Infectious pathogens

Some common causes of healthcare associated infections include:

Bacteria

Escherichia coli can cause diarrhea, while others cause urinary tract infections, bacteremia, pneumonia, surgical site infections, and other illnesses.

Clostridioides difficile one of the most common healthcare-associated infections in the United States 

Coagulase-negative staphylococci are normal adult skin flora.  However, it is an important healthcare acquired pathogens associated with bacteremia, in neonates, especiallylow birth weight and premature neonates in the NICU, perhaps related to invasive interventions.

Staphylococcus aureus pathogenesis can be serious or fatal, including:

• Bacteremia or sepsis
• Pneumonia, which most often affects people with underlying lung disease including those on mechanical ventilators.
• Endocarditis (infection of the heart valves), which can lead to heart failure or stroke.
• Osteomyelitis (bone infection), which can be caused by staph bacteria traveling in the bloodstream or put there by direct contact such as following trauma (puncture wound of foot or intravenous (IV) drug abuse).

Klebsiella ssp. causes healthcare-associated infections, including pneumonia, bacteremia, wound or surgical site infections, and meningitis.

Enterobacter ssp: bacteremia, lower respiratory tract infections, skin and soft tissue infections, urinary tract infections (UTIs), endocarditis, intra-abdominal infections, septic arthritis, osteomyelitis, CNS infections, and ophthalmic infections

Enterococcus faecalis, urinary tract infections, wound infections, bacteremia, and endocarditis. Most of these infections take place in hospitals.

Proteus mirabilis, urinary tract infection, cystitis, prostatitis, pyelonephritis

Pseudomonas aeruginosa, bacteremia, sepsis, pneumonia, and surgical site infections.

Mycobacterium tuberculosis (Tuberculosis).

Viruses

• Chickenpox and Shingles
• Prevention of Seasonal Influenza in Healthcare Settings
• Herpes simplex
• Human Immunodeficiency Virus in Healthcare Settings
• Human papillomavirus 
• Infectious mononucleosis
• Mumps
• Measles in Healthcare settings
• Norovirus
• Rubella
• Viral gastroenteritis
• Viral hepatitis
• Viral meningitis
• Viral pneumonia

Fungi

Opportunistic fungal infections can occur in patients with weakened immune systems. They also can occur when antibiotics kill helpful bacteria (Higuera, 2017).

Parasites

There are three main classes of parasites that can cause disease in humans:

• Protozoa
• Helminths
• Ectoparasites.