Coping with outbreaks of the norovirus: the norovirus can have devastating effects on the health of the very young and the elderly. It can also have devastating effects on the ability of hospitals, emergency departments in particular, to function effectively when both patients and staff are infected.

Infectious diseases are nothing new in hospital settings. Outbreaks of highly contagious, debilitating illnesses have the potential to affect not only patients, but staff and visitors as well. Several such outbreaks have occurred in New Zealand hospitals. These have resulted in strenuous isolation efforts and closure of wards. The impact of this has seriously strained both physical and staff resources. The cause of these particular outbreaks is a virus which causes diarrhoea and vomiting, one of the fatuity of noroviruses.

Norovirus is prevalent in the community and causes little serious illness in a healthy individual The consequences for the elderly, very young and already debilitated can be quite different, however. For staff who are infected, there is a recommended 48 hours' sick leave, until symptoms have cleared. The impact on hospital settings is serious. With staff shortages already a problem, any outbreak of contagious disease has the potential to result in unsafe staffing, either through tow numbers or poor skill mix. New Zealand hospitals have elaborate plans for dealing with potentially disastrous outbreaks such as severe acute respiratory syndrome (SARS), but how prepared are we for the relatively tow key infections? How many patients with such general and nebulous symptoms as nausea, diarrhoea and vomiting can be effectively isolated in the average emergency department (ED)? With hearth services already leering the strain of hospital overcrowding, how many beds, wards or hospitals can we afford to dose, white trying to control such infections?

Definition of noroviruses

Noroviruses are defined as a group of related, single stranded RNA, non-enveloped viruses. Noroviruses are a major cause of both sporadic and epidemic gastroenteritis in humans, and are identified as one of the main causes of acute outbreaks in nursing, geriatric and children's homes. (1,2)

A report from New Zealand Environmental Science and Research (ESR) showed 35 reported norovirus outbreaks in New Zealand in the first quarter of 2004, resulting in 890 cases of the disease. This shows a considerable increase from the 348 cases reported for 2003. (3) Already, there have been 24 reported outbreaks of norovirus for 2005, 11 occurring in hospitals or rest-homes. (4) The virus has previously resulted in closed wards and cancelled surgery at Wellington, Kenepuru, Horowhenua, and Dunedin hospitals. Bed closures have also occurred in Christchurch, Blenheim and Waikari hospitals. Four wards were dosed in Christchurch's Princess Margaret Hospital in August 2004, with 19 rest-homes in the city also affected. (5)

Norovirus outbreaks are characterised by a rapid spread of infection, high uptake rate, and a high proportion of cases presenting with projectile vomiting. Vomiting is not the predominant feature in other gastrointestinal infections such as salmonella, campytobacter or cryptospiridium. White vomiting and nausea are typical indicators for the infection, there can be occasional clusters of cases where vomiting is infrequent or absent. Other features include watery, non-broody diarrhoea with abdominal cramps and generalised nausea. Diarrhoea tends to be short-lived and Less severe than in other causes of gastroenteritis. The incubation period is usually between 24 and 48 hours, but cases can occur after 12 hours of exposure. Individuals are typically ill for a 48-hour period, although this can fast up to 60 hours, and is usually followed by a complete recovery. (6,7) (See table 1.)

Transmission

Noroviruses are highly contagious, with exposure to as little as 10 viral particles sufficient to cause infection. Several different mechanisms of transmission have been identified during outbreaks, but the primary means is the faecal-oral route, either by consumption of contaminated food or drink or by direct person to person spread. (6.7) Transmission by asymptomatic individuals is also possible. (8)

Environmental contamination may act as a source of infection, and aerotisation of vomitus can result in droplets contaminating surface structures or being directly ingested. There is no evidence of respiratory transmission. There is no specific therapy available to treat viral gastroenteritis, so interventions are symptomatic and supportive, focusing on fluid and electrolyte replacement.

Hospital outbreaks

Little can be done to prevent the introduction of norovirus into a hospital setting, given its prevalence in the community in general. The focus needs to be on limiting its subsequent spread, through infection control and isolation measures (see table 2). When outbreaks do occur, the consequences can be serious. Up to 50 percent of patients on a ward can be infected following the admission of a single symptomatic individual and ward closures are often necessary to contain the spread of infection. This affects the ability to carry out patient investigations and medical treatment, as patient movement is restricted. Similarly, in addition to loss of staff from illness, movement of remaining nursing, allied health and support workers needs to be restricted. This has the potential to result in severe staff shortages and compromises the ability to reallocate staff in times of crisis. (9)

The impact on emergency departments

The ED is the "gateway" to the hospital a key point for identifying, controlling and limiting infectious outbreaks. White the initial source of infection in a hospital outbreak may be an arranged admission, a staff member or visitor, once an outbreak has been identified, heightened awareness of community sources occurs. Any patient with a history or primary complaint of diarrhoea and vomiting becomes a potential carrier of the virus, and the index of suspicion is raised. A high proportion of ED patients will have current or recent symptoms of nausea, vomiting or diarrhoea, and the ability to determine the differential diagnosis can take a significant period of time. The questions raised, then, are how aggressive isolation practices should be, and how realistic is it in terms of staff, facilities and resources to enact widespread isolation in an acute area.

Emergency departments in New Zealand, as elsewhere, are experiencing increased levels of patient throughput. When patients are being cared for in the corridors of our hospitals, how realistic is it to provide isolation for large groups of potentially infectious patients? Norovirus is typically prevalent in winter months, but so too is influenza, another condition requiring isolation. The need to use a mixture of respiratory and enteric isolation precautions places strain on physical resources--most EDs have limited specific isolation rooms, and indeed many patient treatment areas are separated only by curtains or partitions.

Impact at ward level

Identification of potential cases of norovirus at the ED point of entry is only the beginning of the problem. Once a case is identified, diagnostic tests are commenced, but results are not instantaneous, and if the patient requires admission, in-patient isolation needs to be arranged. While isolation is a routine nursing measure, having to deal with large numbers of cases places additional strain on services. The limited number of available isolation rooms compounds this, and the overall process adds considerably to the nursing workload.

In addition to acute admissions, there are other potential sources of entry for the norovirus. Arranged admission patients may not develop symptoms of community-acquired infection until after arrival in the ward. Visitors may carry the infection, and poor food handling practices can result in food service transfer of the virus. Staff may also be affected, either in the community or following contact with infected patients or colleagues, often not realising the significance of seemingly "minor" symptoms. Reluctance to take sick days can result in an early return to work or a desire to "soldier on", often while the individual is still symptomatic and contagious.

Charge nurses, patient care duty managers and other senior nursing staff are faced with increasing pressure to identity the most appropriate placement of patients, often requiring major bed shifts to group isolation patients, or to empty side rooms for isolation purposes. Staffing levels are affected, with staff infected or unable to transfer from one ward to another. The current national nursing crisis means that often there are not enough pool agency or casual staff to fill the unexpected gaps. Ward staff may end up under-resourced, and with a heavier than usual workload because of a combination of staff shortages and the additional needs of isolation nursing.

No 'quick fixes'

There are no simple answers or "quick fixes" to the problem of norovirus outbreaks. While ongoing surveillance, recognition and isolation are key elements, there are wider structural and political implications that need to be acknowledged. Hospitals and health professionals know how to deal with patients who require isolation care; they know how to protect themselves, visitors and other patients. Yet despite this, outbreaks continue to occur. One aspect that is apparent is limited forward planning at a systems level Norovirus is to some extent seasonal peaking in the winter months. Forward planning would see the allocation of isolation beds, rooms or wards as a contingency measure. Instead, many facilities manage such outbreaks on a day-by-day basis, with each new admission triggering a further crisis in bed management and staffing.

It is not because managers, nurses or other health care workers don't care, nor is it a simple lack of insight. Our health care system is in a constant state of flux with managers battling to maintain services in the face of ballooning deficits, and tight financial constraints combined with staff shortages seeing in-patient beds closed. With hospital overcrowding a growing concern in New Zealand, it is no longer a simple matter of planning ahead for seasonal outbreaks of influenza, norovirus or other viral infections. Until the underlying problems are addressed, each outbreak will continue to stress hospital and staff to breaking point. The impact of an ageing nursing population, difficulty recruiting and retaining nurses, and chronically low nursing numbers needs to be addressed. The inability to safely "flex" bed numbers up and down in reaction to changing needs is a complex issue. While staffing shortages do Lead to bed closures, so too does reallocation of funding, inability to discharge patients into an already over loaded community system and lack of ongoing support systems. None of these problems can be dealt with in isolation, nor effectively on an individual basis. There needs to be a strong commitment at a ministerial level to addressing issues such as overcrowding and hospital bed block, and to putting in place strategies to enable the health care workforce to be self sustaining.

At a district health board and hospital level, managers need to be able to articulate the needs of their communities, without fearing political censure for failing to meet budgets. No one doubts the reality of scarce funding, but failing to acknowledge the impact of mounting fiscal deficits is foolhardy. Patient care standards are affected when hospitals are overcrowded and staff are burnt out and disaffected. How much more are hospital and nursing standards affected when faced with crises such as the norovirus outbreaks?

Conclusion

New Zealand hospitals are under strain. We read constantly of ED overcrowding, hospital bed block and cancelled admissions in response to staff and resource shortages. The international perspective suggests that we are merely following an established trend. There are no "quick fix" solutions, rather we need to find ways of coping and maximising our abilities within current constraints. There needs to be a nationwide, co-ordinated response to dealing with these issues, and a realisation that certain "crises" can not only be expected, but actively anticipated. We know that influenza is a seasonal constant, putting strain on systems and health care resources. What we also need to recognise is that other conditions, such as norovirus outbreaks, are also predictable. Forward planning and resource allocation are not Luxuries, but essentials. Infectious outbreaks have the potential to seriously disrupt hospital routines and functioning. They affect staff, visitors and patients and need to be actively managed, not just endured.

References:

(1) Isakbaeva, E.T., Widdowson, M-A., Beard, S., Butens, S.N., Mullins, J. Monroe, S.S., Bresee, J., Sasssano, P., Cramer, E.H. & Glass, R.I. (2005) Norovirus transmission on cruise ship. Emerging infectious diseases; 11: 1, 154-8.

(2) Hutson, A.M., Atmar, R.L., & Estes, N.K. (2004) Norovirus disease: changing epidemiology and host susceptibility factors. Trends in microbiology; 12: 6, 279-287.

(3)MacDonald, N. (2004) Virus causes mayhem in hospitals, resthomes. The Dominion Post. Retrieved 30.09.04 from http://www.stuff.co.nz/stuff/pdnt/0,1478,3017952a7144,00.html

(4) Environmental Science and Research Ltd (2005) Hew Zealand Public Health Surveillance Report; 3: 2, 7.

(5) Hayman, K. (2004) Virus shuts Christchurch Hospital wards. The Press. Retrieved 4.10.04 from http://www.stuff.co.nz/sLuff/0,2106,3007521a11aT,00.html

(6) Health Protection Agency (2004) Outbreaks of gastroenteritis associated with norovirus on cruise ships. Retrieved 2/9/04 from http://www.hpa.org.uk/infections/topics_az/norovirus/cruiseships.htm

(7) Centre for Disease Control. (2004) Norovirus: Technical Fact Sheet. Retrieved 1/9/04 from http://www.cdc.gov/ncidod/dvrd/revb/gastro/ norovirus-factsheet.htm.

(8) Calderon-Margalit, R., Sheffer, R., Halperin, T., Orr, N., Cohen, D. & Shohat, T. (2005) A Large-scale gastroenteritis outbreak associated with Norovirus in nursing homes. Epidemiology and Infection; 133, 35-40.

(9) Chadwick, P.R., Beards, G., Brown, O., Caul, E.O., Cheesebrough, J., Clarke, I., Curry, A., O'Brien, S., Quigley, K., Sellwood, J. & Westmoreland, D. (2000) Management of hospital outbreaks of gastroenteritis due to small round structured viruses. Journal of Hospital Infection; 45, 1-10.

Table 1

NOROVIRUS: CLINICAL PRESENTATION

Incubation: 12-48 hours

Symptoms:

* acute onset vomiting (often projectile)

* watery, non-bloody diarrhoea

* abdominal cramps

* low grade fever in up to 50 percent of cases

* up to 30 percent of infections may be asymptomatic

Duration:

* symptoms usually Last 24-60 hours

* relapse is not usual

* reinfection is possible

This virus is highly contagious.

Table 2

SUGGESTIONS FOR DEALING WITH A NOROVIRUS OUTBREAK

* Nurse patients in contact isolation

* Group symptomatic patients where possible

* Avoid/limit patient movements from ward/infected area where possible

* Limit staff movements from area of infection

* Infected staff members should be symptom free for 48 hours before
  returning to work

* All staff, visitors, patients should wash their hands when leaving a
  ward/infected area.

* Limit visitors

This article was reviewed by Kai Tiaki Nursing New Zealand's editorial review committee in June 2005.

Sandra Richardson, RGON, BA, DipSocSci, PG DipHealSci, is a nurse researcher in the Emergency Department, Christchurch Hospital, Canterbury District Health Board.