(Author, Department, University,
Corresponding Address and email)
Hospital-acquired infections, also known as nosocomial infections, hospital-onset infections, or healthcare-associated infections are those infections that are usually not present in a patient before admission to a hospital. In hospital-acquired infections, microbial flora of a patient starts acquiring characteristics of the bacterial pool in the surrounding. Most of the infections appear within 48 hours of admission to hospital. However, infections may also appear after the discharge of patient though the organisms that were acquired during the stay of a patient in hospital (Magill et al., 2014).
According to estimations of Centers for Disease Control and Prevention (CDC) and reports published in The New England Journal of Medicine, about 722,000 hospital-acquired infections occurred in the U.S. acute care hospitals in the year 2011. At that time, about 75,000 deaths were related to hospital-acquired infections. About 4% of patients were reported to have minimum one health-care associated infection. However, it is important to consider that many of these infections can be prevented (Magill et al., 2014).
Causes of Hospital-acquired infections
Hospital-acquired infections have a wide-ranging safety concern in the medical field. They can be systemic or localized; they can affect any system present in the body; they can be related to medical devices and/or blood product transfusions. Healthcare professionals have special interest in gram-negative bacteria as they have ability to up-regulate or acquire genes that are helpful in coding for mechanisms to resist antibiotic drugs. Data from U.S. National Healthcare Safety Network showed that Gram-negative bacteria cause more than 30% of hospital-acquired infections, and in Intensive Care Units (ICUs) in the U.S. these bacteria result in approximately 70% of such infections. Several microorganisms are involved in these infections including multidrug-resistant organisms such as Acinetobacter baumannii, Pseudomonas aeruginosa and extended-spectrum β-lactamase (Peleg & Hooper, 2010). Recent studies are showing that Clostridium difficile was the most common pathogen resulting in health-care associated infections (accounting for nearly 12% of health-care associated infections). Staphylococcus aureus was the second most common cause of infection (accounting for 10.7% of infections) followed by Klebsiella oxytoca and K. pneumoniae (accounting for 9.9% of infections), and Escherichia coli (accounting for 9.3% of infections) (Magill et al., 2014).
Types of Hospital-acquired infections
Usually, hospital-acquired infections include urinary tract infections, which are commonly related to the urethral catheterization; bloodstream infections, which is usually associated with central vascular catheter; bacteraemia; hospital-associated diarrhea, and pneumonia, which are the most commonly encountered life-threatening condition and most of the cases of pneumonia are related to mechanical ventilation. Patients of hospital-acquired pneumonia may have a coexisting illness, thereby increasing the chances of death. About 42.9% of non-surgical site infections developed during 48 hours of stay in a critical care unit, and nearly 42.4% of those infections developed during 48 hours of stay in non-nursery ward (Magill et al., 2014, Peleg & Hooper, 2010)
Device-associated infections such as those caused by catheter, central-catheter, and ventilator accounted for about 25.6% of all healthcare-associated infections. Hospital-acquired infections can also occur at surgery sites, and in that case, they are called as surgical-site infections, which are about 21.8% of all health-care associated infections. Most of the surgical-site infections include colon surgeries (accounting for nearly 14.5% of infections), hip arthroplasties (accounting for nearly 10% of infection), and small-bowel surgeries (accounting for nearly 6.4% of infections). Approximately 9.1% of surgical-site infections were caused by unspecified procedures. Taken together, surgical-site infections and device-associated infections account for approximately 47.4% of all healthcare associated infections. The remaining percentage of infections, i.e. 52.6% of healthcare-associated infections, are not caused by devices or surgeries. Hospital-acquired infections are becoming a huge challenge for patient safety, and delays in the use of appropriate therapeutic strategies can increase the chances of mortality among patients (Magill et al., 2014, Peleg & Hooper, 2010).
Risk Factors for Hospital-acquired infections
Chances of healthcare-associated infections increase in older patients; in patients with longer stay in hospitals; in patients having a central catheter in place; in patients have support of mechanical ventilator, and/or in patients in critical care unit (Magill et al., 2014).
Prevention of Hospital-acquired infections
Prevention of hospital-acquired infections can help in reducing most of the cases of mortality and morbidity. In order to prevent such infections, it is important to identify patients, who are at risk of getting infections; hand hygiene has to be considered, and standard precautions must be followed to decrease the transmission of infection. According to World Health Organization (WHO), there are five important moments for hand hygiene; before touching a patient, before any aseptic procedure, after touching any patient, after touching the surroundings of patients, and after exposure risk to body fluids. Environmental factors such as disinfection, room ventilation, decontamination, and cleaning as well as architectural plans, particularly in designing ICU, are also important to reduce the infections. Healthcare experts and laboratory experts have to identify the organisms, their sources, and methods of their killing, so that the chances of infection in other patients could be reduced (Mehta et al., 2014).
Concluding Remarks
Hospital-acquired infections are among the most important issues faced by healthcare community. In the U.S., about one in every 25 inpatients faces such infections. Pneumonia is one of the most common types of hospital-acquired infection, and C. difficile is an important cause behind such infections. These infections required special attention, especially the infections other than those caused by urinary catheters, central catheters, and ventilators. Prevention of such infections can help in improving the life of patients and decreasing the burden on a country’s economy, and this prevention can be achieved by following standard procedures and continuous prevalence surveys.
References
Magill, S. S., Edwards, J. R., Bamberg, W., Beldavs, Z. G., Dumyati, G., Kainer, M. A., . . . Antimicrobial Use Prevalence Survey, T. (2014). Multistate point-prevalence survey of health care-associated infections. N Engl J Med, 370(13), 1198-1208. doi: 10.1056/NEJMoa1306801
Mehta, Y., Gupta, A., Todi, S., Myatra, S., Samaddar, D. P., Patil, V., . . . Ramasubban, S. (2014). Guidelines for prevention of hospital acquired infections. Indian J Crit Care Med, 18(3), 149-163. doi: 10.4103/0972-5229.128705
Peleg, A. Y., & Hooper, D. C. (2010). Hospital-acquired infections due to gram-negative bacteria. N Engl J Med, 362(19), 1804-1813. doi: 10.1056/NEJMra0904124
