Hospital-Acquired Infections Clinical Presentation

Updated: Dec 08, 2016
  • Author: Haidee T Custodio, MD; Chief Editor: Russell W Steele, MD  more...
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Presentation

History

Healthcare-associated infections are most commonly caused by viral, bacterial, and fungal pathogens. These pathogens should be investigated in all febrile patients who are admitted for a nonfebrile illness or those who develop clinical deterioration unexplained by the initial diagnosis.

Most patients who have healthcare-associated infections caused by bacterial and fungal pathogens have a predisposition to infection caused by invasive supportive measures such as endotracheal intubation and the placement of intravascular lines and urinary catheters. Ninety-one percent of bloodstream infections were in patients with central intravenous lines (CVL), 95% of pneumonia cases were in patients under going mechanical ventilation, and 77% of urinary tract infections were in patients with urinary tract catheters. [27]

Risk factors for the development of catheter-associated bloodstream infections in neonates include catheter hub colonization, exit site colonization, catheter insertion after the first week of life, duration of parenteral nutrition, and extremely low birth weight (< 1000 g) at the time of catheter insertion. [1] In patients in the PICU, risks for catheter-associated bloodstream infections increase with neutropenia, prolonged catheter dwell time (>7 d), use of percutaneously placed CVL (higher than tunneled or implanted devices), and frequent manipulation of lines. [2] Disruption of catheter dressings has also been shown to increase risk for catheter-related infections. [28]

Candida spp are increasingly important pathogens in the NICU. Risk factors for the development of candidemia in neonates include gestational age less than 32 weeks, 5-min Apgar scores of less than 5, shock, disseminated intravascular coagulopathy, prior use of intralipids, parenteral nutrition administration, CVL use, H2 blocker administration, intubation, or length of stay longer than 7 days. [3]

Risk factors for the development of ventilator-associated pneumonia (VAP) in pediatric patients include reintubation, genetic syndromes, immunodeficiency, and immunosuppression. [4, 5] In neonates, a prior episode of bloodstream infection is a risk factor for the development of VAP. [6]

Risk factors for the development of healthcare-associated urinary tract infection in pediatric patients include bladder catheterization, prior antibiotic therapy, and cerebral palsy. [7]

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Physical

In addition to the presence of systemic signs and symptoms of infection (eg, fever, tachycardia, tachypnea, skin rash, general malaise), the source of healthcare-associated infections may be suggested by the instrumentation used in various procedures. For example, an endotracheal tube may be associated with sinusitis, tracheitis, and pneumonia; an intravascular catheter may be the source of phlebitis or line infection; and a Foley catheter may be associated with a urinary tract infection.

Patients with pneumonia may have fever, cough, purulent sputum and abnormal chest auscultatory findings such as decreased breath sounds, crackles or wheezes.

Patients with urinary tract infection may present with or without fever. Patients with cystitis can have suprapubic tenderness while those with pyelonephritis can have costovertebral tenderness. Upon inspection, their urine can be cloudy and foul-smelling.

Neonates on the other hand usually do not present with any of the above findings and may have very subtle and nonspecific signs of infection. Fever may or may not be present. Signs of infection can include temperature and/or blood pressure instability, apnea, bradycardia, lethargy, fussiness, and feeding intolerance.

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Causes

In a survey done on 110,709 pediatric ICU patients, 6,290 healthcare-associated infections were noted. [27] The top 3 major sites of infections, accounting for 64% of all healthcare-associated infections, were bloodstream infections (28%), pneumonia (21%), and urinary tract infection (15%). Each of these infections was strongly associated with use of an invasive device.

The top 3 pathogens in bloodstream infections were coagulase-negative staphylococci (38%), Enterococcus (11%), and S aureus (9%). Candida albicans accounted for about 5.5% of bloodstream infections. The top 3 pathogens for pneumonia were P aeruginosa (22%), Saureus (17%), and Haemophilus influenzae (10%). The top 3 pathogens for urinary tract infections were Escherichia coli (19%), C albicans (14%), and P aeruginosa (13%). Gram-negative enteric organisms accounted for about 50% of all urinary tract infections. The top 3 pathogens for surgical site infections were S aureus (20%), P aeruginosa (15%), and coagulase-negative staphylococci (14%).

Methicillin-resistant staphylococcus aureus (MRSA) has become a prevalent cause of infections. Traditionally, community-associated MRSA infections have been associated with USA300 or USA400 strains and healthcare-associated infections with USA100 or USA200 strains. However this distinction is becoming less clear with USA300 strains now increasingly identified as a cause of HAI. A population-based study showed MRSA USA300 was not associated with mortality for either central line–associated bloodstream infections or community-onset pneumonia. [29]

Surgical site infections (SSI) occur within 30 days after the operative procedure or within 1 year if an implant was placed. Criteria for the diagnosis of SSI include purulent drainage at the site of incision, clinical symptoms of infection (such as pain, redness, swelling, etc), presence of an abscess, isolation of organism from the site culture, and clinical diagnosis of SSI by the surgeon. [30]

Rotavirus continues to be a cause of acute gastroenteritis in hospitalized children, with greatest susceptibility in children younger than 3 years. Aside from having nonbloody diarrhea, patients may present with fever, vomiting, and abdominal cramps. Other viruses that can cause hospital-associated gastroenteritis include norovirus and adenoviruses. Gastroenteritis due to adenovirus can be especially debilitating in immunocompromised patients.

Clostridium difficile is the most important bacterial cause of healthcare-associated gastroenteritis. Associated clinical conditions include asymptomatic carriage, diarrhea, and pseudomembranous colitis. Diagnosis is suspected in a patient with diarrhea and recent history of antibiotic use (especially cephalosporins and clindamycin).

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