Overview and Implications
Urinary Tract Infection (UTI)
UTIs can be divided into upper tract infections, which involve the kidneys (pyelonephritis), and lower tract infections, which involve the bladder (cystitis), urethra (urethritis), and prostate (prostatitis). Infection may spread from one site to the other. Although urethritis and prostatitis are infections that involve the urinary tract, the term UTI usually refers to pyelonephritis and cystitis (Imam 2013).
Most cases of cystitis and pyelonephritis are caused by bacteria. The most common nonbacterial pathogens are fungi (usually candidal species), and, less commonly, mycobacteria, viruses, and parasites. Nonbacterial pathogens usually affect patients who are immunocompromised; have diabetes, urinary tract obstruction, or structural abnormalities; or have had recent urinary tract instrumentation. Urethritis is usually caused by sexually transmitted infections (STI). Prostatitis is usually caused by bacteria and sometimes STIs (Imam 2013).
Healthcare-associated UTI is the fourth leading cause of healthcare associated infections after pneumonia, surgical site infections and intra-abdominal infection (Magill et al, 2014).
Approximately 80 per cent of healthcare associated UTIs are attributable to indwelling urethral catheters (IHI 2012).
Catheter-Associated Urinary Tract Infection (CAUTI)
CAUTI is the presence of symptoms of infection along with a positive catheter or midstream urine specimen in a patient who was previously catheterized within 48 hours (Hooton et al, 2010).
A urinary catheter provides a portal of entry into the urinary tract. The source of bacteria causing CAUTI is usually endogenous—typically via meatal, rectal, or vaginal colonization—but rarely may be exogenous, from equipment or contaminated hands of healthcare personnel (APIC 2014).
The most important risk factor for development of CAUTI is the duration of catheterization. Daily risk of acquisition of bacteriuria with urinary catheters is around seven per cent and among those with catheter-associated bacteriuria, symptomatic CAUTI will develop in 24 per cent (95 per cent CI, 16-32 per cent) and bacteremia will develop in 3.6 per cent (95 per cent CI, 3.4-3.8 per cent) (Saint, 2000).
Other factors predispose CAUTI including patient-related factors such as diabetes, fecal incontinence, incomplete emptying of the bladder, dehydration etc.; care provider related factors such as poor hand hygiene practices, poor insertion technique, etc.; and hospital, equipment, and/or environmental systems (APIC 2014). The CDC reports that the most frequent pathogens associated with CAUTI in hospitals between 2006 and 2007 were Escherichia coli (21.4 per cent) and Candida spp (21 per cent), followed by Enterococcus spp (14.9 per cent), Pseudomonas aeruginosa (10 per cent), Klebsiella pneumoniae (7.7 per cent), and Enterobacter spp (4.1 per cent). A smaller proportion was caused by other gram-negative bacteria and Staphylococcus spp (APIC, 2014).
CAUTIs account for the majority of healthcare-associated UTIs and have been associated with increased morbidity, mortality, hospital cost, and length of stay (APIC 2014). It is well established that the duration of catheterization is directly related to risk for developing a UTI. With a catheter in place, the daily risk of developing a UTI ranges from 3 to 7 per cent (IHI, 2012). During hospitalization, from 12 to 16 per cent of patients may receive short-term indwelling urinary catheters. The average rate of CAUTI is higher in ICU patients than in non-ICU patients (APIC 2014).
An estimated 17 to 69 per cent of CAUTIs may be preventable with implementation of evidence-based practices. Although there has been modest improvement in CAUTI rates, progress has been much slower than other device-associated infections (APIC 2014).
Post-partum UTI may begin as asymptomatic bacteriuria during pregnancy and is sometimes associated with bladder catheterization to relieve urinary distention during or after labor (Imam 2013). Physiological changes in the bladder occur during pregnancy and predispose women to develop post-partum urinary retention (PUR) during the first hours to days after birth which can lead to UTI (Leach 2011). PUR after vaginal birth is a relatively common event, with the reported incidence ranging from 1.7 to 17.9 per cent (Leach 2011). The risk is higher among instrument-assisted births and use of regional analgesia. Other common risk factors include primiparity, prolonged first and second stage perineal tearing and oxytocin use. Unrecognized PUR may lead to upper urinary tract damage and permanent voiding difficulties (Leach 2011).
Pyelonephritis may occur postpartum if bacteria ascend from the bladder. The infection may begin as asymptomatic bacteriuria during pregnancy and is sometimes precipitated by peripartum urinary retention and/or bladder catheterization during or after labor (Imam 2013).
UTIs Among Neonates
The characteristics of UTI in neonates differ from UTIs in infants and children. Its prevalence is much higher, male sex is affected predominantly non-Escherichia coli infections are more frequent, and there is a higher risk of urosepsis than in older age groups. UTI in neonates may be the first indicator of underlying abnormalities of kidneys and the urinary tract (Beetz 2012). Some 35 to 50 per cent of term and preterm neonates with UTI have abnormal urinary tract ultrasounds (Bonadio et al, 2014, Ismaili et al, 2011, Goldman et al, 2000, Sastre et al, 2007).
The prevalence of UTIs among full-term neonates has been reported to be up to 1.1 per cent, increasing up to seven per cent among those with fever. Evidence indicates that up to approximately 15 per cent of febrile neonates have positive urine culture (Bonadio et al, 2014, Ismaili et al, 2011) and most UTI in neonates is related to pyelonephritis as compared to cystitis in older children. The presence of UTI is significantly higher in uncircumcised vs circumcised boys (Beetz 2012).
Prevention of urinary tract infection by implementing recommended components of care.