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La surveillance de la santé consiste en l’utilisation systématique et continue de données sur la santé recueillies régulièrement en vue d’orienter les mesures de santé publique en temps opportun. Ce document décrit la création et l’essor des systèmes nationaux de surveillance au Canada et les répercussions de ces systèmes sur la prévention des maladies chroniques et des blessures. En 2008, les auteurs ont commencé à retracer l’historique des débuts de la surveillance nationale des maladies chroniques au Canada, en commençant à 1960, et ils ont poursuivi leur examen jusqu’en 2000. Une publication de 1967 a retracé l’historique de la création du Laboratoire d’hygiène de 1921 à 1967. Notre étude fait suite à cette publication et décrit l’historique de l’établissement de la surveillance nationale des maladies chroniques au Canada, à la fois avant et après la création du Laboratoire de lutte contre la maladie (LCDC).

Rapport d’étape - Historique des débuts de la surveillance nationale des maladies chroniques au Canada et rôle majeur du Laboratoire de lutte contre la maladie (LLCM) de 1972 à 2000.La surveillance de la santé consiste en l’utilisation systématique et continue de données sur la santé recueillies régulièrement en vue d’orienter les mesures de santé publique en temps opportun. Ce document décrit la création et l’essor des systèmes nationaux de surveillance au Canada et les répercussions de ces systèmes sur la prévention des maladies chroniques et des blessures. En 2008, les auteurs ont commencé à retracer l’historique des débuts de la surveillance nationale des maladies chroniques au Canada, en commençant à 1960, et ils ont poursuivi leur examen jusqu’en 2000. Une publication de 1967 a retracé l’historique de la création du Laboratoire d’hygiène de 1921 à 1967. Notre étude fait suite à cette publication et décrit l’historique de l’établissement de la surveillance nationale des maladies chroniques au Canada, à la fois avant et après la création du Laboratoire de lutte contre la maladie (LCDC).

In the future, quantitative techniques will probably be used in industry as part of Tier II studies for the evaluation of chemicals and drugs for their neurotoxic potential. Movement towards quantifying some structures or neuropathological changes will be made possible by advances in tissue preparation and computer technology. Emphasis will need to be placed on standardized techniques, good quality samples and sampling techniques in order to produce good quantitative data in a reasonable time. In this paper, different sampling techniques are evaluated using a cross section of rat sural nerve as the tissue for quantitative investigation.

Optimal experimental methods for antigenicity studies in guinea pigs were investigated on : (1) the effects of different immunizing methods using complete or incomplete Freund's adjuvants (CFA or IFA), and various injection sites, the number of immunizations, the immunizing doses, and the immunizing periods, (2) the relationship between the severity of active systemic anaphylaxis (ASA) reactions and passive cutaneous anaphylaxis (PCA) titers, (3) positive control for oral administration, and (4) the effects of incubation mixture of drug and serum protein as the challenge for the ASA assay. The following results provided useful information for designing more appropriate methods for antigenicity studies : (1) The optimal immunization method for benzylpeni-cillin (PcG), cephaloridine, 2, 4, 6-trinitrobenzene sulfonic acid and adriamycin, which were selected as positive controls for low molecular medicines in this experiment, involved subcutaneous administration of 1 ml of a test substance in CFA (1st immunization) or IFA (2nd and 3rd immunizations) at two doses, 1 and 10 mg/animal, 3 times at 2-week intervals on the back of a guinea pig. Blood collection for PCA assay was needed 2 weeks after the last immunization, and ASA assay, 1 or 2 days after the blood collection. (2) The insensitivity of ASA reactions in bovine serum albuminimmunized animals with very high PCA titers was overcome by increasing the challenge antigen dose from 1 to 10 mg/animal. (3) Most animals administered lysozyme at 0.1, 1 or l0 mg/animal by gavage for 2 weeks or more showed ASA and PCA reactions. (4) Incubation of a mixture of 20 mg/ml of PcG and 2 mg/ml of guinea pig serum albumin for 4 hr was the most effective as challenge for the induction of ASA reaction in PcG-immunized guinea pigs.

The literature on the diseases caused byTrypanosoma evansi is reviewed and the gaps in the available information are emphasized.Trypanosoma evansi, on the basis of combined similarities in morphology, biological behaviour, and to some degree based on geographical distribution, is a species closely related to and probably originating fromT.brucei. The distribution ofT. evansi is very wide in the Old and New World and it is transmitted by biting flies and vampire bats. It has a patchy distribution in any region and new foci of infection have a high incidence. Diagnosis is made on demonstration of trypanosomes, biochemical tests detecting increase in serum proteins, and on specific serological tests. The clinical signs vary with the acuteness of the syndrome, often being characterized by a chronic course with lack of pathognomonic signs. There is very little information on the pathology of the diseases in various species of animals, but the lesions apper to be similar to those caused byT. brucei and are associated with the distribution of trypanosomes in solid tissues. Immunological studies habe been limited primarily to serology in connection with diagnostic procedures. Laboratory models have been studied and the syndromes are similar to those produced byT.brucei. Chemotherapy is varied and to some degree dependent on the species of host. More information on the incidence and severity of diseases is required to identify priorities for further research.

The effects of high-dose subacute acrylamide treatment of up to 50 mg/kg/day for 4 or 10 d were compared to those of subchronic exposure, up to 12 mg/kg/day for 90 d. In the subacute study, Purkinje cells, long ascending tracts of the spinal cord, optic tract terminal or preterminal regions in superior colliculus, sensory ganglion cells, and distal large-caliber peripheral axons were severely affected. Purkinje cells and fasciculus gracilis changes were the earliest lesions. In the subchronic study, the dominant lesion was confined to the distal peripheral axon, with only minor changes occurring in spinal cord and medulla. Paranodal swellings with the characteristic appearance of neurofilament aggregations were not seen. This morphological study suggests a significant difference between high- and low-dose acrylamide-induced lesions. If there is a reduced tendency for long-term low-dose acrylamide exposure to produce CNS lesions, the risk of irreversible nervous system damage would be less than that predicted from subacute studies.

A comprehensive summary report of quality-control data is of great value in monitoring the accuracy and precision of the clinical chemistry laboratory. This report allows a retrospective appraisal alerting laboratory personnel to possible test control material degradation or instrument malfunction. A microcomputer-based program package is described, designed to reduce the errors and lengthy preparation inherent in the manual generation of such a report. Quality-control summary data is automatically compared with a predefined set of statistical criteria, and any aberrant values are flagged, thus eliminating subjective and nonuniform data interpretation. Statistical comparisons include: number of control points, delta mean, delta standard deviation, standard deviation index, and F-ratio. The summary report is well accepted by the laboratory staff, and its incorporation into the decision-making process allows for an efficient, critical, and uniformly rigorous examination of analytic proficiency.

In cattle infected experimentally with Trypanosoma brucei the trypanosomes localized extravascularly in the connective tissues and produced inflammatory reactions in the skin, subcutaneous tissue, heart, central nervous system, and eye. These observations indicate that, as in other domestic and laboratory animals, T. brucei is a parasite of connective tissues in cattle.

Storage and coding of anatomic pathology data usually is accomplished by expensive main frame systems. The authors of this article have developed a microcomputer based program package for autopsy pathology which stores patient demographic data, provisional or final anatomic diagnoses, and coded diagnoses obtained from an on-line Systematized Nomenclature of Pathology (SNOP) code lexicon. The system includes limited text editor functions as well as rapid data retrieval with the generation of final reports. Data files containing SNOP codes and diagnoses are searched easily by a variety of parameters, making data retrieval of autopsy material simple and efficient.

Twenty-five steers were infected with T. vivax (EATRO 1721), 25 steers with T. congolense (EATRO 1800) and 25 steers kept as controls. Serum levels of immunoglobulins (IgG1, IgG2, IgM), natural antibodies to erythrocytes of chicken and sheep, and complement-fixing antibodies to T. vivax were measured. A significant decrease of serum IgM and natural antibodies to chicken erythrocytes occurred in the T. vivax group at day 9, i.e. at the decline of the first parasitemic wave. This was followed by a transient moderate increase of IgM accompanied by a transient decrease of IgG2. The T. congolense group had moderate decreases (less than 30%) of the mean IgG1 levels and moderate increases (less than or equal to 50%) of the mean IgG2, levels. It was concluded that there was little evidence for polyclonal activation of lymphocytes and that the decreased IgG1 levels in the T. congolense group might have been a reflection of immunosuppression. The complement-fixation test proved to be a sensitive tool for monitoring the antibody response to T. vivax.

SummaryThe study of pathogenicity of haemoprotozoa and the pathogenesis of the diseases they cause requires quantitative descriptions. Statistical and mathematical methods are introduced to describe infectivity, parasitaemia, total body parasitosis and the severity of diseases.

The authors have developed a microcomputer-based system for interpretative reporting of sequential cardiac profile data, which consists of creatine kinase and lactate dehydrogenase isoenzyme levels. Patient demographic data and test results (total creatine kinase [CK], MB isoenzyme of CK [CK-MB], lactate dehydro-genase isoenzyme 1 [LD-1], and lactate dehydrogenase isoenzyme 2 [LD-2]) are entered manually through the keyboard. Percent MB and LD ratio are calculated. The test results are compared with normal range values, and an interpretative report is generated, including all pertinent demographic information and graphic display of up to 36 previous CK and LD isoenzyme determinations. Interpretative statements are printed beneath the graphic display after analysis of previous test results. The combination of graphic data display and interpretations based on prior data provides useful and accurate information to the cardiologist. Significant discrepancies between computer-assisted and pathologist interpretation were not encountered.

Recent advances in immunocytochemical techniques allow the localization of specific antigens in tissue sections. The work reported here attempts to evaluate the application of antibody-labeled, disease-related protein, followed by microscopy and computerized image analysis. Using an experimental anti-tumor, polyclonal antibody (anti-oncomodulin) as a model, various tissues were prepared for light microscope immunocytochemistry. Sections were incubated with primary antibody, then biotinylated secondary antibody. This was followed by incubation with avidin-biotin-peroxidase (ABC method). Marker was visualized by the presence of precipitated diaminobenzidine. Samples were evaluated using a Zeiss/Kontron IBAS I & II semi-automatic digital image analysis system. Statistical analyses were performed on output data. Results demonstrated the localization and determined optical density of immunolabel. Statistical comparisons showed significant differences between control and experimental sections. The practical application of these combined techniques provides the toxicologic pathologist with a powerful tool for accurate and objective determination of the location and relative amount of selected proteins in normal and abnormal tissues.

Serum collected from cattle infected with Trypanosoma vivax or Trypanosoma congolense inhibited bovine granulocyte/macrophage colony formation in methyl cellulose cultures. Maximum inhibition was caused by serum collected two and three weeks post infection. The degree of inhibition appeared to be related to the degree of parasitemia. Inhibition of erythroid colony formation by serum collected from these animals was not observed.

Twenty-five Holstein-Friesian steers were experimentally infected with Trypanosoma congolense EATRO 1721. They were tested for their J blood group status. Twelve steers were found to belong to Ja blood group and thirteen steers were either Js or Jcs. The level of parasitemia did not significantly differ between these two groups of cattle. It was concluded that the level of parasitemia is not influenced by J blood group antigens.

Both trimethyltin and triethyltin salts are known to produce toxic lesions in the central nervous system. Triethyltin intoxication has been associated with central intramyelin edema, while trimethyltin has been shown to produce neuronal necrosis in selected limbic and sensory regions of the brain. Only scant attention has been paid to peripheral nerves of animals treated with alkyltins. In this study, we have treated rats with 6 or 8 mg/kg trimethyltin, and 1, 2, 4, 6, or 8 mg/kg triethyltin (single or multiple exposure), and evaluated in detail at the light microscope level both central and peripheral nervous system lesions. In addition to the central neuron necrosis or myelin edema described previously, both compounds produced peripheral axon degeneration and chromatolysis of large spinal cord and brain stem neurons. Chromatolysis was seen in reticular neurons of the brain stem and ventral horn or spinal cord in rats receiving high doses (6 or 8 mg/kg) of triethyltin, and in these same areas plus mesencephalic trigeminal nucleus in animals treated with trimethyltin. Wallerian-like degeneration of peripheral axons was seen in sciatic and tibial nerve and ventral roots of animals receiving 3 injections of 4 mg/kg or single or multiple injections of 6 or 8 mg/kg triethyltin. Axon degeneration was also seen in sciatic and tibial nerves 21 days after a single exposure to 8 mg/kg trimethyltin. Since myelin edema is believed to be reversible, the axonal changes described here may be of greater clinical significance in relation to human exposure.

In the first 5 years of surveillance of reports of the acquired immune deficiency syndrome (AIDS) in Canada, from February 1982, the Laboratory Centre for Disease Control, Ottawa, was notified of 1133 cases reported through provincial ministries of health that met the case definition developed by the US Centers for Disease Control, Atlanta. Most cases (82.2%) were reported from the homosexual/bisexual risk group. Other risk groups were less frequently represented, in contrast to the experience in the United States, where a higher proportion of cases in drug abusers has been observed, and in Africa, where heterosexual spread is far more common. The presenting clinical picture and length of survival after diagnosis were similar to those reported for other countries. Differences between projected estimates of the number of AIDS cases obtained with polynomial and logistic growth models emphasize the need for solid epidemiologic data on the number of people infected with human immunodeficiency virus, the rates of transmission and the rates of progression to disease.

A microcomputer based program package has been developed which utilizes a modified "average of normals" method to analyze data and monitor random and systematic error in the clinical hematology laboratory. The daily workload of normal patient values for leukocyte count, erythrocyte count, hemoglobin, mean corpuscular volume, prothrombin time, and activated partial thromboplastin time is entered through the keyboard and sorted by sex. The daily mean, standard deviation, standard error index, and F-ratio are then calculated for each test. Significant deviations from target values are automatically flagged. The system combines ease of data input with automatic statistical calculation, graphic display, and printout of the calculated data. The system has the capability of data analysis by shift, and incorporates cumulative sum, Trigg's tracking algorithm, and analysis of variance calculations. This statistical analysis had proven to be a sensitive indicator of random and systematic error in our laboratory and has allowed us to decrease the assay frequency of expensive commercial control material.

Cattle infected with Trypanosoma congolense were intravenously immunized with Leptospira biflexa 15 days after trypanosomal infection. The primary immune response to L. biflexa was considerably reduced as compared to uninfected controls. The infected cattle mounted a secondary response when they were cured of trypanosomes by treatment with Berenil 25 days after infection and re-immunized 8 days later. The mean secondary response in these previously infected animals was lower tha, but not significantly different from that of the uninfected control animals. Serum collected 15, 20 and 25 days after infection was inhibitory to the migration of both autologous and isologous (control) peripheral blood leucocytes. The migration inhibitory activity was abolished by heating the serum at 56 degrees C for 30 minutes implying the involvement of a heat labile serum component(s). The same serum did not modify the mitogenic effect of PHA on autologous peripheral lymphocytes.

Infections with Trypanosoma congolense or T vivax did not significantly depress the neutralising antibody response of cattle to live rinderpest vaccine when vaccination was carried out eight or 25 days after infection.

A microcomputer based system for interpretative reporting of protein electrophoretic data has been developed. Data for serum, urine, and cerebrospinal fluid protein electrophoreses as well as Immunoelectrophoresis can be entered. Patient demographic information is entered through the keyboard, followed by manual entry of total and fractionated protein levels obtained after densitometer scanning of the electrophoretic strip. Protein patterns are coded, interpreted, and final reports generated. In most cases, interpretation time is less than one second. Computer misinterpretation is uncommon and easily corrected by edit functions within the system. Discrepancies between computer and pathologist interpretation are automatically stored in a separate data file for later review and possible program modification. Any or all previous tests on a patient may be reviewed, with graphic display of the electrophoretic pattern. The system is well-accepted by the laboratory staff, and allows rapid storage, retrieval, and analysis of protein electrophoretic data.

Twenty five cattle were infected with T. vivax, 25 with T. congolense, and 25 served as controls. Pathogenic clinical signs of trypanosomal infection were not observed. Secondary bacterial infections were common. Fever, increased heart and respiratory rates, anorexia, and emaciation developed. Elevations in parasitemai and body temperature were positively correlated in the T. vivax group. Infected groups were affected non-uniformly, with some animals in each group remaining asymptomatic and tending to have lower parasitemias. The T. vivax parasitemia was cyclic and the organisms had a genaration time of 7.9 SD 2.5 hours. The first peak of parasitemia in both infections was closely associated with the development of pancytopenia, i.e. anemia, leukopenia, and thrombocytopenia. The bone marrow erythroid response in the T. congolense group was significantly greater thn that in either the T. vivax or control groups. Leukopenia was due to concomitant neutropenia and lymphopenia.

Serum levels of total protein, albumin, activity of hemolytic complement, and complement component C3 were decreased in cattle infected with either T. congolense or T. vivax. The hemolytic complement activity was reduced most, i.e. to 20% (T. congolense) or 5% (T. vivax) of control levels. The development of hypocomplementemia was closely associated with the first peak of parasitemia.

Using 90 albino rats, a comparison was made between the response to experimental infections of Trypanosoma brucei and T congolense of approximately three weeks duration by observation of parasitaemia, packed cell volume values, post mortem spleen and lymph weights, and histology of thymus, spleen, lymph nodes and bone marrow. In T congolense infection, phagocytosis of trypanosomes in the spleen appeared to be the main response of the host's haemopoietic tissues to the parasites, which were observed only intravascularly. In T brucei infection immunological responses occurred in the spleen and lymph nodes in addition to trypanosome phagocytosis. Trypanosomes were seen intercellularly in thymus, mediastinal tissue and lymph node sinuses and parasitaemia reached considerably higher values than in T congolense infection. Erythrophagocytosis in the spleen was the only histological feature which could account for the reduction in packed cell volume which occurred near death in both infections, medullary haemopoiesis being increased. Changes in the thymus, incorporating plasma cell production and depletion of cortical small lymphocytes, occurred in both infections.

We have developed an inexpensive, microcomputer-based, multiuser hard disk system for surgical pathology that uses a commercially available word processor and data base manager, linked together by several BASIC programs written by us. System functions include keyboard input of patient demographic data and specimen information, word processing with the generation of preliminary and final surgical reports, on-line access to the surgical pathology data base, generation of daily secretarial and histology log sheets, and computer-assisted SNOMED coding. Successful implementation of this system has produced greater efficiency and productivity in the surgical pathology department at a reasonable cost.

Dolan T. T. , Young A.S. , Losos G.J. , McMillan I. , Minder Ch.E. and Soulsby K. 1984. Dose dependent responses of Theileria parva stabilate. International Journal for Parasitology14: 89–95. A tick derived stabilate of Theileria parva (Maguga) was titrated in a large group of Boran (Bos indicus) cattle of the same age, sex and origin. The infectivity data was analysed using the independent action model. The cattle were identified as heterogeneous in their response to infection with 75% showing one ID50 (0.0014) and 25% showing another (0.01). The disease responses of the cattle given different dose levels were compared for a variety of parameters. The results obtained showed these parameters to be dose dependent including the time to onset of piroplasm parasitaemia. The stabilate is of large volume and can be used for controlled challenge in immunity studies and for comparison of susceptibility between cattle of different breeds and from different epidemiological backgrounds.

Sheep inoculated intravenously with Trypuiiosom bviicei had fever, irregular parasitaeniia, moderate anaemia, subcutaneous oedenia, dullness, anorexia, and nervous signs followed by death in 29-69 days. Emaciation, serous effusions into body cavities and generalised enlargement and oedenia of lymph nodes were seen at necropsy. Micro- scopically there was extensive localisation of trypanosonies in the extravascular body fluids, and in interstitial connective tissues, resulting in mononuclear inflammatory reactions in the heart, skeletal muscle, skin, brain, pituitary, eye, serosal surfaces, urinary bladder, epididyniis and testis, and in generalised lymphoid hyperplasia. These observa- tions in sheep are comparable to those made in other animals infected with trypanosornes of the brucei group. Trypanosoma brucei, T. congolense, and T. vivax cause the most econom- ically important forms of animal trypanosomiases in Africa. There is rela- tively little information on the pathogenesis and pathology of the diseases produced by these species in domestic animals (l 11. Infections and diseases causcd in sheep by T. brzxei occur naturally (2, 131, but there is little informa- tion on either the prevalence or the pathology. Sheep, however, have been used extensively in the past in investigations of the virulence of various human and animal isolates of trypaiiosonies in the brucei subgroup. Many of these isolates were associated with severe diseases characterized by ema- ciation, subcutaneous oedema, enlargement of lymph nodes, and corneal opacity (I, 3, 71. The present report is based on studies in sheep experimentally infected with T. brzrcei. This was part of a major investigation of the pathology of the diseases caused in ruminants by T. brucei, T. vivax, and T. congolense.

This paper describes a case of multiple myeloma in a 3-year-old mongrel bitch. The diagnosis was established by histopathological examination of post-mortem material. The tumour formed nodular masses on the fourth left rib and third and fourth lumbar vertebrae; it also involved the sternal lymph nodes, spleen, liver and kidneys. Demonstration of amyloid deposits in the kidney was inconclusive. Resume. Observation d'un cas de myelome multiple chez une chienne bâtarde de 3 ans. Le diagnostic a ete fait d'apres les donnees histopathologiques apres autopsie. La tumeur formait des masses nodulaires au niveau de la 4eme cote gauche et des vertebres L 3 et L 4; elle interessait aussi les ganglions lymphatiques parasternaux, la rate, le foier et les reins. La presence de depots amyloides dans le rein n'apportait aucun renseignement complementaire. Zusammenfassung. Diese Abhandlung beschreibt einen Fall von multiplem Myelom bei einer 3 Jahre alten Bastardhundin. Die Diagnose beruhte auf der histopathologischen Untersuchung von Autopsiematerial. Der Tumor bildete nodulare Massen an der vierten Rippe links und am dritten und vierten Lendenwirbel; er involvierte auch die sternalen Lymphknoten, Milz, Leber und Nieren. Der Nachweis von Amyloidablagerungen in der Niere war nicht uberzeugend.

In rats, rabbits, sheep, and goats experimentally infected with several strains of Trypanosoma brucei, the trypanosomes were observed to localise extravascularly in connective tissues. Focal inflammatory reactions were associated with the localisation of the parasites. Trypanosoma congolense in the same species of animals and T. vivax in sheep and goats, were not observed to localise outside blood vessels. On the basis of these observations it appears that the pathogenesis of the disease caused by T. brucei differs from that caused by T. congolense and T. vivax.