Prevailing effectiveness of the 2009 influenza A(H1N1)pdm09 vaccine during the 2010/11 season in Sweden.

Sixty per cent of the Swedish population received the monovalent AS03-adjuvanted pandemic influenza vaccine in the autumn of 2009. We assessed the age-specific effectiveness of this pandemic vaccine against hospitalisation with laboratory-confirmed influenza A(H1N1)pdm09 during the season 2010/11, in the age group from six months to 64 years in Sweden. The screening method was applied to available surveillance data. Our results suggest a prevailing effectiveness of 72% (95% confidence interval (CI): 63­80%) with the highest effectiveness among children, six months to nine years-old (92%, 95%CI: 80­97%). However, there were limitations in data quality and study design due to the lack of systematic recording of administered vaccinations, which underline the importance of preparing for an evaluation when planning for large public health actions. Despite these limitations, we believe the results reflect true, high prevailing vaccine effectiveness. Indeed, there were fewer deaths caused by influenza and the impact of influenza on intensive care units was less severe during the 2010/11 season in Sweden than in countries with lower pandemic vaccination coverage. The association between the pandemic vaccine and narcolepsy has increased the importance of assessing the risks and benefits of the vaccination; studies on the effectiveness and the duration of protection are needed for this.

A variety of respiratory viruses found in symptomatic travellers returning from countries with ongoing spread of the new influenza A(H1N1)v virus strain.

Clinical specimens from 79 symptomatic individuals with a recent history of travel to countries with verified transmission of influenza A(H1N1)v (North America) were tested with a multiple real-time PCR targeting a broad range of agents that may cause acute respiratory infection. This analysis revealed that besides four cases of influenza A(H1N1)v, other respiratory viruses were diagnosed in almost 60% of the samples. These observations are a reminder that many different viral transmissions occur simultaneously in countries with ongoing spread of influenza A(H1N1)v. The findings demonstrate that the definition of suspected cases by clinical and epidemiological criteria has only a poor capacity for discriminating influenza A(H1N1)v from other viral infections.

Effective control measures limited measles outbreak after extensive nosocomial exposures in January-February 2008 in Gothenburg, Sweden.

In January-February 2008, one imported case of measles initiated a series of exposures with around 380 nosocomial secondary contacts. Susceptible individuals were traced early and control measures were initiated that managed to limit the consequences considerably. Only four secondary cases were identified by the end of March. This minor outbreak illustrates the importance and efficiency of early control measures as well as the fact that the risk of measles outbreaks still exists in a country that has high measles, mumps, rubella vaccination coverage among children.

A curriculum for training healthcare workers in the management of highly infectious diseases.

The SARS epidemic, the threat of bioterrorism, and recent examples of imported highly infectious diseases (HID) in Europe have all highlighted the importance of competent clinical and public health management of infectious disease emergencies. Although the European Union of Medical Specialists in Europe and the Infectious Diseases Society of America have developed curricula for training in infectious disease medicine, neither of those mentions training in the management of HIDs. The European Network for Infectious Diseases (EUNID, http://www.eunid.com) is a European Commission co-funded network of experts in HID management, created to help improve the preparedness for HID emergencies within Europe. One of EUNID's agreed tasks is the development of a curriculum for such a training. Between April 2005 and September 2006, EUNID developed a curriculum and accompanying training course on the basis of a questionnaire that was sent to all country representatives and discussion, followed by amendment of drafts shared through the project website, and a final consensus meeting. The resulting curriculum consists of a two-module course covering the core knowledge and skills that healthcare workers need to safely treat a patient who has, or who may have, an HID. The first module introduces theoretical aspects of HID management, including disease-specific knowledge, infection control, and the public health response, through didactic teaching and class-based discussion. The second module involves a "skill station" and a clinical scenario, and equips trainees with relevant practical skills, including the use of specialised equipment and teamwork practice in patient management. Together, the curriculum and course contribute to the creation of a common framework for training healthcare professionals in Europe, and although they are designed primarily for clinicians that are directly involved in patient care, they are relevant also to public health professionals and others who may be involved in HID management and emergency response.

Degranulation in human neutrophils primes the cells for subsequent responsiveness to the chemoattractant N-formylmethionylleucylphenylalanine but does not increase the sensitivity of the NADPH-oxidase to an intracellular calcium rise.

Both the chemotactic peptide formylmethionylleucylphenylalanine (FMLP) and the calcium-specific ionophore ionomycin can activate the NADPH-oxidase in human neutrophils. However, since ionomycin and FMLP activity differ in their requirement for azide, a potent inhibitor of the hydrogen peroxide consuming enzymes catalase and myeloperoxidase, we propose that the two stimuli can activate different pools of the oxidase. Degranulation, induced in vitro by sn-1,2-dedecaoylglycerol or in vivo by an exudation process, resulted in a priming of the cells using FMLP as stimulating agent as well as in a reduced capacity to generate H2O2 in response to ionomycin. The sensitivity of the plasma membrane-bound NADPH-oxidase to an intracellular [Ca2+] rise, induced by the ionophore was, however, not changed by the degranulation. From these results we propose that FMLP activates the plasma membrane-bound oxidase, whereas the ionophore is capable of activating a granule-bound pool of the oxidase.

Phorbol myristate acetate-induced NADPH oxidase activity in human neutrophils: only half the story has been told.

The paradigm for activation of the neutrophil NADPH oxidase with the protein kinase C activator phorbol myristate acetate (PMA) states that the oxidase assembles the plasma membrane and that the metabolites generated are released extracellularly. This paradigm is challenged by the results presented. Most of the PMA-induced oxidase activity measured as chemiluminescence and dichlorofluorescein fluorescence was insensitive to scavengers of superoxide anion and hydrogen peroxide. This indicates that oxidase activity also takes place in a cellular compartment that the scavengers cannot reach. From the results obtained with granule-deficient HL-60 cells and cord blood neutrophils, we suggest that the scavenger-insensitive part of the NADPH oxidase activity in normal neutrophils resides in an intracellular compartment identical to or originating from granules. Our results also indicate that specific and azurophil granules have to be in very close contact to allow the generated oxygen metabolites to reach and react with myeloperoxidase.

Skin chamber technique for study of in vivo exudated human neutrophils.

The development of new techniques for isolation of neutrophils extravasated in vivo have been essential for studying the dynamics of the inflammatory response in humans. Methods for generating inflammatory skin reactions were first presented in the mid 1950s, and later a skin blistering technique based on suction was introduced. With this procedure, small areas of denuded dermis, called "skin windows", are created and covered with special chambers containing a medium that attracts exudated neutrophils. By comparing the neutrophils collected in such chambers with those isolated from peripheral blood, it is possible to investigate the functional modifications that neutrophils undergo when attracted to an inflammatory process. The skin-blister chamber technique represents an aseptic, non-traumatic and reproducible model of inflammation that can be used to study in vivo activated human neutrophils. The background, methodological aspects and options of this technique are described, together with the functional characteristics of exudated neutrophils.

Human neutrophil chemiluminescence and f-Meth-Leu-Phe receptor exposure in bacterial infections.

Polymorphonuclear leukocytes were isolated from 12 patients with acute bacterial infections and the ability of the chemoattractant formylmethionyl-leucyl-phenylalanine (FMLP) to bind and induce a metabolic response in these cells was investigated. Cells isolated from the patients showed a significantly increased metabolic response in a luminol enhanced chemiluminescence assay compared to cells, isolated and analyzed in parallel, from healthy controls i.e. the patient cells were primed. The primed state was, as calculated by Scatchard analysis, accompanied by a significantly increased number of FMLP receptors exposed on the cell surface while the receptor binding affinity remained unchanged. There was, however, no correlation between the degree of priming and the degree of receptor upregulation. Furthermore, it was found that stimulation also with phorbol myristate acetate (PMA), a substance lacking specific cell surface receptors on the PMNL, gave rise to an increased metabolic response in the primed cells. These results indicate that the priming activity induced by a bacterial infection can only partly be explained by receptor modulation and that other mechanisms must also be considered. This study was approved by the Ethics Committee of the Medical Faculty, University of Linköping.

Phagocytosis by lipopolysaccharide-primed human neutrophils is associated with increased extracellular release of reactive oxygen metabolites.

The effect of priming human neutrophils with lipopolysaccharide was investigated regarding the respiratory burst activity generated during phagocytosis of IgG- or C3b-opsonized yeast particles. LPS pretreatment significantly enhanced the respiratory burst activity, measured as luminol-amplified chemiluminescence, of both types of opsonized particles. In control cells most of the activity was produced intracellularly, probably in the phagosomes. In the primed cells, however, extracellular release of reactive oxygen metabolites was significantly increased during Fc- and CR3-mediated phagocytosis (P less than 0.01 and P less than 0.002, respectively). The release was most pronounced when using C3b-opsonized particles. Potent oxygen metabolites acting together with lysosomal enzymes are of importance in inflammatory-induced tissue damage. An increased extracellular release of reactive oxygen species by phagocytizing primed neutrophils can therefore lead to greater damage to the surrounding tissues.

Relationship between intracellularly and extracellularly generated oxygen metabolites from primed polymorphonuclear leukocytes differs from that obtained from nonprimed cells.

The ability of primed human polymorphonuclear leukocytes (PMNLs) to respond metabolically to stimulation with formylmethionyl-leucyl-phenylalanine (FMLP) was investigated. Cells isolated from an aseptic inflammatory reaction and from patients with a severe bacterial infection as well as cells that had been treated with a bacterial lipopolysaccharide were investigated. When these cells were compared to peripheral blood cells isolated from healthy controls, they were found to be metabolically primed, i.e., the cells gave rise to an increased chemiluminescence response to subsequent stimulation with the peptide. It was also shown that proportionally more of the activity generated from the primed PMNL was of an intracellular origin compared with that obtained from nonprimed cells. The biological effects induced by radicals produced extracellularly and intracellularly are discussed.

EuroNHID checklists for the assessment of high-level isolation units and referral centres for highly infectious diseases: results from the pilot phase of a European survey.

Healthcare settings have been identified as preferential for the transmission of many agents causing highly infectious diseases (HIDs). Infection control procedures strongly reduce the risk of transmission of HIDs in hospital settings, when adequately applied. The main objective of the European Network for Highly Infectious Diseases (EuroNHID), a network co-funded by the European Commission, is to assess the current capabilities for dealing with HIDs in Europe, specifically in the context of infection control and healthcare worker (HCW) safety, through conducting an on-the-field survey of high-level isolation units (HLIUs)/referral centres for the management of HIDs in participating countries. During the first year of the project's activities, specifically designed, evidence-based checklists were developed. This review introduces the EuroNHID checklists as a standard tool for the assessment of hospital capabilities concerning infection control and HCW safety in the management of patients with HIDs, and presents preliminary results from five HLIUs.

European concepts for the domestic transport of highly infectious patients.

Highly infectious diseases involve clinical syndromes ranging from single to multiorgan infections and pose a constant threat to the public. In the absence of a definite treatment for most causative agents, patients benefit from maximum supportive care as clinical conditions may deteriorate in the short term. Hence, following initial case identification and isolation, rapid transportation to a specialized treatment unit must be considered in order to minimize the risk of secondary infections, but this is limited by available infrastructure, accessible care en route and the patient's clinical condition. Despite the development of consensus curricula for the clinical management of highly infectious patients, medical transportation lacks a common European approach. This article describes, as examples, three current European concepts for the domestic relocation of highly infectious patients by ground vehicles and aircraft with respect to national legislation and geography.

Isolation rooms for highly infectious diseases: an inventory of capabilities in European countries.

Isolation of patients with highly infectious diseases (HIDs) in hospital rooms with adequate technical facilities is essential to reduce the risk of spreading disease. The European Network for Infectious Diseases (EUNID), a project co-funded by European Commission and involving 16 European Union member states, performed an inventory of high level isolation rooms (HIRs, hospital rooms with negative pressure and anteroom). In participating countries, HIRs are available in at least 211 hospitals, with at least 1789 hospital beds. The adequacy of this number is not known and will depend on prevailing circumstances. Sporadic HID cases can be managed in the available HIRs. HIRs could also have a role in the initial phases of an influenza pandemic. However, large outbreaks due to natural or to bioterrorist events will need management strategies involving healthcare facilities other than HIRs.

Altered O2-/H2O2 production ratio by in vitro and in vivo primed human neutrophils.

Human neutrophils were primed by exudation or pretreatment with a synthetic diacylglycerol (diC10), the Ca2+ ionophore ionomycin or lipopolysaccharide (LPS). Compared to control cells, these primed cells showed a significantly decreased O2-/H2O2 ratio when stimulated with formylmethionyl-leucyl-phenylalanine (FMLP). This shift indicates a comparative (and net) increased H2O2 detection in the extracellular medium and can not be explained by a dose-dependent impairment in either O2- or H2O2 detecting capacity. An altered H2O2 degenerating capacity was not observed in the primed cells. We propose that priming enhances the capacity to divalently reduce oxygen and thereby directly produce H2O2.

Successful interferon-gamma therapy in a chronic granulomatous disease (CGD) patient suffering from Staphylococcus aureus hepatic abscess and invasive Candida albicans infection.

A 16-year old boy with an early history of recurrent lower respiratory tract infections exhibited symptoms of prolonged septic fever and liver abscess. Cultures from liver puncture were positive for Staphylococcus aureus, and the patient initially responded to antibacterial therapy. After a period of 4 months, however, the infection relapsed, and further treatment with broad antibacterial, antifungal and tuberculostatic drugs was ineffective. Neither soluble nor particulate stimuli were found to elicit the respiratory burst response in granulocytes from the patient. Spectral analysis of granulocyte cytochrome-b confirmed the diagnosis of chronic granulomatous disease. Since the patient's physical condition deteriorated severely during the prolonged (10-week) septic course, immunosupportive interferon-gamma was added to the anti-microbial therapy. With this regime, the fever subsided and the general condition of the patient improved dramatically. He could be discharged from hospital 9 weeks after the introduction of interferon-gamma and was, at an elective follow-up control 1 month later, convalescing and showed no signs of active infection.

Intracellular production of reactive oxygen species in human neutrophils following activation by the soluble stimuli FMLP, dioctanoylglycerol and ionomycin.

The stimuli, sn-1, 2-dioctanoylglycerol; (DG8) the calcium specific ionophore, ionomycin, and the chemotactic peptide formylmethionyl-leucyl-phenylalanine (FMLP) can interact with normal human neutrophils and activate their superoxide/hydrogen peroxide generating NADPH-oxidase. In response to the peptide as well as DG8, the neutrophils produced both superoxide (O2-) and hydrogen peroxide (H2O2). Since interaction between the cells and ionomycin was not associated with any notable superoxide production and hydrogen peroxide was induced only in the presence of azide, a potent inhibitor of the hydrogen peroxide-consuming enzymes catalase and myeloperoxidase, we conclude that this stimulus can generate oxygen metabolites intracellularly. Since the DG8-induced production of hydrogen peroxide was increased in the presence of azide, whereas the FMLP-induced response was largely unaffected, we concluded that the three stimuli differ in their capacity to generate oxygen metabolites intracellularly. The use of sn-1,2-didecanoylglycerol (DG10) as stimulating agent did not result in any detectable activation of the NADPH-oxidase. However, preincubation caused an increased (primed) response during stimulation with the chemotactic peptide FMLP. The response of primed neutrophils to FMLP proceeds with a time-course different from that seen in normal cells. From the results presented on FMLP-induced activity in the presence of azide, we conclude that FMLP causes normal cells to produce oxygen radicals which are released from the cells. However, the primed cells are also capable of generating oxygen metabolites that are retained inside the cells. In fact, measurement of the intracellularly generated metabolites discloses this to be the predominant part of the response.

Mechanisms in neutrophil priming: characterization of the oxidative response induced by formylmethionyl-leucyl-phenylalanine in human exudated cells.

Exudate human polymorphonuclear neutrophils were isolated and investigated regarding oxidative responsiveness and priming ability. The exudate neutrophils were found to produce an increased amount of O2- and H2O2 when stimulated with formylmethionyl-leucyl-phenylalanine (fMLP), i.e. these cells were metabolically primed. Cytochalasin B (cyt B) pretreatment affected the production of O2- by exudate cells, although to a lesser extent than the production by peripheral blood cells, in which a substantial increase was induced. Addition of N-ethylmaleimide (NEM) to activated exudate and peripheral blood cells revealed no difference in oxidase inactivation rate. To induce further priming, the cells were incubated in vitro with a synthetic diacylglycerol (sn-1,2-didecanoylglycerol; diC10), or the Ca2+ ionophore ionomycin. Results of this procedure showed significant differences between exudate and peripheral blood neutrophils: the peripheral cells expressed a primed response, which was measured as increased fMLP-induced O2- production following incubation with both these substance; whereas the metabolic activity of exudated cells was not affected by diC10, but was significantly primed by ionomycin (P less than 0.01). The exact route for diacylglycerol priming is unknown. However, our results with human neutrophils primed during exudation indicate an exhausted diC10-priming pathway, with a retained sensitivity for priming [Ca2+]i rises.

Galectin-3 activates the NADPH-oxidase in exudated but not peripheral blood neutrophils.

Galectin-3, a lactose-binding mammalian lectin that is secreted from activated macrophages, basophils, and mast cells, was investigated with respect to its ability to activate the human neutrophil NADPH-oxidase. The galectin-3-induced activity was determined with in vivo exudated cells (obtained from a skin chamber) and compared with that of peripheral blood neutrophils. Galectin-3 was found to be a potent activator of the NADPH-oxidase only in exudated neutrophils and the binding of galectin-3 to the surface of these cells was increased compared with peripheral blood cells. Different in vitro priming protocols resulting in degranulation were used to mimic the exudation process in terms of increasing the receptor exposure on the cell surface. Galectin-3 could induce an oxidative response similar to that in exudated cells only after a significant amount of the intracellular organelles had been mobilized. This increase in oxidative response was paralleled by an increased binding of galectin-3 to the surface of the cells. The major conclusion of the study is that galectin-3 is a potent stimulus of the neutrophil respiratory burst, provided that the cells have first experienced an extravasation process. The results also imply that the neutrophil response to galectin-3 could be mediated through receptors mobilized from intracellular granules, and we report the presence of galectin-3-binding proteins in such organelles.

Vertebral hydatid cyst infection (Echinococcus granulosus): a case report.

Spinal echinococcosis is a rare but serious condition. Within bone tissue hydatid cysts enlarge by daughter cyst formation. The value of drug treatment in bone echinococcosis is questionable. The aim of surgery is therefore removal of all the cysts. The best way to achieve this is at the first operation early in the progress of the disease. An anterior or circumferential approach is generally required to give the necessary accessibility. Owing to diffuse spread of the infection within the bone and the canal, recurrence is common. If neurological deterioration occurs, reintervention is necessary.

Quantitative slot-blot chemiluminescence assay for determination of myeloperoxidase from human granulocytes.

Using slot blot, we show that myeloperoxidase (MPO), a constituent of azurophil granules of neutrophil polymorphonuclear leukocytes, can be measured quantitatively using a commercially available chemiluminescence kit, originally developed for detection of specific proteins on Western blots. MPO is determined through its ability to catalyze the oxidation of luminol, resulting in the emission of light which is recorded on a photographic film. The sensitivity of the method is high and allows MPO from less than 100 cells to be detected. This method was used to determine MPO in exudate fluid and in neutrophil fractions following disintegration and subcellular fractionation of the postnuclear supernatant on two-layer Percoll gradients.