Strategies to reduce Gram-negative infections: a community perspective

Despite many infections reducing in healthcare, Gram-negative bloodstream infections (GNBSIs) continue to rise. These are believed to have contributed to approximately 5500 NHS patient deaths in 2015 (Public Health England (PHE), 2017a). The NHS Long Term Plan supports a 50% reduction in GNBSIs by 2024/25 (NHS Improvement, 2019). An ambitious plan by the Government requires all services, from the hospital to the community, to play a part in reducing this number. This will mean standard infection prevention and control (IP&C) practices continue, with opportunities for organisations to develop and be innovative to improve and meet the targets (PHE, 2017a).

Differentiating bacteria

Being able to differentiate bacterial species is important for diagnosing and treating bacterial infections. Bacteria can be classified on the basis of gram-staining findings, which are in turn based on the structure of bacterial cell walls. Gram-positive organisms stain purple, while Gram-negative organisms stain red. The cell wall of Gram-positive bacteria comprises a thick layer of peptidoglycan, which contains lipids and other protein components, surrounding a lipid membrane (Figure 1). In contrast, Gram-negative bacteria possess a much thinner peptidoglycan layer sandwiched between two cell membranes (Figure 2).

Figure 1. Cell wall of Gram-positive bacteria Figure 2. Cell wall of Gram-negative bacteria. LPS=lipopolysaccharide

Peptidoglycan, the substance that retains the purple colour in Gram-positive bacteria, is not usually found in the human body (Madigan et al, 2015). This means that they are more easily recognised and targeted by the immune system. Gram-positive bacteria (Staphylococcus, Streptococcus and Clostridium botulinum) are also more susceptible to beta-lactam antibiotics such as penicillin, as well as the action of detergents, drying and physical disruption. Some Gram-positive bacteria can acquire antibiotic resistance (for example, methicillin-resistant Staphylococcus aureus), which makes them more difficult to treat, as the choice of antibiotics is limited. Antibiotic resistance is the ability of bacteria to resist the effects of an antibiotic to which they were once sensitive.

Gram-negative bacteria (e.g. Escherichia coli, Pseudomonas aeruginosa and Klebsiella spp.) do not tend to take up the purple Gram stain, as they have little peptidoglycan in their cell walls, which stop antibiotics from penetrating the bacteria, making Gram-negative bacterial infections more difficult to treat than Gram-positive ones. Gram-negative bacteria are a concern in the health service because they are becoming resistant to available antibiotics, leading to prescribing challenges (Ventola, 2015).

Transmission of E. coli

Although many Gram-negative bacteria cause bloodstream infections (e.g. E. coli, P. aeruginosa and Klebsiella spp.), PHE (2017a) decided to focus on reducing E. coli bloodstream infections, because they represent 55% of all GNBSIs (PHE, 2017b). E. coli is a Gram-negative, facultative anaerobic, rod-shaped bacterium that is commonly found in the lower intestine of humans, where it aids digestion. However, if present elsewhere in the body, it can cause serious infection. E. coli is also associated with diarrhoea and food poisoning, as well as pneumonia and urinary tract infections (UTIs) (Karch et al, 2012).

One of the many lessons learnt from an outbreak of E. coli (Monk et al, 2008) was an understanding of how the pathogen could transmit from the animal food chain to humans (Vidovic and Korber, 2014). These bacteria commonly develop resistance through two mechanisms: (1) easy transfer of resistance genes among commensal bacteria in the gastrointestinal tract (Skurnik et al, 2015) where the bacteria exist at a high density, and (2) the indiscriminate use of antimicrobial agents in humans and domestic animals, which allows for the selection of resistant strains. Domestic animals are also given antibiotics to aid growth, which has led to increased antibiotic resistance (Ventola, 2015).

Healthcare-associated E. coli bacteraemia

Mandatory surveillance has indicated a rise in the rate of E. coli bacteraemia (Vihta et al, 2018). The total number of cases reported by NHS trusts in England increased by 1.1% between 2016/17 and 2017/18 and by 27.1% since 2012/13. It is estimated that GNBSIs contributed to 5500 NHS patient deaths in 2015 (PHE, 2017a). The UK 5-year national action plan for tackling antimicrobial resistance highlighted a rise in the incidence of these infections as one of the biggest drivers of antimicrobial resistance in the UK (Department of Health and Social Care (DHSC), 2013).

In most cases, GNBSIs are community acquired (71%), occurring in older people and primarily through a UTI originating from the person's own bowel flora (PHE, 2017b). Community-onset GNBSIs (71%) occur before hospital admission, with hospital-based onset (29%) occurring 48 hours after admission (PHE, 2017b). A sentinel surveillance study in England looking at risk factors associated with E. coli BSIs found that, in approximately half of the community-onset cases, there was some healthcare intervention in the 4 weeks prior to the bacteraemia onset (Abernethy et al, 2017). These statistics form the basis of the case for targeting ‘community onset non-healthcare associated’ infections, according to the terminology the NHS uses to categorise healthcare-associated GNBSIs depending on where they are detected (community or hospital), as well as their relationship to healthcare (healthcare vs. non-healthcare associated) (PHE, 2017b).

There are many sources of E. coli infection, with some 15% having an unknown source (Abernethy et al, 2017). Targeted interventions may reduce E. coli BSIs, but there are contentions whether these can be undertaken for an infection that is often endogenous—that is, one that arises from an infectious agent already present in the body. Resident microorganisms (normal flora) can cause an infection when they move to a part of the body where they do not normally reside, for example, organisms from faeces causing food poisoning (National Institute for Health and Care Excellence (NICE), 2008).

The focus on the community in preventing GNBSIs will require support from healthcare workers, local clinical commissioning groups (CCGs) and PHE to deploy increased resources to people in the community, for example, those being cared for in nursing or care homes, those being cared for in their own homes and those living rough. NHS Improvement and PHE champion a whole health economy approach to reducing GNBSIs (Abernethy et al, 2017; PHE, 2017b).

Strategies to reduce GNBSIs

Despite Government strategy for more nursing care to be delivered in the community, this has proved difficult due to staff shortages, lack of resources in the community and the healthcare system remaining focused on hospital care (Royal College of Nursing (RCN), 2019a). In the coming years, as community service providers experience significantly growing demand and face acute workforce challenges, there is a serious risk that poor or declining health quality will not be identified promptly (Foot et al, 2014). Ultimately, this will make the job of reducing infections in the community more of a challenge than those occurring in hospitals.

Despite these challenges, there has been evidence of care improvements that have helped to reduce numbers of infection in the community and assisted in achieving the Government's targets of reducing GNBSIs (PHE, 2017a). These improvements include enhanced sepsis prevention, antimicrobial stewardship, UTI and catheter-related UTI prevention; better dissemination of patient information; improved education and training of staff, incentives and surveillance (NHS Improvement, 2019).

A sentinel surveillance scheme in England examined risk factors for E. coli BSIs in the community and hospitals and found that the urogenital tract was the most common source of infection (51.2%); key secondary risk factors included prior hospitalisation, antimicrobial therapy and urinary catheterisation (Bradley et al, 2018). Especially in the case of patients in the community, personal hygiene is imperative. However, targeting the prevention of E. coli BSIs requires directing efforts around three specific aspects, namely, reducing UTIs, improving hydration and controlling antibiotic usage (Murni et al, 2014).

Urinary tract infections

UTIs are caused by the presence and multiplication of microorganisms in the urinary tract, with an infection defined by a combination of clinical features and the presence of bacteria in the urine (NICE, 2015). A UTI can occur anywhere in the urinary tract. Community nurses can provide patients with a simple checklist that may alert them to the symptoms, and they can then seek advice or treatment (Box 1).

Box 1.Signs and symptoms of a urinary tract infection

Most UTIs only involve the urethra and bladder in the lower tract. However, UTIs can also involve the ureters and kidneys, in the upper tract. Although upper-tracts UTIs are more rare than lower-tract UTIs, they are also usually more severe (NICE, 2015).

Symptoms of a UTI depend on what part of the urinary tract is infected. Symptoms of lower-tract UTIs include burning micturation, increased frequency and urgency of urination, strong odour, cloudiness of urine and pain. Symptoms of an upper-tract UTI include: pain and tenderness in the upper back and sides and can produce chills, fever, nausea and vomiting. Upper-tract UTIs can be potentially life-threatening if the bacteria move from the infected kidney into the blood. This condition, called urosepsis, can cause dangerously low blood pressure, shock and death.

One of the most effective practices to prevent recurrent UTIs among patients in the community is making some simple changes to personal hygiene:

• Wiping ‘front to back’: After going to the toilet, it is important to push the toilet paper from the front, near the water pipe, towards the bottom. If the paper is pulled from near the anus to the urethra, it can transfer bacteria
• Avoiding soaps, shower gels and ‘intimate hygiene’ products: Washing with soap or other products removes the natural protection of vaginal secretions and can even cause chemical irritation, which promotes infection
• Limiting washing the vaginal area to once a day: those with UTIs often believe the infection occurs because they are not cleaning adequately, and so they try to improve hygiene in the vaginal area by washing more than once a day. Unfortunately, this practice has the opposite effect, as it washes the healthy vaginal secretions away
• Ensuring sexual hygiene: Many women experience UTIs after having intercourse. Passing water and washing gently with warm water after sex can help reduce the number of infection-causing bacteria present
• Avoiding constipation by following a diet full of fibre and a healthy intake of fluid
• Treating incontinence, whether urinary or faecal, can help reduce the risk of UTIs.

Testing for UTIs

As well as trying to prevent UTIs, it is necessary to educate staff on the correct procedures for testing urine in the event of a suspected UTI. Testing with dipsticks can lead to false diagnosis of infection and unnecessary prescribing of antibiotics (NICE, 2014).

The advice at present is not to send urine for culture in asymptomatic cases with positive dipsticks and only send urine for culture if two or more signs of infection (i.e. dysuria, fever>37.9 degrees or new incontinence). Doctors are advised not to treat asymptomatic bacteriuria in older adults, as it is very common, and treatment does not prevent symptomatic episodes, but increases side effects and antibiotic resistance (PHE, 2019).

Catheter care

UTIs are also common among those with indwelling catheters, and improved management of patients with catheters will reduce catheter-associated UTIs (CAUTIs) and prevent unnecessary use of antibiotics. A significant reduction in infections has been observed when practices around catheter care are improved (Richards et al, 2017), for example, via a multimodal approach that focuses efforts on high-yield interventions, which can contribute to reducing CAUTIs, such as the ‘ABCDE’ approach (Saint et al, 2009):

• Adherence to general infection control principles is important (e.g. hand hygiene, surveillance and feedback, aseptic insertion, proper maintenance, education)
• Bladder ultrasound may avoid indwelling catheterisation
• Condom catheters or other alternatives to an indwelling catheter, such as intermittent catheterisation, should be considered where appropriate (e.g. GentleCath (Convatec), Speedicath (Coloplast), LoFrict (Wellspect), Liquick X-treme (Teleflex), InstantCath and VaPro (Hollister))
• Do not use indwelling catheters unless unavoidable
• Early removal of the catheter using a reminder or nurse-initiated removal protocol is warranted.

There is a wealth of literature on the topic of catheter care with the aim of reducing infections (Loveday et al, 2014; NICE, 2015; RCN 2019b). The standard messages have been around educating patients to have autonomy when caring for their own urinary catheter. Practical advice for healthcare staff caring for patients with catheters is to always wear gloves (non-sterile) and wear a disposable apron when caring for catheters (Yates, 2016), and patients should wash their hands. All urinary catheters should be secured to the patient's leg by a retaining strap; this is to prevent the catheter from sliding up and down the urethra (Nicolle, 2014). This could lead to trauma to the urethra, bladder neck and glans of the penis. It also prevents accidental disconnection or removal. Using soap and water to clean the catheter is sufficient. This can be done in the shower or bath. Daily bathing should be encouraged (Loveday et al, 2014).

Improving hydration

Research has shown a link between dehydration, UTIs and E. coli Gram-negative sepsis (Francis et al, 2019). A number of system actions are linked to improving hydration in the community, with community nurses being stalwarts for these initiatives. Dehydration can affect both physical and mental health, altering mood and feelings. Community nurses should recognise the signs of dehydration, monitor for it, encourage hydration and know what physical conditions may ensue if patients are not adequately hydrated, as this will enable them to take prompt action and prevent the consequences of dehydration (RCN, 2018). Equally, it should be acknowledged that this may be problematic due to the short time community nurses have to spend with patients.

Initiatives have been underway in community NHS trusts to improve hydration among patients and staff, using an array of posters developed to create awareness that maintaining hydration is important as a means of preventing UTIs. Posters are a good way of attracting attention, and recently developed displays highlight how urine colour can indicate the level of hydration and what types of food improve fluid uptake (Omar et al, 2019). Displaying these on community premises or given them to people as handouts can help to promote hydration.

People who are unwell, in particular, tend to drink less. Community nurses can enable patients to improve their fluid intake by reminding them to drink regularly during the day and advising them to keep drinking cups handy. If patients are showing signs of dehydration and do not have the appropriate cups to drink from, the matter should be addressed. Those with dementia may require 1:1 care, as they are at a higher risk of dehydration and require careful support and management with their drinking and eating (Ullrich and McCutcheon, 2008).

For the general public as well, drinking water regularly during the day is advised, in order to prevent UTIs (RCN, 2018). However, the necessary infrastructure needs to be in place for this to happen. A recent report has shown over half (56%) of the public restrict fluid intake due to concerns over the lack of toilet facilities (Royal Society for Public Health (RSPH), 2019). Thus, greater investments in civic infrastructure are needed to ensure public access to toilets. (RSPH, 2019).

Water should also be available free of charge in public places (Health and Safety Executive (HSE), 2011). Water refill apps are becoming more popular and can be installed on mobile phones to alert people to where the nearest ‘free’ water fountain is.

Antibiotic usage

The NHS is aiming to reduce the amount of antibiotics it uses by 15% by 2024, as part of a new drive to tackle the growing scourge of drug-resistant pathogens (DHSC, 2019). Strategies to reduce antibiotic prescribing have been successful in primary care, and similar interventions are underway nationally to reduce antibiotic prescribing (Germeni et al, 2018). The UK 5-year antimicrobial resistance strategy is a key driver in reducing the spread of antibiotic resistance (DHSC, 2013). Community nurses have a role in reducing antibiotic usage. Those involved in prescribing are expected to remain up-to-date with emerging evidence on resistance and appropriate antibiotic usage. This can be through continuing professional development and wider use of resources, such as the ‘Start Smart-Then Focus’ guidance on antibiotic stewardship (NICE, 2018).

The community nurse's role would also be to have an awareness of the control and monitoring of antibiotic usage to prevent antimicrobial resistance (Chater and Courtenay, 2019). Community nurses should also encourage patients on antibiotics to complete the prescribed course.

Many health professionals identify themselves as antibiotic guardians, but patient expectations, time constraints and a lack of confidence can influence decisions to prescribe. Similarly, while nurse prescribers welcome the opportunity to be antibiotic stewards in the community, they are often faced with barriers to antibiotic stewardship activities, such as time with patients, level of knowledge and skill and lack of opportunity to undertake the role (Chater and Courtenay, 2019). These barriers may be overcome with development of knowledge, confidence and effective communication with both peer antibiotic prescribers and antibiotic consumers.

While antibiotics can be life-saving, community nurses must recognise the negative consequences of inappropriate prescribing, including treatment failure, with increased morbidity and mortality, longer duration of hospital stay and increased costs. Overuse of antibiotics has also led to an increased risk of healthcare-associated infections, including methicillin-resistant S. aureus and Clostridioides difficile (Ventola, 2015).

Community nurses frequently visit older residents in care homes who are prescribed antibiotics for various reasons, such as chest infections, wound infections or UTIs, and having an awareness of inappropriate antibiotic use can ensure effective care is given to patients (Thornley et al, 2019). Antibiotics should not be used to treat viral infections, such as influenza, the common cold, a runny nose or a sore throat. Other measures to prevent overuse of antibiotics include:

• Starting antibiotics unnecessarily (e.g. for viral infections or using two or more antibiotics where only one is needed)
• Using antibiotics unlikely to cover the suspected infection based on the likely causative organism and its resistance patterns
• Overuse of broad-spectrum antibiotics (e.g. inappropriate initial choice and/or failure to narrow the antibiotic spectrum based on culture or test results)
• Failing to switch intravenous antibiotics to oral when appropriate
• Continuing antibiotics unnecessarily (e.g. failing to stop when a non-infectious diagnosis is confirmed or exceeding recommended course lengths)
• Failing to recognise actual or potential safety concerns (e.g. failure to take account of allergies or to monitor for or recognise toxicity).

Conclusion

Despite much improvement in the adoption of IP&C practices and many successful initiatives to reduce infection rates, GNBSIs continue to rise. Therefore, the response needs to be rapid, innovative and targeted to facilitate resources and adopt practices that work. IP&C practices and the three-aspect plan discussed here (to cover UTIs, adequate hydration and antibiotic usage) are not only a necessity but also acutely vital if reductions in these infections are to be realised. This article has shown that for the target of reducing GNBSIs, especially E. coli BSIs, it is imperative that a national defence is agreed, and collaboration with the NHS community, public health and the wider economy supervenes. This will ensure optimum practices are being adopted targeting UTIs, hydration and the prudent use of antibiotics.

As mentioned in this article, E. coli can cause a range of infections including UTIs, respiratory and intestinal infection (Lee et al, 2018). Targeting the sources of infection by improving IP&C practices, such as hand hygiene, ensuring a clean environment and the wearing of personal protective equipment, should help to limit their spread (Loveday et al, 2014). Other measures, such as ensuring better hydration, antibiotic stewardship and better personal hygiene practices can also reduced the frequency of UTIs (NICE, 2015) and, consequently, GNBSIs.

KEY POINTS

• The government has a plan to reduce gram-negative bloodstream infections (GNBSIs) by 2024/25
• Healthcare policy makers need to target community-onset healthcare-associated infections to reduce GNBSIs
• The cause of infection can be identified based on the physiology of the pathogens, and they can then be treated accordingly
• Infection prevention and control practices help to reduce infections
• Reducing urinary tract infections, improving hydration and antibiotic prescribing can help to reduce GNBSIs

CPD REFLECTIVE QUESTIONS

• What are the infection prevention and control (IP&C) practices that are required when caring for a patient with a urinary tract infection (UTI)?
• What measures could be put in place in the community to ensure adequate hydration among older adults?
• What steps are being taken at your organisation to promote antibiotic stewardship?
• What personal hygiene measures could be taken to reduce the risk of a UTI?