Intensified hand-hygiene campaign including soap-and-water wash may prevent acute infections in office workers, as shown by a recognized-exposure -adjusted analysis of a randomized trial.

BACKGROUND: Variable exposure to causative agents of acute respiratory (RTI) or gastrointestinal tract infections (GTI) is a significant confounding factor in the analysis of the efficacy of interventions concerning these infections. We had an exceptional opportunity to reanalyze a previously published dataset from a trial assessing the effect of enhanced hand hygiene on the occurrence of RTI or GTI in adults, after adjustment for reported exposure and other covariates. METHODS: Twenty-one working units (designated clusters) each including at least 50 office employees, totaling 1,270 persons, were randomized into two intervention arms (either using water-and-soap or alcohol-rub in hand cleansing), or in the control arm. Self-reported data was collected through weekly emails and included own symptoms of RTI or GTI, and exposures to other persons with similar symptoms. Differences in the weekly occurrences of RTI and GTI symptoms between the arms were analyzed using multilevel binary regression model with log link with personal and cluster specific random effects, self-reported exposure to homologous disease, randomization triplet, and seasonality as covariates in the Bayesian framework. RESULTS: Over the 16 months duration of the trial, 297 persons in the soap and water arm, 238 persons in the alcohol-based hand rub arm, and 230 controls sent reports. The arms were similar in age distribution and gender ratios. A temporally-associated reported exposure strongly increased the risk of both types of infection in all trial arms. Persons in the soap-and-water arm reported a significantly - about 24% lower weekly prevalence of GTI than the controls whether they had observed an exposure or not during the preceding week, while for RTI, this intervention reduced the prevalence only during weeks without a reported exposure. Alcohol-rub did not affect the symptom prevalence. CONCLUSIONS: We conclude that while frequent and careful hand washing with soap and water partially protected office-working adults from GTI, the effect on RTI was only marginal in this study. Potential reasons for this difference include partially different transmission routes and a difference in the virus load. In this trial, frequent standardized hand rubbing with ethanol-based disinfectant did not reduce the weekly prevalence of either type of infections. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00821509, 12 March 2009.

Development of a prognostic model based on demographic, environmental and lifestyle information for predicting incidences of symptomatic respiratory or gastrointestinal infection in adult office workers.

BACKGROUND: Occurrence of respiratory tract infection (RTI) or gastrointestinal tract infection (GTI) is known to vary between individuals and may be a confounding factor in the analysis of the results of intervention trials. We aimed at developing a prognostic model for predicting individual incidences of RTI and GTI on the basis of data collected in a hand-hygiene intervention trial among adult office workers, and comprising a prior-to-onset questionnaire on potential infection-risk factors and weekly electronic follow-up reports on occurrence of symptoms of, and on exposures to RTI or GTI. METHODS: A mixed-effect negative binomial regression model was used to calculate a predictor-specific incidence rate ratio for each questionnaire variable and for each of the four endpoints, and predicted individual incidences for symptoms of and exposures to RTI and GTI. In the fitting test these were then compared with the observed incidences. RESULTS: Out of 1270 eligible employees of six enterprises, 683 volunteered to participate in the trial. Ninety-two additional participants were recruited during the follow-up. Out of the 775 registered participants, 717 returned the questionnaire with data on potential predictor variables and follow-up reports for determination of outcomes. Age and gender were the strongest predictors of both exposure to, and symptoms of RTI or GTI, although no gender difference was seen in the RTI incidence. In addition, regular use of public transport, and history of seasonal influenza vaccination increased the risk of RTI. The individual incidence values predicted by the model showed moderate correlation with those observed in each of the four categories. According to the Cox-Snell multivariate formula the model explained 11.2% of RTI and 3.3% of GTI incidences. Resampling revealed mean and 90% confidence interval values of 10.9 (CI 6.9-14.5)% for RTI and 2.4 (0.6-4.4)% for GTI. CONCLUSION: The model created explained a relatively small proportion of the occurrence of RTI or GTI. Unpredictable exposure to disease agents, and individual susceptibility factors are likely to be key determinants of disease emergence. Yet, the model might be useful in prerandomization stratification of study population in RTI intervention trials where the expected difference between trial arms is relatively small. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with Identifier NCT00821509 on 12 March 2009.

Exposure to persons with symptoms of respiratory or gastrointestinal infection and relative risk of disease: self-reported observations by controls in a randomized intervention trial.

BACKGROUND: Little is known about the quantitative relationships between a self-recognized exposure to people with symptoms of respiratory (RTI) or gastrointestinal tract infection (GTI) and subsequent occurrence of homologous symptoms in the exposed person. METHODS: Adult office employees, controls in an intervention trial, reported weekly own symptoms of RTI or GTI and exposures to other persons with similar symptoms. To ascertain the reliability of the self-reported data, the participants received both in-advance training and repeated instructions in the weekly Email requests for reports. The relationship of self-reported exposures to self-reported homologous symptoms during the same or the following week was analyzed including, in the statistical models, cluster effects and longitudinal aspects in the data, seasonality, and cluster-specific baseline values. RESULTS: Altogether 11,644 weekly reports were received from 230 participants during the 16-month duration of the study. The mean age of the reporters was 42.9 years (standard deviation 11.1 years), and the female/male ratio 157/68 (for 5 participants this information was not available). A reported exposure to RTI was associated with an almost 5-fold higher relative risk for a reported homologous infection during the same week (4.9; 95% confidence interval (CI) 4.0 to 5.9), and with a 3-fold risk during the following week (3.3; CI 2.8 to 3.8). For GTI the corresponding figures were 15.1 (CI 10.4 to 21.8) and 4.3 (CI 3.1 to 5.8), respectively. On the other hand, for 24% of the designated RTI episodes, a homologous exposure had been reported during neither the same nor the preceding week. For GTI this figure was even greater (40%). For both RTI and GTI, weeks with a reported exposure were more frequent outside the workplace than only at the workplace (434 versus 262, and 109 versus 41, respectively). CONCLUSION: A reported exposure to persons with obvious symptoms of RTI or GTI significantly increased the relative risk of reported homologous infection in the exposed adult persons. Yet, a substantial part of reported designated RTI and, especially, GTI episodes occurred without a reported exposure during the same or the previous week. TRIAL REGISTRATION: ClinicalTrials.gov with an identifier of NCT00821509 (12 March 2009).

Recombination in the evolution of enterovirus C species sub-group that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99.

Genetic recombination is considered to be a very frequent phenomenon among enteroviruses (Family Picornaviridae, Genus Enterovirus). However, the recombination patterns may differ between enterovirus species and between types within species. Enterovirus C (EV-C) species contains 21 types. In the capsid coding P1 region, the types of EV-C species cluster further into three sub-groups (designated here as A-C). In this study, the recombination pattern of EV-C species sub-group B that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99 was determined using partial 5'UTR and VP1 sequences of enterovirus strains isolated during poliovirus surveillance and previously published complete genome sequences. Several inter-typic recombination events were detected. Furthermore, the analyses suggested that inter-typic recombination events have occurred mainly within the distinct sub-groups of EV-C species. Only sporadic recombination events between EV-C species sub-group B and other EV-C sub-groups were detected. In addition, strict recombination barriers were inferred for CVA-21 genotype C and CVA-24 variant strains. These results suggest that the frequency of inter-typic recombinations, even within species, may depend on the phylogenetic position of the given viruses.

The evolution of Vp1 gene in enterovirus C species sub-group that contains types CVA-21, CVA-24, EV-C95, EV-C96 and EV-C99.

Genus Enterovirus (Family Picornaviridae,) consists of twelve species divided into genetically diverse types by their capsid protein VP1 coding sequences. Each enterovirus type can further be divided into intra-typic sub-clusters (genotypes). The aim of this study was to elucidate what leads to the emergence of novel enterovirus clades (types and genotypes). An evolutionary analysis was conducted for a sub-group of Enterovirus C species that contains types Coxsackievirus A21 (CVA-21), CVA-24, Enterovirus C95 (EV-C95), EV-C96 and EV-C99. VP1 gene datasets were collected and analysed to infer the phylogeny, rate of evolution, nucleotide and amino acid substitution patterns and signs of selection. In VP1 coding gene, high intra-typic sequence diversities and robust grouping into distinct genotypes within each type were detected. Within each type the majority of nucleotide substitutions were synonymous and the non-synonymous substitutions tended to cluster in distinct highly polymorphic sites. Signs of positive selection were detected in some of these highly polymorphic sites, while strong negative selection was indicated in most of the codons. Despite robust clustering to intra-typic genotypes, only few genotype-specific 'signature' amino acids were detected. In contrast, when different enterovirus types were compared, there was a clear tendency towards fixation of type-specific 'signature' amino acids. The results suggest that permanent fixation of type-specific amino acids is a hallmark associated with evolution of different enterovirus types, whereas neutral evolution and/or (frequency-dependent) positive selection in few highly polymorphic amino acid sites are the dominant forms of evolution when strains within an enterovirus type are compared.

Characteristics of an environmentally monitored prolonged type 2 vaccine derived poliovirus shedding episode that stopped without intervention.

Vaccine derived poliovirus (VDPV) type 2 strains strongly divergent from the corresponding vaccine strain, Sabin 2, were repeatedly isolated from sewage in Slovakia over a period of 22 months in 2003-2005. Cell cultures of stool specimens from known immune deficient patients and from an identified putative source population of 500 people failed to identify the potential excretor(s) of the virus. The occurrence of VDPV in sewage stopped without any intervention. No paralytic cases were reported in Slovakia during the episode. According to a GenBank search and similarity plotting-analysis, the closest known relative of the first isolate PV2/03/SVK/E783 through all main sections of the genome was the type 2 poliovirus Sabin strain, with nucleotide identities in 5'UTR, P1, P2, P3, and 3'UTR parts of the genome of 88.6, 85.9, 87.3, 88.5, and 94.0 percent, respectively. Phenotypic properties of selected Slovakian aVDPV strains resembled those of VDPV strains isolated from immune deficient individuals with prolonged PV infection (iVDPV), including antigenic changes and moderate neurovirulence in the transgenic mouse model. One hundred and two unique VP1 coding sequences were determined from VDPV strains isolated from 34 sewage specimens. Nucleotide differences from Sabin 2 in the VP1 coding region ranged from 12.5 to 15.6 percent, and reached a maximum of 9.6 percent between the VDPV strains under study. Most of the nucleotide substitutions were synonymous but as many as 93 amino acid positions out of 301 in VP1 showed substitutions. We conclude that (1) individuals with prolonged poliovirus infection are not as rare as suggested by the studies on immune deficient patients known to the health care systems and (2) genetic divergence of VDPV strains may remain extensive during years long replication in humans.

Evolution of type 2 vaccine derived poliovirus lineages. Evidence for codon-specific positive selection at three distinct locations on capsid wall.

Partial sequences of 110 type 2 poliovirus strains isolated from sewage in Slovakia in 2003-2005, and most probably originating from a single dose of oral poliovirus vaccine, were subjected to a detailed genetic analysis. Evolutionary patterns of these vaccine derived poliovirus strains (SVK-aVDPV2) were compared to those of type 1 and type 3 wild poliovirus (WPV) lineages considered to have a single seed strain origin, respectively. The 102 unique SVK-aVDPV VP1 sequences were monophyletic differing from that of the most likely parental poliovirus type 2/Sabin (PV2 Sabin) by 12.5-15.6%. Judging from this difference and from the rate of accumulation of synonymous transversions during the 22 month observation period, the relevant oral poliovirus vaccine dose had been administered to an unknown recipient more than 12 years earlier. The patterns of nucleotide substitution during the observation period differed from those found in the studied lineages of WPV1 or 3, including a lower transition/transversion (Ts/Tv) bias and strikingly lower Ts/Tv rate ratios at the 2(nd) codon position for both purines and pyrimidines. A relatively low preference of transitions at the 2(nd) codon position was also found in the large set of VP1 sequences of Nigerian circulating (c)VDPV2, as well as in the smaller sets from the Hispaniola cVDPV1 and Egypt cVDPV2 outbreaks, and among aVDPV1and aVDPV2 strains recently isolated from sewage in Finland. Codon-wise analysis of synonymous versus non-synonymous substitution rates in the VP1 sequences suggested that in five codons, those coding for amino acids at sites 24, 144, 147, 221 and 222, there may have been positive selection during the observation period. We conclude that pattern of poliovirus VP1 evolution in prolonged infection may differ from that found in WPV epidemics. Further studies on sufficiently large independent datasets are needed to confirm this suggestion and to reveal its potential significance.

Review and assessment of poliovirus immunity and transmission: synthesis of knowledge gaps and identification of research needs.

With the intensifying global efforts to eradicate wild polioviruses, policymakers face complex decisions related to achieving eradication and managing posteradication risks. These decisions and the expanding use of inactivated poliovirus vaccine (IPV) trigger renewed interest in poliovirus immunity, particularly the role of mucosal immunity in the transmission of polioviruses. Sustained high population immunity to poliovirus transmission represents a key prerequisite to eradication, but poliovirus immunity and transmission remain poorly understood despite decades of studies. In April 2010, the U.S. Centers for Disease Control and Prevention convened an international group of experts on poliovirus immunology and virology to review the literature relevant for modeling poliovirus transmission, develop a consensus about related uncertainties, and identify research needs. This article synthesizes the quantitative assessments and research needs identified during the process. Limitations in the evidence from oral poliovirus vaccine (OPV) challenge studies and other relevant data led to differences in expert assessments, indicating the need for additional data, particularly in several priority areas for research: (1) the ability of IPV-induced immunity to prevent or reduce excretion and affect transmission, (2) the impact of waning immunity on the probability and extent of poliovirus excretion, (3) the relationship between the concentration of poliovirus excreted and infectiousness to others in different settings, and (4) the relative role of fecal-oral versus oropharyngeal transmission. This assessment of current knowledge supports the immediate conduct of additional studies to address the gaps.

Recombination in the evolution of human rhinovirus genomes.

Human rhinoviruses (HRV) are highly prevalent human respiratory pathogens that belong to the genus Enterovirus. Although recombination within the coding region is frequent in other picornavirus groups, most evidence of recombination in HRV has been restricted to the 5' untranslated region. We analysed the occurrence of recombination within published complete genome sequences of members of all three HRV species and additionally compared sequences from HRV strains spanning 14 years. HRV-B and HRV-C showed very little evidence of recombination within the coding region. In contrast, HRV-A sequences appeared to have undergone a large number of recombination events, typically involving whole type groups. This suggests that HRV-A may have been subject to extensive recombination during the period of diversification into types. This study demonstrates the rare and sporadic nature of contemporary recombination of HRV strains and contrasts with evidence of extensive recombination within HRV-A and between members of different species during earlier stages in its evolutionary diversification.

Expert review on poliovirus immunity and transmission.

Successfully managing risks to achieve wild polioviruses (WPVs) eradication and address the complexities of oral poliovirus vaccine (OPV) cessation to stop all cases of paralytic poliomyelitis depends strongly on our collective understanding of poliovirus immunity and transmission. With increased shifting from OPV to inactivated poliovirus vaccine (IPV), numerous risk management choices motivate the need to understand the tradeoffs and uncertainties and to develop models to help inform decisions. The U.S. Centers for Disease Control and Prevention hosted a meeting of international experts in April 2010 to review the available literature relevant to poliovirus immunity and transmission. This expert review evaluates 66 OPV challenge studies and other evidence to support the development of quantitative models of poliovirus transmission and potential outbreaks. This review focuses on characterization of immunity as a function of exposure history in terms of susceptibility to excretion, duration of excretion, and concentration of excreted virus. We also discuss the evidence of waning of host immunity to poliovirus transmission, the relationship between the concentration of poliovirus excreted and infectiousness, the importance of different transmission routes, and the differences in transmissibility between OPV and WPV. We discuss the limitations of the available evidence for use in polio risk models, and conclude that despite the relatively large number of studies on immunity, very limited data exist to directly support quantification of model inputs related to transmission. Given the limitations in the evidence, we identify the need for expert input to derive quantitative model inputs from the existing data.

Single treatment with ethanol hand rub is ineffective against human rhinovirus--hand washing with soap and water removes the virus efficiently.

Ethanol-containing hand rubs are used frequently as a substitute for hand washing with water and soap. However, not all viruses are inactivated by a short term rubbing with alcohol. The capacity of a single round of instructed and controlled hand cleaning with water and soap or ethanol-containing hand rub, respectively, was tested for removal of human rhinovirus administered onto the skin of healthy volunteers on the back of the hands. Hand washing with soap and water appeared to be much more efficient for removing rhinoviruses from skin than rubbing hands with an ethanol-containing disinfectant. After washing with soap and water the virus was detected in 3/9 (33.3%) test persons from the left hand and 1/9 (11.1%) cases from the right hand, whereas the virus was detected invariably by real-time RT-PCR from both hands after cleaning with alcohol hand rub (P-value <0.01). Both substances evaluated clinically were also tested in vitro for virucidal efficacy against Human rhinovirus2 (HRV2) using a standardized assay. Both tested substances were poor within the contact time used in the hand-cleaning test. In conclusion, thorough and conventional hand washing with water and soap can clean efficiently hands contaminated with the virus responsible for an extensive share of common cold episodes.

Hand washing with soap and water together with behavioural recommendations prevents infections in common work environment: an open cluster-randomized trial.

BACKGROUND: Hand hygiene is considered as an important means of infection control. We explored whether guided hand hygiene together with transmission-limiting behaviour reduces infection episodes and lost days of work in a common work environment in an open cluster-randomized 3-arm intervention trial. METHODS: A total of 21 clusters (683 persons) were randomized to implement hand hygiene with soap and water (257 persons), with alcohol-based hand rub (202 persons), or to serve as a control (224 persons). Participants in both intervention arms also received standardized instructions on how to limit the transmission of infections. The intervention period (16 months) included the emergence of the 2009 influenza pandemic and the subsequent national hand hygiene campaign influencing also the control arm. RESULTS: In the total follow-up period there was a 6.7% reduction of infection episodes in the soap-and water arm (p = 0.04). Before the onset of the anti-pandemic campaign, a statistically significant (p = 0.002) difference in the mean occurrence of infection episodes was observed between the control (6.0 per year) and the soap-and-water arm (5.0 per year) but not between the control and the alcohol-rub arm (5.6 per year). Neither intervention had a decreasing effect on absence from work. CONCLUSIONS: We conclude that intensified hand hygiene using water and soap together with behavioural recommendations can reduce the occurrence of self-reported acute illnesses in common work environment. Surprisingly, the occurrence of reported sick leaves also increased in the soap-and water-arm. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00981877 SOURCE OF FUNDING: The Finnish Work Environment Fund and the National Institute for Health and Welfare.

Specific viruses detected in nigerian children in association with acute respiratory disease.

Occurrence of different viruses in acute respiratory tract infections of Nigerian children was examined. Respiratory swabs were collected from 246 children referred to hospital clinics because of acute respiratory symptoms from February through May 2009. Validated real-time RT-PCR techniques revealed nucleic acids of at least one virus group in 189 specimens (77%). Human rhinoviruses and parainfluenza viruses were present each in one third of the children. Adenoviruses, enteroviruses, human metapneumovirus, human bocavirus, and influenza C virus were also relatively common. Possibly due to their seasonal occurrence, influenza A and B virus, and respiratory syncytial virus were detected rarely. We conclude that all major groups of respiratory tract viruses are causing illness in Nigerian children.

Temporal association between rhinovirus circulation in the community and invasive pneumococcal disease in children.

BACKGROUND: Mucosal coinfections with respiratory viruses and Streptococcus pneumoniae are common, but the role of rhinovirus infections in the development of invasive pneumococcal disease (IPD) in children has not been studied. METHODS: During 1995 and 2007, we analyzed the association of IPD in children less than 5 years of age with respiratory virus epidemics by combining data from the National Infectious Disease Register, 3 prospective epidemiologic studies, and the database of the Department of Virology, University of Turku, Finland. RESULTS: The mean IPD rate in children younger than 5 years of age in Finland was 2.9 cases per week (95% confidence interval [CI], 2.5-3.3) during periods of high rhinovirus activity, and 1.4 (95% CI, 1.2-1.6) during periods of low rhinovirus activity (P < 0.001). The IPD rate correlated with the rhinovirus activity recorded at the Department of Virology (correlation coefficient, 0.23; P = 0.001) and in the epidemiologic studies (correlation coefficients, 0.28, 0.25, and 0.31). The IPD rate was moderately increased during periods of high respiratory syncytial virus activity (mean, 2.1 cases per week; 95% CI, 1.8-2.3) compared with periods of low respiratory syncytial virus activity (mean, 1.7; 95% CI, 1.6-1.9; P = 0.008). There were no differences in the IPD rate between the periods of high and low influenza activity. CONCLUSIONS: Rhinovirus circulation in the community had an association with IPD in children younger than 5 years of age. This study suggests that rhinovirus infection may be a contributor in the development of IPD in the population of young children.

Analysis of genetic diversity and sites of recombination in human rhinovirus species C.

Human rhinoviruses (HRVs) are a highly prevalent and diverse group of respiratory viruses. Although HRV-A and HRV-B are traditionally detected by virus isolation, a series of unculturable HRV variants have recently been described and assigned as a new species (HRV-C) within the picornavirus Enterovirus genus. To investigate their genetic diversity and occurrence of recombination, we have performed comprehensive phylogenetic analysis of sequences from the 5' untranslated region (5' UTR), VP4/VP2, VP1, and 3Dpol regions amplified from 89 HRV-C-positive respiratory samples and available published sequences. Branching orders of VP4/VP2, VP1, and 3Dpol trees were identical, consistent with the absence of intraspecies recombination in the coding regions. However, numerous tree topology changes were apparent in the 5' UTR, where >60% of analyzed HRV-C variants showed recombination with species A sequences. Two recombination hot spots in stem-loop 5 and the polypyrimidine tract in the 5' UTR were mapped using the program GroupingScan. Available HRV-C sequences showed evidence for additional interspecies recombination with HRV-A in the 2A gene, with breakpoints mapping precisely to the boundaries of the C-terminal domain of the encoded proteinase. Pairwise distances between HRV-C variants in VP1 and VP4/VP2 regions fell into two separate distributions, resembling inter- and intraserotype distances of species A and B. These observations suggest that, without serological cross-neutralization data, HRV-C genetic groups may be equivalently classified into types using divergence thresholds derived from distance distributions. The extensive sequence data from multiple genome regions of HRV-C and analyses of recombination in the current study will assist future formulation of consensus criteria for HRV-C type assignment and identification.

Characterization of a putative ancestor of coxsackievirus B5.

Like other RNA viruses, coxsackievirus B5 (CVB5) exists as circulating heterogeneous populations of genetic variants. In this study, we present the reconstruction and characterization of a probable ancestral virion of CVB5. Phylogenetic analyses based on capsid protein-encoding regions (the VP1 gene of 41 clinical isolates and the entire P1 region of eight clinical isolates) of CVB5 revealed two major cocirculating lineages. Ancestral capsid sequences were inferred from sequences of these contemporary CVB5 isolates by using maximum likelihood methods. By using Bayesian phylodynamic analysis, the inferred VP1 ancestral sequence dated back to 1854 (1807 to 1898). In order to study the properties of the putative ancestral capsid, the entire ancestral P1 sequence was synthesized de novo and inserted into the replicative backbone of an infectious CVB5 cDNA clone. Characterization of the recombinant virus in cell culture showed that fully functional infectious virus particles were assembled and that these viruses displayed properties similar to those of modern isolates in terms of receptor preferences, plaque phenotypes, growth characteristics, and cell tropism. This is the first report describing the resurrection and characterization of a picornavirus with a putative ancestral capsid. Our approach, including a phylogenetics-based reconstruction of viral predecessors, could serve as a starting point for experimental studies of viral evolution and might also provide an alternative strategy for the development of vaccines.

Proposals for the classification of human rhinovirus species C into genotypically assigned types.

Human rhinoviruses (HRVs) are common respiratory pathogens associated with mild upper respiratory tract infections, but also increasingly recognized in the aetiology of severe lower respiratory tract disease. Wider use of molecular diagnostics has led to a recent reappraisal of HRV genetic diversity, including the discovery of HRV species C (HRV-C), which is refractory to traditional virus isolation procedures. Although it is heterogeneous genetically, there has to date been no attempt to classify HRV-C into types analogous to the multiple serotypes identified for HRV-A and -B and among human enteroviruses. Direct investigation of cross-neutralization properties of HRV-C is precluded by the lack of methods for in vitro culture, but sequences from the capsid genes (VP1 and partial VP4/VP2) show evidence for marked phylogenetic clustering, suggesting the possibility of a genetically based system comparable to that used for the assignment of new enterovirus types. We propose a threshold of 13% divergence for VP1 nucleotide sequences for type assignment, a level that classifies the current dataset of 86 HRV-C VP1 sequences into a total of 33 types. We recognize, however, that most HRV-C sequence data have been collected in the VP4/VP2 region (currently 701 sequences between positions 615 and 1043). We propose a subsidiary classification of variants showing > 10% divergence in VP4/VP2, but lacking VP1 sequences, to 28 provisionally assigned types (subject to confirmation once VP1 sequences are determined). These proposals will assist in future epidemiological and clinical studies of HRV-C conducted by different groups worldwide, and provide the foundation for future exploration of type-associated differences in clinical presentations and biological properties.

STOPFLU: is it possible to reduce the number of days off in office work by improved hand-hygiene?

BACKGROUND: Acute infectious diseases are major causes of short periods of days off from work, day care and school. These diseases are mainly caused by viruses and hands have a key role in their transmission. Thus, hypothetically, they can be controlled with means of intensified hand hygiene. In this study we aim to elucidate the effect of acute infectious diseases on the work contribution in common office work and study the influence of improved hand hygiene on possible reduction of infectious disease episodes and days off from work due to acute infectious diseases. DESIGN: The voluntary participants have been recruited from six companies in the Helsinki region. The designated 21 study clusters were identified as operationally distinct working units each containing at least 50 people. The clusters were matched and randomized based on results of a pre-trial contagion risk survey. Improved hand hygiene is being executed with guided hand-washing with soap and water in one intervention arm and with alcohol based hand rubbing disinfectant in the other. Participants in both arms have received guidance on how to avoid infections and how to implement contagion stopping habits. A control arm is acting as before regarding hand hygiene. Data collection for evaluation of the efficacy of the interventions is based on self-reporting through weekly electronic reports. The questionnaire is enquiring about possible respiratory or gastrointestinal symptoms during the preceding week, and requests a daily report of presence of symptoms and working capacity. Etiology of the symptoms is not searched for individually, but contribution of different viruses is evaluated by sentinel surveillance, where occupational health clinics located in the premises of the participating companies collect specimens from employees visiting the clinic. Common causative agents of the diseases are being searched for using real-time PCR techniques. The duration of the intervention will be 16 months. Primary endpoints of the study are the number of reported infection episodes in a cluster within a time frame of 100 reporting weeks and the number of reported sick leave episodes in a cluster within a time frame of 100 reporting weeks. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00821509.

Outbreak of poliomyelitis in Finland in 1984-85 - Re-analysis of viral sequences using the current standard approach.

In 1984, a wild type 3 poliovirus (PV3/FIN84) spread all over Finland causing nine cases of paralytic poliomyelitis and one case of aseptic meningitis. The outbreak was ended in 1985 with an intensive vaccination campaign. By limited sequence comparison with previously isolated PV3 strains, closest relatives of PV3/FIN84 were found among strains circulating in the Mediterranean region. Now we wanted to reanalyse the relationships using approaches currently exploited in poliovirus surveillance. Cell lysates of 22 strains isolated during the outbreak and stored frozen were subjected to RT-PCR amplification in three genomic regions without prior subculture. Sequences of the entire VP1 coding region, 150 nucleotides in the VP1-2A junction, most of the 5' non-coding region, partial sequences of the 3D RNA polymerase coding region and partial 3' non-coding region were compared within the outbreak and with sequences available in data banks. In addition, complete nucleotide sequences were obtained for 2 strains isolated from two different cases of disease during the outbreak. The results confirmed the previously described wide intraepidemic variation of the strains, including amino acid substitutions in antigenic sites, as well as the likely Mediterranean region origin of the strains. Simplot and bootscanning analyses of the complete genomes indicated complicated evolutionary history of the non-capsid coding regions of the genome suggesting several recombinations with different HEV-C viruses in the past.

Vitronectin receptors, alpha v integrins, are recognized by several non-RGD-containing echoviruses in a continuous laboratory cell line and also in primary human Langerhans' islets and endothelial cells.

Previously published data suggest that the RGD-recognizing integrin, alphavbeta3, known as the vitronectin receptor, acts as a cellular receptor for RGD-containing enteroviruses, coxsackievirus A9 (CAV-9) and echovirus 9 (E-9), in several continuous cell lines as well as in primary human Langerhans' islets. As this receptor is also capable of binding the ligands by a non-RGD-dependent mechanism, we investigated whether vitronectin receptors, alpha v integrins, might act as receptors for other echoviruses that do not have the RGD motif. Blocking experiments with polyclonal anti-alphavbeta3 antibody showed that both primary human islets and a continuous laboratory cell line of green monkey kidney origin (GMK) are protected similarly from the adverse effects of several non-RGD-containing echovirus (E-7, -11, -25, -30, -32) infections. In contrast, corresponding studies on primary human endothelial cells showed that the receptor works only for E-25, E-30, E-32 and CAV-9. The inhibitory effect of the antibody was not restricted to prototype strains of echoviruses, as GMK cells infected with several field isolates of the corresponding serotypes were also protected from virus-induced cytopathic effects. Co-localization of virus particles with the receptor molecules in both GMK and primary human endothelial cells was demonstrated by live-cell stainings and confocal microscopy. Remarkably, in spite of similar virus-receptor co-localization and a comparable protective effect of the alphavbeta3 antibody, the entry pathways of the studied virus strains seemed to be divergent.