General Medical Officer (GMO) Manual: Clinical Section
Urinary Tract Infections
Department of the Navy
Bureau of Medicine and Surgery
Peer Review Status: Internally Peer Reviewed
(1) Introduction
Urinary tract infections are common, and can affect both males and females at any age. Clinical symptoms
can vary widely, ranging from lower tract complaints of frequency, urgency, dysuria, to septic shock.
Although modern antibiotics are quite effective in treating UTIs, occasionally patients will succumb to
infections of the solid organs of the urinary tract. Therefore, urinary tract infections, especially associated
with a febrile response, should not be taken lightly, and aggressive management is necessary.
(2) Sources of the UTI
The ascending route of bacterial entry is the typical means of developing an infection, however,
hematogenous and lymphatic channels can rarely provide the path to the urinary system. Infections are at
times associated with indwelling catheters, urolithiasis, impaired bladder function, bladder outlet
obstruction or vesicoureteral reflux. In these instances, treating the infection without addressing the actual
problem may be less than satisfactory and a urology consultation should be considered.
(3) Organisms
The most common organisms isolated are the gram negative enteric bacteria, with E. coli being cultured in
approximately 85 percent of community acquired infections. Other organisms include Enterobacter,
Proteus, Klebsiella, Pseudomonas and Enterococcus species to name a few. Gram positive organisms such
as Staphylococcal and Streptococcal species, as well as atypical organisms must be suspected in those
patients that do not respond to the antimicrobials most commonly used to treat the usual offenders.
(4) Management of uncomplicated UTIs
Uncomplicated, or isolated, infrequent urinary tract infections are not associated with anatomic or
physiologic abnormalities. The clinical manifestations include frequency, urgency, dysuria, nocturia,
hematuria, small volume voiding, suprapubic or lower abdominal pain. A minimal diagnostic work-up is
necessary, and an adequate history, physical examination, urinalysis, and culture will reveal the diagnosis
will yield an accurate assessment in the overwhelming majority of cases. This will also assist in identifying
less common etiologies of conditions that could present with similar complaints. The differential diagnosis
includes sexually transmitted diseases, vaginitis, trauma or sexual abuse, urothelial tumor, retained foreign
bodies, and an overactive bladder. Treatment of uncomplicated UTIs for 3 days (in women) or 30 days (in
men) with an appropriate broad spectrum antibiotic oral medication such as Septra (TMP/SMX),
Nitrofurantoin, or Amoxicillin is generally adequate and can be tailored according to sensitivity patterns of
the organisms cultured. Fluoroquinolones are also very effective, however, are much more costly, and
nonjudicious use for uncomplicated UTIs and other community-acquired infections is promoting drug
resistance in the United States. Therefore this class of antibiotics should be reserved for those patients with
treatment failures or multiple drug allergies to sulfa or penicillin derivatives. Follow-up cultures should be
obtained 1 to 2 weeks after treatment is completed to ensure urine sterility.
(5) Management of recurrent infections
Treatment failures are typically secondary to drug resistance, reinfection, or bacterial persistence.
Underdosing and non-compliance to treatment recommendations may also contribute to unsuccessful
therapy. Prophylactic antibiotics may be necessary for patients with frequent, recurrent infections, and
studies have shown that one half of a typical dose at bedtime significantly reduces reinfection rates.
Patients failing multiple adequate courses of antibiotics may need urinary tract imaging or functional
studies to rule out complicating pathology. These may include intravenous urogram, computed
tomography, magnetic resonance imaging, ultrasound, cystoscopy, or cystometrogram and can be done in
coordination with a urologic consultation.
(6) Management of complicated UTIs
Complicated urinary tract infections pose a significant health risk and can result in increased morbidity and
mortality if inadequately treated or if treatment is delayed. Acute pyelonephritis has historically been
universally treated with intravenous antibiotics. Patients present with symptoms of fevers, chills, flank
pain, pyuria, and bacteruria. The gram-negative organisms are again the most common organisms
recovered, and treatment should be directed with broad-spectrum agents to empirically treat these bacteria
until urine and blood culture and sensitivity results are available. Outpatient treatment has been proven
safe for patients who are hemodynamically stable, and 14-day treatment is recommended. Patients with
known anatomic or functional abnormalities require an additional 7 days of therapy to eradicate the
infection. Non-responders to oral or parenteral medications, or those who’s condition deteriorates, should
undergo upper tract imaging to rule out a perinephric abscess or obstructed collecting system, both of
which require immediate drainage.
(7) Pregnancy
Pregnancy is associated with physiologic changes such as hydronephrosis, increased renal size, and
anterosuperior bladder displacement, which increase the incidence of acute pyelonephritis when compared
to non-pregnant females. This places the mother and unborn fetus at great risk for antenatal complications.
Sepsis, preterm labor, infant prematurity, and fetal demise are outcomes that can be avoided with the
routine use of screening urine cultures in asymptomatic gravid women and treating all with bacteruria.
(8) Prostatitis
Prostatitis is a common disorder, which accounts for approximately 25 percent of visits for men presenting
for urologic evaluation of lower urinary tract symptoms. Most prostatitis is uncomplicated and can be
treated adequately with a 30-day course of antibiotics as stated above. Acute febrile prostatitis accounts for
less than five percent of all patients with prostatitis. Fevers, chills, rigors, frequency, urgency, dysuria,
difficulty emptying the bladder, or even acute urinary retention are all common complaints. Temperature
elevations to 1040 and a distended, tender lower abdomen are frequently encountered on physical
examination. Prostate massage should be avoided in the acutely infected patient as this could result in
severe pain, bacteremia, and unrecoverable urosepsis. Urine and blood cultures must be obtained before
starting antibiotic therapy, and treatment should then begin empirically with broad spectrum agents such as
ampicillin or vancomycin and an aminoglycocide until culture and sensitivity results are available.
Hospitalization along with intravenous hydration, bladder drainage, and hemodynamic stabilization are
imperative for the septic patient. Four weeks of treatment is required, however, most patients when afebrile
and stable, can continue treatment with oral medications as an outpatient according to organism
sensitivities. Persistent spiking fevers despite appropriate antibiotic coverage necessitates an investigation
for a prostatic abscess, as antibiotics alone are typically inadequate. Surgical drainage by a urologist is
necessary if an abscess is discovered.
(9) Chronic Prostatitis
Chronic prostatitis can be debilitating to those afflicted and is at times a difficult condition to treat.
Diagnosis is made by demonstrating > 10 white blood cells per high powered field light microscopy and
bacteria in the expressed prostatic secretions and VB3 urine culture. The VB3 (or voided bladder-3)
specimen is obtained by collecting the first 5-10 milliliters of urine voided after a vigorous prostate
massage. This will produce colony counts ten-fold higher than the midstream clean-catch specimen (VB2).
Four to six week of treatment is successful in the majority of cases, TMP/SMX or a fluoroquinolone being
the medications of choice due to their penetrability into the prostatic tissue. Treatment duration may be
extended to 12 weeks and occasionally 6 months of once a day suppression if cure is not achieved with the
initial treatment.
Submitted by CAPT M. Melanie Haluszka, MC, USN, LCDR Brian K. Auge, MC, USN, and LT Timothy
F. Donahue, MC, USNR, National Naval Medical Center, Bethesda (1999).