Laboratory manual for physicians : aids in diagnosis and treatment.

  • New York (State). Department of Health. Division of Laboratories and Research.
Date:
1951
Catalogue details

Licence: Public Domain Mark

Credit: Laboratory manual for physicians : aids in diagnosis and treatment. Source: Wellcome Collection.

    38/92 (page 30)
    tigen will establish the diagnosis if both acute-phase and _ convalescent- phase sera are examined'and if the re- sults are interpreted in conjunction with the clinical course of the patient. Products Supplied by the Laboratory Lygranum for making the Frei test is available on request to the Division of Laboratories and Research, Albany. Malaria Very few cases of malaria occurred in New York State in the years just prior to World War II. Since mem- bers of the armed forces have returned from assignments in the tropics, the incidence has increased considerably. The anopheline mosquito, which is the intermediate host, is found in various parts of the State. Hence, human car- riers who may be living here may serve as a reservoir from which the infection may be transmitted. Blood films to be examined for malaria para- sites should be prepared if possible be- ‘fore the initiation of chemotherapy. Occasionally, sternal punctures may be advisable. | Specimens for Laboratory Examination In accordance with the requirements of Chap. II, Reg. 9, Sanitary Code, thick and thin films of blood on glass slides (slide outfit), preferably taken between twelve and twenty-four hours after a chill, should be examined in a laboratory approved for the purpose. Repeated films may be necessary for demonstration of the plasmodia. In fulminating cases, prompt examina- tion is important, since delay in treat- ment may be fatal. For examinations required when blood or blood derivatives are to be used for therapeutic or prophylactic purposes, see Sanitary Code, Chap. IV-A. Directions for preparing thick films. A thick film should consist of from three to 30 five average-sized drops of blood. These may be deposited on an area about three- quarters of an inch in diameter (the size of a dime) and promptly combined with a needle or the corner of another slide; or the surface of the slide may be touched to a large drop of blood and the slide moved in narrow circles until a prepara- tion of the size mentioned is obtained. The film must be fairly thick in order to have sufficient blood for adequate exami- nation, but must not be so thick that it will peel from the slide during staining. When the thick blood film is still wet, ordinary printing can just be read through it. In order to protect the specimen from dust during drying, the slide should be supported with the film side down. A wooden slide container may be used for the purpose. It is important to have the slide level, since otherwise the blood might collect at one side of the film and not be evenly distributed. From eight to twelve hours should be allowed for drying unless the process can be hastened by using an electric fan. In this procedure, the slide should be placed with the film side up in front of the fan. The distance from the fan should be such that the current of air will not pile the blood on one side of the film. The slides should not be mailed until the films are entirely dry. The sooner the specimens reach the laboratory after collection the better, | since malaria parasites stain most characteristically in freshly prepared — films. If a sternal puncture is made, the films should be prepared in the same manner as blood films. Measles Measles is caused by a filtrable virus, but practical laboratory aids in diagnosis are not available at present. If the patient should develop symp- toms of pneumonia or encephalitis, however, the examination of specimens described under Pneumonia, p. 37, or Encephalitides (Virus), p. 20, is de- sirable. Products Supplied by the Laboratory Immune serum globulin (hu- man). At present, immune serum glo-