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Biomedical subjects

W D Leers

Publications and source records attributed to W D Leers.

At least 19 recordsLinked to original sources
PubMed1987

Norwalk-like gastroenteritis epidemic in a Toronto hospital.

An epidemic of gastroenteritis in a teaching hospital affected 57 patients and 69 staff over a 26-day period. The index case was a patient admitted with acute abdominal pain and diarrhea two days prior to the outbreak. The epidemic curve indicated person-to-person transmission. The incubation period, duration and types of symptoms were typical of Norwalk gastroenteritis, and Norwalk-like virus particles, serologically different from the prototype Norwalk virus strain, were observed in 17 of 20 fecal specimens examined by immune-electron microscopy.

Disease Outbreaks↗
PubMed1985

Syngamosis, an unusual cause of asthma: the first reported case in Canada.

The first case of syngamosis in a human in Canada is reported. The patient, a traveller to the Caribbean islands, presented with a chronic dry cough. The nematode Syngamus laryngeus is found in wild and domestic birds and mammals in the tropics and subtropics. Humans are only accidental hosts. The diagnosis of syngamosis is usually made by fibreoptic bronchoscopic examination, which reveals the Y-shaped worms in the bronchi or the characteristic eggs in the sputum or feces. Physicians must be alerted to the possibility of syngamosis in patients with symptoms of asthma who have recently travelled to South America or the Caribbean islands.

Aged↗
PubMed1984

Pleuropulmonary melioidosis in a Cambodian refugee.

A 47-year-old Cambodian refugee presented with an acute respiratory illness that featured consolidation of the lower lobe of the left lung and progressive involvement of the adjacent pleura caused by Pseudomonas pseudomallei. Initial difficulty in identifying the organism resulted in an inadequate duration of therapy. Chronic pleural disease followed, and the organism became resistant to many antibiotics during therapy. A diagnosis of pleuropulmonary melioidosis should be entertained and the microbiology laboratory alerted when patients with pneumonia who are from endemic areas are encountered, so that a diagnosis can be made early and the appropriate treatment begun.

Anti-Bacterial Agents↗
PubMed1984

Clinical evaluation of the Ortho Rubella ELISA Test System.

The Ortho Rubella ELISA Test System (Ortho Diagnostics Canada Ltd., Toronto, Ontario) is an enzyme-linked immunosorbent assay (ELISA) for the determination of IgG antibodies to rubella virus. Comparison of the Ortho Rubella ELISA with a commercial hemagglutination inhibition (HAI) test revealed that the ELISA is well suited for routine use as a qualitative screening test for rubella immune status or the demonstration of seroconversions. Quantitation of rubella antibodies by the Ortho Rubella ELISA, however, requires that ELISA endpoint determination be made on serial serum dilutions.

Antibodies, Viral↗
PubMed1982

Treatment of blepharitis and blepharoconjunctivitis: comparison of gentamicin-betamethasone, gentamicin alone and placebo.

At two university centres 46 patients presenting with symptomatic infective blepharitis or blepharoconjunctivitis participated in a double-blind study of a new antibiotic-steroid ointment containing gentamicin and betamethasone. There was no significant difference in response to 2 weeks of therapy between the patients treated with this ointment and those treated with either an ointment containing gentamicin alone or a placebo ointment. There was also no significant correlation between the clinical response and the results of the bacterial cultures of swabs obtained at the beginning and the end of the study. However, the patients treated with the placebo had a much higher rate of recurrence of their symptoms over a 6-week follow-up period. The patients who before treatment had associated rosacea, dry eyes and a long duration of symptoms showed a poor response to therapy.

Adolescent↗
PubMed1980

Disinfecting endoscopes: how not to transmit Mycobacterium tuberculosis by bronchoscopy.

Mycobacterium tuberculosis was cultured from the bronchial washings of two patients who underwent bronchoscopy consecutively with the same bronchoscope. Active pulmonary tuberculosis was later confirmed in the first patient, whereas the second patient had clinical and serologic evidence of infection with respiratory syncytial virus. The bronchoscope had been cleaned with an iodophor disinfectant, which had not destroyed the tubercle bacilli. The agent recommended for chemical disinfection of fibreoptic bronchoscopes is 2% glutaraldehyde solution; the instrument should be immersed in it for 10 to 30 minutes. Five hours' exposure to ethylene oxide is recommended for sterilization of instruments. These procedures must be preceded by adequate mechanical cleaning. Then transmission of pathogenic organisms during endoscopy, which can result in nosocomial disease, misdiagnosis or inappropriate treatment, will be avoided.

Adult↗
PubMed1977

Prevalence of hepatitis B surface antibodies in ethnic groups of a Canadian hospital staff population.

Hospital staff members were analyzed with respect to ethnic origin and prevalence of anti-hepatitis B surface antibodies (Anti-HBs). The staff members were categorized into four "risk groups" according to frequency of exposure to blood, patients' speciments, and patient care. Of the total 526 staff members studied, one-half (51.5%) were of North American origin, one-quarter came from Europe (25.9%), and the rest came from Asia, the West Indies, Africa, and Australia. The prevalence of Anti-HBs was lowest among North American staff members (8.1%) and highest among Asians (42.3%) (P less than or equal to 0.05). Low-risk administrative staff had the significantly lowest number of Anti-HBs-positive members (6.1%), whereas low-risk dietary staff (29.6%) and hospital assistants (30.6%) had the significantly highest prevalence of Anti-HBs staff members. In contrast, the high-risk group of laboratory workers and special nurses had only 16.1% of staff members with Anti-HBs. Our results show that ethnic background and socioeconomic conditions have to be considered when various risk groups are compared for the presence of Anti-HBs. The frequency of exposure to blood and patients' specimens or patient care is not the only determining factor in the prevalence of Anti-HBs in health workers.

Antibodies↗
PubMed1976

Feasibility of routine testing for hepatitis B surface antigen in hospital employees and restriction of carriers.

In 1972-73, 48 hospital staff members were tested selectively for hepatitis B surface antigen (HBsAg); 4 (8.3%) were found to be HBsAg-positive. In 1974-75, 1415 staff members were tested routinely before employment and at periodic health examination; 25 (1.8%) were found to be HBsAg-positive. Of the HBsAg-positive staff members 55.2% were Asians, this proportion being significantly (P less than 0.05) greater than that of any other ethnic group, and 31.0% were southern Europeans. Nurses and laboratory technologists were the largest professional groups among the HBsAg-positive staff, each accounting for 20.7%. Our results indicate that it is impractical to carry out routine testing of hospital staff for HBsAg. Selective testing and restriction from work in their units is proposed for staff of the renal and peritoneal dialysis units, the emergency department and the intravenous team and dietary staff who handle food directly.

Adult↗
PubMed1975

Prevalence of hepatitis B antibodies in hospital personnel.

Of 426 hospital staff tested for hepatitis B surface antibody (anti-HBS) by the radioimmunoassay method 57 (13.4%) had positive results. Laboratory staff had the highest prevalence, followed by nurses, and both values were significantly higher than that of administrative staff. Clerical staff working in laboratories were at the same risk for hepatitis B as general-duty nurses. Significantly more staff with anti-HBS had a history of hepatitis (19.3%) compared with staff without anti-HBS (79%), and significantly more staff with a history of hepatitis had anti-HBS (25.6%) compared with staff without such a history (12.0%). History of blood transfusions was not related to prevalence of anti-HBS. The risk for hepatitis B is greater in hospital staff who are in direct contact with patients or handle patients' blood and other specimens. However, contact with patients is less important than contact with patients' blood and other specimens.

Antibodies, Viral↗
PubMed1975

In vitro sensitivity of hemophilus influenzae and streptococcus pyogenes to co-trimoxazole.

The invitro testing of Hemophilus influenzae and Streptococcus pyogenes for co-trimoxazole sensitivity requires certain "defined" media that have to be free of inhibitory substances. The use of Columbia agar base with Fildes extract for H. influenzae or of blood agar for S. pyogenes may produce "false-resistant" strains. The addition of thymidine phosphorylases in the form of gentlylysed horse blood (2 to 10%) does not remove all inhibitors in those tests, especially where "undefined" agar bases are used, and results in scanty growth of H. influenzae; the addition of more than 2% results in dark plates, making reading of sensitivities difficult. Fildes agar for testing H. influenzae may be made with enriched sheep or horse blood if the proper "defined" agar base is used. The use of Wellcotest or DST (Oxoid) agar is recommended with Fildes extract for H. influenzae or with blood for S. pyogenes for in vitro testing for co-trimoxazole sensitivity. The addition of thymidine phosphorylase in the form of 2% lysed horse blood does not interfere with reading. However, it results in scanty growth of H. influenzae. Proper inoculation of plates is important. The growth on the plates should be light, dense, but not confluent. Heavy growth may render some strains "false-resistant" even when defined media are used. Our results indicate that many of the previously reported resistant strains of H. influenzae and S. pyogenes may have been "false-resistant" because of the use of "undefined" media. We believe that, in view of our results, respiratory infections may be treated with co-trimoxazole until bacteriologic studies prove that this treatment is contraindicated, since H. influenzae and S. pyogenes are usually found sensitive in vitro under proper conditions.

Animals↗
PubMed1975

Occurrence of hepatitis and hepatitis B surface antigen in adult patients with acute leukemia.

Fifty-eight adult patients with acute leukemia were screened at the onset of the disease for hepatitis B antigen (HBSAg) in the serum, and during the course of the disease for the development of hepatitis B. One patient had a positive test for HBSAg by the radioimmunoassay technique only at the time leukemia was diagnosed; this patient had received transfusions some years before. In six patients icteric hepatitis B developed; five recovered completely and one died of leukemia during the course of hepatitis. All patients in whom hepatitis developed had received transfusions as a part of supportive therapy for leukemia. The hepatitis risk for patients who received transfusions of blood found to be negative for HBSAg by counterimmunoelectrophoresis was 0.26 percent per unit of blood administered.

Acute Disease↗
PubMed1975

Intravenous catheter infection study: a prospective trial in patients with neoplastic disease.

This study was designed to determine the frequency and significance of infection at the site of indwelling intravenous catheters. Eligible patients were randomly assigned to have an intravenous infusion utilizing either a plastic cannula or or a short metal needle. Both of these groups were further randomly divided into two groups, one having the intravenous catheter removed every 48 hr and the other having the catheter changed only when necessary. One hundred and eighty-seven catheters from 50 patients were cultured. Eleven (5.9%) of the catheters were found to be colonized by organisms. Metal needles and plastic cannulas were infected with similar frequency. The incidence of local infection was not influenced by concurrent antibiotic therpy, local phlebitis, or the level of the granulocyte count during the period of intravenous infusion. Six of 31 catheter tips in place for longer than 56 hr were colonized by organisms, compared with 5 of 156 catheter tips in place for less than 56 hr (p less than 0.0001). The study indicates that indwelling intravenous catheters should be changed at least every 48 hr in order to prevent colonization of the tip of the intravenous catheter.

Candidiasis↗
PubMed1975

Comparison of the reversed passive hemagglutination with radioimmunoassay methods for hepatitis B antigen.

Radioimmunoassay for the detection of hepatitis B antigen has been accepted in many diagnostic laboratories now. The question of nonspecific positives has always been a matter of controversy. Two improved radioimmunoassay tests, namely Ausria II-125 by Abbott Laboratories and a radioimmunoassay method by Connaught Laboratories Limited (Hebria), were compared with the original Ausria 125I. Included in the comparison was the reversed passive hemagglutination test (Auscell, Abbott). Five hundred sera of clinical patients were tested. Fifty-five or 11% were found to have hepatitis B antigen. Three tests, Ausria 125I, Ausria II-125, and Hebria showed the same number of positive sera, whereas Auscell missed one. However, Ausria 125I indicated two additional false positives. Dilution experiments, however, indicated that Ausria II-125 and Hebria were the most sensitive tests, with the reversed passive hemaglutination showing the least sensitivity. Therefore, the new Ausria II-125 and the Hebria radioimmunoassay tests are preferable in view of their sensitivity and specificity.

Blood↗
PubMed1974

Hepatitis B antigen in screened blood units for transfusion in renal dialysis patients.

Blood units for transfusion are screened routinely in Ontario for the presence of hepatitis B antigen (HB-Ag) by counter-immunoelectrophoresis (CIEP). Since the radioimmunoassay (RIA) method is more sensitive for this purpose we used it to test blood units delivered to the hospital's Renal Dialysis Unit in order to determine if HB-Ag-carrying blood donors were being missed by the less sensitive CIEP method.Out of the 606 blood units tested, eight were found to contain HB-Ag, an incidence of 13 out of 1000 donors. This finding indicates that the counter-immunoelectrophoresis method is insufficiently sensitive as a safe screening method for detection of hepatitis antigen.

Blood Donors↗