Epidemiology and Prevention of Infections in Long-term Care Facilities
Epidemiology and Prevention of Infections in Long-term Care Facilities
Suzanne F. Bradley
WHAT IS LONG-TERM CARE?
Increasingly, delivery of healthcare is provided outside of the traditional acute care hospital setting as soon as the patient is stable enough to be discharged. Long-term care has generally referred to skilled nursing facilities or nursing homes, residential care, hospice services, home health services, and adult day care; terminology may vary from country to country.1,2,3,4,5,6 For the purposes of this chapter, long-term care facilities (LTCFs) will refer to licensed facilities with inpatient beds that provide skilled care and other healthcare services provided by nurses and other professional staff beyond assistance with activities of daily living (ADLs). In LTCFs, the registered nurse is responsible for the oversight of residents and much of the direct care is carried out by nurse’s aides or medical technicians.1,4,6,7 The typical registered nurse/resident ratio in LTCF is 1:25, in contrast with 1:5 RNs per patient in acute care, and routine evaluation of residents by physicians occurs every 30 days.1,7 In LTCFs, the primary goal is the implementation of a predetermined care plan that seeks to treat stable and chronic conditions or to provide short-term rehabilitation.1,2,4,5,6,7 For LTCF, the focus is not on provision of unskilled care by lay personnel in residential homes or the diagnosis and management of new, acute, or unstable conditions that require the resources of a hospital or long-term acute care hospital (LTACH).
THE INCREASING NEED FOR LONG-TERM CARE
While some LTCFs specifically care for children, older adults remain the most frequent consumers of acute and post-acute healthcare, and this chapter will focus on that population.4,5 The world’s population is aging; it is estimated that the number of persons aged 60 years and older will reach 2 billion worldwide by 2050.8 By 2030, 20% of the population in the United States will be aged 65 years or older.9 However, it is anticipated that most older adults will reside in the developing world (eg, Asia [414 million] with a smaller proportion of in Europe [161 million] and in North America [65 million]).8 In the European Union (E.U.), it is expected that the percentage of adults aged 65 years and older will almost double from 16.0% in 2010 to 29.3% by 2060.10
With increasing age will come more illness and functional impairment with a need for more supportive and long-term care services.11 In the United States, ˜66% of American adults aged 65 years and older will require an average of 3 years of long-term care services during their lifetime; 33% of those adults will require a stay in a LTCF.2 In Europe, it is already clear that ˜10% of older adults aged 65 years and older will require long-term care services and more than one-third of those services will be provided in an institutional setting.10 As of 2010, 3.7 million EU residents required care in an LTCF. As the population continues to live even longer, it is estimated that greater numbers of LTCF beds will be required. For example, 10% of European older adults aged 65-79 years currently reside in an LTCF, but after age 80 years and older, the proportion of older adults needing an LTCF increases to ˜50%.8
Use of long-term care services will also vary from country to country due to differences in cultural norms and financial considerations.12 The greatest use of long-term care services (>15%) has been seen in countries with universal and comprehensive healthcare services such as Scandinavia, Austria, the Netherlands, Switzerland, and New Zealand. In contrast, use of long-term care services is less common in Italy, Korea, and most of Eastern Europe (1%-4%).8
HOW COMMON ARE HEALTHCAREASSOCIATED INFECTIONS IN LONG-TERM CARE?
In contrast with acute care hospitals, it has been difficult to accurately estimate the prevalence and incidence of healthcare-associated infections (HAIs) in LTCFs, and most data have been obtained from single institutions or from regional networks rather than from national surveillance systems. One limitation is that infection surveillance reporting in LTCF is frequently initiated in response to an outbreak. Only recently have national and multinational efforts attempted to define the extent of endemic HAIs in LTCFs.
In 2013, the Healthcare-Associated Infections in Long-Term Care Facilities (HALT-2) study assessed a representative sample obtained from 43 235 LTCFs with 2 390 789 beds reported by 19 European countries.5 The participating facilities were characterized as general nursing homes (64.5%), mixed LTCFs (19.1%), rehabilitation centers (5.8%), and residential homes (5.3%).5 The final HALT-2 point-prevalence survey encompassed a cross-sectional sample of 1051 LTCFs with 79 285 beds, which represented 2.3% of facilities and 3.3% of beds in the EU.5 National sampling was judged to be good in 10 of 19 countries reporting (Table 32-1).
TABLE 32-1 Healthcare-Associated Infections (HAIs) in U.S. Veterans Affairs (VA) and European Long-Term Care Facilities (LTCFs): Results of Point-Prevalence Surveys
Adapted from Tsan L, Davis C, Langberg R, et al. Prevalence of nursing home associated infections in the Department of Veteran Affairs Nursing Home Care Units. Am J Infect Control. 2008;36:173-179; Tsan L, Langberg R, Davis C, et al. Nursing home-associated infections in the Department of Veterans Affairs Community Living Centers. Am J Infect Control. 2010;38:461-446.
The approach to defining of HAIs in LTCFs has also differed widely from study to study. For HALT-2, the diagnosis of an HAI required the presence of new or acutely worsening symptoms or treatment for the same on the date of the survey; microbiological confirmation was not required.5 On that basis, 4202 (5.4%) residents either had the diagnosis of a confirmed HAI or received an antibiotic; 2626 (3.4%) received an antimicrobial agent for presumptive HAI. Thus, it has been estimated that on any given day, 115 416 LTCF residents in Europe will have an HAI and 150 657 residents will receive at least one antimicrobial agent.5 Hospitalization rates and length of stay were similar for residents who had an HAI or received antimicrobial agents.5 In the EU, HAI rates and antibiotic use have varied widely from 0.4% in Croatia to 9.5% in Portugal and from 1.0% in Hungary to 12.1% in Greece, respectively.
Until recently, in the United States, nationwide data have been limited primarily to surveys conducted in 2003, 2005, and 2007 in ˜130 Veterans Affairs (VA) LTCFs representing ˜11 000 patients.13,14,15 Despite differences in surveillance definitions and patient populations, HAI rates in Europe were remarkably similar to results of several prevalence surveys done in VA LTCFs (5.2%-5.3%); the VA studies used modified Centers for Disease Control and Prevention (CDC) criteria (Table 32-1).14,15 These reported LTCF HAI rates have been similar to those found in US acute care hospitals.14,15
Less is known about national HAI rates among community-based non-VA facilities, but strides are being made to bridge that gap. In 2016, there were 15 600 LTCFs in the United States encompassing 1.66 million beds.2 All Medicare- and Medicaid-certified LTCFs have been required to track information about urinary tract infections (UTIs), pneumonias, Clostridioides difficile, and antibiotic-resistant bacteria occurring in its residents upon admission and on a quarterly basis using the Minimum Data Set (MDS) 2.0 and 3.0.16 While MDS definitions are not the same infection surveillance definitions, they do provide some idea of the number of infections present in the United States; in 2013, 1.1-2.7 million infections occurred in LTCF.16 Infection surveillance in LTCF has been included as part of the U.S. National Healthcare Safety Network (NHSN) since 2008, but only a small number of institutions has enrolled on a voluntary basis. Since 2012, the CDC has expanded NHSN with a goal to increase participation by LTCFs nationwide as part of the LTCF National Action Plan; ˜20% of LTCF have enrolled to date,17,18,19 and all LTCF will need to participate as of November 2019.16,20,21 Goals have included tracking of laboratory confirmed C difficile, catheter-associated urinary tract infections (CA-UTI), and pneumococcal and influenza vaccination rates in patients, influenza vaccination rates in healthcare providers (HCP), and antimicrobial stewardship.21
WHY ARE LTCF RESIDENTS AT RISK FOR HAIs?
It has been estimated that 1-3 million HAIs will occur in LTCF each day resulting in 300 000 deaths annually.18,21 Increasing age, declining functional status, comorbid illnesses, and other factors have been postulated to contribute to HAI risk in LTCF residents7,22,23 (Table 32-2).
Age
In the past, the typical LTCF resident was an older woman with dementia who was otherwise healthy and had outlived her family. In 2014, women still account for 65.5% of the US LTCF population.3 While younger adults are increasingly receiving post-acute care in LTCF after discharge from hospital (15.5%), older adults continue to make up a significant proportion of the population. In the United States, 84.5% of LTCF residents are aged 65 years and older, and 41.6% are older than 85 years.3 In Europe, almost half of LTCF residents are aged 85 years and older (median 49.1%) and primarily female (mean 69.3%).5 The VA population is, not surprisingly, predominantly male and somewhat younger; the largest proportion of patients was aged 60-79 years (43.4%-45.5%) followed by those aged 80 years and older (37.9%).13,14,15 Aging alone has not been associated with increased risk of infection; no significant difference in HAI rates has been seen with increasing age.14
TABLE 32-2 Risk Factors for Healthcare-Associated Infections (HAIs) in Residents of Long-term Care Facilities (LTCFs)
HAIs
Pathophysiology of HAIs in LTCF residents
Common risk factors associated with HAIs
All infections
Alteration nonspecific host defenses
Declining mucociliary reflexes
Increased urinary stasis
Breaks in mucocutaneous barriers
Declining gastric acid
Declining functional status
Increased immobility
Increased assistance with self-care
Increased comorbid illnesses
Increased exposure to pathogens
See specific clinical syndrome
Respiratory
Promotion oral colonization with pathogens
Xerostomia
Achlorhydria
Inadequate oral care
Impairment cough/increased aspiration
Swallowing disorder
Altered cognition
Impaired mobility
Altered immunity
Increased exposure to pathogens
Resident-to-resident spread
Transmission by HCPs
Medications
Anticholinergic activity
Impaired gastric acid
Sedating effects
Immunosuppression
○ Steroids
○ Chemotherapy
Devices
Feeding tubes
Tracheostomies
Ventilators
Comorbid conditions
Neurological disorders
○ Seizures
○ Stroke
○ Dementia
○ Delirium
Cardiopulmonary disease
○ COPD
○ CHF
Neoplasms
Urinary
Increased bacteriuria
Incontinence
○ Immobility
○ Impaired cognition
Increased perineal soiling
Increased urinary stasis
Increased exposure to pathogens
Resident-to-resident spread
Transmission by HCP
Increased urinary device use
Comorbid conditions
Neurogenic bladder
Stones
Cystocoeles
Tumors
Medications
Skin and soft tissue
Impaired skin integrity
Pressure
Maceration
Impaired blood flow
Peripheral edema
Trauma
Increased exposure to pathogens
Resident-to-resident spread
Transmission by HCPs
Comorbid conditions
Immobility
Peripheral neuropathy
Incontinence
Peripheral arterial dis.
Venous insufficiency
Cardiac, renal, and liver failure
Endogenous infections
Fungal (candidosis)
Herpetic infections
Devices
Phlebitis
Enteral tube infection
Exogenous infections
Primary infections
○ Bacterial
○ Viral
○ Ectoparasitic
Secondary wound infections
Postprocedure
Gastrointestinal
Impaired gastric acid
Increased exposure to pathogens
Person to person
○ Patients
○ HCP and other staff
○ Visitors, for example, children
○ Pet therapy
Food- and waterborne
Environmental/fomites
Transmission by HCP
Devices
Enteral feeding tubes
Thermometers
Medications
Acid blockers
Antibiotic use
Immunosuppression
○ Steroids
○ Chemotherapy
HCP, Healthcare providers.
Functional Impairment
Impairment in functional status with a decline in the ability to perform ADLs is common. A majority of LTCF residents will have moderate to severe cognitive impairment (61.4%) and 63.1% will require assistance with 4-5 ADLs, including locomotion (92%), transfers (86.8%), dressing (92.7%), feeding (59.9%), and toileting (89.3%). Urinary incontinence has been reported in 34.3% of residents.3 In small studies, acute changes in functional status have been associated with the diagnosis of infection in almost 80% of residents. Impaired functional status has been associated with increased infection risk.24 In Europe, incontinence (65.8%), disorientation (54.9%), or impaired mobility (52.6%) have been reported most often.5
Device Use
Device use is likely more common among US LTCF residents when compared with Europe. In VA LTCFs, devices were commonly present in 24.5%-24.6% of residents; most had indwelling urinary devices (36.3%) including suprapubic urinary catheters (7.7%), peripherally inserted central catheters (PICCs) (11.5%), peripheral intravenous catheters (PIV) (6.4%), and gastrostomy tubes (17.7%).13,14,15 For European LTCF residents on average, 8.8% had a urinary or vascular catheter (1.4%).5
Rates of device use in an LTCF may vary depending upon the medical needs of its residents, the type of unit where the resident receives their care, and length of stay. Some wards or facilities care for mixed populations of residents with a wide range of medical issues vs specialty units designed to care for residents with specific problem(s). Device use has been found to be most common on longstay units devoted to spinal cord injury (61.5%) and skilled nursing care (39.9%) and least common for patients requiring maintenance care (18.8%), dementia care (9.8%), and psychiatric care (7.9%). For short-stay units, device use was most common on medical evaluation (43.3%), skilled nursing care (32.4%), rehabilitation (21.6%), and hospice care (32.4%) and least common on dementia (4.5%) and psychiatric care units (1.5%).15
Device use is probably the most important patient factor associated with increased risk HAIs. Device use has correlated with increased risk of infection independent of age.14,23 Residents with devices were threefold more likely to have an HAI (10.8%) vs those without a device (3.5%) (P < .0001).11 PIV (26.2%) and central (14.4%) venous catheters, ventilators (20.0%), and tracheostomy tubes (14.2%) were most commonly associated with HAIs. HAIs were also primarily associated with device use rather than the resident’s length of stay or treatment category. Further discussion of risk factors for HAI will be discussed separately under individual clinical syndromes.
Detection of Infection in LTCFs
The exact prevalence of infectious syndromes and their causative organisms in LTCFs worldwide is uncertain. The frequency of infections reported can be biased by focusing on outbreaks vs endemic infections, the ease with which a specimen can be collected, access to diagnostic testing, costs, and the likelihood that the results will alter treatment. The most prevalent infection, UTI, is also the most often overdiagnosed clinical syndrome as cultures of urine are easily obtained and positive results are frequent even in the absence of symptoms.7,22,24,25
In contrast, the causes of respiratory tract infections (RTI) frequently escape detection. Collection of sputum for culture is difficult; specimens may be collected in <30% of LTCF residents with pneumonia and half of them may be inadequate.26,27,28 Many common but fastidious bacterial respiratory pathogens may not grow on routine culture, and newer molecular tests for many atypical bacterial and viruses may not be readily available.26,27,28,29 Without a culture of blood or tissue, the etiology of skin and soft tissue infection (SSTI) is rarely known, and differentiation between infection and superficial colonization is difficult.1,7,30,31 Gastroenteritis and diarrhea are also common, often self-limited, and frequently viral in etiology in the setting of an outbreak; care is generally supportive unless C difficile is suspected.1,7,32,33 With the exception of C difficile, fecal samples are rarely tested for viruses as routine polymerase chain reaction (PCR) testing is generally not available and would not alter treatment or enteric isolation practices, and parasites and other bacterial etiologies are relatively uncommon as causes of LTCF-associated diarrhea.1,7,32,33,34,35
Endemic vs Epidemic Infections Most studies confirm that UTI, RTI, and SSTI are the most common endemic infections found in LTCF. In Europe, RTI (31.2%), UTI (31.1%), and SSTI (22.1%) were the most frequent HAIs.5 Similar findings were found among VA LTCF residents; symptomatic UTI accounted for 29.2% of endemic HAIs followed by SSTI and pressure ulcer infections (22.9%) and pneumonia (8.0%) (Table 32-1).14,15 In the epidemic setting, the prevalence of clinical syndromes in LTCFs may shift with RTI noted most often (45%) followed by gastrointestinal infection (36%), SSTI (7%), and eye infection (2%).36,37 Outbreak reporting in LTCF may also be subject to bias given that many of these reports originated from English-speaking countries, predominantly the United States, Canada, the United Kingdom, and Australia.37
Respiratory Tract Infections In LTCF, overall RTI surveillance typically focuses on the detection of clinically important infections such as pneumonia and lower RTI or outbreaks due to influenzalike illnesses that are potentially preventable (Table 32-3). Per the McGeer criteria, the diagnosis of pneumonia requires the presence of a new or worsening infiltrate on chest radiograph, whereas the diagnosis of lower RTI can still be made with the same constellation of signs and symptoms even if a chest radiograph is not performed. Lower RTI and pneumonia risk may be increased in LTCF residents due to patient and institutional factors. Patient factors that promote changes in oropharyngeal flora, such as conditions and treatments that contribute to xerostomia and achlorhydria, inadequate oral care, and alterations in immunity can contribute to colonization with pathogenic bacteria. Other factors such as cognitive or swallowing disorders, sedating medications, presence of a feeding tube or tracheostomy, and immobility may impair host lung defenses, leading to reduced cough and aspiration. Exposure to respiratory pathogens is also increased in a closed group setting especially when debilitated patients require care by HCP who may facilitate transmission of pathogens from resident to resident by direct contact.1,7,26,27
TABLE 32-3 Recommended Priorities for Infection Surveillance in Long-term Care Facilities (LTCFs)
Points to consider
Infections
Comments
A. Infections that should not be routinely included in surveillance
Limited
1. Transmissibility
Ear, sinus, oral infections, fungal or (herpetic) viral skin infections
Rarely transmitted
2. Preventability
Due to comorbid conditions
At-risk populations
Postoperative, CLABSI, VAP
Include only if an issue in the LTCF; use NHSN definitions
B. Infections that should be routinely included in surveillance
1. Transmission evident
Influenzalike infection Clostridioides difficile, viral gastroenteritis, and conjunctivitis
Associated outbreaks in patients and healthcare providers
2. Prevention possible
3. Significant clinically
LRTI, UTI, pressure ulcers, SSTIs
Leads to morbidity and hospitalizations
4. Serious outbreaks
Group A streptococci, scabies, viral hepatitis, norovirus, influenza
Rare, but highly contagious
LRTI, lower respiratory tract infection; UTI, urinary tract infection; SSTIs, skin and soft tissue infection; CLABSI, central line-associated blood stream infection; VAP, ventilator-associated pneumonia; NHSN, U.S. National Healthcare Surveillance Network.
Adapted from Stone ND, Ashraf MS, Calder J, et al. Definitions of infection for surveillance in long-term care facilities: revisiting the McGeer criteria. Infect Control Hosp Epidemiol. 2012;33:965-977.
Risk factors for aspiration appear to be the strongest predictors of pneumonia in LTCF residents.27,38 In VA LTCF residents, a facility-level association between pneumonia rates and the use of nasogastric tubes (P = .0022) and tracheostomies (P = .0095) was confirmed, although a direct relationship between use of the device and the HAI could not be made in individual residents.14 Devices that promoted aspiration were common in this population (24.2%-25.5%); most had a gastrostomy tubes (17.7%-19.0%), nasogastric tubes (1.4%-1.8%), or tracheostomy tubes (4.5%-4.6%) or required a ventilator (0.3%-0.4%).14,15
RTI has frequently been reported as the second most common infection in LTCFs overall. Interpretation of RTI rates is difficult because HAI rates may include endemic as well as epidemic infections. In addition, an inability to obtain a chest roentgenogram in LTCF could lead to misclassification of pneumonia as a lower RTI. In Europe, all RTI accounted for 31.1% of HAIs in LTCFs (Table 32-1).5 Of the 857 RTIs reported, most were due to lower RTI (58.9%) vs pharyngitis/common colds (28.8%), pneumonia (8.3%), and influenzalike illness (4.0%).5 In contrast, in VA LTCF, pneumonia (8.0%-9.4%) was most common vs upper respiratory infection (URI) (2.3%), bronchitis without pneumonia (0.8%-1.9%), tracheobronchitis without pneumonia (0.2%), other lower RTI (0.5%), and laryngitis or pharyngitis (0.2%-0.3%) (Table 32-1).14,15 Pneumonia rates in VA LTCF seemed low given that most facilities had ready access to chest radiography and the presence of infiltrate is required to meet CDC surveillance definitions.39
In few carefully performed studies in the LTCF setting, the bacterial causes appear to most closely mirror those seen in older adults in the community rather than in hospitals. Streptococcus pneumoniae (13%), aerobic GNB (13%), nontypeable Haemophilus influenzae (6.5%), Staphylococcus aureus (6.5%), and Moraxella catarrhalis (4.5%) are most common.26,27,28 In general, pneumonias due to aerobic Gram-negative bacilli appear to be relatively uncommon; when they have occurred, Klebsiella spp. was the most common genera isolated.40
Atypical pneumonia is uncommonly described in LTCFs except in the context of outbreaks in part because access to laboratories and newer antigen testing may be lacking. RTI outbreaks in LTCF are most commonly due to influenza followed by S pneumoniae, respiratory syncytial virus (RSV), and other pathogens including parainfluenza virus, rhinoviruses, coronaviruses, and Chlamydia pneumoniae.29,36,37,41,42,43,44 Median attack rates have ranged from 13% for S pneumoniae and >40% for parainfluenza, RSV, and C pneumoniae with highest hospitalization rates for legionellosis and influenza.37 The median case fatality rate appears to be greatest for infections due to Legionella, S pneumoniae, and RSV (>20%) and lowest for C pneumoniae (2%) and influenza (6.5%).37 Influenza and other viruses may contribute to postviral or secondary bacterial pneumonia due to pneumococci or S aureus.45 Primary pneumonia due to due to influenza, RSV, parainfluenza, adenoviruses, coronaviruses, rhinoviruses, and metapneumovirus is uncommon, but it can occur with significant morbidity and mortality.29,36,41,42,43,44 Reactivation tuberculosis (TB) should be considered in LTCF residents with persistent infiltrates and symptoms that do not respond to conventional antimicrobials, particularly if they involve the upper lobes and if there is a history of prior exposure.46
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