The postoperative wound infection experience in 11 Israeli hospitals wasinvestigated with two objectives: (1) to utilize the variability amonghospitals for a better understanding of the determinants of theseinfections, and (2) to present surgeons and infection control teams withinformation upon which they can take action. This article summarizes themethods that were applied to maximize the uniformity of information obtainedfrom hospitals. (1) The same kind of patients were sampled in everyhospital. (2) The data collection system was standardized, and analyzed forerrors. The overall error rate was small (2%) but there were potentialproblem areas, such as missing information on underlying diagnoses (12%).Few errors (1%) were found in the nurses' observations of the wounds. (3)All wound infections were diagnosed in a uniform manner by convening a panelof four specialists at the central Israeli Study of Surgical Infections(ISSI) office. (4) The definition of infection that was finally chosen forthis multicenter study had to be broadened to include, in addition to pus,“discharge other than pus,” because of the higher reliability among panelmembers. This definition was also clinically valid in terms of morbidity.(5) The rate of postdischarge infections was estimated and was not found tobe related to the discharge policies in the various hospitals.

In a study of 5,571 patients from the general surgery departments of 11Israeli hospitals, the crude overall wound infection rates showedinterhospital heterogeneity. The rates ranged from 6.3% to 12.4% (P(X2) = 0.039). Controllingfor the different distributions of procedures performed in the variousinstitutions did not reduce this variability. None of the hospitals hadeither consistently high or consistently low infection rates. A hospitalcould have low rates for one procedure and high rates for another.Therefore, the decision was made to proceed with procedure-specificanalyses. This article details results of the analysis of 1,487 herniaoperations. Four variables (old age, infection at another site,incarceration, and introduction of drains) accounted for almost all thedifferences in infection rates among the institutions. Of the four, presenceof drains had the strongest association with infection (P derived from thelogistic model <0.001). The risk was consistent in all hospitals and wasunconfounded by other measurable factors. In contrast, the pattern of usingdrains seemed arbitrary and inconsistent, ranging from 9% of patients in onehospital to 41% in another. These findings were used as a basis fordiscussion with the surgical teams and for the initiation of a randomizedclinical trial on the use of drains in hernia operations.

We initiated a prospective study of penile prosthesis implant surgery toevaluate risk factors for infection and other complications. Twenty-onepatients admitted for surgery or related complications were evaluated over aseven-month period. The two types of penile prostheses implanted were (1)inflatable and (2) semirigid. Nine of 21 patients (43%) developedpostoperative complications. Although cephapirin and gentamicin were givenprophylactically, four of nine patients had four wound infections and onecase of pneumonia. One case of Bacteroides fragilisbacteremia was due to stool incontinency during surgery. In two of the woundinfections, removal and reinsertion of the prosthesis was necessary. Othercomplications included hypotension during surgery, prosthesis malfunctionand malposition, and urethral tears. There were no significant associationsbetween infection and age, length of surgery, or type of prosthesis used.These complications contributed to prolonged hospital stay and readmission(87 extra days for the infected patients at a cost of $44,000). Antibioticcosts to treat the infections totaled $1,900. Prospective evaluation byinfection control practitioners of various elective surgeries can be usefulin quantitating the complication rate and targeting patients at risk, withthe goal of minimizing hospital costs.

During an eight-month period, 25 hospitalized patients became infected orcolonized with methicillin-resistant Staphylococcus aureus(MRSA) in a 464-bed acute care, medical-surgical teaching hospital. Therewere only five cases during the eight months prior to the outbreak period (P < 0.0001). Initial measures, includingcategory-specific isolation and education, did not limit the spread of theoutbreak of a strain of MRSA. This prompted institution of additionalmeasures including (1) strict isolation of all infected and colonized cases;(2) prospective microbiological surveillance to detect additional cases; (3)multiple site cultures of identified cases to determine the extent ofcolonization; (4) employee and environment surveillance; (5) antibioticdecolonization of patients and employees; and (6) educational efforts. Thehighest number of personnel carriers were noted in one of the critical careunits where most of the cases occurred. The decolonization protocol was 100%effective for personnel carriers. The incidence of nosocomial cases of MRSAfell to zero in the five months following the implementation of thestrategy. The cost of the entire eradication process was approximately halfthat of treating a single MRSA bacteremia.

Methicillin-resistant Staphylococcus aureus (MKSA)infections have become a major problem in many US hospitals in the last tenyears.‘,’ Attempts to solve the problem have been hampered by many factors.One of these factors is the difficulty in eradicating the organism fromcolonized sites and thereby removing one of the reservoirs of endemicity.Another complicating factor is the lack of consistency in the publishedliterature regarding what constitutes eradication and, therefore, when it isappropriate to discontinue isolation of patients or work restrictions ofpersonnel. Even the decisions regarding when and how often to culturepersonnel remain difficult to define.” Finally, although the Australianexperience illustrated an environmental component to an MRSA outbreak, therole of the environment in MRSA infections remains unclear. The followingreport describes the measures utilized to eradicate low-level MRSA skincolonization in a long-term psychiatric patient and illustrates severalproblems of-long-term MRSA carriage in institutionalized patients.

Recent concerns about the clinical relevance of susceptibility testing echothose expressed previously by a number of authors.’-” These concerns arewell founded and are perhaps even more important today because of theproliferation of new antibiotics and the changes in reimbursementphilosophy.” Ultimately, the question becomes that raised by DavidGreenwood: “In vitro veritas?” Thefollowing discussion will review the role of susceptibility testing inclinical medicine with emphasis on myth versus reality. In addition, newdirections for susceptibility testing that promise increased clinicalrelevance will be covered.

This is the second in a series of articles addressing legal issues ininfection control. The first article (Infect Control Hosp Epidemiol 1988: 9(3):127-129) discussed the basic elements ofliability law as it relates to infection control in the hospital setting.This article will focus on confidentiality in the infection controlprocess.

Infection monitoring and control, as it occurs in most hospital settings,depends on ready access to relevant information, careful evaluation of thedata, and appropriate communication of conclusions and recommendations.Equally obvious, however, is the risk associated with free-floatinginformation of this significance. Infection control programs produce amultitude of documents that are of potential interest to outsiders such asfellow staff members, other health care institutions, and attorneys. Withoutspecific attention to mechanisms for protecting its confidentiality,information gathered in the infection control process may well becomeavailable to some or all of those interested parties.

Much of clinical and hospital epidemiology involves the identification andenumeration of cases or the comparison of case frequencies between two ormore groups of interest. Because both of these activities involve the use ofstatistics, it is important to pay careful attention to biostatisticalissues involved in the collection and the analysis of such data.

In this article, the first in a series of biostatistical papers, we discusssome general issues that are important in the design, analysis, andinterpretation of clinical epidemiologic data. Subsequent papers in thisseries will deal with specific methods of analysis, examples of thesemethods of analysis, and limitations and interpretations of the methods.