UTIs, HEART INFECTIONS, LYME DISEASE, AND OSTEOARTICULAR
INFECTIONS
URINARY TRACT INFECTIONS (UTIs)
ASYMPTOMATIC BACTERIURIA (ASB)
UTIs FEATURES
The urinary tract infection (UTIs) is a broad term that encompasses a spectrum of infectious
syndromes that affect the urinary tract anywhere, from kidneys to the urethra. These infections can
be easily managed (e. g. cystitis), while
others are more severe (e. g.
pyelonephritis, immunocompromised
patients). They are some of the most
common infections; indeed, about 50%-
60% of women have at least 1 UTI in their
life. These infections are commonly
caused by Gram-negative bacteria,
especially E. coli, which accounts for most
of the infections (high presence of
fluoroquinolone-resistance due to
incorrect use). Other pathogens can be Klebsiella pneumonia and Proteus mirabilis. The infections
caused by Proteus spp. can increase the risk of developing kidney stones.
The bacteria that typically cause these infections are from the GI tract (Enterobacteriaceae). Another
possible source of UTIs is bacteria in the bloodstream migrating to kidneys or bladder, despite being
rare. The risk factors for UTIs include female sex, recent sexual intercourse, diabetes mellitus, and
structural or functional urological abnormalities.
FEATURES AND NOT-SCREENED PATIENTS
The asymptomatic bacteriuria (ASB) is the presence of one or more species of bacteria growing in the
urine at specified quantitative counts (>10 5CFU/mL), irrespective of the presence of pyuria, in the
absence of signs or symptoms attributable to UTI.
The ASB is a common finding in some healthy female
populations and in several women or men with
abnormalities of the urinary tract that impair voiding.
In most cases, these patients should not perform a urine
culture. Categories of patients in which is recommended
against screening for or treating ASB are several, which are:
• Healthy post-menopausal, nonpregnant, and
healthy post-menopausal women.
• Older patients.
• Patients with diabetes.
• Kidney transplant recipients (up to clinicians): more than 1-month prior surgery.
• Patients with non-renal solid organ transplant.
• Patients with high-risk neutropenia (<100/mmc).
• Patients with short-term indwelling urethral catheter (<30 days).
• Patients with long-term indwelling urethral catheter.
PATIENTS TREATED FOR ASB
The patients that should be tested in case of asymptomatic bacteriuria belong to two main groups,
which are:
• Pregnant women: it is recommended a screening for and treating ASB; it is suggested a urine
culture collected at one of the initial visits early in pregnancy; there is insufficient evidence to
, inform a recommendation for or against repeat the test if it results negative; ABS occurs in 2%-
7% of pregnant women; in this category antimicrobials probably reduce the risk of
pyelonephritis and may reduce the
risk of low birth weight; antimicrobial
also reduce the risk of preterm labour;
however, to avoid side effects, 4-7
days of therapy is suggested at lower
dose.
• Patients who will undergo endoscopic
urologic procedure: it is
recommended screening for and
treating ASB prior to surgery; it is
suggested to test the urine to avoid
possible contamination of the surgical
field during the operation, which may result in postoperative complications (e. g. urosepsis);
the therapy should be shorter (1-2 days) and started 30-60 minutes before the procedure.
The treatment for asymptomatic bacteriuria is based on prophylactic procedures.
Note that it is important to determine whether the patient should be tested or not for ASB. Indeed,
the unnecessary treatment of ASB may result in an increased risk of developing side effects, as well
as of antimicrobial resistance.
CYSTITIS AND PYLONEPHRITIS
ACUTE UNCOMPLICATED CYSTITIS
The acute uncomplicated cystitis is a type of UTI, specifically an infection of the bladder in an
otherwise immunocompetent host with normal urinary tract (i. e. uncomplicated). The classical
symptoms of UTIs are three, which are:
• Dysuria: it corresponds to difficulty and pain
during urination.
• Pollakiuria: it refers to increased urinary
frequency.
• Urinary urgency.
The diagnosis of cystitis is based on these three symptoms
(plus suprapubic pain), together with absence of systemic
illness and flank pain (upper urinary tract infection). The
cystitis does not need any laboratory evaluation.
Conversely, pyelonephritis requires laboratory evaluation before diagnosing it.
COMPLICATED UTIs AND TESTING
The complicated UTI is a broad term that has been traditionally used to define the UTI syndromes that
do not meet the description of simple cystitis, as well as the ones that occur in patients with severe
immunosuppression.
The diagnosis of these UTIs is primarily made by
the presence of typical symptoms (i. e. dysuria,
pollakiuria, urinary urgency) and can be
confirmed by 2 main laboratory tests, which are
urinalysis and urine culture.
The urinary microscopy can identify the
presence of WBC in urine (i. e. pyuria). Having
more than 10WBC/L in urine is suggestive but not diagnostic of a UTI. Indeed, pyuria may be
associated with other inflammatory, but not infectious conditions. It can be rather used as NPV
(>85%), and therefore to rule out UTI.
,The urine cultures are a more direct way to assess the presence of pathogenic bacteria in the urine,
and they can be used to completely diagnose UTIs. The classic cut-off for a positive urine culture to
reflect the presence of bladder bacteriuria is more than 105CFU/mL. Note that, as said before, urine
cultures are suggested only in case of complicated UTIs, and not in uncomplicated cystitis.
The urinalysis and urine culture should be sent when evaluating a patient for a UTI who presents
specific situations, which are:
• Signs or symptoms of upper tract disease or systemic illness.
• Atypical symptoms (e. g. vaginal symptoms).
• Patients at high risk of developing complications (e. g. immunocompromised, urological
abnormalities patients, etc.).
• Patients at risk of multidrug resistance infection.
• Lack of improvement or progression of symptoms after about 48-72h of initial empiric
antibiotics.
UNCOMPLICATED CYSTITIS TREATMENT
The first line treatment for acute uncomplicated cystitis is nitrofurantoin for 5 days. Fosfomycin
(Monurol) is an acceptable alternative if nitrofurantoin cannot be used. Note that these two drugs
should not be given in case of pyelonephritis since
they have poor drug penetration to renal
parenchyma. Instead, the accumulate in the urine,
and therefore are useful for cystitis.
The trimethoprim sulphamethoxazole (Bactrim,
folic acid inhibitors) can be also used empirically as
a first line agent except in cases where local
resistance of Enterobacteriales exceed 20%, or in
patients who have used of Bactrim for an infection
in the past 3 months.
Oral -lactams (e. g. amoxicillin-clavulanate) are effective second-line agent in treating UTIs, since
there are limited data suggesting their efficacy and a longer duration of administration is required.
The fluoroquinolones (e. g. ciprofloxacin) should not be used in case of complicated cystitis, but only
for pyelonephritis. This is due to their side effects profile (e. g. tendon ruptures) and increase
resistance.
UNCOMPLICATED CYSTITIS
Infectious agent E. coli, K. pneumoniae, Proteus mirabilis
Dysuria
Pollakiuria
Symptoms
Urinary emergency
Suprapubic pain
Based on symptoms
Diagnosis
No laboratory tests
Nitrofurantoin (100mg, 2 x 5 days)
Fosfomycin (Monurol, 3g)
Treatment
Bactrim
Oral -lactam (2nd level)
PYELONEPHRITIS
The pyelonephritis presents the same specific symptoms of cystitis (i. e. dysuria, pollakiuria, urinary
emergency), with accompanied general symptoms (e. g. pain, fever, nausea, vomiting) and flank pain.
The diagnosis of pyelonephritis should be made by clinical assessment and laboratory testing
(urinalysis and urine culture). Imaging is not required for all comers, and it can be reserved for cases
, where the patient is critically ill (e. g. diabetic patients), not improving on initial therapy, or with
suspected complication.
Examples of complications of pyelonephritis include:
• Sepsis: more than 30% of patients with pyelonephritis develop bacteraemia, 20% of whom
will develop sepsis; urosepsis is a
common condition in the ICU.
• Acute renal failure.
• Renal or perinephric abscess.
• Kidney stones.
• Emphysematous pyelonephritis.
The CT scan of the abdomen with IV contrast
is typically the first line imaging in most
complicated pyelonephritis. Renal ultrasound
is less sensitive, but it can be performed if
patients’ exposure to either radiation or contrast medium is problematic.
The management of these complications may require drainage of collections and a multidisciplinary
approach involving specialties such as urologist and interventional radiology.
As regards uncomplicated pyelonephritis, the treatment is based on oral ciprofloxacin.
PYLONEPHRITIS
Infectious agent E. coli, K. pneumoniae, Proteus mirabilis
Dysuria
Pollakiuria
Symptoms Urinary emergency
Flank pain
Systemic symptoms (nausea, vomiting, fever)
Based on symptoms
Diagnosis Laboratory tests (urinalysis and urine culture)
Imaging (CT scan, if complicated)
Treatment Oral ciprofloxacin (500mg 2 x 7 days)
CAUTI AND PROSTATITIS
CATHETER-ASSOCIATED URINARY TRACT INFECTION (CAUTI)
The catheter-associated urinary tract infection (CAUTI) is the most frequent healthcare-related
infection worldwide, and it has been associated with the development of bacteraemia and increase
mortality due to sepsis. There is also an
increased risk of developing mental
confusion; indeed, in inpatients the most
common cause of mental confusion is
urosepsis.
The most common bacterial causes of
CAUTI include E. coli, Klebsiella spp., P.
aeruginosa, and Enterococcus spp.
The diagnosis of CAUTI can be difficult
because pyuria is an expected finding in
patients, and symptoms are often
nonspecific. The CDC definition states that to diagnose CAUTI three criteria should be met, which are:
• Indwelling catheter in place for more than 2 consecutive days in an inpatient location.
• Urine culture with no more than 2 organisms present, and 1 organism with bacteria with
more than 105CFU/mL.
• Presence of at least one of the following symptoms, which are:
INFECTIONS
URINARY TRACT INFECTIONS (UTIs)
ASYMPTOMATIC BACTERIURIA (ASB)
UTIs FEATURES
The urinary tract infection (UTIs) is a broad term that encompasses a spectrum of infectious
syndromes that affect the urinary tract anywhere, from kidneys to the urethra. These infections can
be easily managed (e. g. cystitis), while
others are more severe (e. g.
pyelonephritis, immunocompromised
patients). They are some of the most
common infections; indeed, about 50%-
60% of women have at least 1 UTI in their
life. These infections are commonly
caused by Gram-negative bacteria,
especially E. coli, which accounts for most
of the infections (high presence of
fluoroquinolone-resistance due to
incorrect use). Other pathogens can be Klebsiella pneumonia and Proteus mirabilis. The infections
caused by Proteus spp. can increase the risk of developing kidney stones.
The bacteria that typically cause these infections are from the GI tract (Enterobacteriaceae). Another
possible source of UTIs is bacteria in the bloodstream migrating to kidneys or bladder, despite being
rare. The risk factors for UTIs include female sex, recent sexual intercourse, diabetes mellitus, and
structural or functional urological abnormalities.
FEATURES AND NOT-SCREENED PATIENTS
The asymptomatic bacteriuria (ASB) is the presence of one or more species of bacteria growing in the
urine at specified quantitative counts (>10 5CFU/mL), irrespective of the presence of pyuria, in the
absence of signs or symptoms attributable to UTI.
The ASB is a common finding in some healthy female
populations and in several women or men with
abnormalities of the urinary tract that impair voiding.
In most cases, these patients should not perform a urine
culture. Categories of patients in which is recommended
against screening for or treating ASB are several, which are:
• Healthy post-menopausal, nonpregnant, and
healthy post-menopausal women.
• Older patients.
• Patients with diabetes.
• Kidney transplant recipients (up to clinicians): more than 1-month prior surgery.
• Patients with non-renal solid organ transplant.
• Patients with high-risk neutropenia (<100/mmc).
• Patients with short-term indwelling urethral catheter (<30 days).
• Patients with long-term indwelling urethral catheter.
PATIENTS TREATED FOR ASB
The patients that should be tested in case of asymptomatic bacteriuria belong to two main groups,
which are:
• Pregnant women: it is recommended a screening for and treating ASB; it is suggested a urine
culture collected at one of the initial visits early in pregnancy; there is insufficient evidence to
, inform a recommendation for or against repeat the test if it results negative; ABS occurs in 2%-
7% of pregnant women; in this category antimicrobials probably reduce the risk of
pyelonephritis and may reduce the
risk of low birth weight; antimicrobial
also reduce the risk of preterm labour;
however, to avoid side effects, 4-7
days of therapy is suggested at lower
dose.
• Patients who will undergo endoscopic
urologic procedure: it is
recommended screening for and
treating ASB prior to surgery; it is
suggested to test the urine to avoid
possible contamination of the surgical
field during the operation, which may result in postoperative complications (e. g. urosepsis);
the therapy should be shorter (1-2 days) and started 30-60 minutes before the procedure.
The treatment for asymptomatic bacteriuria is based on prophylactic procedures.
Note that it is important to determine whether the patient should be tested or not for ASB. Indeed,
the unnecessary treatment of ASB may result in an increased risk of developing side effects, as well
as of antimicrobial resistance.
CYSTITIS AND PYLONEPHRITIS
ACUTE UNCOMPLICATED CYSTITIS
The acute uncomplicated cystitis is a type of UTI, specifically an infection of the bladder in an
otherwise immunocompetent host with normal urinary tract (i. e. uncomplicated). The classical
symptoms of UTIs are three, which are:
• Dysuria: it corresponds to difficulty and pain
during urination.
• Pollakiuria: it refers to increased urinary
frequency.
• Urinary urgency.
The diagnosis of cystitis is based on these three symptoms
(plus suprapubic pain), together with absence of systemic
illness and flank pain (upper urinary tract infection). The
cystitis does not need any laboratory evaluation.
Conversely, pyelonephritis requires laboratory evaluation before diagnosing it.
COMPLICATED UTIs AND TESTING
The complicated UTI is a broad term that has been traditionally used to define the UTI syndromes that
do not meet the description of simple cystitis, as well as the ones that occur in patients with severe
immunosuppression.
The diagnosis of these UTIs is primarily made by
the presence of typical symptoms (i. e. dysuria,
pollakiuria, urinary urgency) and can be
confirmed by 2 main laboratory tests, which are
urinalysis and urine culture.
The urinary microscopy can identify the
presence of WBC in urine (i. e. pyuria). Having
more than 10WBC/L in urine is suggestive but not diagnostic of a UTI. Indeed, pyuria may be
associated with other inflammatory, but not infectious conditions. It can be rather used as NPV
(>85%), and therefore to rule out UTI.
,The urine cultures are a more direct way to assess the presence of pathogenic bacteria in the urine,
and they can be used to completely diagnose UTIs. The classic cut-off for a positive urine culture to
reflect the presence of bladder bacteriuria is more than 105CFU/mL. Note that, as said before, urine
cultures are suggested only in case of complicated UTIs, and not in uncomplicated cystitis.
The urinalysis and urine culture should be sent when evaluating a patient for a UTI who presents
specific situations, which are:
• Signs or symptoms of upper tract disease or systemic illness.
• Atypical symptoms (e. g. vaginal symptoms).
• Patients at high risk of developing complications (e. g. immunocompromised, urological
abnormalities patients, etc.).
• Patients at risk of multidrug resistance infection.
• Lack of improvement or progression of symptoms after about 48-72h of initial empiric
antibiotics.
UNCOMPLICATED CYSTITIS TREATMENT
The first line treatment for acute uncomplicated cystitis is nitrofurantoin for 5 days. Fosfomycin
(Monurol) is an acceptable alternative if nitrofurantoin cannot be used. Note that these two drugs
should not be given in case of pyelonephritis since
they have poor drug penetration to renal
parenchyma. Instead, the accumulate in the urine,
and therefore are useful for cystitis.
The trimethoprim sulphamethoxazole (Bactrim,
folic acid inhibitors) can be also used empirically as
a first line agent except in cases where local
resistance of Enterobacteriales exceed 20%, or in
patients who have used of Bactrim for an infection
in the past 3 months.
Oral -lactams (e. g. amoxicillin-clavulanate) are effective second-line agent in treating UTIs, since
there are limited data suggesting their efficacy and a longer duration of administration is required.
The fluoroquinolones (e. g. ciprofloxacin) should not be used in case of complicated cystitis, but only
for pyelonephritis. This is due to their side effects profile (e. g. tendon ruptures) and increase
resistance.
UNCOMPLICATED CYSTITIS
Infectious agent E. coli, K. pneumoniae, Proteus mirabilis
Dysuria
Pollakiuria
Symptoms
Urinary emergency
Suprapubic pain
Based on symptoms
Diagnosis
No laboratory tests
Nitrofurantoin (100mg, 2 x 5 days)
Fosfomycin (Monurol, 3g)
Treatment
Bactrim
Oral -lactam (2nd level)
PYELONEPHRITIS
The pyelonephritis presents the same specific symptoms of cystitis (i. e. dysuria, pollakiuria, urinary
emergency), with accompanied general symptoms (e. g. pain, fever, nausea, vomiting) and flank pain.
The diagnosis of pyelonephritis should be made by clinical assessment and laboratory testing
(urinalysis and urine culture). Imaging is not required for all comers, and it can be reserved for cases
, where the patient is critically ill (e. g. diabetic patients), not improving on initial therapy, or with
suspected complication.
Examples of complications of pyelonephritis include:
• Sepsis: more than 30% of patients with pyelonephritis develop bacteraemia, 20% of whom
will develop sepsis; urosepsis is a
common condition in the ICU.
• Acute renal failure.
• Renal or perinephric abscess.
• Kidney stones.
• Emphysematous pyelonephritis.
The CT scan of the abdomen with IV contrast
is typically the first line imaging in most
complicated pyelonephritis. Renal ultrasound
is less sensitive, but it can be performed if
patients’ exposure to either radiation or contrast medium is problematic.
The management of these complications may require drainage of collections and a multidisciplinary
approach involving specialties such as urologist and interventional radiology.
As regards uncomplicated pyelonephritis, the treatment is based on oral ciprofloxacin.
PYLONEPHRITIS
Infectious agent E. coli, K. pneumoniae, Proteus mirabilis
Dysuria
Pollakiuria
Symptoms Urinary emergency
Flank pain
Systemic symptoms (nausea, vomiting, fever)
Based on symptoms
Diagnosis Laboratory tests (urinalysis and urine culture)
Imaging (CT scan, if complicated)
Treatment Oral ciprofloxacin (500mg 2 x 7 days)
CAUTI AND PROSTATITIS
CATHETER-ASSOCIATED URINARY TRACT INFECTION (CAUTI)
The catheter-associated urinary tract infection (CAUTI) is the most frequent healthcare-related
infection worldwide, and it has been associated with the development of bacteraemia and increase
mortality due to sepsis. There is also an
increased risk of developing mental
confusion; indeed, in inpatients the most
common cause of mental confusion is
urosepsis.
The most common bacterial causes of
CAUTI include E. coli, Klebsiella spp., P.
aeruginosa, and Enterococcus spp.
The diagnosis of CAUTI can be difficult
because pyuria is an expected finding in
patients, and symptoms are often
nonspecific. The CDC definition states that to diagnose CAUTI three criteria should be met, which are:
• Indwelling catheter in place for more than 2 consecutive days in an inpatient location.
• Urine culture with no more than 2 organisms present, and 1 organism with bacteria with
more than 105CFU/mL.
• Presence of at least one of the following symptoms, which are:
