Morris L. V. French

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.

Risk Factors for Disseminated or Fatal Histoplasmosis: Analysis of a Large Urban Outbreak

An outbreak of histoplasmosis in Indianapolis involving 488 clinically recognized cases including 60 patients with disseminated or fatal infection permitted statistical analysis of risk factors. Being male, white, under 5 years of age, having chronic obstructive lung disease, and living near the presumed source of the outbreak were not risk factors for fatal or disseminated histoplasmosis. Age greater than 54 years and immunosuppression were the only risk factors for disseminated or fatal infection. Dissemination should be excluded in patients with histoplasmosis who are immunosuppressed or older than 54 years. Specific antifungal treatment is more likely to be required in those two groups rather than in patients without risk factors.

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.

Cavitary Histoplasmosis Occurring During Two Large Urban Outbreaks: Analysis Of Clinical, Epidemiologic, Roentgenographic, And Laboratory Features

We have compared risk factors for cavitary histoplasmosis in 62 patients with that manifestation of the infection and in 679 patients with other forms of histoplasmosis, and we have evaluated the clinical and laboratory findings in 45 patients with cavitary histoplasmosis who were cared for at the Indiana University Medical Center hospitals during two large histoplasmosis outbreaks. Chronic obstructive lung disease and old age were the strongest risk factors for cavitary histoplasmosis but male sex, white race and immunosuppression were also important in certain patient groups. Fever, sweats, weight loss, productive cough, anemia, lymphopenia, and alkaline phosphatase elevation were common findings. The patients were occasionally incorrectly treated for presumed class 3 tuberculosis. Cultures were positive in 58% of patients, with sputum samples providing the highest yield (61%). Histoplasmal serologic tests provided useful clues to the diagnosis, positive in over 90% of cases. About one-third of patients recovered spontaneously while another 35% improved following treatment. About 4% developed chronic untreated cavitary histoplasmosis characterized by clinical and roentgenographic exacerbations and remissions. Of the deaths in four patients with untreated disease, one was caused by disseminated histoplasmosis while three died of other causes. Ketoconazole appeared effective in three of seven patients while its effect in three additional patients was uncertain. Toxicity precluded completion of ketoconazole therapy in one patient. Only amphotericin B has been proven to be effective therapy for cavitary histoplasmosis.

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.

Virus Isolation and Identification

Cell Cultures: Monolayer cultures of primary, diploid, and continuous cell lines are the hosts of choice for virus isolation. Quality cell cultures are available commercially and are conveniently maintained in the laboratory. After proper decontamination and purification, each clinical sample is inoculated into several types of cell cultures; the preferred lines vary from virus to virus.

Differentiation of lymphoma from histoplasmosis in children with mediastinal masses

The differentiation of mediastinal masses caused by lymphoma from those caused by histoplasmosis may require thoracotomy. We reviewed the medical records of 37 children undergoing initial evaluation for anterior or middle mediastinal masses. Sixteen had biopsy-proved lymphoma, and 21 had histoplasmosis; seven with histoplasmosis underwent thoracotomy. Age, sex, fever, weight loss, duration of illness, anemia, erythrocyte sedimentation rate, nonspecific reactants, and lung infiltrates and calcifications were similar in both groups. Masses were in the middle mediastinum in all patients with histoplasmosis and in 69% with lymphoma. Masses were in the anterior mediastinum in one of 21 (5%) with histoplasmosis and 13 of 16 (81%) with lymphoma. Among patients with lymphoma, histoplasmal complement fixation antibody titers were less than 1:8 in 14 of 15 (93%); a single patient had a titer of 1:16. The CF titers were greater than or equal to 1:32 in 14 of 21 (67%) with histoplasmosis. In children with middle mediastinal masses, a histoplasmal CF yeast or mycelial titer greater than or equal to 1:32 is strongly suggestive of acute histoplasmosis and biopsy is not required. Children not fulfilling these criteria should undergo diagnostic biopsy.