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W F Schlech

Publications and source records attributed to W F Schlech.

At least 37 records · Page 2Linked to original sources
PubMed1991

Lowbury Lecture. Listeriosis: epidemiology, virulence and the significance of contaminated foodstuffs.

Recent epidemiological evidence confirms that sporadic, as well as outbreak-associated, cases of listeriosis are primarily foodborne in origin. Implicated foodstuffs include meat products, dairy products, fruit, seafood and raw and processed vegetables. Large community-acquired outbreaks in North America and Europe have been complemented by smaller outbreaks involving hospitalized patients. Anecdotal reports and case clusters of nosocomial cases also support foodborne transmission. Cross-infection may be a major mode of transmission as demonstrated in a recent outbreak in Costa Rica. The sporadic nature of outbreaks of listeriosis are more consistent with changes in organism virulence rather than host susceptibility. The population of patients at risk for listeriosis (pregnant women and immunocompromised hosts) may not vary greatly. Establishment of infection is probably dose-dependent and gastric acidity may be protective. However, other organism-specific virulence factors, such as haemolysin production, may affect the post-intestinal phase of infection. Virulence factors other than haemolysins have not been characterized as yet. In summary, acquisition of Listeria monocytogenes infection from the environment by susceptible hosts may be widespread but invasive infection remains rare and the determinants of invasion require further elucidation.

Disease Outbreaks↗
PubMed1991

Development and application of a multiple typing system for Clostridium difficile.

A combination of bacteriocin, bacteriophage, and plasmid typing techniques was used to differentiate strains of Clostridium difficile. A typing set of 20 bacteriocin-producing strains was established after 400 isolates of C. difficile were screened for the ability to produce bacteriocin. These strains were used to type a collection of 114 isolates of C. difficile. Forty-six (40%) of the 114 isolates were typeable, and 31 typing patterns were distinguishable. Plasmid typing of the same 114 isolates of C. difficile showed that 67 (59%) of the isolates carried up to four plasmids ranging from 7 to 60 kb in size, although most strains contained only one or two plasmids. Twenty different plasmid typing patterns were observed among the isolates. A combination of bacteriocin and plasmid typing provided 77% typeability. Fifteen (13%) of the 114 strains were typeable with five bacteriophages isolated in our laboratory, but the increase in typeability of strains over that obtainable by plasmid and bacteriocin typing was only 1.8%. Isolates that were nontypeable by bacteriocins, plasmids, or phages could be divided into two groups on the basis of positive or negative cytotoxin production. This further division of strains would increase the typeability potential by 7%; i.e., the ability to differentiate strains would rise from 77 to 84%, or perhaps 86%, if phage typing were included. We conclude that more than one of the techniques reported in this paper must be used to achieve an acceptable level of typeability of this species.

Bacterial Typing Techniques↗
PubMed1991

Urinary tract infections--a survey.

Urinary tract infections (UTIs) occur frequently in hospitalized patients and are associated with significant morbidity. The infection control department of the Victoria General Hospital in Halifax, Nova Scotia conducted prospective hospital-wide surveillance for one month to evaluate the incidence of UTIs. There were 40 UTIs: 62.5% in patients with indwelling catheters; 20% in patients undergoing intermittent catheterization; and 17.5% in uncatheterized patients, for an attack rate of 19.9 per 1000 patient discharges. Escherichia coli was the most common organism, isolated in 47.5% of the study population. Trimethoprim-sulphamethoxazole was used to treat 57.5% of the UTIs. The findings from this survey are consistent with those of other authors in comparable institutions.

Cross Infection↗
PubMed1989

Passive transfer of HIV antibody by hepatitis B immune globulin.

Two newborns of mothers carrying hepatitis B and at high risk for human immunodeficiency virus (HIV) infection developed HIV-positive test results by enzyme-linked immunosorbent assay and Western blot tests after birth. Both had been administered hepatitis B immune globulin within 48 hours of birth. Serological tests detected HIV antibody as long as 17 days after birth. Both newborns had received lots of hepatitis B immune globulin containing antibody to HIV. While hepatitis B immune globulin cannot transmit HIV infection to recipients, physicians should be aware that administration of older lots of this preparation may result in transiently positive tests for HIV antibody in the recipients. Lots manufactured from screened plasma do not contain antibody to HIV.

Adult↗
PubMed1988

The risk of infection in anaesthetic practice.

Infectious hazards to anaesthesia personnel are real but the appropriate use of immunization, universal blood and body fluid precautions, and respiratory precautions where appropriate, should minimize the risk of infection at work. In particular, the resistance of physicians to immunization, especially to hepatitis B, needs to be changed. Protection against other blood-borne pathogens for which immunization is not available, such as HIV, may also depend on the willingness of anaesthesia personnel to accept and carry out recommendations for universal blood and body fluid precautions. Regulatory agencies and compensation boards are likely to look closely at adherence to established guidelines when determining benefits for work-related infections. Complaints that the routine use of gloves interferes with anaesthetic practice are frequent but unacceptable in the current climate and it behooves the profession to ensure that compliance with currently accepted infection control guidelines is complete.

Anesthesiology↗
PubMed1986

Nosocomial outbreak of Pseudomonas aeruginosa folliculitis associated with a physiotherapy pool.

Outbreaks of community-acquired Pseudomonas aeruginosa folliculitis have recently been described in association with health spa whirlpools. In February 1984 we detected an outbreak of Pseudomonas folliculitis among hospital staff and patients using a swimming pool in a newly constructed physiotherapy unit. A rash developed in 5 (45%) of the 11 physiotherapists who had used the pool, as compared with 0 of the 17 who had not (p less than 0 005). Pseudomonas folliculitis also developed in 6 (21%) of 29 outpatients and 4 (33%) of 12 inpatients who had used the facility; Pseudomonas infection of a surgical wound also developed in 1 of the 4 inpatients. The epidemic curve was consistent with a continuing common-source outbreak. P. aeruginosa, serotype O:10, was isolated from three physiotherapists, the patient with an infected surgical wound and the pool. A case-control study of pool users did not identify risk factors for infection, although the physiotherapists had spent longer in the pool than had the patients. After hyperchlorination and structural repairs to the pool, no further cases were identified among pool users. This outbreak is the first reported nosocomial outbreak of Pseudomonas folliculitis. Further investigation is needed to determine the risk of serious Pseudomonas infections in hospitalized patients using physiotherapy pools.

Adult↗
PubMed1986

Q fever pneumonia associated with exposure to wild rabbits.

4 patients with atypical pneumonia and a history of exposure to wild rabbits were found to have antibodies to Coxiella burnetii but not to the other organisms also commonly associated with atypical pneumonia. 10 (45%) of 22 snowshoe hares caught in the area where 1 of the patients snared his rabbits had antibodies to Coxiella burnetii. Q fever ought to be included in the differential diagnosis of pneumonia acquired following exposure to wild rabbits.

Animal Population Groups↗
PubMed1986

Pneumococcal vaccine efficacy in selected populations in the United States.

The efficacy of pneumococcal vaccine in groups of patients in the United States at high risk for pneumococcal disease was estimated by comparing distributions of serotypes of Streptococcus pneumoniae isolated from vaccinated and unvaccinated persons. Between May 1978 and March 1984, 187 blood isolates and 62 cerebrospinal fluid isolates from vaccinated patients, and 1447 blood isolates and 191 cerebrospinal fluid isolates from unvaccinated patients were serotyped at the Centers for Disease Control. The study did not include patients who were less than 2 years old or who had Hodgkin's disease, multiple myeloma, or immunoglobulin deficiency. In patients with bacteremic disease, the overall efficacy of pneumococcal vaccine was estimated at 64% (95% confidence limits, 47% to 76%); efficacy did not differ significantly with age. In persons over 65 years of age with diabetes mellitus, chronic heart disease, pulmonary disease, or no underlying illnesses, efficacy was 61% (95% confidence limits, 1% to 85%). These findings support the use of pneumococcal vaccine in selected populations in the United States.

Adolescent↗
PubMed1985

Legionnaires' disease in the Caribbean. An outbreak associated with a resort hotel.

Outbreaks of legionnaires' disease (LD) in tourists visiting Italian and Spanish resorts have been recently reported. An unusual number of reports of LD in tourists visiting the US Virgin Islands prompted an investigation of risk factors for development of LD in this area. Twenty-seven cases of LD were identified between 1979 and 1982 through press reports, personal communication, the national LD surveillance system, a review of hospital records, and a mail survey. Twenty-four of 27 persons with the disease had visited St Croix and 12 of them had stayed at a single hotel in 1981. Available evidence suggested that infection was due to Legionella pneumophila serogroup 1; L pneumophila serogroups 1 and 3 and several new Legionella species were isolated from the potable water system at the hotel. Following hyperchlorination of the potable water system, no further cases of LD in hotel visitors have been identified to date.

Disease Outbreaks↗
PubMed1984

New perspectives on the gastrointestinal mode of transmission in invasive Listeria monocytogenes infection.

The route or mechanism of transmission of Listeria monocytogenes from its rural veterinary reservoir to newborn and older human populations has been obscure. Anecdotal reports of milk-borne infection from cows with Listeria mastitis have been published, but intensive investigations of small outbreaks of L. monocytogenes infections in humans have not supported a gastrointestinal mode of infection. Several recent studies, however, strongly suggest this possibility, and case-control studies of epidemic listeriosis in the Canadian Maritime provinces in 1981 documented an association between ingestion of uncooked vegetables and the development of illness (p = 0.02). In that study, coleslaw from a regional producer which was distributed throughout the Maritimes was considered to be the vehicle of transmission. Cabbage, the raw product in the production of coleslaw, was contaminated at a farm prior to arrival at the plant. Contamination occurred through fertilization with raw manure from a flock of sheep known to harbour L. monocytogenes. Therefore, an indirect link was established between Listeria monocytogenes infection of sheep on a cabbage farm and subsequent development of invasive listeriosis in humans. This study supports findings from other epidemiologic studies of human listeriosis and is consistent with results of investigations into the mode of transmission of natural and laboratory-acquired listeriosis in animals.

Animals↗
PubMed1983

Recurrent urban histoplasmosis, Indianapolis, Indiana, 1980-1981.

In January 1981, informal surveillance of acute histoplasmosis in Indianapolis, Indiana, revealed a marked increase in disease activity for the last quarter of 1980. Fifty-one patients with onset of acute histoplasmosis during this period were identified through review of hospital admissions, emergency room visits, and serologic records at Indianapolis hospitals and the Indiana State Board of Health. In a retrospective case-control study, the authors found a significant association between developing acute histoplasmosis during this period and working or attending classes in a 2 sq mi (5.2 sq km) area encompassing the Indiana University-Purdue University campus (p = 0.015, Fisher's exact test). A review of construction activities on or near the campus during the epidemic period suggested that the probable source of infection was excavation activity for a large new indoor swimming complex (natatorium). Skin tests and serosurveys of students on campus by a newly developed radioimmunoassay for histoplasmal immunoglobulin M antibodies supported the association of infection with exposure to this site (p less than 0.05).

Disease Outbreaks↗
PubMed1983

Medical management of visceral actinomycosis.

A patient had extensive retroperitoneal actinomycosis with renal and vertebral involvement. Abdominal computed tomography was invaluable in defining the extent of the disease and in assessing the effects of therapy. A cure was accomplished with a prolonged course of oral penicillin and probenecid, and surgical exploration was avoided.

Abscess↗