Wednesday, February 09, 2011

EID Journal: Nosocomial Transmission Of 2009 H1N1

 

 

 

# 5301

 

 

From an expedited report in the CDC’s  EID Journal we get further evidence that a hospital is really no place for a sick person; a review of nosocomial (in-hospital) transmission of the 2009 pandemic virus in the United Kingdom.

 

First the link and abstract (reformatted), and then some discussion.

 

 

Nosocomial Pandemic (H1N1) 2009, United Kingdom, 2009–2010


J.E. Enstone et al.  (170 KB, 14 pages)

DOI: 10.3201/eid1704.101679 
Enstone JE, Myles PR, Openshaw PJM, Gadd EM, Lim WS, Semple MS, et al.  Emerg Infect Dis. 2011 Apr

To determine the effect of nosocomial infections on health in the United Kingdom, we studied 1,520 patients in 75 National Health Service hospitals. We identified and characterized patients who acquired influenza in hospitals during the pandemic (H1N1) 2009 outbreak.

 

Of 30 patients, 12 (80%) of 15 adults and 14 (93%) of 15 children had serious underlying illnesses. Only 12 (57%) of 21 patients who received antiviral therapy did so within 48 hours after symptom onset, but 53% needed escalated care or mechanical ventilation; 8 (27%) of 30 died.

 

Despite national guidelines and standardized infection control procedures, nosocomial transmission remains a problem when influenza is prevalent. Health care workers should be routinely offered influenza vaccine, and vaccination should be prioritized for all patients at high risk. Staff should remain alert to the possibility of influenza in patients with complex clinical problems and be ready to institute antiviral therapy while awaiting diagnosis during influenza outbreaks.

(Continue . . .)

 

While only 30 nosocomial flu infections were identified and analyzed in this study, the authors were quick to point out that they were unlikely to detect all cases among the patient cohort studied.   


The definition of a `nosocomial’ infection adopted for this study was very strict, so as to exclude any potential community acquired infections.

 

Additionally, patients already compromised by serious illness were most likely to be identified, mild cases were likely overlooked, and some patients may have been infected in the hospital, but were discharged before becoming symptomatic.

 

As far as the route of infection, the authors had this to say:

 

On the basis of information obtained in the study, we cannot determine where and from whom patients acquired influenza. However, 3 routes are possible.

 

First, infection could have been acquired from other patients; 1 patient shared a bay with a patient who was presymptomatic at the time but for whom influenza was diagnosed 1 day later.

 

Second, transmission from visitors of patients cannot be ruled out. Although national guidelines strongly discourage persons with influenza-like symptoms from visiting patients (29), this recommendation may have been difficult to implement, particularly for parents of sick children who often provide most hands-on care in a hospital.

 

Third, transmission may have occurred from an infectious health care worker (because staff continue to work when infected with influenza [33]) or from contaminated hands of a health care worker.

 

Transmission from asymptomatic persons might occur in all 3 instances

 

The authors conclude:

 

Nosocomial infections with pandemic (H1N1) 2009 in this case series were associated with high rates of illness and death. This finding highlights the need for adherence to infection control guidelines for staff and visitors (including the need to urge visitors not to visit when they are ill, particularly when providing hands-on care for vulnerable children), staff vaccination, maintenance of clinical suspicion for influenza in areas of high risk, prompt (empirical) antiviral treatment for vulnerable patients in whom influenza is possible or likely, and consideration of postponing nonurgent procedures for hematology patients during periods of known high influenza activity.

 

This report demonstrates that nosocomial transmission is a recurrent problem when the prevalence of influenza is high and the total effect of nosocomial influenza is underestimated by outbreak reports alone.

 

 

Concerns over the spread of influenza in healthcare facilities have been the driving force behind the repeated calls for mandatory yearly vaccination of HCWs (Health Care Workers) against the flu.

 

A few recent blogs on that contentious subject include:

 

APIC Calls For Mandatory Flu Vaccination For HCWs
AAP: Recommends Mandatory Flu Vaccinations For HCWs
SHEA: Mandatory Vaccination Of Health Care Workers
IDSA Urges Mandatory Flu Vaccinations For Healthcare Workers

 

While strongly advocating HCW influenza vaccination, the CDC has stopped short of mandating them. I blogged on this back on June 23rd, 2010  in  CDC: Proposed Influenza Infection Control Guidance.

 

Similarly, a UK Department of Health report issued in June 2010 called Learning The Lessons From the H1N1 Vaccination Campaign For Healthcare Workers  – while not mandating vaccination – stresses the `professional duty’ of all HCWs to get the vaccine.

 

While many infection control experts see this as a long overdue step in patient and co-worker protection, the obstacles that lay before these sorts of policies are substantial.

 

This is a hugely divisive issue, with many HCWs believing that it is an infringement of their rights to decide what will be injected into their bodies.

 

I’ve covered HCW’s objections to forced flu shots in the past, including:

 

HCWs: Refusing To Bare Arms

HCWs: Developing a Different Kind Of Resistance

 

Complicating matters, HCWs are often pressured into working when they are sick – simply because of the difficulty in finding someone to cover their shifts.

 

This is a subject I wrote about at some length back in September of 2009 (see A Hospital Is No Place For A Sick Person).

 

Between the spread of flu via asymptomatic individuals, and the less-than-100% immunity conveyed by the yearly flu vaccine, it is no doubt impossible to completely eliminate the nosocomial spread of influenza in healthcare settings.

 

But hospitalized individuals are at particular risk of complications, and even death, from the flu. Which makes it not only morally incumbent, but economically imperative, that healthcare facilities do what they can to prevent infection.

 

Reasonable measures that can reduce the spread of the virus – such as improved vaccination rates and better infection control measures - are vital areas that many healthcare facilities need to review and improve.