Harold E. Eitzen

A large urban outbreak of histoplasmosis: clinical features.

An outbreak of histoplasmosis estimated to involve more than 100,000 residents in Indianapolis, Indiana, occurred between September 1978 and August 1979. In the 435 cases evaluated, 52% of the patients were between 15 and 34 years old, and 63% were black. Fifteen patients died, and 46 progressive disseminated infection. Twenty-four patients had pericarditis, and 26 had rheumatologic syndromes. Unusual manifestations that occurred in 18 patients included esophageal and vocal cord ulcers, parotitis, adrenal insufficiency, uveitis, fibrosing mediastinitis, interstitial nephritis, intestinal lymphangiectasia, and epididymitis. The highest attack rate was in the central part of the city, which is a densely populated, disproportionately black section. The source of the outbreak has not been proved by positive culture results; two sites, however, were suspected on an epidemiologic basis.

The diagnostic laboratory tests for histoplasmosis: analysis of experience in a large urban outbreak.

Of 495 patients reported in a large urban histoplasmosis outbreak, we studied 276 whose serologic tests were done in a single laboratory. Serologic test results were positive in 96% of these patients (compared with less than 5% of controls from an endemic area), cultures were positive in 22%, and special stains in 19%. The immunodiffusion test results were negative in 13% of patients who had positive findings by complement fixation, and 1% had positive results only by immunodiffusion. The complement fixation test was almost twice as sensitive as the immunodiffusion test in patients with subclinical infection. The serologic response differed significantly among the clinical syndromes with higher titers in cavitary and lower titers in disseminated disease. Factors associated with titers of 1:64 or greater to both antigens were black race and immunocompetence. High mycelial titers were also associated with more intense exposure, and high yeast titers were associated with age less than 36 years. No prognostic significance could be proved for fourfold titer rises or falls or persistence of precipitins.

The operating room environment as affected by people and the surgical face mask.

The microbiological counts were determined in an operating room suite of 8 rooms and a hallway. The bacterial counts in an empty operating room jumped statistically from 13 CFU/ft2/hr (+/- 31) to 24.8 (+/- 58.8) when the doors were left open (people in the hallways) and 447.3 (+/- 186.7) when 5 people were introduced. The wearing of a surgical face mask had no effect upon the overall operating room environmental contamination and probably work only to redirect the projectile effect of talking and breathing. People are the major source of environmental contamination in the operating room.

The plastic surgical adhesive drape: an evaluation of its efficacy as a microbial barrier.

A microbial evaluation was made of adhesive plastic surgical drapes and cloth surgical drapes. These studies were done both during surgery and in the laboratory. The plastic drape does not allow bacterial penetration, lateral migration does not occur, skin bacteria do not multiply under the drape within the time periods studied and the patient drapes are held in place with their use. When wet, cloth drapes showed profuse bacterial penetration. Dry cloth showed less bacterial penetration as compared to wet cloth. Lateral migration under cloth drapes was not possible to assess due to a high level of penetration. The surface of cloth showed a higher level of bacterial contamination during the surgical procedures. Deep wound cultures collected just prior to closing showed 60% contamination when cloth was used compared to 6% when plastic was employed. The microorganisms recovered from the various sites sampled were identified. Finally, in addition to the positive aseptic benefits afforded by plastic adhesive drapes, aesthetic features such as a more delineated operative field and elimination of towel clips make this product a useful adjunct to the surgeons armamentarium.

The surgeon's garb.

A comprehensive evaluation of all factors associated with the surgeons garb worn with and without laminar air flow revealed that in a conventional operating room, all personnel should wear an impermeable one-piece suit with foot attachments, any type of head cover, and, if they are going to be near the operative site or instrument table, a disposable mask. Scrub personnel should wear some type of a disposable gown to reduce the amount of surface contamination. The best way to reduce the environmental and surface contamination would be for all personnel to wear some type of a hooded exhaust equipment, but this is impractical both for circulating nurses and for anesthesiologists. Despite the reduction obtained from all the above controls, the reduction in the amount of bacterial contamination would not be as great as that obtained with laminar air flow, 93% (p < 0.005). Laminar air flow produced the greatest single reduction in environmental and surface contamination and variables such as time, people and attire did not influence the overall counts. The attire recommended for the conventional operating room can be used in laminar air flow with an expectation of overall reduction in contamination.

The effect that time, touch and environment have upon bacterial contamination of instruments during surgery.

Hemostats were evaluated for frequency of contamination and such contamination was correlated with increasing operating room exposure time. The studies were performed under surgical conditions in operating rooms with and without laminar air flow. The study was also designed to show whether contamination of hemostats were influenced by the scrub nurses handling. Hemostats were more frequently contaminated in the conventional operating room without laminar air flow (P < 0.001). Handling by the scrub nurses gloved hand statistically increased the number of contaminated hemostats (P < 0.01). Laminar air flow reduced the frequency of contamination statistically (P < 0.001) to a point where time and touch by a gloved hand of the scrub nurse were not important factors.

Evaluation of microbial contamination of surgical gloves during actual use.

The contamination rate of gloves is about the same for all scrubbed personnel, be they single or double gloves (33%). More holes are noted in the gloves of personnel who use their hands more strenuously. A double pair of gloves does not reduce the amount of contamination but does reduce the number of holes. The contamination could not be associated with the hole in the glove in our study. The amount of contamination beneath the glove does not influence its exterior contamination. Contamination generally comes from somewhere else in the operative field environment.

Bacterial contamination of the surgical knife.

Two hundred and eight skin knives and 374 deep knives were evaluated in 153 clean orthopedic cases with and without a horizontal wall-less laminar air-flow system. There was no statistical difference in contamination frequency between the skin and the deep knives with and without the laminar air-flow. However, the knife blades were found to be contaminated less than laminar air-flow was used than when it was not (P less than 0.005). No correlation could be made between the cultures of the wound edges and the depth of the wound with the contaminated knife blades.

Comparison of Horizontal and Vertical Unidirectional (Laminar) Air-flow Systems in Orthopedic Surgery

The microbiological evaluation of a horizontal walled unit, a horizontal wall-less unit and a vertical wall-less unidirectional airflow unit revealed a statistical reduction in the wound and back table air settle plate counts for the 2 horizontal systems as compared to the vertical system.