Epidemiology of influenza vaccination in Canada

To assess influenza vaccine coverage among Canadian adults, questions about the fall/winter 1990-91 immunization campaign were added to the Statistics Canada 1991 General Social Survey. A total of 11,924 usable responses were obtained (response rate 80%). Overall, an estimated 13.8% (95% CI 13.1-14.5) of the Canadian population surveyed and 44.8% (95% CI 42.7-46.9) of the population 65 years of age and over received a "flu" shot during the fall/winter 1990-91 immunization campaign. A logistic regression model run separately in populations less than 65 years of age and in populations 65 and over reveals that, by far, the major predictor for receiving influenza vaccine was a recommendation by a nurse or physician. Two major reasons listed by persons 65 and over for not receiving the flu vaccine were 1) the belief they hardly ever get the flu (39%), and 2) they fear side effects (22%).

Current thoughts on the risks and benefits of immunisation

Despite a continuous search for safer and more immunogenic vaccines, adverse reactions still occur. Adverse reactions to vaccines are generally mild; severe events resulting in death or permanent damage are rare. In every instance, the benefits of preventing the disease far outweigh the risks of vaccination. In the early days of vaccine development, a number of accidents were associated with faulty production. Most recent problems encountered with the use of vaccines are due to programmatic errors. Because of the large number of doses administered it is probable that there will be some temporal and merely coincidental association between adverse events and vaccine administration. Immunisation has a direct protective effect for the individual and an indirect effect on herd immunity for the community. The major goal of postmarketing surveillance is the early detection of and appropriate response to adverse events in order to curtail a negative impact on immunisation programmes. Risk-benefit analyses for immunisation are faced with a number of potential difficulties; definition of the risks and benefits themselves, individual versus community risks and benefits, and the continuously evolving nature of risks with changes in disease epidemiology. Based on risk-benefit studies, for an individual just as for the community, it may not always be of interest to use the vaccine with the lowest complication rate. Good immunisation programmes should help to decrease the risk of adverse effects.

Flash flood disaster--Nîmes, France, 1988

On October 3, 1988, at 7:45 a.m. a flash flood occurred in the region of Nîmes, France. Though the homes of 45,000 people were damaged and more than 1,100 vehicles were destroyed, only 3 severe injuries and 9 deaths were reported. A community survey was conducted to study (1) what factors might have contributed to the limited number of deaths, (2) the reactions of the population to the disaster, and (3) the health effects associated with the impact and postimpact phases of the disaster. Overall, 108 questionnaires were completed from a systematic sample of 187 households living in ground-level dwellings in two of the most seriously affected areas of the city. Only 17% of all interviewees knew that they lived in an area subject to flood. When they realized they were in danger, 93% of all persons were in their houses or other buildings, 4% were in the streets, and 3% were in cars. Fifty-six percent of the interviewees tried to get to safety. Thirty percent of the interviewees reported that they were rescued; 20% of these persons reported being saved from a direct life threat. Neighbors (40%), family members (20%), firefighters (12%), the Red Cross (10%), and military personnel (8%) conducted rescue operations. Six percent of all members of interviewed households were reportedly suffering mild injuries that, in 70% of these cases, had been sustained during the impact phase. Health problems and injuries during the postimpact phase may have been limited by the response of trained military personnel and by the distribution of boots and gloves to other responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Mycobacterium tuberculosis transmission in a health clinic

Between January 1 and June 30, 1988, 30 (39.5%) of 76 staff members tested at a health clinic in Florida had positive tuberculin skin test reactions. This case-control study showed that people whose skin test converted were more likely than those whose skin test did not convert to have been present while patients were being treated with aerosolized pentamidine (odds ratio = 15.0; 95% confidence interval = 1.4 - 730.0) and to have worked on the first floor of the clinic (odds ratio = 9.3; 95% confidence interval = 1.1 - 420). The clinic building was poorly ventilated, and aerosolized pentamidine treatments were given in a room from which the air tended to flow into the hallway. Aerosolized pentamidine should be administered in a well-ventilated area from which the air is exhausted directly outside. All persons who are given such treatments should first be screened for tuberculosis. Use of trade names is for identification only and does not constitute endorsement by the Public Health Services or the U.S. Department of Health and Human Services.

[New technic of surgical treatment of periapical lesions using carbon dioxide laser]

After briefly reviewing the use of the CO2 laser in dentistry, the authors will describe the materials and method for laser radiation after peri-apical surgery. The laser application will result in the sterilization of the apical region. The authors explain the importance of the "LASER-MIRROR" a mini contra-angle head which can maintain the integrity of the apex or minimize apical ressection while reflecting the laser beam at a 90 degree angle. Two case reports will be described and the authors will give the indications and contra-indications of their technic.

The 1987 forest fire disaster in California: assessment of emergency room visits

During a 5-d period that commenced on August 30, 1987, dry lightning strikes ignited more than 1,500 fires that destroyed in excess of 600,000 acres of California forests. To evaluate the public health impact of the smoke on the general population, all hospital emergency rooms located in the six counties most severely affected by smoke or fire were surveyed. Selected hospital information was abstracted for a 2 1/2-wk period during the fires and during two reference periods. During the period of major forest fire activity, visits of persons with asthma and chronic obstructive pulmonary disease increased in number (observed/expected ratios of 1.4 and 1.3, respectively), as did visits of persons with sinusitis, upper respiratory infections, and laryngitis. A few patients with acute respiratory or eye irritation also visited the emergency rooms. Even recognizing the limited sensitivity of emergency room surveys, the overall public health impact was relatively modest. The increased respiratory morbidity detected in this survey, however, supports the notion that persons with pre-existing respiratory disease represent a sensitive subpopulation, who should be targeted for purposes of public health intervention when exposure to forest fire smoke is likely.

Isolation and plaque purification of a syncytial forming component of myxoma virus

Using the endpoint dilution and plaque purification technique performed on rabbit kidney cells, two stable syncytial clones of myxoma virus have been isolated. No eosinophilic intracytoplasmic inclusion bodies nor intranuclear granulations could be detected in cells infected with these clones. Traditional plaques with the central area of detached cells surrounded by round cells also could not be recognized. However, when enough virus was added, one large complete syncytium developed in 24 on the monolayer. Syncytial activity was associated with the entire particle. This was the first time that myxoma virus is reported to demonstrate such an intense syncytial activity.

Carbon source assimilation and fermentation tests: study of 77 animal Pasteurella strains by a microtechnique

77 strains of Pasteurella from various animal species were tested using the API micromethod for their ability to assimilate 147 carbon substrates and ferment 49 carbohydrates. Typical profiles of P. multocida and P. haemolytica were determined. This micromethod should prove useful in establishing the biotypes of Pasteurella species and in studying their epidemiology and pathogenicity.

Changes in adenohypophyseal cytology and nucleic acid content in the rat 32 days after bilateral adrenalectomy and the chronic injection of cortisol

Control, adrenalectomized, and cortisol-treated rats were maintained under rigidly controlled conditions, and the adenohypophyses were examined histologically with two staining procedures which differentiate six distinct cell types. Only one cell type demonstrated cytological evidence of increased synthetic activity 32 days after adrenalectomy (the changes were, however, minimal) and decreased synthetic activity following the chronic injection of cortisol. This cell type, which we designate as the corticotroph, would be classed as a chromophobe (no stainable granules) with use of standard histological techniques, but is, in fact, as Herlant's Tetrachrome demonstrates, a distinct acidophilic cell type different from the prolactin cell and the somatotroph. The determination of adenohypophyseal DNA and RNA revealed no evidence of increased protein synthetic activity following bilateral adrenalectomy, but did reveal evidence of decreased protein synthetic activity following the chronic injection of cortisol.