of patients can still provide evidence of antiviral drug effects.

Meeting report: 32nd International Conference on Antiviral Research

The 32nd International Conference on Antiviral Research (ICAR), sponsored by the International Society for Antiviral Research (ISAR), was held in Baltimore, Maryland, USA, on May 12-15, 2019. This report gives an overview of the conference on behalf of the Society. It provides a general review of the meeting and awardees, summarizing the presentations, and their main conclusions from the perspective of researchers active in many different areas of antiviral research and development. As in past years, ICAR promoted and showcased the most recent progress in antiviral research, and continued to foster collaborations and interactions in drug discovery and development. The 33rd ICAR will be held in Seattle, Washington, USA, March 30th-April 3rd, 2020.

Meeting report: 31st International Conference on Antiviral Research

The 31^st International Conference on Antiviral Research (ICAR) was held in Porto, Portugal from June 11–15, 2018. In this report, volunteer rapporteurs provide their summaries of scientific presentations, hoping to effectively convey the speakers' goals and the results and conclusions of their talks. This report provides an overview of the invited keynote and award lectures and highlights of short oral presentations, from the perspective of experts in antiviral research. Of note, a session on human cytomegalovirus included an update on the introduction to the clinic of letermovir for the prevention of CMV infection and disease. The 31^st ICAR successfully promoted new discoveries in antiviral research and drug development. The 32^nd ICAR will be held in Baltimore, Maryland, USA, May 6–10, 2019.

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The 31st ICAR was held in Porto, Portugal, June 11–15, 2018.

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This article provides an overview of the invited keynote and award lectures and highlights of short oral presentations.

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ICAR provided an interdisciplinary forum to review recent developments in all areas of antiviral research.

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The 32nd ICAR will be held in Baltimore, Maryland, USA, May 6–10, 2019.

Second International Conference on Crimean-Congo Hemorrhagic Fever

The Second International Conference on Crimean-Congo Hemorrhagic Fever (CCHF) was held in Thessaloniki, Greece, from September 10-13, 2017, and brought together international public health professionals, clinicians, ecologists, and basic laboratory researchers. Nearly 100 participants, representing 24 countries and the World Health Organization (WHO), were in attendance. Meeting sessions covered the epidemiology of CCHF in humans; ticks and virus-tick interactions; wild and domestic animal hosts; molecular virology; taxonomic classification; pathogenesis and animal models; clinical aspects and diagnosis; clinical management and clinical trials; and disease prevention in humans. The concluding session focused on recent WHO recommendations for public health measures and future research. This report summarizes lectures by the invited speakers and highlights advances in the field.

Highlights of the 30th International Conference on Antiviral Research

The 30th International Conference on Antiviral Research (ICAR) was held in Atlanta, GA, USA from May 18 to 21, 2017. This report provides an account of award lectures, invited keynote addresses and oral presentations during the meeting. The 2017 Gertrude Elion Memorial Lecture Award by Michael Sofia highlighted one of the most important accomplishments in recent drug discovery in antiviral research, the identification of the hepatitis C virus direct-acting antiviral sofosbuvir and new alternatives to combat hepatitis B virus (HBV) infection. The Antonín Holý Lecture Award by David Chu on medicinal chemistry provided an overview of early developments of nucleoside analogs for the treatment of HIV and varicella zoster virus infection and how this knowledge serves to develop new drugs targeting HBV. Priscilla Yang gave the first ISAR Women in Science lecture. She reported on pharmacological validation of new antiviral targets for dengue, Zika and other flaviviruses. The William Prusoff Young Investigator Lecture Award by Maaike Everts described the Alabama Drug Discovery Alliance and the Antiviral Drug Discovery and Development Consortium, and how they are helping to accelerate the development of new antivirals. The 30th ICAR was a success in promoting new discoveries in antiviral drug development and research. The 31st ICAR will be held in Porto, Portugal, June 11–15, 2018.

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The 30th ICAR was held in Atlanta, Georgia, USA from May 18–21, 2017.

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This article summarizes presentations by ISAR award recipients, principal invited lectures and keynote addresses.

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Mini-symposium topics included antiviral immunity and emerging viral infections.

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Other sessions and topics included hepatitis and retroviruses, respiratory viruses, DNA viruses and medicinal chemistry.

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The 31st ICAR will be held in Porto, Portugal, June 11–15, 2018.

A historical perspective on the discovery and elucidation of the hepatitis B virus

The discovery in 1965 of the "Australia antigen," subsequently identified as the hepatitis B virus surface antigen (HBsAg), was such a watershed event in virology that it is often thought to mark the beginning of hepatitis research, but it is more accurately seen as a critical breakthrough in a long effort to understand the pathogenesis of infectious hepatitis. A century earlier, Virchow provided an authoritative explanation of "catarrhal jaundice," which did not consider an infectious etiology, but the transmission of jaundice by human serum was clearly identified in two outbreaks in 1885, and the distinction between "infectious" and "serum" hepatitis was recognized by the early 1920s. The inability to culture a virus or reproduce either syndrome in laboratory animals led to numerous studies in human volunteers; by the end of World War II, it was known that the diseases were caused by different filterable agents, and the terms "hepatitis A" and "B" were introduced in 1947 (though some long-incubation cases then designated B must in retrospect have been hepatitis C). The development of a number of liver function tests during the 1950s led to the recognition of anicteric infections and the existence of chronic carriers, but little more could be done until an infectious agent had been identified. Once Blumberg and colleagues had found a specific viral marker, the vast amount of accumulated epidemiologic and clinical data, together with huge numbers of stored serum samples, enabled rapid progress in understanding hepatitis B, and revealed the existence of a vast population of chronically infected people in Asia, Oceania and Africa. In this article, we place the identification of the Australia antigen within the historical context of research on viral hepatitis. Following a chronological review from 1865 to 1965, we summarize how the discovery led to improved safety of blood transfusion, the development of a highly effective vaccine and the eventual identification of the hepatitis C, D and E viruses. This article forms part of a symposium in Antiviral Research on "An unfinished story: from the discovery of the Australia antigen to the development of new curative therapies for chronic hepatitis B."

Low-dose ribavirin potentiates the antiviral activity of favipiravir against hemorrhagic fever viruses

Favipiravir is approved in Japan to treat novel or re-emerging influenza viruses, and is active against a broad spectrum of RNA viruses, including Ebola. Ribavirin is the only other licensed drug with activity against multiple RNA viruses. Recent studies show that ribavirin and favipiravir act synergistically to inhibit bunyavirus infections in cultured cells and laboratory mice, likely due to their different mechanisms of action. Convalescent immune globulin is the only approved treatment for Argentine hemorrhagic fever caused by the rodent-borne Junin arenavirus. We previously reported that favipiravir is highly effective in a number of small animal models of Argentine hemorrhagic fever. We now report that addition of low dose of ribavirin synergistically potentiates the activity of favipiravir against Junin virus infection of guinea pigs and another arenavirus, Pichinde virus infection of hamsters. This suggests that the efficacy of favipiravir against hemorrhagic fever viruses can be further enhanced through the addition of low-dose ribavirin.

Planning for Uncertainty and Fallbacks Can Increase the Number of Transplants in a Kidney-Paired Donation Program

A kidney-paired donation (KPD) pool consists of transplant candidates and their incompatible donors, along with nondirected donors (NDDs). In a match run, exchanges are arranged among pairs in the pool via cycles, as well as chains created from NDDs. A problem of importance is how to arrange cycles and chains to optimize the number of transplants. We outline and examine, through example and by simulation, four schemes for selecting potential matches in a realistic model of a KPD system; proposed schemes take account of probabilities that chosen transplants may not be completed as well as allowing for contingency plans when the optimal solution fails. Using data on candidate/donor pairs and NDDs from the Alliance for Paired Donation, the simulations extend over 8 match runs, with 30 pairs and 1 NDD added between each run. Schemes that incorporate uncertainties and fallbacks into the selection process yield substantially more transplants on average, increasing the number of transplants by as much as 40% compared to a standard selection scheme. The gain depends on the degree of uncertainty in the system. The proposed approaches can be easily implemented and provide substantial advantages over current KPD matching algorithms.

Mechanisms of immunity in post-exposure vaccination against Ebola virus infection

Ebolaviruses can cause severe hemorrhagic fever that is characterized by rapid viral replication, coagulopathy, inflammation, and high lethality rates. Although there is no clinically proven vaccine or treatment for Ebola virus infection, a virus-like particle (VLP) vaccine is effective in mice, guinea pigs, and non-human primates when given pre-infection. In this work, we report that VLPs protect Ebola virus-infected mice when given 24 hours post-infection. Analysis of cytokine expression in serum revealed a decrease in pro-inflammatory cytokine and chemokine levels in mice given VLPs post-exposure compared to infected, untreated mice. Using knockout mice, we show that VLP-mediated post-exposure protection requires perforin, B cells, macrophages, conventional dendritic cells (cDCs), and either CD4+ or CD8+ T cells. Protection was Ebola virus-specific, as marburgvirus VLPs did not protect Ebola virus-infected mice. Increased antibody production in VLP-treated mice correlated with protection, and macrophages were required for this increased production. However, NK cells, IFN-gamma, and TNF-alpha were not required for post-exposure-mediated protection. These data suggest that a non-replicating Ebola virus vaccine can provide post-exposure protection and that the mechanisms of immune protection in this setting require both increased antibody production and generation of cytotoxic T cells.

Virus-like particles activate type I interferon pathways to facilitate post-exposure protection against Ebola virus infection

Ebola virus (EBOV) causes a severe hemorrhagic disease with high fatality. Virus-like particles (VLPs) are a promising vaccine candidate against EBOV. We recently showed that VLPs protect mice from lethal EBOV infection when given before or after viral infection. To elucidate pathways through which VLPs confer post-exposure protection, we investigated the role of type I interferon (IFN) signaling. We found that VLPs lead to accelerated induction of IFN stimulated genes (ISGs) in liver and spleen of wild type mice, but not in Ifnar^-/- mice. Accordingly, EBOV infected Ifnar^-/- mice, unlike wild type mice succumbed to death even after VLP treatment. The ISGs induced in wild type mice included anti-viral proteins and negative feedback factors known to restrict viral replication and excessive inflammatory responses. Importantly, proinflammatory cytokine/chemokine expression was much higher in WT mice without VLPs than mice treated with VLPs. In EBOV infected Ifnar^-/- mice, however, uninhibited viral replication and elevated proinflammatory factor expression ensued, irrespective of VLP treatment, supporting the view that type I IFN signaling helps to limit viral replication and attenuate inflammatory responses. Further analyses showed that VLP protection requires the transcription factor, IRF8 known to amplify type I IFN signaling in dendritic cells and macrophages, the probable sites of initial EBOV infection. Together, this study indicates that VLPs afford post-exposure protection by promoting expeditious initiation of type I IFN signaling in the host.

The cyanobacterial lectin scytovirin displays potent in vitro and in vivo activity against Zaire Ebola virus

The cyanobacterial lectin scytovirin (SVN) binds with high affinity to mannose-rich oligosaccharides on the envelope glycoprotein (GP) of a number of viruses, blocking entry into target cells. In this study, we assessed the ability of SVN to bind to the envelope GP of Zaire Ebola virus (ZEBOV) and inhibit its replication. SVN interacted specifically with the protein's mucin-rich domain. In cell culture, it inhibited ZEBOV replication with a 50% virus-inhibitory concentration (EC50) of 50 nM, and was also active against the Angola strain of the related Marburg virus (MARV), with a similar EC50. Injected subcutaneously in mice, SVN reached a peak plasma level of 100 nm in 45 min, but was cleared within 4h. When ZEBOV-infected mice were given 30 mg/kg/day of SVN by subcutaneous injection every 6h, beginning the day before virus challenge, 9 of 10 animals survived the infection, while all infected, untreated mice died. When treatment was begun one hour or one day after challenge, 70-90% of mice survived. Quantitation of infectious virus and viral RNA in samples of serum, liver and spleen collected on days 2 and 5 postinfection showed a trend toward lower titers in treated than control mice, with a significant decrease in liver titers on day 2. Our findings provide further evidence of the potential of natural lectins as therapeutic agents for viral infections.

Ebola virus-like particles stimulate type I interferons and proinflammatory cytokine expression through the toll-like receptor and interferon signaling pathways

Ebola viruses (EBOV) can cause severe hemorrhagic disease with high case fatality rates. Currently, no vaccines or therapeutics are approved for use in humans. Ebola virus-like particles (eVLP) comprising of virus protein (VP40), glycoprotein, and nucleoprotein protect rodents and nonhuman primates from lethal EBOV infection, representing as a candidate vaccine for EBOV infection. Previous reports have shown that eVLP stimulate the expression of proinflammatory cytokines in dendritic cells (DCs) and macrophages (MΦs) in vitro. However, the molecular mechanisms and signaling pathways through which eVLP induce innate immune responses remain obscure. In this study, we show that eVLP stimulate not only the expression of proinflammatory cytokines but also the expression of type I interferons (IFNs) and IFN-stimulated genes (ISGs) in murine bone marrow-derived DCs (BMDCs) and MΦs. Our data indicate that eVLP trigger host responses through toll-like receptor (TLR) pathway utilizing 2 distinct adaptors, MyD88 and TRIF. More interestingly, eVLP activated the IFN signaling pathway by inducing a set of potent antiviral ISGs. Last, eVLP and synthetic adjuvants, Poly I:C and CpG DNA, cooperatively increased the expression of cytokines and ISGs. Further supporting this synergy, eVLP when administered together with Poly I:C conferred mice enhanced protection against EBOV infection. These results indicate that eVLP stimulate early innate immune responses through TLR and type I IFN signaling pathways to protect the host from EBOV infection.

Crimean-Congo hemorrhagic fever: history, epidemiology, pathogenesis, clinical syndrome and genetic diversity

Crimean-Congo hemorrhagic fever (CCHF) is the most important tick-borne viral disease of humans, causing sporadic cases or outbreaks of severe illness across a huge geographic area, from western China to the Middle East and southeastern Europe and throughout most of Africa. CCHFV is maintained in vertical and horizontal transmission cycles involving ixodid ticks and a variety of wild and domestic vertebrates, which do not show signs of illness. The virus circulates in a number of tick genera, but Hyalomma ticks are the principal source of human infection, probably because both immature and adult forms actively seek hosts for the blood meals required at each stage of maturation. CCHF occurs most frequently among agricultural workers following the bite of an infected tick, and to a lesser extent among slaughterhouse workers exposed to the blood and tissues of infected livestock and medical personnel through contact with the body fluids of infected patients. CCHFV is the most genetically diverse of the arboviruses, with nucleotide sequence differences among isolates ranging from 20% for the viral S segment to 31% for the M segment. Viruses with diverse sequences can be found within the same geographic area, while closely related viruses have been isolated in far distant regions, suggesting that widespread dispersion of CCHFV has occurred at times in the past, possibly by ticks carried on migratory birds or through the international livestock trade. Reassortment among genome segments during co-infection of ticks or vertebrates appears to have played an important role in generating diversity, and represents a potential future source of novel viruses. In this article, we first review current knowledge of CCHFV, summarizing its molecular biology, maintenance and transmission, epidemiology and geographic range. We also include an extensive discussion of CCHFV genetic diversity, including maps of the range of the virus with superimposed phylogenetic trees. We then review the features of CCHF, including the clinical syndrome, diagnosis, treatment, pathogenesis, vaccine development and laboratory animal models of CCHF. The paper ends with a discussion of the possible future geographic range of the virus. For the benefit of researchers, we include a Supplementary Table listing all published reports of CCHF cases and outbreaks in the English-language literature, plus some principal articles in other languages, with total case numbers, case fatality rates and all CCHFV strains on GenBank.

Mouse models for filovirus infections

The filoviruses marburg- and ebolaviruses can cause severe hemorrhagic fever (HF) in humans and nonhuman primates. Because many cases have occurred in geographical areas lacking a medical research infrastructure, most studies of the pathogenesis of filoviral HF, and all efforts to develop drugs and vaccines, have been carried out in biocontainment laboratories in non-endemic countries, using nonhuman primates (NHPs), guinea pigs and mice as animal models. NHPs appear to closely mirror filoviral HF in humans (based on limited clinical data), but only small numbers may be used in carefully regulated experiments; much research is therefore done in rodents. Because of their availability in large numbers and the existence of a wealth of reagents for biochemical and immunological testing, mice have become the preferred small animal model for filovirus research. Since the first experiments following the initial 1967 marburgvirus outbreak, wild-type or mouse-adapted viruses have been tested in immunocompetent or immunodeficient mice. In this paper, we review how these types of studies have been used to investigate the pathogenesis of filoviral disease, identify immune responses to infection and evaluate antiviral drugs and vaccines. We also discuss the strengths and weaknesses of murine models for filovirus research, and identify important questions for further study.

Progress in the experimental therapy of severe arenaviral infections

A number of viruses in the family Arenaviridae cause severe illness in humans. Lassa virus in West Africa and a number of agents in South America produce hemorrhagic fever in persons exposed to aerosolized excretions of the pathogens' rodent hosts. Because arenaviruses are not transmitted by arthropods, and person-to-person spread is rare, human infections occur singly and sporadically, and are usually not diagnosed until the patient is severely ill. Because the arenaviruses are naturally transmitted by the airborne route, they also pose a potential threat as aerosolized bioterror weapons. The broad-spectrum antiviral drug ribavirin was shown to reduce mortality from Lassa fever, and has been tested against Argentine hemorrhagic fever, but it is not an approved treatment for either disease. Human immune convalescent plasma was proven to be effective for Argentine hemorrhagic fever in a controlled trial. New treatments are needed to block viral replication without causing toxicity and to prevent the increased vascular permeability that is responsible for hypotension and shock. In this paper, we review current developments in the experimental therapy of severe arenaviral infections, focusing on drugs that have been tested in animal models, and provide a perspective on future research.

Eczema vaccinatum

Eczema vaccinatum (EV) is a complication of smallpox vaccination that can occur in persons with eczema/atopic dermatitis (AD), in which vaccinia virus disseminates to cause an extensive rash and systemic illness. Because persons with eczema are deferred from vaccination, only a single, accidentally transmitted case of EV has been described in the medical literature since military vaccination was resumed in the United States in 2002. To enhance understanding of EV, we review its history during the era of universal vaccination and discuss its relationship to complications in persons with other diseases or injuries of the skin. We then discuss current concepts of the pathophysiology of AD, noting how defective skin barrier function, epidermal hyperplasia, and abnormal immune responses favor the spread of poxviral infection, and identify a number of unanswered questions about EV. We conclude by considering how its occurrence might be minimized in the event of a return to universal vaccination.

Basic clinical and laboratory features of filoviral hemorrhagic fever

The filoviruses Marburg and Ebola cause severe hemorrhagic fever (HF) in humans. Beginning with the 1967 Marburg outbreak, 30 epidemics, isolated cases, and accidental laboratory infections have been described in the medical literature. We reviewed those reports to determine the basic clinical and laboratory features of filoviral HF. The most detailed information was found in descriptions of patients treated in industrialized countries; except for the 2000 outbreak of Ebola Sudan HF in Uganda, reports of epidemics in central Africa provided little controlled or objective clinical data. Other than the case fatality rate, there were no clear differences in the features of the various filovirus infections. This compilation will be of value to medical workers responding to epidemics and to investigators attempting to develop animal models of filoviral HF. By identifying key unanswered questions and gaps in clinical data, it will help guide clinical research in future outbreaks.

Filovirus infection of STAT-1 knockout mice

We evaluated the susceptibility to Ebola and Marburg virus infection of mice that cannot respond to interferon (IFN)-α/β and IFN-γ because of deletion of the STAT-1 gene. A mouse-adapted Zaire ebolavirus (ZEBOV) caused rapidly lethal disease; wild-type ZEBOV and Sudan Ebolavirus and 4 different Marburg virus strains produced severe, but more slowly progressive illness; and Reston Ebolavirus caused mild disease that was late in onset. The virulence of each agent was mirrored by the pace and severity of pathologic changes in the liver and lymphoid tissues. A virus-like particle vaccine elicited strong antibody responses but did not protect against mouse-adapted ZEBOV challenge.

Infection of cynomolgus macaques with a recombinant monkeypox virus encoding green fluorescent protein

Monkeypox virus (MPXV) causes a vesiculopustular rash illness resembling smallpox in humans and produces a similar disease in nonhuman primates. To enhance the ability of researchers to study experimental MPXV infections, we inserted a gene encoding green fluorescent protein (GFP) into Monkeypox virus Zaire-79. Wild-type and MPXV-GFP replicated with similar kinetics in cell culture and caused a similar disease when injected intravenously into cynomolgus macaques. In MPXV-GFP-infected animals, examination under fluorescent light facilitated the identification of skin lesions during disease development and internal sites of replication at necropsy. MPXV-GFP could improve the quantitative assessment of antiviral therapy and vaccine efficacy.

Computer-assisted detection of infectious lung diseases: a review

Respiratory tract infections are a leading cause of death and disability worldwide. Although radiology serves as a primary diagnostic method for assessing respiratory tract infections, visual analysis of chest radiographs and computed tomography (CT) scans is restricted by low specificity for causal infectious organisms and a limited capacity to assess severity and predict patient outcomes. These limitations suggest that computer-assisted detection (CAD) could make a valuable contribution to the management of respiratory tract infections by assisting in the early recognition of pulmonary parenchymal lesions, providing quantitative measures of disease severity and assessing the response to therapy. In this paper, we review the most common radiographic and CT features of respiratory tract infections, discuss the challenges of defining and measuring these disorders with CAD, and propose some strategies to address these challenges.

Molecular imaging of influenza and other emerging respiratory viral infections

Research on the pathogenesis and therapy of influenza and other emerging respiratory viral infections would be aided by methods that directly visualize pathophysiologic processes in patients and laboratory animals. At present, imaging of diseases, such as swine-origin H1N1 influenza, is largely restricted to chest radiograph and computed tomography (CT), which can detect pulmonary structural changes in severely ill patients but are more limited in characterizing the early stages of illness, differentiating inflammation from infection or tracking immune responses. In contrast, imaging modalities, such as positron emission tomography, single photon emission CT, magnetic resonance imaging, and bioluminescence imaging, which have become useful tools for investigating the pathogenesis of a range of disease processes, could be used to advance in vivo studies of respiratory viral infections in patients and animals. Molecular techniques might also be used to identify novel biomarkers of disease progression and to evaluate new therapies.

Assessing changes in vascular permeability in a hamster model of viral hemorrhagic fever

Background

A number of RNA viruses cause viral hemorrhagic fever (VHF), in which proinflammatory mediators released from infected cells induce increased permeability of the endothelial lining of blood vessels, leading to loss of plasma volume, hypotension, multi-organ failure, shock and death. The optimal treatment of VHF should therefore include both the use of antiviral drugs to inhibit viral replication and measures to prevent or correct changes in vascular function. Although rodent models have been used to evaluate treatments for increased vascular permeability (VP) in bacterial sepsis, such studies have not been performed for VHF.

Results

Here, we use an established model of Pichinde virus infection of hamsters to demonstrate how changes in VP can be detected by intravenous infusion of Evans blue dye (EBD), and compare those measurements to changes in hematocrit, serum albumin concentration and serum levels of proinflammatory mediators. We show that EBD injected into sick animals in the late stage of infection is rapidly sequestered in the viscera, while in healthy animals it remains within the plasma, causing the skin to turn a marked blue color. This test could be used in live animals to detect increased VP and to assess the ability of antiviral drugs and vasoactive compounds to prevent its onset. Finally, we describe a multiplexed assay to measure levels of serum factors during the course of Pichinde arenavirus infection and demonstrate that viremia and subsequent increase in white blood cell counts precede the elaboration of inflammatory mediators, which is followed by increased VP and death.

Conclusions

This level of model characterization is essential to the evaluation of novel interventions designed to control the effects of virus-induced hypercytokinemia on host vascular function in VHF, which could lead to improved survival.

Radiolabeled antiviral drugs and antibodies as virus-specific imaging probes

A number of small-molecule drugs inhibit viral replication by binding directly to virion structural proteins or to the active site of a viral enzyme, or are chemically modified by a viral enzyme before inhibiting a downstream process. Similarly, antibodies used to prevent or treat viral infections attach to epitopes on virions or on viral proteins expressed on the surface of infected cells. Such drugs and antibodies can therefore be thought of as probes for the detection of viral infections, suggesting that they might be used as radiolabeled tracers to visualize sites of viral replication by single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. A current example of this approach is the PET imaging of herpes simplex virus infections, in which the viral thymidine kinase phosphorylates radiolabeled thymidine analogues, trapping them within infected cells. One of many possible future applications might be the use of a radiolabeled hepatitis C protease inhibitor to image infection in animals or humans and provide a quantitative measure of viral burden. This article reviews the basic features of radionuclide imaging and the characteristics of ideal tracer molecules, and discusses how antiviral drugs and antibodies could be evaluated for their suitability as virus-specific imaging probes. The use of labeled drugs as low-dose tracers would provide an alternative application for compounds that have failed to advance to clinical use because of insufficient in vivo potency, an unsuitable pharmacokinetic profile or hepato- or nephrotoxicity.

Pulmonary pathologic findings of fatal 2009 pandemic influenza A/H1N1 viral infections

CONTEXT

In March 2009, a novel swine-origin influenza A/H1N1 virus was identified. After global spread, the World Health Organization in June declared the first influenza pandemic in 41 years.

OBJECTIVE

To describe the clinicopathologic characteristics of 34 people who died following confirmed A/H1N1 infection with emphasis on the pulmonary pathology findings.

DESIGN

We reviewed medical records, autopsy reports, microbiologic studies, and microscopic slides of 34 people who died between May 15 and July 9, 2009, and were investigated either by the New York City Office of Chief Medical Examiner (32 deaths) or through the consultation service of a coauthor (2 deaths).

RESULTS

Most of the 34 decedents (62%) were between 25 and 49 years old (median, 41.5 years). Tracheitis, bronchiolitis, and diffuse alveolar damage were noted in most cases. Influenza viral antigen was observed most commonly in the epithelium of the tracheobronchial tree but also in alveolar epithelial cells and macrophages. Most cases were reverse transcription-polymerase chain reaction positive for influenza. Histologic and microbiologic autopsy evidence of bacterial pneumonia was detected in 55% of cases. Underlying medical conditions including cardiorespiratory diseases and immunosuppression were present in 91% of cases. Obesity (body mass index, >30) was noted in 72% of adult and adolescent cases.

CONCLUSIONS

The pulmonary pathologic findings in fatal disease caused by the novel pandemic influenza virus are similar to findings identified in past pandemics. Superimposed bacterial infections of the respiratory tract were common. Preexisting obesity, cardiorespiratory diseases, and other comorbidities also were prominent findings among the decedents.

Pulmonary pathologic findings of fatal 2009 pandemic influenza A/H1N1 viral infections

CONTEXT

In March 2009, a novel swine-origin influenza A/H1N1 virus was identified. After global spread, the World Health Organization in June declared the first influenza pandemic in 41 years.

OBJECTIVE

To describe the clinicopathologic characteristics of 34 people who died following confirmed A/H1N1 infection with emphasis on the pulmonary pathology findings.

DESIGN

We reviewed medical records, autopsy reports, microbiologic studies, and microscopic slides of 34 people who died between May 15 and July 9, 2009, and were investigated either by the New York City Office of Chief Medical Examiner (32 deaths) or through the consultation service of a coauthor (2 deaths).

RESULTS

Most of the 34 decedents (62%) were between 25 and 49 years old (median, 41.5 years). Tracheitis, bronchiolitis, and diffuse alveolar damage were noted in most cases. Influenza viral antigen was observed most commonly in the epithelium of the tracheobronchial tree but also in alveolar epithelial cells and macrophages. Most cases were reverse transcription-polymerase chain reaction positive for influenza. Histologic and microbiologic autopsy evidence of bacterial pneumonia was detected in 55% of cases. Underlying medical conditions including cardiorespiratory diseases and immunosuppression were present in 91% of cases. Obesity (body mass index, >30) was noted in 72% of adult and adolescent cases.

CONCLUSIONS

The pulmonary pathologic findings in fatal disease caused by the novel pandemic influenza virus are similar to findings identified in past pandemics. Superimposed bacterial infections of the respiratory tract were common. Preexisting obesity, cardiorespiratory diseases, and other comorbidities also were prominent findings among the decedents.

Triage and management of accidental laboratory exposures to biosafety level-3 and -4 agents

The recent expansion of biocontainment laboratory capacity in the United States has drawn attention to the possibility of occupational exposures to BSL-3 and -4 agents and has prompted a reassessment of medical management procedures and facilities to deal with these contingencies. A workshop hosted by the National Interagency Biodefense Campus was held in October 2007 and was attended by representatives of all existing and planned BSL-4 research facilities in the U.S. and Canada. This report summarizes important points of discussion and recommendations for future coordinated action, including guidelines for the engineering and operational controls appropriate for a hospital care and isolation unit. Recommendations pertained to initial management of exposures (ie, immediate treatment of penetrating injuries, reporting of exposures, initial evaluation, and triage). Isolation and medical care in a referral hospital (including minimum standards for isolation units), staff recruitment and training, and community outreach also were addressed. Workshop participants agreed that any unit designated for the isolation and treatment of laboratory employees accidentally infected with a BSL-3 or -4 pathogen should be designed to maximize the efficacy of patient care while minimizing the risk of transmission of infection. Further, participants concurred that there is no medically based rationale for building care and isolation units to standards approximating a BSL-4 laboratory. Instead, laboratory workers accidentally exposed to pathogens should be cared for in hospital isolation suites staffed by highly trained professionals following strict infection control procedures.

Ebola Zaire virus blocks type I interferon production by exploiting the host SUMO modification machinery

Ebola Zaire virus is highly pathogenic for humans, with case fatality rates approaching 90% in large outbreaks in Africa. The virus replicates in macrophages and dendritic cells (DCs), suppressing production of type I interferons (IFNs) while inducing the release of large quantities of proinflammatory cytokines. Although the viral VP35 protein has been shown to inhibit IFN responses, the mechanism by which it blocks IFN production has not been fully elucidated. We expressed VP35 from a mouse-adapted variant of Ebola Zaire virus in murine DCs by retroviral gene transfer, and tested for IFN transcription upon Newcastle Disease virus (NDV) infection and toll-like receptor signaling. We found that VP35 inhibited IFN transcription in DCs following these stimuli by disabling the activity of IRF7, a transcription factor required for IFN transcription. By yeast two-hybrid screens and coimmunoprecipitation assays, we found that VP35 interacted with IRF7, Ubc9 and PIAS1. The latter two are the host SUMO E2 enzyme and E3 ligase, respectively. VP35, while not itself a SUMO ligase, increased PIAS1-mediated SUMOylation of IRF7, and repressed Ifn transcription. In contrast, VP35 did not interfere with the activation of NF-κB, which is required for induction of many proinflammatory cytokines. Our findings indicate that Ebola Zaire virus exploits the cellular SUMOylation machinery for its advantage and help to explain how the virus overcomes host innate defenses, causing rapidly overwhelming infection to produce a syndrome resembling fulminant septic shock.

Ebola Zaire virus causes severe hemorrhagic fever in humans that is fatal in almost 90% of cases. The rapid spread of the virus to macrophages and dendritic cells results in the release of high levels of inflammatory cytokines, causing shock and bleeding. The ability of Ebola virus to overwhelm host defenses is believed to result from its suppression of the type I interferon (IFN) response. The Ebola viral protein VP35 is known to block IFN responses, but the precise mechanisms have not been identified. We expressed VP35 in mouse dendritic cells and found that the cells failed to develop a normal IFN response when infected with Newcastle Disease virus. By a yeast two-hybrid system and other biochemical experiments, we showed that the blockade resulted from the conjugation of a Small Ubiquitin-like Modifier (SUMO) protein to IRF-7, the principal cellular factor required for IFN gene expression. However, the cells were still able to activate NF-κB, a transcription factor responsible for the release of proinflammatory cytokines. Our findings provide a first example where a virus hijacks the host SUMO system to undermine innate immunity, and help to explain how Ebola virus spreads rapidly in lymphoid tissues to cause a lethal inflammatory syndrome.