A nosocomial infection is an infection that a patient contracts as a result of staying at or receiving treatment in
- a hospital,
- a nursing facility, or
- a rehabilitation clinic
. In most cases (71 percent), such hospital-acquired infections are caused by bacteria. Many of these bacteria are multidrug-resistant, meaning that common antibiotics are ineffective against them. However, viruses (21 percent) and, in rare cases, fungi and parasites can also cause nosocomial infections.
Since these pathogens are found primarily in hospitals, they are also referred to as hospital-acquired pathogens.
The consequences of such an infection with hospital germs are often severe. Due to their resistance, the germs—and thus the infection—can spread rapidly throughout the body. This often happens faster than the simultaneous search for the causative pathogen and an antibiotic to which the pathogen is not resistant.
A nosocomial infection can
- lead to severe illness,
- amputation of the infected limb, or
- even life-threatening conditions for the patient
.
To classify an infection as nosocomial, it must be proven that the patient actually contracted the infection in the hospital. It must be verifiable that the patient was free of the pathogen prior to admission.
A nosocomial infection is considered to have occurred if it is detected at least 72 hours after the patient’s admission.
Consistent hygiene measures could prevent many nosocomial infections © auremar | AdobeStock
According to a study published in 2012 by the Robert Koch Institute (RKI), the most common hospital-acquired infections in German hospitals by far include
- postoperative wound infections,
- urinary tract infections,
- respiratory tract infections, and
- blood poisoning (sepsis).
24.7 percent of nosocomial infections are surgical site infections following surgical procedures. 22.4 percent are urinary tract infections caused by a urinary catheter. At 21.5 percent, lower respiratory tract infections rank third in terms of the frequency of hospital-acquired infections. The most common respiratory tract infection—and the most feared due to its high mortality rate—is pneumonia.
Blood poisoning (sepsis) accounts for 6 percent of hospital-acquired infections.
The most common and dangerous hospital-acquired pathogen in Germany is the bacterium Staphylococcus aureus. This bacterium is resistant to the antibiotic methicillin as well as other common antibiotics. For this reason, it is usually referred to as methicillin-resistant Staphylococcus aureus—MRSA for short.
MRSA can cause severe to fatal
- wound infections,
- respiratory infections,
- urinary tract infections, and
- sepsis.
Because it is resistant to most antibiotics, these infections are difficult to treat.
Other important hospital-acquired pathogens include, among others,
- enterobacteria,
- enterococci,
- the bacterium Pseudomonas aeruginosa, and
- Acinetobacter bacteria.
Enterobacteria
Enterobacteria are part of the normal human gut flora. However, they pose a significant risk to people with weakened immune systems. In hospitalized patients, they can cause, among other things,
- intestinal and urinary tract infections,
- sepsis, and
- inflammation of the lung tissue
in hospital patients. The most important member of the enterobacteria group is the bacterium Escherichia coli.
Enterococci
Enterococci also colonize the gut flora of many healthy people. In addition, they are found in many foods because of their beneficial effect on the human gut flora.
In immunocompromised individuals, however, enterococci can cause dangerous
- intestinal infections,
- urinary tract infections,
- sepsis, or
- endocarditis
in immunocompromised individuals.
The bacterium Enterococcus faecium, for example, belongs to the enterococci group.
Many enterococci are resistant to the antibiotic vancomycin. For this reason, they are also referred to as vancomycin-resistant enterococci—or VRE for short.
Pseudomonas aeruginosa
The bacterium Pseudomonas aeruginosa is found primarily in moist environments such as
- tap water,
- sinks,
- showers, or
- toilets
. It is responsible for about ten percent of nosocomial infections in Germany. This makes it one of the most common hospital-acquired pathogens.
Among other things, it causes
- purulent pneumonia,
- urinary tract infections,
- wound infections,
- sepsis,
- meningitis, and
- intestinal inflammation
.
Acinetobacter bacteria
Bacteria of the genus Acinetobacter, such as Acinetobacter baumannii, are increasingly developing resistance to common antibiotics. As a result, they are causing hospital-acquired infections in immunocompromised patients with growing frequency.
Ventilated patients in intensive care units are particularly affected. In these patients, the bacterium frequently causes pneumonia.
Other possible consequences of an infection with Acinetobacter bacteria include
- sepsis,
- meningitis, and
- wound infections.
Hospital-acquired infections can generally be transmitted in three different ways: through
- direct skin contact,
- transmission via a contaminated surface, or
- airborne transmission.
The most common route of transmission is direct contact with contaminated skin. In this way, multidrug-resistant pathogens are transmitted directly from one patient to another. Transmission is also possible from a patient to a doctor or nurse, and from there to another patient.
This can happen, for example, when changing dressings or inserting a catheter on another patient.
In most cases, transmission occurs via the hands. That is why consistent hand hygiene is the most important preventive measure in the fight against hospital-acquired infections.
Transmission through contact with contaminated objects or surfaces is referred to as environmental or cross-contamination. Preventive measures include
- consistent cleaning with disinfectants as well as
- the disposal of contaminated objects and surfaces
are used as preventive measures.
Transmission via the air is also referred to as droplet infection. The germs are thus transferred to
- surfaces,
- objects, or
- fabrics, as well as
- directly onto other people.
The most important preventive measure against such transmission is wearing a face mask.
In recent years, the spread of multidrug-resistant hospital-acquired germs has been steadily increasing. Nosocomial infections are therefore a serious problem.
The cause of this increase is, on the one hand, linked to the overuse of antibiotics. Antibiotics were long considered a panacea and were often prescribed unnecessarily and administered improperly.
Hospital-acquired germs such as MRSA or VRE are gradually becoming resistant due to the high use of antibiotics in hospitals. In other words, they develop defense mechanisms against one or more antibiotics. These medications then no longer work against these germs.
Another important factor in the spread of hospital-acquired infections is poor hygiene in hospitals. For example, doctors and nurses do not disinfect their hands often enough, causing them to unintentionally transmit germs from one patient to another. Negligence in the cleaning and disinfection of potentially contaminated objects also facilitates transmission.
In addition, there are high-risk patients who are particularly susceptible to hospital-acquired infections. They have an increased risk of contracting a nosocomial infection while in the hospital.
These high-risk patients include, among others, patients
- who are in an intensive care unit,
- are on mechanical ventilation,
- are receiving antibiotics or immunosuppressive medications, as well as
- cancer patients,
- people with diabetes,
- dialysis patients, and
- people with chronic wounds or skin conditions.
Advanced age also increases a patient’s risk of contracting hospital-acquired infections.
How many hospital-acquired infections occur each year in Germany?
Exact figures on the incidence of hospital-acquired infections in Germany are not available, as reporting is not mandatory. However, a study published in August 2012 by the Robert Koch Institute (RKI) provides a figure. According to the study, 3.33 percent of all patients treated in German hospitals contract hospital-acquired infections during their stay.
According to estimates by the Federal Ministry of Health, this amounts to 400,000 to 600,000 people annually. Approximately 15,000 of these people die as a result of the infection.
According to hygiene experts, many of these severe cases could be prevented. To achieve this, hygiene measures to combat multidrug-resistant hospital-acquired infections must be consistently followed.
What are the costs associated with hospital-acquired infections?
Hospital-acquired infections cost 2.5 billion euros annually in Germany. They thus represent a significant cost factor for the German healthcare system.
They also result in significant financial losses for hospitals. For each nosocomial infection, hospitals must bear additional costs ranging from 4,000 to 20,000 euros.
These additional costs are caused, on the one hand, by longer hospital stays and care periods. Depending on the type of infection, a patient infected with hospital-acquired germs stays in the hospital an average of four days longer. On the other hand, the additional costs result from the extra expenses required for diagnostic and therapeutic measures.
How can infections caused by hospital-acquired germs be prevented or reduced?
Improving hygiene in German hospitals is the most important preventive measure. For this reason, a new Infection Protection Act was enacted in 2011. It requires hospitals to comply with mandatory hygiene regulations. These hygiene regulations include, in particular, the consistent implementation of standard hygiene measures by hospital staff.
Measures for hospital staff include
- washing hands with disinfectant after every patient contact,
- wearing gloves and face masks when coming into contact with bodily fluids,
- consistently cleaning surfaces and objects with disinfectants.
There are also other measures to improve hygiene in hospitals. For example, all hospital staff should regularly attend continuing education courses on hygiene and infection prevention. Hospitals with 300 or more beds should employ at least one specialist in hygiene and environmental medicine or a hygiene specialist.
In addition, antibiotics should be used more sparingly. This reduces the development of resistance, making it easier to treat nosocomial infections.
Screening high-risk patients before admission to the hospital can also help. The purpose of this measure is to identify and isolate individuals who are already carrying a hospital-acquired pathogen. High-risk patients are screened in advance for existing infections using a swab of the nasal vestibule or throat. If the test result is positive, they are placed in isolation.
These high-risk patients include, among others, people
- who have open wounds,
- live in a long-term care facility, or
- who have already spent more than three days as inpatients in a hospital within the past year.
What devices are available to prevent or reduce hospital-acquired infections?
Room air disinfection can effectively reduce or eliminate hospital-acquired germs, thereby preventing nosocomial infections.
Specialized hygiene systems add disinfecting substances to the air in hospitals via the ventilation systems. These substances kill existing germs and pathogens and provide lasting protection against the re-establishment of pathogens.
To achieve this, a special disinfection and air-freshening system is connected to the hospital’s ventilation system.
These systems can also add fragrances to the air, which help freshen the air and create a pleasant indoor environment.
