Frederick G. Hayden

INFLUENZA IN THE ACUTE HOSPITAL SETTING

Influenza poses special hazards inside healthcare facilities and can cause explosive outbreaks of illness. Healthcare workers are at risk of acquiring influenza and thus serve as an important reservoir for patients under their care. Annual influenza immunisation of high-risk persons and their contacts, including healthcare workers, is the primary means of preventing nosocomial influenza. Despite influenza vaccine effectiveness, it is substantially underused by healthcare providers. Influenza can be diagnosed by culturing the virus from respiratory secretions and by rapid antigen detection kits; recognition of a nosocomial outbreak is important in order to employ infection-control efforts. Optimal control of influenza in the acute-care setting should focus upon reducing potential influenza reservoirs in the hospital, including: isolating patients with suspected or documented influenza, sending home healthcare providers or staff who exhibit typical symptoms of influenza, and discouraging persons with febrile respiratory illness from visiting the hospital during a known influenza outbreak in the community. (Note: influenza and other respiratory viruses can cause non-febrile illness but are still transmissible.) The antiviral M2 protein inhibitors (amantadine, rimantadine) and neuraminidase inhibitors (zanamivir, oseltamivir) have proven efficacy in treating and preventing influenza illness; however, their role in the prevention and control of influenza in the acute hospital setting remains to be more fully studied.

Viral infections in relation to age, atopy, and season of admission among children hospitalized for wheezing.

n Abstractn n Backgroundn Viral respiratory tract infections and atopy are associated with attacks of wheezing during childhood. However, information about the relationship between viral infections and atopy among children whose attacks of wheezing lead to hospitalization is unclear.n n n Objectiven To evaluate the prevalence of viral respiratory tract pathogens among infants and children hospitalized for wheezing and to analyze the results in relation to the patients age, atopic characteristics, and season of admission.n n n Methodsn This was a case-control study of children (age 2 months to 18 years) admitted for wheezing to the University of Virginia Medical Center over a period of 12 months. Children without wheezing were enrolled as controls. Nasal secretions were evaluated for viral pathogens by using cultures, PCR tests, and antigen detection. Total IgE and specific IgE antibody to common aeroallergens was measured in serum.n n n Resultsn Seventy percent of children hospitalized for wheezing before age 3 years (n=79) were admitted between December and March, whereas 46% of children age 3 to 18 years (n=54) were hospitalized between September and November. Among children younger than 3 years, viral pathogens were detected in 84% (66/79) of wheezing children and 55% (42/77) of controls (P < .001). Respiratory syncytial virus was the dominant pathogen during the winter months, but rhinovirus was more common during other months. Total serum IgE levels were generally low, and values from wheezing and control subjects overlapped considerably. Among children 3 years and older, 61% (33/54) of subjects admitted for wheezing tested positive for virus (predominantly rhinovirus), compared with 21% (12/56) of controls (P < .001). The total serum IgE values among wheezing children (geometric mean, 386 IU/mL; 95% CI, 259-573) were substantially elevated compared with those of controls (geometric mean, 38 IU/mL; 95% CI, 26-56; P < .001). A significantly higher percentage of wheezing children compared with controls was sensitized to at least 1 of the inhaled allergens tested: 84% (36/43) compared with 33% (15/45; P < .001). The atopic characteristics of wheezing children who tested positive or negative for virus were similar.n n n Conclusionsn Viral infections were the dominant risk factor for wheezing among children hospitalized before 3 years of age. By comparison, a large majority of the wheezing children age 3 to 18 years had striking atopic characteristics that may be critical as a risk factor for hospitalization and an adverse response to viral infections, especially infections caused by rhinovirus.n n

Preventing nosocomial influenza by improving the vaccine acceptance rate of clinicians.

OBJECTIVESnTo assess the effects of interventions to prevent transmission of influenza and to increase employee compliance with influenza vaccination.nnnDESIGNnThe change in the proportion of hospitalized patients with laboratory-confirmed nosocomial influenza was observed over time and assessed using chi-square for trend analysis. The association between nosocomial influenza in patients and healthcare worker (HCW) compliance with vaccine was assessed by logistic regression.nnnSETTINGnA 600-bed, tertiary-care academic hospital.nnnMETHODSnAfter an outbreak of influenza A at this hospital in 1988, a mobile cart program was instituted with increased efforts to motivate employees to be vaccinated and furloughed when ill as well as new measures to prevent nosocomial spread.nnnRESULTSnHCW vaccination rates increased from 4% in 1987-1988 to 67% in 1999-2000 (P < .0001). Proportions of nosocomially acquired influenza cases among employees or patients both declined significantly (P < .0001). Logistic regression analysis revealed a significant inverse association between HCW compliance with vaccination and the rate of nosocomial influenza among patients (P < .001).nnnCONCLUSIONnA mobile cart vaccination program and an increased emphasis on HCWs to receive the vaccine were associated with a significant increase in vaccine acceptance and a significant decrease in the rate of nosocomial influenza among patients.

Nasopharyngeal reservoir of bacterial otitis media and sinusitis pathogens in adults during wellness and viral respiratory illness

Background The carriage rate of pathogenic bacteria in the nasopharynx (NP) was determined using three separate techniques for obtaining samples. Methods The NP of 99 healthy adults was sampled with (1) nasal swab, (2) oral swab, and (3) nasal aspiration; 49 adults with common cold were sampled with an oral swab and nasal aspiration. Three selective agars were used to detect Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis. Results Seventy-three percent of healthy adults and 74% of cold sufferers had at least one pathogen detected in the NP. Detection rates were 65% (oral NP swab), 38% (catheter aspiration), and 28% (nasal swab; p < 0.001). Carriage rates for S. pneumoniae, M. catarrhalis, and H. influenzae were 45, 33, and 30%, respectively. Both a nasal and an oral sample were required for optimal detection. Conclusion Bacterial pathogens were present in the NP of three-quarters of adults during wellness and during colds.

Towards improving clinical management of Middle East respiratory syndrome coronavirus infection

544 www.thelancet.com/infection Vol 14 July 2014 5 Lowe R, Barcellos C, Coelho C, et al. Dengue outlook for the World Cup in Brazil: an early warning model framework driven by real-time seasonal climate forecasts. Lancet Infect Dis 2014; published online May 17. http://dx. doi.org/10.1016/ S1473-3099(14)70781-9 6 Macdonald G. The epidemiology and control of malaria. London: Oxford University Press, 1957. 7 Gubler DJ. Dengue. In: Monath TP, ed. Epidemiology of arthropod-borne viral diseases. Boca Raton, FL: CRC Press, Inc, 1988: 223–60. 8 Halstead SB. Dengue. Lancet 2007; 370: 1644–52. 9 Waldock J, Chandra NL, Lelieveld J, et al. The role of environmental variables on Aedes albopictus biology and chikungunya epidemiology. Pathog Glob Health 2013; 107: 224–41. 10 Bannister-Tyrrell M, Williams C, Ritchie SA, et al. Weather-driven variation in dengue activity in Australia examined using a process-based modeling approach. Am J Trop Med Hyg 2013; 88: 65–72. *David Harley, Elvina Viennet National Centre for Epidemiology and Population Health, The Australian National University, Canberra, ACT 0200, Australia David.Harley@anu.edu.au

Middle ear pressure in preschool age children: influence of respiratory illness, season, and picornavirus or bacteria in the nasopharynx

Conclusion. Middle ear pressure was affected by respiratory illness and season; picornavirus (without illness) or pathogenic bacteria in the nasopharynx had no or minor effect. Objective. To examine the effect of respiratory illness, season, and nasopharyngeal microbial flora on middle ear pressure. Subjects and methods. Thirteen children were followed longitudinally with daily recording of respiratory symptoms, weekly tympanometry, and weekly testing of nasal aspirate/washes for Streptococcus pneumoniae, Hemophilus influenzae, Moraxella catarrhalis by culture and for picornavirus by RT-PCR. Results. Abnormal middle ear pressure was present at 47% of 473 weekly visits by 11 preschool age (≤5years) vs 28% of 212 visits by 2 school age children. Symptomatic illness predicted abnormal middle ear pressure (63% of 107 ill visits in preschoolers vs 43% of 366 well visits, p<0.004). Abnormal tympanometry in preschoolers at well visits rose from 26% (80 visits) in summer to 54% (100 visits) in spring (p≤0.03). No increase in abnormal tympanometry occurred during 18 picornavirus infections without illness. The presence of one or more of the bacterial species at ill or well visits had no effect on middle ear pressure except for a 12% increase (p=0.008) in abnormal tympanometry associated with H. influenzae at well visits in preschoolers.