Hospital Acquired Infection (aka Nosocomial Infection)

Definition

Christened the “next asbestos crisis” a flood of lawsuits are anticipated from the mounting occurrences of hospital acquired infections, conveniently abbreviated to HAI, and know to the bacteriologists as nosocomial. The group describes where the infection was caught, not what kind of infection it is, and not how clinically severe it is. Intrinsic to the definition, the patient did not have these germs when he entered the hospital.

Frequency

A study in the USA, performed by the Centers for Disease Control, reported in the course of one year there were 1.7 million HAI, and that they “contributed to” the death of 99,000 persons. (note: “contributed to” is not the same as “caused.”)

In the UK, in one year, 100,000 persons developed an HAI, and 5,000 of them died.

What Are The Organisms? How Do They Infect?

There are some procedures most typically carried out on the old and infirm, in other words those least able to resist infection and most likely to die from an infection a young healthy person would shrug off.

             Ventilator associated pneumonia

This occurs in persons who are artificially ventilated by respirator, for which an indwelling endotracheal tube is required. Bacteria are easily acquired from the air in the Intensive Care Unit where they are usually housed, the air they breathe is not filtered, there is no coughing, and the lung secretions have to be aspirated out at regular intervals. One of the many reasons old persons are not put on ventilators if it is possible to avoid it, and are taken off as soon as possible.

             Urinary Tract Infections (UTI)

The commonest of HAI infections. The mentally disabled, the aged and infirm are often incontinent, and in the male indwelling (continuous) catheters are used to drain the bladder and prevent bedsores. Women are particularly prone to urinary infections, attributed to the short distance between exit and bladder, and also the likelihood of incomplete bladder emptying in the supine patient. Typically the organism is E Coli, symptoms may be slight but a general toxic (septic) state sets in.

             Hospital Acquired Pneumonia (HAP)

Second most common HAI. Non-specific cause, very frequent in older persons and commonly the terminal event after fractured hip or other injury in the very old and frail who breathe poorly; the most common direct cause of death in ICU.

             Legionella

The organism is particularly likely to be found in stagnant water such as window air conditioners, it is another lung disease prone to cause death in older persons, and comes in epidemics in hospitals.

             Gastroenteritis

Non-specific term implying infection of the alimentary canal, a nuisance in the healthy, liable to be fatal in the very young, the infirm and the old. There are numerous different organisms that might cause it, but it is usually associated with contaminated food – some food such as chicken is a carrier for infection and precautions have to be taken in the kitchen against that.

             C. difficile

Has developed a notorious reputation in cruise ships, and is occasionally epidemic in hospital. It has to be initiated by a person, and is typically associated with contaminated food handling.

             MRSA

The acronym for methcillin resistant staph. aureus, the usual organism found in pustules and boils, but now highly resistant to antibiotics, including methcillin to which it used to be sensitive (i.e. methcillin killed staph). This has become very common in hospitals and nursing homes, and in emergency the patient’s room is marked as contaminated, requiring special protective clothing.

             VRE

Vancomycin resistant enterococcus present a great problem since vancomycin is almost at the end of useful antibiotics when organisms are resistant to those in standard practice. It is probably introduced by carriers, unaware they are infected.

             Acinetobacter baumanii (aka MDRAB, Iraqibacter)

A relatively new arrival on the hospital scene, but now found to be the cause of death in many persons, involving lung, urinary tract, and bloodstream. Was common in the wounds of US wounded in Iraq, and is resistant to all commonly employed antibiotics.