A six-year study on respiratory viral infections in a bull testing facility

Viral infection dynamics and bovine respiratory disease (BRD) treatment rates were studied over six years at a Swedish bull testing station with an 'all in, all out' management system. In August of each of the years 1998-2003, between 149 and 185 4-8-month-old calves arrived at the station from 99 to 124 different beef-breeding herds, and remained until March the following year. Only calves that tested free from bovine viral diarrhoea virus (BVDV) were allowed to enter the station and original animal groups were kept isolated from new cattle in their original herds for three weeks before admission. Although neither prophylactic antibiotics, nor BRD vaccines were used, less than 0.7-13.2% (mean 5%) of the calves (n=970) required treatment for BRD during the first five weeks following entry. This was probably due, at least in part, to the season (the summer months) when the animals were commingled. In the six-month period August-February, 38% of the animals were treated one or more times for BRD and mortality was 0.7%. Hereford and Aberdeen Angus calves had significantly higher treatment rates than Charolais, Simmental and Blonde d'Aquitaine. Serological testing on samples obtained in August, November and January indicated that bovine parainfluenza virus 3 (PIV-3) infections occurred each year before November after entry. Bovine coronavirus (BCoV) infections also occurred every year, but in 3/6 years this was not until after November. Bovine respiratory syncytial virus (BRSV) infections occurred only every second year and were associated with a treatment peak and one death on one occasion (December). The herd remained BVDV free during the entire study period. The infection patterns for PIV-3 and BCoV indicated a high level of infectivity amongst bovine calves, whereas the incidence for BRSV was observed at a lower level. Although the rearing of the animals differed from conventional beef production, the study has shown that commingling animals from many sources is not necessarily associated with high morbidity within the first few weeks after arrival. By preventing BRD soon after commingling the prerequisites for protective vaccination at entry might be improved. Applied management routines are discussed.

Should healthy children be vaccinated against influenza? A consensus report of the Summits of Independent European Vaccination Experts

Influenza is often regarded as an illness of the elderly portion of the population because most of the excess mortality associated with influenza epidemics occurs in that age group. However, evidence derived from a large number of clinical studies carried out in different countries and various settings has clearly demonstrated that the burden of influenza is also substantial in children. The attack rates of influenza during annual epidemics are consistently highest in children, and young children are hospitalized for influenza-related illnesses at rates comparable to those for adults with high-risk conditions. Especially among children younger than 3 years of age, influenza frequently predisposes the patient to bacterial complications such as acute otitis media. Children also serve as the main transmitters of influenza in the community. A safe and effective vaccine against influenza has been available for decades, but the vaccine is rarely used even for children with high-risk conditions. Despite several existing problems related to influenza vaccination of children, the current evidence indicates that the advantages of vaccinating young children would clearly outweigh the disadvantages. Considering the total burden of influenza in children, children younger than 3 years of age should be regarded as a high-risk group for influenza, analogously with the age-based definition of high risk among persons 65 years of age or older. Annual influenza vaccination should be recommended to all children from 6 months to 3 years of age.

Modeling control strategies of respiratory pathogens

Contact network epidemiology can provide quantitative input even before pathogen is fully characterized.

Effectively controlling infectious diseases requires quantitative comparisons of quarantine, infection control precautions, case identification and isolation, and immunization interventions. We used contact network epidemiology to predict the effect of various control policies for a mildly contagious disease, such as severe acute respiratory syndrome, and a moderately contagious disease, such as smallpox. The success of an intervention depends on the transmissibility of the disease and the contact pattern between persons within a community. The model predicts that use of face masks and general vaccination will only moderately affect the spread of mildly contagious diseases. In contrast, quarantine and ring vaccination can prevent the spread of a wide spectrum of diseases. Contact network epidemiology can provide valuable quantitative input to public health decisionmaking, even before a pathogen is well characterized.

A randomized, controlled trial of a multifaceted intervention including alcohol-based hand sanitizer and hand-hygiene education to reduce illness transmission in the home

OBJECTIVE

Good hand hygiene may reduce the spread of infections in families with children who are in out-of-home child care. Alcohol-based hand sanitizers rapidly kill viruses that are commonly associated with respiratory and gastrointestinal (GI) infections. The objective of this study was to determine whether a multifactorial campaign centered on increasing alcohol-based hand sanitizer use and hand-hygiene education reduces illness transmission in the home.

METHODS

A cluster randomized, controlled trial was conducted of homes of 292 families with children who were enrolled in out-of-home child care in 26 child care centers. Eligible families had > or =1 child who was 6 months to 5 years of age and in child care for > or =10 hours/week. Intervention families received a supply of hand sanitizer and biweekly hand-hygiene educational materials for 5 months; control families received only materials promoting good nutrition. Primary caregivers were phoned biweekly and reported respiratory and GI illnesses in family members. Respiratory and GI-illness-transmission rates (measured as secondary illnesses per susceptible person-month) were compared between groups, adjusting for demographic variables, hand-hygiene practices, and previous experience using hand sanitizers.

RESULTS

Baseline demographics were similar in the 2 groups. A total of 1802 respiratory illnesses occurred during the study; 443 (25%) were secondary illnesses. A total of 252 GI illnesses occurred during the study; 28 (11%) were secondary illnesses. The secondary GI-illness rate was significantly lower in intervention families compared with control families (incidence rate ratio [IRR]: 0.41; 95% confidence interval [CI]: 0.19-0.90). The overall rate of secondary respiratory illness was not significantly different between groups (IRR: 0.97; 95% CI: 0.72-1.30). However, families with higher sanitizer usage had a marginally lower secondary respiratory illness rate than those with less usage (IRR: 0.81; 95% CI: 0.65-1.09).

CONCLUSIONS

A multifactorial intervention emphasizing alcohol-based hand sanitizer use in the home reduced transmission of GI illnesses within families with children in child care. Hand sanitizers and multifaceted educational messages may have a role in improving hand-hygiene practices within the home setting.

Instructions for infection control in outpatient care of patients with cystic fibrosis

RATIONALE AND GOALS

Infections of the respiratory tract with multiresistant bacteria and other pathogens lead to a poor prognosis in patients with cystic fibrosis. The patient-to-patient transmission of infectious agents during the clinic visit and the transmission via the hands of healthcare workers has gained increased attention in the cystic fibrosis community. For this reason practical and possibly evidence-based instructions for infection control measures are needed that are feasible in every day outpatient management of patients with cystic fibrosis. -

METHODS

For generating these instructions, a committee consisting of medical doctors and nursing staff providing care to cystic fibrosis patients, infectious diseases specialists and members of the department of infection control analyzed the patients' route through our cystic fibrosis unit during a routine clinic visit. First, the expert committee defined instructions concerning important infection control measures for each step. Next, each instruction was compared with the published literature and categorized as to its grade of evidence (I, II, 0). Instructions with grades of evidence I and II and instructions without demonstrated evidence (0) but theoretically reasonable and practically feasible, were accepted and outlined in a flow diagram. All other instructions were rejected. -

RESULTS

The expert committee defined 45 instructions for infection control measures during an outpatient visit of a cystic fibrosis patient. 43 instructions within the categories "principles", "measures before entering the clinic", "measures in the examination room" and "measures when leaving the clinic" matched the criteria mentioned above and were accepted. 2 instructions were rejected. -

CONCLUSIONS

Here we report evidence-based instructions for infection control in the setting of outpatient care for cystic fibrosis patients which are feasible in every day care. Since some instructions could only be assigned low evidence grade levels, i. e. II or 0, a further clarification of these issues by scientific investigations is warranted. Unresolved issues are primarily the recommendation for or against wearing a face mask for patients with certain pathogens and the issues of colonization with Stenotrophomonas maltophilia and Alcaligines xylosidans, but also with Aspergillus spp.. Continuous education of patients and healthcare workers as well as the validation of these practical instructions by a close monitoring and documentation of pathogens are of great importance.

Emergence and spread of Streptococcus pneumoniae with erm(B) and mef(A) resistance

Streptococcus pneumoniae isolates (N = 31,001) were collected from patients with community-acquired respiratory tract infections during the PROTEKT US surveillance study (2000–2003). While the macrolide (erythromycin) resistance rate remained stable at ≈29%, the prevalence of resistant isolates containing both erm(B) and mef(A) increased from 9.7% in year 1 to 16.4% in year 3, with substantial regional variability. Almost all (99.2%) dual erm(B)+mef(A) macrolide-resistant isolates exhibited multidrug resistance, whereas 98.6% and 99.0% were levofloxacin- and telithromycin-susceptible, respectively. These strains were most commonly isolated from the ear or middle-ear fluid of children. Of 152 representative erm(B)+mef(A) isolates, >90% were clonally related to the multidrug-resistant international Taiwan^19F-14 clonal complex 271 (CC271). Of 366 erm(B)+mef(A) isolates from the PROTEKT global study (1999–2003), 83.3% were CC271, with the highest prevalence seen in South Africa, South Korea, and the United States. This study confirms the increasing global emergence and rapidly increasing US prevalence of this multidrug-resistant pneumococcal clone.

A case-control study of acute respiratory tract infection in general practice patients in The Netherlands

BACKGROUND

Acute respiratory tract infections (ARTIs) are responsible for considerable morbidity in the community, but little is known about the presence of respiratory pathogens in asymptomatic individuals. We hypothesized that asymptomatic persons could have a subclinical infection and thus act as a source of transmission.

METHODS

During the period of 2000-2003, all patients with ARTI who visited their sentinel general practitioner had their data reported to estimate the incidence of ARTI in Dutch general practices. A random selection of these patients (case patients) and an equal number of asymptomatic persons visiting for other complaints (control subjects) were included in a case-control study. Nose and throat swabs of participants were tested for a broad range of pathogens.

RESULTS

The overall incidence of ARTI was 545 cases per 10,000 person-years, suggesting that, in the Dutch population, an estimated 900,000 persons annually consult their general practitioner for respiratory complaints. Rhinovirus was most common in case patients (24%), followed by influenza virus type A (11%) and coronavirus (7%). Viruses were detected in 58% of the case patients, beta -hemolytic streptococci group A were detected in 11%, and mixed infections were detected in 3%. Pathogens were detected in approximately 30% of control subjects, particularly in the youngest age groups.

CONCLUSION

This study confirms that most ARTIs are viral and supports the reserved policy of prescribing antibiotics. In both case and control subjects, rhinovirus was the most common pathogen. Of bacterial infections, only group A beta-hemolytic streptococci were more common in case patients than in control subjects. Furthermore, we demonstrated that asymptomatic persons might be a neglected source of transmission.

Bound for Sydney town: health surveillance on international cruise vessels visiting the Port of Sydney

A program for routine health surveillance on international cruise ships visiting the Port of Sydney has been developed since 1998. Before introduction of this program, ships only reported quarantinable diseases and were not aware of the Australian requirement to report other infectious diseases. Voluntary routine reporting, developed in partnership with the cruise ship industry, provides timely information on all infectious diseases of public health interest during every cruise. During 1999-2003, the program resulted in detection of and response to 14 outbreaks of gastroenteritis or acute respiratory infection, affecting more than 1400 passengers and crew. The program has improved preventive action, and risk communication and management by cruise ship operators, and led to more timely investigation and support by public health authorities.

Respiratory infections during air travel

An increasing number of individuals undertake air travel annually. Issues regarding cabin air quality and the potential risks of transmission of respiratory infections during flight have been investigated and debated previously, but, with the advent of severe acute respiratory syndrome and influenza outbreaks, these issues have recently taken on heightened importance. Anecdotally, many people complain of respiratory symptoms following air travel. However, studies of ventilation systems and patient outcomes indicate the spread of pathogens during flight occurs rarely. In the present review, aspects of the aircraft cabin environment that affect the likelihood of transmission of respiratory pathogens on airplanes are outlined briefly and evidence for the occurrence of outbreaks of respiratory illness among airline passengers are reviewed. (Intern Med J 2005; 35: 50–55)

Genomic and bioinformatics analysis of HAdV-7, a human adenovirus of species B1 that causes acute respiratory disease: implications for vector development in human gene therapy

Human adenovirus serotype 7 (HAdV-7) is a reemerging pathogen identified in acute respiratory disease (ARD), particularly in epidemics affecting basic military trainee populations of otherwise healthy young adults. The genome has been sequenced and annotated (GenBank accession no. ). Comparative genomics and bioinformatics analyses of the HAdV-7 genome sequence provide insight into its natural history and phylogenetic relationships. A putative origin of HAdV-7 from a chimpanzee host is observed. This has implications within the current biotechnological interest of using chimpanzee adenoviruses as vectors for human gene therapy and DNA vaccine delivery. Rapid genome sequencing and analyses of this species B1 member provide an example of exploiting accurate low-pass DNA sequencing technology in pathogen characterization and epidemic outbreak surveillance through the identification, validation, and application of unique pathogen genome signatures.

Illness transmission in the home: a possible role for alcohol-based hand gels

OBJECTIVES

The widespread use of child care has altered the epidemiology of respiratory and gastrointestinal (GI) infection in the community. Our primary objective was to measure transmission of respiratory and GI illnesses among families with children enrolled in child care. We also sought to examine potential predictors of reduced illness transmission in the home in a secondary analysis.

METHODS

We performed an observational, prospective cohort study to determine transmission rates for respiratory and GI illnesses within families with at least 1 child between 6 months and 5 years of age enrolled in child care. A survey about family beliefs and practices was mailed at the beginning of the study. Symptom diaries were provided for families to record the timing and duration of respiratory and GI illnesses. To ensure the accuracy of symptom diaries, biweekly telephone calls were performed to review illnesses recorded by participants. Families with > or =4 weeks of data recorded were included in the analysis. Families were recruited from 5 pediatric practices in the metropolitan Boston area. Of 261 families who agreed to participate in the study, 208 were available for analysis. Secondary transmission rates for respiratory and GI illnesses were measured as illnesses per susceptible person-month.

RESULTS

We observed 1545 respiratory and 360 GI illnesses in 208 families from November 2000 to May 2001. Of these, 1099 (71%) respiratory and 297 (83%) GI illnesses were considered primary illnesses introduced into the home. The secondary transmission rates for respiratory and GI illnesses were 0.63 and 0.35 illnesses per susceptible person-month, respectively. Only two thirds of respondents correctly believed that contact transmission was important in the spread of colds, and fewer than half believed that it was important in the spread of stomach flus. Twenty-two percent of respondents reported use of alcohol-based hand gels all, most, or some of the time; 33% reported always washing their hands after blowing or wiping a nose. In multivariate models, use of alcohol-based hand gels had a protective effect against respiratory illness transmission in the home.

CONCLUSIONS

In homes with young children enrolled in child care, illness transmission to family members occurs frequently. Alcohol-based hand gel use was associated with reduced respiratory illness transmission in the home.

Transmission of infectious diseases during commercial air travel

Because of the increasing ease and affordability of air travel and mobility of people, airborne, food-borne, vector-borne, and zoonotic infectious diseases transmitted during commercial air travel are an important public health issue. Heightened fear of bioterrorism agents has caused health officials to re-examine the potential of these agents to be spread by air travel. The severe acute respiratory syndrome outbreak of 2002 showed how air travel can have an important role in the rapid spread of newly emerging infections and could potentially even start pandemics. In addition to the flight crew, public health officials and health care professionals have an important role in the management of infectious diseases transmitted on airlines and should be familiar with guidelines provided by local and international authorities.

Risk of respiratory infections in health care workers: lessons on infection control emerge from the SARS outbreak

Close proximity of persons together with handling of human secretions (eg respiratory secretions) make health care workers (HCW) particularly vulnerable to transmission of droplet-transmitted respiratory infections. This was tragically highlighted during the international outbreak of severe acute respiratory syndrome (SARS) in 2003 with attack rates of more than 50% in HCW. The purpose of this article is to review common airborne and droplet-transmitted bacterial and viral respiratory tract infections with regard to their impact on health care workers. Lessons need to be learned from the SARS epidemic. The three main strategies to prevent or control occupationally acquired infections are relatively simple and cost-effective-droplet and contact precautions and for some pathogens also vaccination. Enforced implementation of stringent droplet precautions during the SARS crisis should be maintained; and this will most likely have a major additional impact on other nosocomial infections. Employee health services should proactively and creatively devise delivery systems that enhance compliance with vaccination programs for all health care workers. Hospital surveillance should be expanded to all respiratory diseases to facilitate early detection of nosocomial outbreaks, and this should also include surveillance of all HCW. Integrated syndromic and virological surveillance systems set up during the SARS epidemic will also further our understanding of other respiratory infections in the hospital setting. Even if pursuing early diagnosis for unspecific respiratory illnesses is expensive, identification of the causative organism may reduce unnecessary isolation, contact tracing and anxiety, in particular during an outbreak situation. We have a duty to protect our health care workers.

Genomic and bioinformatics analysis of HAdV-4, a human adenovirus causing acute respiratory disease: implications for gene therapy and vaccine vector development

Human adenovirus serotype 4 (HAdV-4) is a reemerging viral pathogenic agent implicated in epidemic outbreaks of acute respiratory disease (ARD). This report presents a genomic and bioinformatics analysis of the prototype 35,990-nucleotide genome (GenBank accession no. AY594253). Intriguingly, the genome analysis suggests a closer phylogenetic relationship with the chimpanzee adenoviruses (simian adenoviruses) rather than with other human adenoviruses, suggesting a recent origin of HAdV-4, and therefore species E, through a zoonotic event from chimpanzees to humans. Bioinformatics analysis also suggests a pre-zoonotic recombination event, as well, between species B-like and species C-like simian adenoviruses. These observations may have implications for the current interest in using chimpanzee adenoviruses in the development of vectors for human gene therapy and for DNA-based vaccines. Also, the reemergence, surveillance, and treatment of HAdV-4 as an ARD pathogen is an opportunity to demonstrate the use of genome determination as a tool for viral infectious disease characterization and epidemic outbreak surveillance: for example, rapid and accurate low-pass sequencing and analysis of the genome. In particular, this approach allows the rapid identification and development of unique probes for the differentiation of family, species, serotype, and strain (e.g., pathogen genome signatures) for monitoring epidemic outbreaks of ARD.

Antiviral KLEENEX

In vitro and in vivo, the active ingredients between the layers of these tissues are virucidal, but virus transferred from nose to tissue without passing through the layer is still infectious. Whether this product can reduce transmission of respiratory infections in real-life households remains to be established. Frequent handwashing might be more effective.

Infectious respiratory illnesses and their impact on healthcare workers: a review

Respiratory illnesses are increasingly recognised as a growing concern for healthcare workers (HCWs) and patients. The recent hospital-based outbreak of Severe Acute Respiratory Syndrome (SARS) has once again highlighted the vulnerability of HCWs. The new epidemic of the 21st century resulted in tremendous economic and psychological impact with its high rates of mortality and nosocomial transmission. Even as the epidemic was brought under control within months, many details about the SARS coronavirus remained a mystery. The threat of another potential global outbreak continues to lurk in the background. Many valuable lessons have been learned through the SARS epidemic. It is, therefore, timely for us to review some of the respiratory pathogens that are well-known to cause nosocomial outbreaks. We need to be better armed to deal with future potential outbreaks and biohazardous situations. The importance of safeguarding the health of our medical staff and the community cannot be over-emphasised. In this paper, we review the incidence, transmission and various preventive strategies of respiratory illnesses in HCWs, in particular, new diagnostic tools, infection control management strategies, personal protective equipments, vaccination programmes and post-exposure prophylaxis.

Research gaps in protecting healthcare workers from SARS and other respiratory pathogens: an interdisciplinary, multi-stakeholder, evidence-based approach

OBJECTIVE

To identify priorities for further research in protecting healthcare workers (HCWs) from severe acute respiratory syndrome (SARS) and other respiratory pathogens by summarizing the basic science of infectious bioaerosols and the efficacy of facial protective equipment; the organizational, environmental, and individual factors that influence the success of infection control and occupational health programs; and factors identified by HCWs as important.

METHOD

An extensive literature review was conducted and 15 focus groups held, mostly with frontline HCWs in Toronto. Critical gaps in knowledge were identified and prioritized.

RESULTS

Highest priority was given to organizational factors that create a climate of safety. Other priority areas included understanding aerosolization risks and practical measures to control bioaerosols at the source.

CONCLUSIONS

Further research is warranted to improve safety climate in health care and, specifically, to provide greater protection against respiratory pathogens.

Nasal plugs for preventing respiratory infections

Nasal plugs were made from an N-95 respirator, surgical mask or a cotton ball and inserted into the nares of volunteer healthcare workers for 30 min. Initial and persistent respiratory resistance, choking sensation, and discomfort in the mouth and nose areas were recorded for the three different nasal plugs, the N-95 respirator and a surgical mask. Nasal plugs were more convenient and better tolerated than the masks. The ability of the nasal plug material to prevent infection by droplet transmission was also tested. A piece of each material was placed on a blood agar plate, the volunteer coughed onto the plate and the material was removed. Bacterial colonies only grew in the areas not previously covered by the nasal plug material. The cotton ball nasal plug is probably as effective as the N-95 respirator or surgical masks at preventing infection, and is much cheaper.