Although by 1931 I. Ph. Semmelweis' achievements and the tragedy of his life had been given their due place in the history of mankind, Alexander Fränkel, formerly Theodor Billroth's assistant and later his biographer, critically stated that the discoverer of the causes of puerperal fever should have defended his discovery with facts rather than with fanaticism. It was only a few years after Semmelweis' death, for instance, that Billroth made laborious experiments. Billroth's work on Coccobacteria had important implications and even influenced Robert Koch, although his hypotheses did not really predict the pathogenic and specific nature of microbes. In 1847 Semmelweis postulated his theory; ie, that the pathological-anatomical changes which he observed in the bodies of the women who died in childbed, in their newborn infants, and in the autopsy findings on his friend Jakob Kolletschka were an entity, morphologically and clinically. He summed them up under the concept of pyemia. Even though Semmelweis was continually abhorred by the evident statistics and would have been able to prove his discovery through animal experiments, he primarily took to the pen to defend his opinion vehemently. Only the clinical facts proved him right during his lifetime; the triumph of bacteriology which began after his death made him not only the “savior of mothers” but also a genial ancestor of bacteriology.

Surveillance activities for the detection of nosocomial infections at the University of Virginia Hospital (Charlottesville, Virginia) and at hospitals participating in the Virginia Statewide Infection Control Program have focused on outbreaks and device-related infections which are potentially preventable. Eleven outbreaks of nosocomial infections were identified at the University of Virginia Hospital between January 1, 1978 and December 31, 1982 (9.8 outbreaks/100,000 admissions). Ten of the 11 were centered in critical care units. The 269 patients involved in the epidemics represented 0.2% of all hospital admissions and 3.7% of all patients who developed nosocomial infections. Eight of the 11 outbreaks involved infection of the bloodstream, and the 90 patients who developed a bloodstream infection as part of an epidemic represented 8% of all patients with nosocomial bloodstream infections identified during the five-year study period. The reservoir of the 11 outbreaks involved devices (5), contaminated cocaine (1), probable blood products (1), other patients (3), and nursing personnel (1). Forty-one percent of all nosocomial bloodstream infections and 41% of all nosocomial pneumonias occurred in intensive care units (ICUs).

In 38 hospitals in the state of Virginia with ICUs and practitioners who voluntarily reported surveillance data between June 1,1980 and May 31,1982, there were 264,757 patients admitted and a crude infection rate of 3%. Of note is that 1,867 of the 7,407 nosocomial infections (25%) occurred in the ICU patients. Several factors point to a compelling argument that the highest priority in infection control resources be assigned to the prevention and control of ICU infections: ICU patients often have serious device-related infections and may be identified as high risk prior to infection. Furthermore, they are at risk of being infected as part of a major outbreak. Such characteristics define a population of hospitalized patients, many of whose infections are preventable.

Nosocomial respiratory tract infections are major causes of excessive morbidity and mortality in US hospitals, affecting an estimated five to ten of every 1,000 patients. Patients with serious underlying diseases have an especially high risk of acquiring these infections, and that risk is magnified by exposure to respiratory therapy. Until recently, contaminated respiratory care devices were a major cause of infection, but procedures for the management of these devices have decreased their role substantially. Now, aspiration of oropharyngeal flora appears to be responsible for most cases of bacterial respiratory infections. Therefore, techniques to alter the flora of the oropharynx and to diminish the risk of aspiration are important priorities for infection control. Exposure to intensive care units (ICUs) is also a major risk factor for nosocomial pulmonary infection, and person-to-person spread of microorganisms within ICUs seems to be responsible for some of these infections.

Increasing numbers of pulmonary infections are being caused by newly identified or previously uncommon pathogens, and this shift requires that traditional control techniques be reevaluated to assure that they remain relevant.

Few new techniques have been developed recently to alter host susceptibility, prevent acquisition of virulent pathogens, or eradicate infectious organisms from their sources, but effective infection control programs in hospitals appear to reduce the incidence of nosocomial pulmonary infection, and implementation of these programs deserves serious consideration in all hospitals.

The incidence of nosocomial infections and antimicrobial resistance rates of nosocomial pathogens vary considerably among countries and even among intensive care units (ICUs) within one hospital. Such differences might be partly due to the selection pressure exerted by certain antibiotics, since intensive care patients are given more antimicrobials than any other group of patients. We therefore compared resistance rates of four important nosocomial pathogens (Staphylococcus aureus, E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) isolated from patients in general wards and ICUs. There were few trends toward higher resistance of ICU isolates, and most differences were found with Klebsiella pneumoniae.

We also tried to relate antibiotic use in ICUs and frequency of antibiotic resistance of five selected nosocomial pathogens. The ampicillin and cephalosporin resistance of E. coli and Klebsiella pneumoniae arose along with an increase in usage of both drugs. Decreasing prescription of cotrimoxazole was not reflected by decrease in resistance of Staphylococcus aureus and Staphylococcus epidermidis. Increasing prescriptions of tetracyclines were followed by an increasing resistance of E. coli, but not of Staphylococci. The oxacillin resistance of Staphylococcus epidermidis almost paralleled the consumption, the opposite was true for Staphylococcus aureus. There seemed to be a rather close relationship between the incidence of resistant Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa strains and the quantities of gentamicin, tobramycin and azlocillin prescribed.

The increase or decrease of prescriptions of certain antimicrobials increased or decreased their resistance rate to the respective drugs of only certain bacterial strains in one ICU, but not in the other. The findings in our hospital cannot necessarily be applied to other hospitals. Restriction of antimicrobial usage however decreased resistance rates in most situations.

Apart from the special mechanisms for spread of IV device and respiratory equipment-related infections, the mechanisms for spread of infections in the intensive care unit (ICU) are no different from other areas of the hospital. Control of transmission must emphasize the necessity of blocking the contact and airborne routes of spread.

Hand disinfection with an alcoholic preparation and the use of patient-bound gowns for all direct patient contact are efficient measures against contact spread of infections.

Airborne spread is best reduced by nursing patients in one-patient rooms with doors closed. A substantial part of the beds should be in such rooms. However, they are of little value if basic barrier nursing techniques are neglected. An ante-room to the one-patient room is practical for hand disinfection, gowning, etc., and if ventilated, offers added protection against airborne spread.

Barriers against transmission of microorganisms must be created between patient rooms. Since basic barrier nursing techniques are the determining factors for infection control, the need for adequate numbers of well-trained and well-educated staff cannot be overestimated.

The prevalence and pattern of nosocomial infections in a new hospital in the United Arab Emirates is presented. During an 18-month period in which there were 6,544 discharges, 379 nosocomial infections occurred in 310 patients, representing an attack rate of 4.7%. The commonest site of infection was the urinary tract which accounted for 42.2% of the total. This was followed by surgical wound infections, cutaneous infections, bloodstream infections, lower and upper respiratory infections, infected burns and gastrointestinal infections. The most common organisms were Escherichia coli (22.7% of isolates), Pseudomonas species (17.5%) and Staphylococcus aureus (16.7%). Escherichia coli was the most common cause of urinary tract infections and bacteremia; Staphylococcus aureus was the most common cause of surgical wound and cutaneous infections. There was only one Serratia marcescens infection. We observed a high incidence of Pseudomonas infections, particularly of the urinary tract, and Staphylococcal surgical wound and other cutaneous infections, but otherwise our data are similar to nosocomial infection data from US hospitals.

By way of introduction, Dr. Nyström described the hospital system in Sweden which is organized in a pyramidal fashion within each county. The largest hospital in each county contains a Department of Clinical Microbiology and the organization of hospital infection control activities follows this county structure.

An infection control unit is located within the clinical microbiology laboratory of the major county hospital. The head of the unit, the hospital epidemiologist, is usually a specialist in clinical microbiology with medical training. The epidemiologist has an infection control committee consisting of clinicians of various specialties, especially surgeons. There are usually two infection control nurses per county (now approximately 1 nurse/3000 beds with an eventual goal of 1 nurse/1000 to 1500 beds). The nurses advise the ward staff in all the county hospitals. There are only some 50 infection control nurses in Sweden; financial restrictions curtail the development of infection control activities.

During the past decade intravascular monitoring has become commonplace in hospital critical care areas. Early reports, such as that of Gardner et al, reassured us that these devices were safe. In fact, Gardner and associates noted not a single local or systemic infection that could be definitely related to radial artery monitoring catheters in 531 patients. Results of a more recent study by Band and Maki are more sobering. They found a 4% incidence of septicemia and an 18% incidence of local infection when they prospectively studied 130 arterial catheters in 95 patients. There were many differences between these two studies, but perhaps the two most important factors leading to the higher incidence of infection in the later study were increased duration of catheter placement and placement of the catheter by surgical cutdown or in a femoral artery.