tions, total and differential white cell counts, blood slide examinations and blood grouping. Over 128,000 serology tests were performed, the most common being the V.D.R.L. floculation slide test for syphilis. In the blood banks 27,503 pints of blood were received during the year, 26,723 pints of which were from the blood collecting centres of the Hong Kong Red Cross Society. A total of over 180,000 examinations of blood were carried out in the blood banks.
Chemical Pathology
72. Some 390,000 specimens were examined, the most common being various quantitive examinations upon blood, which accounted for over 290,000 of the examinations.
Bacteriology and Public Healık
73. Over 583,000 bacteriological examinations were carried out. Samples of nightsoil, well water and imported food from endemic areas were routinely examined throughout the year for cholera vibrios, but no positive findings were obtained.
74. Apart from routine bacteriological diagnosis of tuberculosis, the tuberculosis laboratory was involved in anti-tuberculosis drug sensi- tivity tests in conjunction with the Medical Research Council of the United Kingdom. In this connexion the slide culture technique initiated by a member of the Medical Research Council in this laboratory for rapid testing of anti-tuberculosis drug sensitivity is progressing satisfactorily.
Virology
75. The Government Virus Unit continued diagnostic examination for virus infections and surveys in connection with poliomyelitis. Other projects included studies of respiratory virus infections and follow-up of post-vaccinal measles antibody.
76. In the year there were 24 cases of laboratory-confirmed poliomyelitis. (See paragraph 25 for details). The laboratory continued to function as a World Health Organization National Influenza Centre. Influenza occurred as sporadic outbreaks during the year. Increased incidences were reported in March and August, but no epidemic was observed. A2 influenza virus, antigenically indistinguishable from the A2/Hong Kong/68 variant was prevalent from January up to September, after which period influenza type B virus was predominant,
24
Two different antigenic strains of type B virus were isolated. One was closely related to B/Czechoslovakia/28/70 and the other to B/Rome/ 1/67. The study of other respiratory viruses associated frequently with acute respiratory infections was continued.
77. Cytomegalovirus was prevalent in Hong Kong. This virus was isolated in 36 infants manifested with a wide spectrum of clinical syndromes, such as jaundice, hepatosplenomegaly, convulsion and meningo-encephalitis. Further serological studies are being carried out to determine the epidemiological pattern of this infection.
INDUSTRIAL HEALTII
(Table 45)
78. The health of workers in factories and the other industrial under- takings is the statutory responsibility of the Commissioner of Labour. The Industrial Health Division of the Labour Department, which is staffed by personnel seconded from the Medical and Health Depart- ment, is responsible for advising the Commissioner on all matters affecting the health and welfare of industrial workers. Its principal functions are to prevent occupational diseases and to promote health at work. The inspection of industrial undertakings by medical officers of the Division in company with the factory inspectorate, the monitor- ing of the working environment by the laboratory staff, and the medical surveillance of notified occupational diseases are the principal ways in which these functions are carried out.
79. Envicommental surveys included the measurement of silica dust in quarries, and of the concentrations in the air of, amongst many, lead, manganese, solvents, and sulphur dioxide, and the investigation of standards of thermal comfort, ventilation, noise and lighting.
80. The work of the Workmen's Compensation Unit, which is part of the Industrial Health Division, continued to increase. The introduc- tion of the Industrial Injury Notification system has increased the oumber of recorded industrial accidents from an average of 1,000 a month in 1969 to an average of 2,050 a month in 1970.
81. 33,609 occupational injuries were recorded by industrial health visitors and nurses of the Industrial Health Division; of these 24.610 were accidents which caused the injured person to be off work for more than 3 days and were therefore reportable under the Workmen's Compensation Ordinance. 259 occupational deaths were recorded, but
25