Clinical predictors of bioterrorism-related inhalational anthrax

Limitation of a bioterrorist anthrax attack will require rapid and accurate recognition of the earliest victims. To identify clinical characteristics of inhalational anthrax, we compared 47 historical cases (including 11 cases of bioterrorism-related anthrax) with 376 controls with community-acquired pneumonia or influenza-like illness. Nausea, vomiting, pallor or cyanosis, diaphoresis, altered mental status, and raised haematocrit were more frequently recorded in the inhalational anthrax cases than in either the community-acquired pneumonia or influenza-like illness controls. The most accurate predictor of anthrax was mediastinal widening or pleural effusion on a chest radiograph. This finding was 100% sensitive (95% CI 84.6-100.0) for inhalational anthrax, 71.8% specific (64.8-78.1) compared with community-acquired pneumonia, and 95.6% specific (90.0-98.5) compared with influenza-like illness. Our findings represent preliminary efforts toward identifying clinical predictors of inhalational anthrax.

Child day care risks of common infectious diseases revisited

BACKGROUND

The increased risk of common infectious diseases associated with child day care attendance may vary by age, health plan and parent educational level. This study determined quantitatively the risk of diarrhoeal illness and upper respiratory infection (URI) among day-care children in comparison with home-care children. It examined the extent of risks in day-care children under different conditions of three age groups, enrolled in two health plans, and from families of two levels of education.

METHODS

The study subjects were recruited through two health plans: a Health Maintenance Organization (HMO) and the Medicaid program in Columbia, South Carolina of the USA. The sample was collected using a household survey of children, aged 5 years or younger. The participants were contacted bimonthly for 18 months with 435 attending out-of-home day care facilities and 753 being cared for at home. The potential confounding factors of family characteristics were controlled in examining the odds ratios for day care effect on common infections in children under different conditions.

RESULTS

In general, risks of diarrhoeal illness and URI in day-care children are greater than in home-care children. Children younger than 1.5 years of age attending day care and covered by the Medicaid program are at the greatest risk. The difference in risks between day-care and home-care children, however, is reduced to an insignificant level for children older than 1.5 years of age and for children covered by the HMO health plan. Among day-care children, those who are covered by the Medicaid program are at a significantly higher risk than those who are covered by the HMO health plan.

CONCLUSIONS

Although day-care children in general suffer a greater risk of common infectious diseases, the extent of day care effect on risks of diarrhoeal illness and URI varies significantly by age and type of health insurance plan.

Influence of school closure on the incidence of viral respiratory diseases among children and on health care utilization

We evaluated the effect of school closure on the occurrence of respiratory infection among children ages 6-12 years and its impact on health care services. During this period, there were significant decreases in the diagnoses of respiratory infections (42%), visits to physician (28%) and emergency departments (28%) and medication purchases (35%). The present study provides quantitative data to support school closure during an influenza pandemic.

Studies of the Transmission Routes of Ornithobacterium rhinotracheale and Immunoprophylaxis to Prevent Infection in Young Meat Turkeys

The importance and prevention of the horizontal as well as the vertical transmission of Ornithobacterium rhinotracheale were investigated. In our first experiment we observed that specific-pathogen-free broiler chickens that were placed in hatching incubators at a commercial turkey hatchery during hatch showed respiratory tract lesions at postmortem examination that were positive for O. rhinotracheale by bacteriology and immunohistology. It appeared that vertical transmission occurred and that horizontal transmission of O. rhinotracheale is possible. In a second experiment, the turkeys derived from vaccinated parents showed significantly fewer respiratory tract lesions at postmortem examination at 16 days of age than the birds derived from nonvaccinated parents. In a third experiment, all vaccinated young birds, regardless of the vaccination state of their parents, showed significantly fewer respiratory tract lesions at 6 wk of age. We concluded that vaccination of the breeders reduces vertical transmission and that vaccination of the progeny is needed to resist challenge at 6 wk of age.

Infection control in cystic fibrosis

Over the past 20 years there has been a greater interest in infection control in cystic fibrosis (CF) as patient-to-patient transmission of pathogens has been increasingly demonstrated in this unique patient population. The CF Foundation sponsored a consensus conference to craft recommendations for infection control practices for CF care providers. This review provides a summary of the literature addressing infection control in CF. Burkholderia cepacia complex, Pseudomonas aeruginosa, and Staphylococcus aureus have all been shown to spread between patients with CF. Standard precautions, transmission-based precautions including contact and droplet precautions, appropriate hand hygiene for health care workers, patients, and their families, and care of respiratory tract equipment to prevent the transmission of infectious agents serve as the foundations of infection control and prevent the acquisition of potential pathogens by patients with CF. The respiratory secretions of all CF patients potentially harbor clinically and epidemiologically important microorganisms, even if they have not yet been detected in cultures from the respiratory tract. CF patients should be educated to contain their secretions and maintain a distance of >3 ft from other CF patients to avoid the transmission of potential pathogens, even if culture results are unavailable or negative. To prevent the acquisition of pathogens from respiratory therapy equipment used in health care settings as well as in the home, such equipment should be cleaned and disinfected. It will be critical to measure the dissemination, implementation, and potential impact of these guidelines to monitor changes in practice and reduction in infections.

Spread of Stenotrophomonas maltophilia colonization in a pediatric intensive care unit detected by monitoring tracheal bacterial carriage and molecular typing

In our pediatric intensive care unit in Tours (France), intubated and ventilated inpatients are systematically monitored for tracheal bacterial colonization twice a week. This led us to detect five patients colonized with Stenotrophomonas maltophilia over a 4-month period. Molecular typing of the isolates using random amplified polymorphism DNA (RAPD) and pulsed-field gel electrophoresis (PFGE) confirmed that four of the five isolates were genetically related. The strict isolation of carriers and improvements in hygiene measures stopped the spread. This systematic strategy prevented pulmonary nosocomial infections or allowed their early detection. Moreover, it has made it possible to assess the efficiency of care practices continuously.

Bacteriophage treatment of a severe Escherichia coli respiratory infection in broiler chickens

A bacteriophage to a serotype 02, nonmotile Escherichia coli was isolated from municipal waste treatment facilities and poultry processing plants. A study was conducted to determine the efficacy of multiple vs. single intramuscular (i.m.) injections of bacteriophage to treat a severe E. coli respiratory infection. The birds were challenged at 7 days of age by injection of 6 x 10(4) colony-forming units (cfu) of E. coli into the thoracic air sac followed by an i.m. injection into the thigh with either heat-killed or active bacteriophage. There were 16 treatments with three replicate pens of 10 birds. There were four control treatments, which included untreated birds, birds injected with either heat-killed or active bacteriophage, and birds challenged only with E. coli. In the remaining treatments, birds were injected with heat-killed or active bacteriophage either once immediately after E. coli challenge or immediately after challenge and at 8 and 9 days of age, once at 8 days of age or at 8, 9, and 10 days of age, and once at 9 days of age or at 9, 10, and 11 days of age. Mortality was significantly decreased from 57% to 13% in the birds given a single i.m. injection of bacteriophage immediately after E. coli challenge, and there was complete recovery in birds treated immediately after challenge and at 8 and 9 days of age, which was a significant improvement from the single injection treatment. There was a significant reduction in mortality from 57% to 10% in the birds treated with bacteriophage once at 8 days of age and those birds treated at 8, 9, and 10 days of age, with no difference between single or multiple treatments. The mortality in the single or multiple phage treated birds that started at 9 days of age was reduced from 57% to 28% and 27%, respectively, but was not statistically different from the control. These data suggest that bacteriophage can be an effective treatment when administered early in this experimental E. coli respiratory disease and that early multiple treatments are better than a single treatment. The efficacy of bacteriophage treatment diminishes as it is delayed, with no difference between single or multiple treatments. Bacteriophage may provide an effective alternative to antibiotics, but like and biotic therapy, the effectiveness of phage to rescue animals decreases the longer treatment is delayed in the disease process.

Upper respiratory tract carriage and transmission of pneumococci

Vaccines have been instrumental in preventing childhood morbidity as well as mortality. It is imperative that health professionals have all the necessary information about a vaccine before its introduction into the routine immunisation schedule. This article looks at the possible introduction of a new pneumococcal conjugate vaccine and reviews a longitudinal carriage study of pneumococcus in UK families to determine pneumococcal carriage rates.

Epidemic spread of Pandoraea apista, a new pathogen causing severe lung disease in cystic fibrosis patients

We show that Pandoraea apista must be added to the increasing list of pathogens capable of causing chronic lung infection in cystic fibrosis (CF) patients. It is most likely that this strain of P. apista was transmissible among patients with CF, leading to spread of infection from the index patient to 5 other patients exposed during participation in winter camps and/or hospitalization. All patients developed chronic infection with high levels of antibodies, and 4 patients had a downhill course of lung disease. P. apista must therefore be considered a new and sometimes important pathogen for CF patients. Cohort isolation prevented further spread of P. apista in our CF center.

Épidémie nosocomiale à Burkholderia cepacia dans une unité de réanimation infantile

BACKGROUND

We report an outbreak of Burkholderia cepacia respiratory tract infection and colonization in an intensive pediatric care unit.P PATIENTS AND METHODS: Between February and December 1999, B. cepacia was isolated from five children hospitalized in this unit. We reviewed the charts of the patients, evaluated the antiseptics use and the disinfection practices for reusable patient care equipment. An environmental study was conducted and comparison of B. cepacia was performed with genotypic method (RAPD).

RESULTS

All patients were mechanically ventilated and had received large spectrum antibiotics. The disinfection procedure for reusable equipment was not respected and some single-dose of antiseptics solutions were used for several patients. B. cepacia was not found in 34 environmental samples. The RAPD assay revealed that all five isolates had identical DNA profiles.

CONCLUSION

Despite the investigation the source of the B. cepacia clone in this nosocomial outbreak remained unknown, but antiseptics use and disinfection practices were revised. No new B. cepacia infections were identified after control measures were implemented.

Risk of indoor airborne infection transmission estimated from carbon dioxide concentration

The Wells-Riley equation, which is used to model the risk of indoor airborne transmission of infectious diseases such as tuberculosis, is sometimes problematic because it assumes steady-state conditions and requires measurement of outdoor air supply rates, which are frequently difficult to measure and often vary with time. We derive an alternative equation that avoids these problems by determining the fraction of inhaled air that has been exhaled previously by someone in the building (rebreathed fraction) using CO2 concentration as a marker for exhaled-breath exposure. We also derive a non-steady-state version of the Wells-Riley equation which is especially useful in poorly ventilated environments when outdoor air supply rates can be assumed constant. Finally, we derive the relationship between the average number of secondary cases infected by each primary case in a building and exposure to exhaled breath and demonstrate that there is likely to be an achievable critical rebreathed fraction of indoor air below which airborne propagation of common respiratory infections and influenza will not occur.

POTENTIAL SITES OF VIRUS LATENCY ASSOCIATED WITH INDIGENOUS PSEUDORABIES VIRUSES IN FERAL SWINE

Free-ranging feral swine (Sus scrofa) are known to be present in at least 32 states of the USA and are continuously expanding their range. Infection with pseudorabies virus (PRV) occurs in feral swine and the primary route of transmission in free-living conditions seems to be venereal. Between 1995 and 1999, naturally infected feral swine and experimentally infected hybrid progeny of feral and domestic swine, were kept in isolation and evaluated for occurrence of latent PRV indigenous to feral swine in sacral and trigeminal ganglia and tonsil. Sacral ganglia were shown, by polymerase chain reaction (PCR) amplification of the thymidine kinase (TK) gene of PRV, to be the most frequent sites of latency of PRV. Nine (56%) of 16 sacral ganglia, seven (44%) of 16 trigeminal ganglia, and five (39%) of 13 tonsils from naturally infected feral swine were positive for PCR amplification of TK sequences of PRV. These tissues were negative for PRV when viral isolation was attempted in Vero cells. DNA sequencing of cloned TK fragments from the sacral ganglia of two feral swine, showed only one nucleotide difference between the two fragments and extensive sequence homology to fragment sequences from various domestic swine PRV strains from China, Northern Ireland, and the USA. The hybrid feral domestic swine, experimentally inoculated with an indigenous feral swine PRV isolate by either the genital or respiratory route, acquired the infection but showed no clinical signs of pseudorabies. Virus inoculated into either the genital or respiratory tract could, at times, be isolated from both these sites. The most common latency sites were the sacral ganglia, regardless of the route and dose of infection in these experimentally infected hybrids. Nine of 10 sacral ganglia, six of 10 trigeminal ganglia, and three of 10 tonsils were positive for PCR amplification of TK sequences. No virus was isolated from these tissues in Vero cells. The demonstration of the sacral ganglia as the most common sites of latency of pseudorabies viruses indigenous to feral swine, supports the hypothesis that these viruses are primarily transmitted venereally, and not by the respiratory route as is common in domestic swine, in which the trigeminal ganglia are the predominant sites of virus latency.

Rapid spread of penicillin-resistant Streptococcus pneumoniae among high-risk hospital inpatients and the role of molecular typing in outbreak confirmation

This study describes an outbreak of penicillin-resistant Streptococcus pneumoniae among patients on an ear, nose and throat (ENT) ward. Over a period of 10 days, S. pneumoniae [penicillin minimum inhibitory concentration (MIC) 0.75] was isolated from a total of seven patients with symptoms and signs of lower respiratory tract infection. Standard source isolation was implemented and the ward was closed to admissions and discharges. Screening of nasopharyngeal secretions was undertaken on all patients and staff contacts. Three patients (of eight possible contacts) and none of the staff (47 screened) were identified as colonized with the same strain. Nasal mupirocin and oral rifampicin were administered to carriers. Confirmation of the outbreak was achieved rapidly using a contemporary molecular typing method (pulsed-field gel electrophoresis) and timely introduction of infection control measures successfully contained the outbreak. Implications for pneumococcal vaccination are discussed.

Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission

Infection Control Recommendations for Patients With Cystic Fibrosis: Microbiology, Important Pathogens, and Infection Control Practices to Prevent Patient-to-Patient Transmissionupdates, expands, and replaces the consensus statement,Microbiology and Infectious Disease in Cystic Fibrosispublished in 1994. This consensus document presents background data and evidence-based recommendations for practices that are intended to decrease the risk of transmission of respiratory pathogens among CF patients from contaminated respiratory therapy equipment or the contaminated environment and thereby reduce the burden of respiratory illness. Included are recommendations applicable in the acute care hospital, ambulatory, home care, and selected non-healthcare settings. The target audience includes all healthcare workers who provide care to CF patients. Antimicrobial management is beyond the scope of this document.

Airborne rhinovirus detection and effect of ultraviolet irradiation on detection by a semi-nested RT-PCR assay

BACKGROUND

Rhinovirus, the most common cause of upper respiratory tract infections, has been implicated in asthma exacerbations and possibly asthma deaths. Although the method of transmission of rhinoviruses is disputed, several studies have demonstrated that aerosol transmission is a likely method of transmission among adults. As a first step in studies of possible airborne rhinovirus transmission, we developed methods to detect aerosolized rhinovirus by extending existing technology for detecting infectious agents in nasal specimens.

METHODS

We aerosolized rhinovirus in a small aerosol chamber. Experiments were conducted with decreasing concentrations of rhinovirus. To determine the effect of UV irradiation on detection of rhinoviral aerosols, we also conducted experiments in which we exposed aerosols to a UV dose of 684 mJ/m2. Aerosols were collected on Teflon filters and rhinovirus recovered in Qiagen AVL buffer using the Qiagen QIAamp Viral RNA Kit (Qiagen Corp., Valencia, California) followed by semi-nested RT-PCR and detection by gel electrophoresis.

RESULTS

We obtained positive results from filter samples that had collected at least 1.3 TCID50 of aerosolized rhinovirus. Ultraviolet irradiation of airborne virus at doses much greater than those used in upper-room UV germicidal irradiation applications did not inhibit subsequent detection with the RT-PCR assay.

CONCLUSION

The air sampling and extraction methodology developed in this study should be applicable to the detection of rhinovirus and other airborne viruses in the indoor air of offices and schools. This method, however, cannot distinguish UV inactivated virus from infectious viral particles.

[Nosocomial infections in nursing homes in Oslo]

BACKGROUND

Residents of long-term care facilities are at risk of infection and may deliver resistant microbes to hospitals.

MATERIAL AND METHODS

A point prevalence study was performed, including 3,474 residents in 2000 and 4,650 in 2001.

RESULTS

The infection rate increased from 5.6% in 2000 to 7.5% in 2001 (p < 0.001). Urinary tract infections predominated. Pneumonia increased from 2000 to 2001 (0.7%-1.4%; p < 0.01), as did the rate of operated patients (2.9%-6.5%, p < 0.001), while postoperative wound infections was reduced (p = 0.02). Antibiotics were given to 5.8% in 2000 and 6.1% in 2001. Microbiological assessments were available from 29.6% infections in 2000 and 21.4% in 2001. Staphylococcus aureus and Escherichia coli predominated. Methicillin-resistant S aureus was found in only two patients.

INTERPRETATION

The increased burden of operated patients in understaffed long-term care facilities may have caused an increasing rate of infections. Staffing with sufficient and competent personnel and intensified infection control work is needed.

[The risk of contagious epidemics in geriatric facilities]

THE RISKS OF EPIDEMICS IN INSTITUTIONAL SETTINGS: An epidemic must be suspected when an increase in the number of cases of a same type of infection is observed. Numerous microorganisms are responsible for epidemics in geriatric facilities: viruses, bacteria and parasites. In the case of an epidemic, a certain number of specific measures must be taken in order to prevent the transmission of infection and eradicate the epidemic. IN THE CASE OF INFLUENZA: Other than the vaccination of elderly institutional residents, that of the nursing staff appears essential. If a severe epidemic occurs, specific antivirals can be used, three of which are already available. IN THE CASE OF PNEUMOCOCCI: Examples of epidemics of pneumococcal infections in elderly institutional residents in the United States underlines the interest of pneumococcal vaccines, particularly since the strain responsible corresponded to a serotype contained in the 23 valence vaccine. WITH REGARD TO SCABIES: All the patients and all the staff must be treated on the same day and at the same time their clothing and bed linen. All persons in contact with the patient, the families and friends of the staff, their clothes and the environement must be treated.

Inhalational anthrax outbreak among postal workers, Washington, D.C., 2001

In October 2001, four cases of inhalational anthrax occurred in workers in a Washington, D.C., mail facility that processed envelopes containing Bacillus anthracis spores. We reviewed the envelopes' paths and obtained exposure histories and nasal swab cultures from postal workers. Environmental sampling was performed. A sample of employees was assessed for antibody concentrations to B. anthracis protective antigen. Case-patients worked on nonoverlapping shifts throughout the facility, suggesting multiple aerosolization events. Environmental sampling showed diffuse contamination of the facility. Potential workplace exposures were similar for the case-patients and the sample of workers. All nasal swab cultures and serum antibody tests were negative. Available tools could not identify subgroups of employees at higher risk for exposure or disease. Prophylaxis was necessary for all employees. To protect postal workers against bioterrorism, measures to reduce the risk of occupational exposure are necessary.

[beta-lactam-antibiotics in the treatment of community-acquired respiratory tract infections with penicillin-resistant pneumococci]

Streptococcus pneumoniae is still the most important pathogen of community-acquired respiratory tract infections. During the last decades in many countries an increase in the spread of antibiotic resistant strains (e. g. against beta-lactams, macrolides, tetracyclin) was observed. Resistance against penicillin is often associated with resistance against macrolides and other antibiotic classes. In Germany surveillance studies including isolates from patients with community-acquired respiratory tract infections have shown that about 14 % of strains show a reduced susceptibility against penicillin (MIC-values 0.12 - 1 mg/L) and up to 4 % are highly resistant against penicillin (MIC >/= 2 mg/L). Resistance against tetracycline or macrolides was detected in up to 12 and 15 % of strains, respectively. According to the treatment guidelines of the Paul-Ehrlich-Gesellschaft für Chemotherapie and the Deutschen Atemwegsliga penicillins and cephalosporins are recommended as first line antibiotics for the treatment of community-acquired respiratory tract infections. As pneumococcal strains with reduced susceptibility against penicillin show often also a reduced susceptibility against cephalosporins the questions arises which beta-lactam antibiotics should still be used in empirical treatment of such strains. beta-Lactam-antibiotics highly differ in their in-vitro-activity against S. pneumoniae and their pharmacokinetic properties. In different models is has been demonstrated for beta-lactams that an adequate clinical and bacteriological efficacy is achievable when the serum levels of the free, i. e. not protein bound fraction of drug exceeds the MIC of the pathogen for at least 40 to 50 % of the dosing interval (T > MIC). In a clinical situation where pneumococci with reduced susceptibility against penicillin cannot be ruled out, only beta-lactam antibiotics with favourable pharmacological properties (good in-vitro activity, high and long lasting serum levels) should be used for treatment.

Molecular epidemiology of feline bordetellosis in two animal shelters in California, USA

"Kennel cough" in dogs in animal shelters is readily transmissible, reduces adoption rates, and commonly leads to the euthanasia of affected dogs. In cats, tracheobronchitis, conjunctivitis, and pneumonia have been associated with Bordetella bronchiseptica infection-but most cases of upper-respiratory infection (URI) probably are caused by herpesvirus and calicivirus, and many B. bronchiseptica culture-positive cats are clinically normal. Our prospective observational study was undertaken to document the contribution of B. bronchiseptica to disease in cats and dogs from two animal shelters undergoing outbreaks of canine kennel cough, to evaluate whether cross-species transmission might have occurred, and to determine if the presence of infected cats represented a risk to dogs. Clinically defined cases of kennel cough in dogs and URI in cats were investigated in two shelters by calculating clinical-disease incidence, alveolar-lavage cytological examination, bacterial and viral cultures, antibiotic-susceptibility testing, and molecular fingerprinting by pulsed-field gel electrophoresis. In a 40-cat and 40-dog "no-kill" shelter, the prevalences of culture positivity were 47% for B. bronchiseptica and 36% for calicivirus at the same time as two resident dogs demonstrated clinical cough. When no dogs had kennel cough 3 months later, 10% of cats were B. bronchiseptica-culture-positive and 63% calicivirus positive. In a large traditional shelter, the incidence of kennel cough in dogs increased over 12 weeks to a maximum of 19 cases/week/120 dogs, during which time the culture prevalence was 23% for B. bronchiseptica in dogs and 47% in cats. Three to 6 months before the kennel-cough epidemic, no dogs or cats were B. bronchiseptica positive. Very little genetic variability was detected in isolates from these shelters; all isolates except one corresponded to a single strain type which was identical to the pattern in a vaccine used in these shelters. Isolates from other cats, a horse, a llama, and a sea otter were genetically distinct from the shelter isolates. There was widespread resistance to cephalosporins and ampicillin, but low or no resistance to amoxicillin/clavulanate, trimethoprim-sulfamethoxazole, tetracycline, and enrofloxacin. Greater percent resistance was observed in the traditional shelter than in the no-kill shelter and feline isolates were more likely to be resistant than canine isolates.

Epidemiology of viral respiratory infections

Acute respiratory tract infections are the most common illnesses in all individuals, regardless of age or gender. Epidemiologic surveys and community-based studies conducted since the beginning of the 20th century have determined the rates of illness and the pathogens involved in such infections. These studies have shown that rhinoviruses cause the great majority of these respiratory illnesses, and their findings have examined the means of transmission of respiratory illness. More recently, advances in diagnostic techniques have enabled more complete identification of the viruses involved in respiratory infections, which has aided in the ability to direct specific therapeutic agents at the causative pathogens.

Large epidemic of respiratory illness due to adenovirus types 7 and 3 in healthy young adults

After 25 years of successful control through immunization, respiratory infections due to adenoviruses have reemerged to threaten the health of young adults in the military. Shortly after the loss of adenovirus vaccine supplies, a large outbreak of respiratory illness was observed at the United States Navy's sole basic training center. Laboratory testing confirmed 541 cases of adenovirus infection, including 378 cases due to serotype 7 and 132 cases due to serotype 3. This outbreak was remarkable because of its unique serotype distribution and the large amount of data available to describe demographic factors associated with infection. This was the largest outbreak of respiratory illness due to adenovirus types 7 and 3 documented in recent history, and it portends even greater challenges for young adults in the military in the postvaccine era.

Respiratory infections in infants: interaction of parental allergy, child care, and siblings-- The PIAMA study

OBJECTIVE

To investigate the association between contacts with other children and the development of respiratory infections in the first year of life in children with or without genetic predisposition for allergy.

METHODS

Children (n = 4146) who participate in a prospective birth cohort study (Prevention and Incidence of Asthma and Mite Allergy study) were investigated. Questionnaires were used to obtain information on doctor-diagnosed upper respiratory tract infection (URTI) and lower respiratory tract infection (LRTI), child care attendance, having siblings, family history of allergic disease, and various potential confounders.

RESULTS

Child care attendance in the first year of life was associated with doctor-diagnosed URTI (adjusted odds ratio [AOR]: 2.7; 95% confidence interval [CI]: 2.1-3.4 for large child care facility vs no child care) and doctor-diagnosed LRTI (AOR: 5.6; 95% CI: 3.9-7.9). Having siblings was associated with doctor-diagnosed LRTI (AOR: 2.6; 95% CI: 2.0-3.4). In addition, children who have allergic parents and attend child care or have older siblings have a higher risk of developing doctor-diagnosed LRTI than do children who have nonallergic parents.

CONCLUSIONS

Child care attendance or having siblings increases the risk of developing doctor-diagnosed LRTI in the first year of life to a greater extent in allergy-prone children than in children who are not allergy prone.

Burkholderia cepacia lower respiratory tract infection associated with exposure to a respiratory therapist

OBJECTIVE

To investigate and control a nosocomial outbreak of Burkholderia cepacia lower respiratory tract infection.

DESIGN

Outbreak investigation and case-control study.

SETTING

A 260-bed community hospital.

PATIENTS

Participants were mechanically ventilated intensive care patients without cystic fibrosis. A case was defined as a hospitalized patient with a sputum culture positive for B. cepacia between January 1 and November 6, 1998.

METHODS

Respiratory therapy infection control policies and practices were reviewed; laboratory and environmental studies and a retrospective case-control study were conducted. Case-patients were matched with control-patients on age, gender, diagnosis, and type of intensive care unit.

RESULTS

Nine case-patients were identified; B. cepacia likely caused pneumonia in seven and colonization in two. Two respiratory therapy practices probably contributed to the transmission of B. cepacia: multidose albuterol vials were used among several patients, and nebulizer assemblies often were not dried between uses. B. cepacia was grown from cultures of three previously opened multidose vials; pulsed-field gel electrophoresis patterns of B. cepacia from seven case-patients and two multidose vials were indistinguishable. Case-patients had longer durations of heated humidified mechanical ventilation (mean, 9.8 days vs 4.4 days; P=.03) and were more likely to have exposure to one particular respiratory therapist than controls (odds ratio, undefined; 95% confidence interval, 4.7-infinity; P=.001). The association with the respiratory therapist, a temporary employee, persisted after controlling for duration of heated humidified ventilation. No new B. cepacia infections were identified after control measures were implemented.

CONCLUSIONS

B. cepacia probably was transmitted among patients through use of extrinsically contaminated multidose albuterol vials. Respiratory therapy departments must pay close attention to infection control practices, particularly among new or temporary staff.

[Virus and respiratory allergy in children]

Links between viruses and respiratory allergy are not easy to understand in children. For example, the risk of atopy or asthma is increased after an infection with syncytial respiratory virus. In some studies, more the child suffers from viral infections, more the risk of atopy increases. On the other hand, other studies state that the development of allergy is reduced if a child enters day nursery before 12 months, and consequently if he is exposed early in life to viruses. Measles and hepatitis A viruses could also protect from allergy. In fact, viruses seem modulate the expression of a preexisting atopic status. Depending on their nature and their circumstances of occurrence, they could induce some sensitizations or inversely protect from atopy by facilitating the lymphocyte Th2 or Th1 response.

[Epidemiology of respiratory virus infections]

Respiratory viral infections are very common in young children. They sometimes occur as primary infections (and sometimes re-infections) by influenza and parainfluenza virus, respiratory syncytial virus (VRS), adenovirus, rhinovirus and coronavirus. The clinical pictures are very varied and without strict clinico-virological correlation. In adults the role of the site (frail lung, aged persons) and the type of virus play an important part. Many viral infections develop in an epidemiological way (influenza, VRS bronchiolitis, rhinovirus infections...) and several epidemics by different viruses overlap from September-October to March-April making it very difficult to decide the precise cause. Epidemics are followed thanks to networks of medical practitioners (GROG, SENTINELLE...) and by data from hospitalised patients, but precise identification of epidemic viruses is only possible and validated by virological analysis of samples taken from patients.

Absence of bacterial colonization of the airways after therapeutic rigid bronchoscopy without stenting

Following airway stenting, bacterial colonization of the airways with potentially pathogenic micro-organisms occurs within 4 weeks after treatment in the majority of patients. The objective of this study was to prospectively investigate whether nonstenting therapeutic rigid bronchoscopy (using laser, cryotherapy, mechanical dilatation or debridement) is followed by airway colonization or infection. Protected specimen brush sampling of the central airways and quantitative culture were performed immediately prior to, and 4 weeks after nonstenting therapeutic rigid bronchoscopy in 20 consecutive patients with central airway lesions. Prior to therapeutic bronchoscopy, airway colonization/infection was present in nine of 20 (45%) patients. In these nine patients, 10 different potential pathogens were identified: Streptococcus pneumoniae (four cases), Pseudomonas aeruginosa (three), Haemophilus influenzae (two), and Serratia marcescens (one). Eight of these nine patients had a history of postobstructive infections, of which three were currently being treated with antibiotics. Four weeks following therapeutic bronchoscopy, airway colonization/infection was present in five of 20 (25%) patients, each of whom had airway colonization/infection prior to bronchoscopy. In three of these five patients, the same organisms were found 4 weeks after bronchoscopy as at baseline bronchoscopy. In two of five patients new organisms were identified: one case of Streptococcus viridans and one case of Haemophilus parainfluenzae, both considered to be nonpathogens. In four of nine patients with airway colonization/infection prior to bronchoscopy, the airways were clear of micro-organisms after the procedure. The authors conclude that: 1) nonstenting therapeutic rigid bronchoscopy is not complicated by airway colonization or infection by new potential pathogens; and 2) therapeutic rigid bronchoscopy led to clearing of airway colonization/infection in almost half of the patients studied.

Transmission of viral respiratory infections in the home

Respiratory viruses in the home exploit multiple modes of transmission. RSV is transmitted primarily by contact with ill children and contaminated objects in the environment. Influenza appears to be spread mainly by airborne droplet nuclei. Despite many years of study, from the plains of Salisbury, to the hills of Virginia, to the collegiate environment of Madison, WI, the precise routes rhinovirus takes to inflict the misery of the common cold on a susceptible population remain controversial.

A pseudo-outbreak of Aureobasidium species lower respiratory tract infections caused by reuse of single-use stopcocks during bronchoscopy

OBJECTIVE

To investigate and control an apparent outbreak of lower respiratory tract infections due to Aureobasidium species.

DESIGN

Outbreak investigation.

SETTING

University-affiliated medical center.

PATIENTS

Nine patients who underwent bronchoscopy between June and August 1998.

RESULTS

Ten bronchoalveolar lavage (BAL) fluid cultures from nine patients grew Aureobasidium species during the outbreak period; whereas, respiratory specimens from only two patients grew Aureobasidium species during the preceding 6 years. No patient was judged to have true infection due to Aureobasidium species either before or after bronchoscopy. Nine of the 10 bronchoscopies that yielded Aureobasidium species were performed in the outpatient bronchoscopy suite. The Aureobasidium isolates were not associated with any one bronchoscope. Observation of bronchoscopy procedure revealed that plastic stopcocks labeled for single use were reused on different patients during BAL. There was no record of how many times each stopcock was being reused. After each use, the stopcocks were placed in an automated disinfection machine designed for bronchoscopes. Culture of the stopcocks after they had been "disinfected" yielded a heavy growth of Aureobasidium species, while culture of fluid from the automated disinfection machine was negative. Reuse of the stopcocks was halted, and, during the following 6-month period, Aureobasidium species were not isolated from any BAL specimen.

CONCLUSIONS

Reuse of medical equipment labeled for single use is potentially hazardous, especially if no quality control system is in place to monitor sterility and function after reprocessing.