Emerging and re-emerging infections at the turn of the millennium

Infectious Complications of Transfusion of Blood Components

Transfusions are lifesaving but are not without some risks. During the middle of the last century, infectious complications were common from transfusions. By the mid 1980s the risk of transfusion transmission of infections became much lower. With the advent of emerging diseases, however, infectious risks became more prominent for a period of time. Now we live in a time where death from transfusion transmission is 10%–15% of all transfusion-associated deaths and is the lowest in history. As the risks are identified and new screens or processes are put in place, the associated transfusion transmission of infection will continue to have reducing risks and blood supply will continue to be safer still.

Biology and pathogenesis of cytomegalovirus in periodontal disease

Human periodontitis is associated with a wide range of bacteria and viruses and with complex innate and adaptive immune responses. Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Treponema denticola, cytomegalovirus and other herpesviruses are major suspected pathogens of periodontitis, and a combined herpesvirus–bacterial periodontal infection can potentially explain major clinical features of the disease. Cytomegalovirus infects periodontal macrophages and T‐cells and elicits a release of interleukin‐1β and tumor necrosis factor‐α. These proinflammatory cytokines play an important role in the host defense against the virus, but they also have the potential to induce alveolar bone resorption and loss of periodontal ligament. Gingival fibroblasts infected with cytomegalovirus also exhibit diminished collagen production and release of an increased level of matrix metalloproteinases. This article reviews innate and adaptive immunity to cytomegalovirus and suggests that immune responses towards cytomegalovirus can play roles in controlling, as well as in exacerbating, destructive periodontal disease.

One-health approach as counter-measure against "autoimmune" responses in biosecurity

This Swine flu pandemic of 2009 and the potential Avian flu threat of 2011-2012 have revived a most challenging debate on protection against infectious diseases. The response to the Swine flu pandemic has been ambivalent, both on the societal (political) and the scientific level. While some scientists warned against potential massive loss of human lives and urged for immediate and large-scale vaccination, others accused them of unnecessary scaremongering, arguing that the pandemic would not be that severe. The lab-created virulent Avian flu virus - which has been created in order to 'fight' a potential Avian flu pandemic - sparked a fierce debate on the dual-use risks of such a pre-emptive strategy. This article involves an analysis of the medical-political response to these recent viral threats using Peter Sloterdijk's immunological framework as diagnostic tool. In his trilogy Spheres Sloterdijk uses immunological concepts to analyse and assess the contemporary biopolitical situation. It shows how drawing a parallel between the functioning of the biological immune system and "immune responses" on socio-political level enables to assess and reconceptualise biosecurity. It demonstrates that ideas such as "nature is the biggest terrorist" - as advanced by many virologists - sometimes result in exaggerated "immunisation responses". This strong defensive attitude sometimes brings about collateral damage. In other words, fierce biosecurity measures sometimes risk developing into "autoimmune" responses that actually destruct the body politic they are meant to protect. By drawing on recent insights in the functioning of the biological immune system it is shown how a One-Health approach that incorporates a broader and nuanced "immunological" repertoire could act as counter-measure against "autoimmune" responses in biosecurity.

Killer peptide: a novel paradigm of antimicrobial, antiviral and immunomodulatory auto-delivering drugs

The incidence of life-threatening viral and microbial infections has dramatically increased over recent decades. Despite significant developments in anti-infective chemotherapy, many issues have increasingly narrowed the therapeutic options, making it imperative to discover new effective molecules. Among them, small peptides are arousing great interest. This review will focus in particular on a killer peptide, engineered from an anti-idiotypic recombinant antibody that mimics the activity of a wide-spectrum antimicrobial yeast killer toxin targeting β-glucan cell-wall receptors. The in vitro and in vivo antimicrobial, antiviral and immunomodulatory activities of killer peptide and its ability to spontaneously and reversibly self-assemble and slowly release its active dimeric form over time will be discussed as a novel paradigm of targeted auto-delivering drugs.

Current Controversies in the Formation and Treatment of Alloantibodies to Factor VIII in Congenital Hemophilia A

Hemophilia A is a rare bleeding disorder treated with numerous factor VIII (FVIII)–containing replacement concentrates. This treatment approach has led to the formation of alloantibodies that neutralize the FVIII activity (inhibitors) conveyed by these commercially available concentrates in ∼ 25% of patients with severe hemophilia A (FVIII activity < 1% of normal). This phenomenon significantly complicates the treatment of these patients and compromises the effectiveness and efficiency of these products to reverse or prevent bleeding complications. Studying the population with alloantibody inhibitors is imperative but difficult due to the overall small number of individuals affected and the heterogeneity within this limited group. Furthermore, few randomized clinical trials have been conducted to answer pertinent questions so many controversies persist. This article focuses on the conflicting data on the variables associated with alloantibody FVIII inhibitor development with a particular emphasis on age and intensity of first treatment, the role of primary prophylaxis regimens in modulating this phenomenon, and the degree of purity of FVIII product as a potential contributing risk factor. The optimal dosing regimen and type of FVIII replacement product that should be used to achieve the highest success rate in immune tolerance induction (ITI) protocols are also discussed, as well as whether the addition of immunomodulatory agents, especially rituximab, to ITI regimens enhances the durability of ITI and the eradication of alloantibody FVIII inhibitors.

[Acknowledged risks in transfusion and impact of taken measures on those risks]

Sur la base évidente, d’une part, de l’existence de risques (de différentes natures) en transfusion sanguine et, d’autre part, de l’attente d’une transfusion sans « vice » ni risque, trois niveaux de sécurisation ont pu être proposés ces dernières années : une politique d’analyse de risques généralisée ; des procédures de maîtrise des risques ; une politique généralisée de qualité. Ces constructions sécuritaires ont néanmoins des impacts multidirectionnels, sur les organisations, les coûts et l’économie en général, la disponibilité des produits, et – in fine – possiblement sur l’éthique. Ce sont ces points qui sont analysés dans le présent essai, ainsi que la place éventuelle dans ces dispositifs des procédés d’inactivation/réduction de pathogènes.

[Emergent viral threats in blood transfusion]

Au cours des 20 dernières années, la sécurité en transfusion sanguine a fait de très grands progrès vis-à-vis du risque infectieux et notamment de celui représenté par les rétrovirus (HIV et HTLV) et les virus des hépatites B et C. L’objet de cette revue est de répertorier les risques viraux résiduels ou émergents qui seraient susceptibles d’entraîner de nouvelles contaminations chez les receveurs. À côté de nombreux autres virus (HHV-8, erythrovirus B19, virus des hépatites A et E…), une place toute particulière est faite aux arboviroses émergentes (infections à West Nile virus, dengue et chikungunya) qui menacent de toucher le territoire métropolitain suite à l’implantation en Europe du moustique Aedes albopictus, principal vecteur de la dengue et du chikungunya dans les régions tempérées. Un autre risque sanguin émergent, particulièrement au Royaume-Uni et en France, est constitué par le prion à l’origine de la forme variante de la maladie de Creutzfeldt-Jakob. La revue se termine par un rapide panorama des mesures qui sont susceptibles de contrôler ces émergences : exclusion des donneurs à risque, tests diagnostiques spécifiques de tel ou tel agent, déleucocytation des produits sanguins labiles et traitements physiques ou chimiques capables d’inactiver de façon non spécifique les agents infectieux potentiellement contaminants sans trop altérer les propriétés des composants sanguins. La capacité à maîtriser de façon prospective les nouveaux risques viraux au niveau transfusionnel représente un vrai défi pour préserver la confiance retrouvée des prescripteurs et des receveurs vis-à-vis des produits sanguins.

Promises and pitfalls of recent advances in chemical means of preventing the spread of nosocomial infections by environmental surfaces

Hard, nonporous environmental surfaces in health care settings are now receiving due recognition for their role in the spread of several types of nosocomial pathogens. The corresponding increase in the means to decontaminate such surfaces to interrupt the spread of infections is leading to the marketing of a plethora of products and procedures, including the "green" variety, with varying claims of microbicidal activity, human and environmental safety, and materials compatibility. Limitations of the existing methods to assess environmental surface disinfectants and the regulations that govern their premarket registration make objective evaluations difficult. Label claims of many such products also do not reflect the realities of field use along with a strong tendency to focus on the "bug de jour." Furthermore, whereas wiping is often an integral part of environmental surface decontamination, products meant for the purpose are rarely assessed with the physical effect of wiping incorporated. Many "green" products possess neither the spectrum of microbicidal activity nor the speed of action essential for use in health care settings. In general, "self-sanitizing" surfaces being marketed actively these days require greater scrutiny for field-relevant microbicidal activity as well as the potential to enhance microbicide resistance. The widening use of environmental surface disinfectants is also raising concerns on their human and environmental safety at many levels along with the realization that routine surface disinfection procedures in health care settings are frequently inadequate and possibly counterproductive. All this points to an urgent review of the basic procedures for assessing existing and new environmental surface disinfectants for their microbicidal activity, label claims, registration requirements, overall safety, and routine practices of environmental surface decontamination.