Nosocomial H1N1 infection during 2010–2011 pandemic: a retrospective cohort study from a tertiary referral hospital

Nosocomial transmission of influenza: A retrospective cross-sectional study using next generation sequencing at a hospital in England (2012-2014)

BACKGROUND

The extent of transmission of influenza in hospital settings is poorly understood. Next generation sequencing may improve this by providing information on the genetic relatedness of viral strains.

OBJECTIVES

We aimed to apply next generation sequencing to describe transmission in hospital and compare with methods based on routinely-collected data.

METHODS

All influenza samples taken through routine care from patients at University College London Hospitals NHS Foundation Trust (September 2012 to March 2014) were included. We conducted Illumina sequencing and identified genetic clusters. We compared nosocomial transmission estimates defined using classical methods (based on time from admission to sample) and genetic clustering. We identified pairs of cases with space-time links and assessed genetic relatedness.

RESULTS

We sequenced influenza sampled from 214 patients. There were 180 unique genetic strains, 16 (8.8%) of which seeded a new transmission chain. Nosocomial transmission was indicated for 32 (15.0%) cases using the classical definition and 34 (15.8%) based on genetic clustering. Of the 50 patients in a genetic cluster, 11 (22.0%) had known space-time links with other cases in the same cluster. Genetic distances between pairs of cases with space-time links were lower than for pairs without spatial links (P < .001).

CONCLUSIONS

Genetic data confirmed that nosocomial transmission contributes significantly to the hospital burden of influenza and elucidated transmission chains. Prospective next generation sequencing could support outbreak investigations and monitor the impact of infection and control measures.

Long-term functional and psychological recovery in a population of acute respiratory distress syndrome patients treated with VV-ECMO and in their caregivers

BACKGROUND

Acute respiratory distress syndrome (ARDS) survivors are affected with long-term physical/mental impairments, with improvements limited mostly to the first year after intensive care (ICU) discharge. Furthermore, caregivers of ICU patients exhibit psychological problems after family-member recovery. We evaluated the long-term physical and mental recovery of ARDS survivors treated with veno-venous extracorporeal membrane oxygenation (VV-ECMO), and the long-term psychological impact on their caregivers.

METHODS

Single-center prospective evaluation of a retrospective cohort of 75 ARDS patients treated with VV-ECMO during a seven-year period (25.10.2009-11.08.2016). Primary outcomes were the 36-Item Short-Form Health-Survey (SF-36, patients only), and risks of depression, anxiety or post-traumatic stress disorder (PTSD), both for patients and their caregivers. We investigated correlations between outcomes and population characteristics.

RESULTS

Of 50 ICU-survivors, seven died later and five were not contactable. Among 38 living patients, 33 participated (87%, 31 with their caregiver) with 2.7 years of median follow-up. Physical and mental SF-36 component scores were 42 (inter-quartile range, IQR:22) and 52 (IQR:18.5), respectively. The worst domains of the SF-36 were physical-role limitations (25, IQR:100) and general-health perception (56, IQR:42.5). Psychological tests highlighted high risk of depression (39-42%, patients; 39-52%, caregivers), anxiety (42%, patients; 39%, caregivers), and PTSD (47%, patients; 61%, caregivers). Patient depression or anxiety scores were correlated to age and to the outcome reported by caregivers.

CONCLUSIONS

At almost three-year follow-up, ARDS survivors treated with VV-ECMO showed reduced health-related quality-of-life and high risk of psychological impairment, in particular PTSD. Caregivers of this population were at high psychological risk as well.

Active Surveillance for Influenza Reduces but Does Not Eliminate Hospital Exposure to Patients With Influenza

OBJECTIVE To describe the frequency, characteristics, and exposure associated with influenza in hospitalized patients in a Toronto hospital DESIGN/METHOD Prospective data collected for consenting patients with laboratory-confirmed influenza and a retrospective review of infection control charts for roommates of cases over 3 influenza seasons RESULTS Of the 661 patients with influenza (age range: 1 week-103 years), 557 were placed on additional precautions upon admission. Of 104 with symptoms detected after admission, 57 cases were community onset and 47 were nosocomial (10 nosocomial were part of outbreaks). A total of 78 cases were detected after admission exposing 143 roommates. Among roommates tested for influenza after exposure, no roommates of community-onset cases and 2 of 16 roommates of nosocomial cases were diagnosed with influenza. Of 637 influenza-infected patients, 25% and 57% met influenza-like illness definitions from the Public Health Agency of Canada (PHAC) and Centers for Disease Control and Prevention (CDC), respectively, and 70.3% met the Provincial Infectious Diseases Advisory Committee (PIDAC) febrile respiratory illness definition. Among the 56 patients with community-onset influenza detected after admission, only 13%, 23%, and 34%, met PHAC, CDC, and PIDAC classifications, respectively. CONCLUSIONS In a setting with extensive screening and testing for influenza, 1 in 6 patients with influenza was not diagnosed until patients and healthcare workers had been exposed for >24 hours. Only 30% of patients with community-onset influenza detected after admission met the Ontario definition intended to identify cases, hampering efforts to prevent patient and healthcare worker exposures and reinforcing the need for prevention through vaccination. Infect Control Hosp Epidemiol 2017;38:387-392.

General influenza infection control policies and practices during the 2009 H1N1 influenza pandemic: a survey of women's health, obstetric, and neonatal nurses

BACKGROUND

An evaluation of infection control practices was conducted following the release of the Centers for Disease Control and Prevention (CDC) guidance regarding the care of pregnant women during the 2009 H1N1 influenza pandemic. This paper describes 9 general hospital practices.

METHODS

A questionnaire was distributed electronically to 12,612 members of the Association of Women's Health, Obstetric, and Neonatal Nurses (AWHONN). Respondents (N = 2,304) who reported working in obstetric or neonatal settings during the pandemic completed the questionnaire.

RESULTS

Most (73%) respondents considered the Centers for Disease Control and Prevention's guidance very useful. Significantly more reported a written hospital policy for each practice during versus before the pandemic. Six of the 9 practices were implemented most of the time by at least 70% of respondents; the practices least often implemented were mandatory vaccination of health care personnel involved (52%) and not involved (34%) in direct patient care and offering vaccination to close contacts of newborns prior to discharge (22%). The most consistent factor associated with implementation was the presence of a written policy supporting the practice at the respondent's hospital.

CONCLUSION

We offer a descriptive account of general hospital infection control policies and practices during the 2009 H1N1 pandemic. Factors associated with reported implementation may be useful to inform planning to protect women and children for future public health emergencies.

Healthcare-associated influenza in Canadian hospitals from 2006 to 2012

OBJECTIVE

To determine trends, patient characteristics, and outcome of patients with healthcare-associated influenza in Canadian hospitals.

DESIGN

Prospective surveillance of laboratory-confirmed influenza among hospitalized adults was conducted from 2006 to 2012. Adults with positive test results at or after admission to the hospital were assessed. Influenza was considered to be healthcare associated if symptom onset was equal to or more than 96 hours after admission to a facility or if a patient was readmitted less than 96 hours after discharge or admitted less than 96 hours after transfer from another facility. Baseline characteristics of influenza patients were collected. Patients were reassessed at 30 days to determine the outcome.

SETTING

Acute care hospitals participating in the Canadian Nosocomial Infection Surveillance Program.

RESULTS

A total of 570 (17.3%) of 3,299 influenza cases were healthcare associated; 345 (60.5%) were acquired in a long-term care facility (LTCF), and 225 (39.5%) were acquired in an acute care facility (ACF). There was year-to-year variability in the rate and proportion of cases that were healthcare associated and variability in the proportion that were acquired in a LTCF versus an ACF. Patients with LTCF-associated cases were older, had a higher proportion of chronic heart disease, and were less likely to be immunocompromised compared with patients with ACF-associated cases; there was no significant difference in 30-day all-cause and influenza-specific mortality.

CONCLUSIONS

Healthcare-associated influenza is a major component of the burden of disease from influenza in hospitals, but the proportion of cases that are healthcare associated varies markedly from year to year, as does the proportion of healthcare-associated infections that are acquired in an ACF versus an LTCF.

Epidemiology and Control: Principles, Practice and Programs

Infectious disease epidemiology is concerned with the occurrence of both infection and disease in populations and the factors that determine their frequency, spread, expression and distribution. Viruses show characteristic infectivity, virulence and pathogenicity. The most well established host factors are age, sex and race, but other host biological and behavioral factors affect acquisition of viral infection and/or its course and manifestations. The physical, chemical and biological environment operates on the virus itself and may also alter the host biological or behavioral response. Viral infections have incubation periods lasting days or weeks, while their pathologic sequelae may not manifest for years or decades. Likewise the degree or intensity of host response and clinical expression may range from largely inapparent to highly lethal. The degree of cell, tissue and organ specificity is high. Common syndromes involve the respiratory, gastrointestinal, and central nervous systems, the liver, and mucocutaneous surfaces. Vertical transmission may produce a variety of congenital and perinatal conditions. Viruses spread by multiple modes, using nearly every bodily surface or fluid as a route of exit or entry, either by direct contact or indirectly through an animal vector or other inanimate vehicle. Different viral Infections occur nearly ubiquitously or sporadically; they may be present continuously throughout a population (endemic) or occur in seasonal rhythm or in unexpectedly explosive form (epidemic). Many viruses are refractory to all known therapeutic agents, while for a few, the increasing number of highly effective agents holds great promise. Vaccines have produced many historical successes including the ultimate goal of eradication, but many viral infections continue to elude effective vaccine development. Major government and private sector programs for treatment and prevention have raised expectations of successful control for certain widespread and serious viral diseases; however, in every case a unique set of scientific, socioeconomic, political and behavioral barriers remains to be overcome.