Haematology and Serology and the Blood Bank
108. More than 426,000 haematology specimens were examined, the most common examinations being haemoglobin estimations, total and differential white cell counts, blood examinations and blood grouping. More than 137,500 serology tests were performed, the most common being the V.D.R.L.. floculation slide test for syphilis. In the blood banks, 36,140 pints of blood were received during the year, 33,794 pints of which were from the blood-collecting centres of the Hong Kong Red Cross Society. A total of more than 238,500 blood tests was carried out in the blood banks.
Chemical Pathology
109. Some 479,500 specimens were examined, the most common being various quantitative examinations on blood, which accounted for more than 368,500 of the examinations,
Bacteriology and Public Health
110. More than $92,500 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. V. cholerae, biotype Ellor, serotype Inaba was isolated from nightsoil on three occasions during the period from June and September 1972. bai no clinical case of cholera was recorded.
III. Apart from routing 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.
Virology
112. During the year, the incidence of poliomyelitis remained low. There were only three laboratory-confirmed cases of poliovirus type 2 infection. One case occurred in January and the other two in August. The annual poliomyelitis faecal survey revealed a relatively low excreter rate of 0.20 per cent of 'wild' poliovirus in 501 children under the age of five.
113. There were two outbreaks of influenza in the year. The first outbreak lasted from January to May and was caused by the variant A/HK/5/72. The second outbreak in August - October was due to the variant A/England/42/72 of which a world-wide spread was later reported. Influenza B virus was responsible for sporadic cases. The
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strain B/HK/5/72 isolated in December was under close surveillance for possible epidemic spread in view of its significant change in antigenicity. Of other respiratory viral infections, parainfluenza type 3 and adenovirus type 3 were found more prevalent in the first quarter of the year.
114. A follow-up study of viral conjunctivitis was carried out in the summer season. There was only one case confirmed of infection by the virus HK3454/71, which was responsible for the epidemic in 1971, while most of the sporadic cases were adenovirus type 3 infection.
115. Cytomegalovirus infection was confirmed in 36 children, rang- ing from three weeks to five years. Of these, 30 (83 per cent) had hepatitis, three (8 per cent) pneumonia, and the remaining three (8 per cent) central nervous system diseases,
116. Australia antigen was found positive in 53 (10.8 per cent) of 494 cases of viral hepatitis, while Australia antibody was detected in two cases of aplastic anaemia with repeated transfusions.
Vaccine Production
117. Smallpox, rabies, typhoid-paratyphoid, and cholera vaccines were prepared at the Institute of Immunology, and issued free to doctors if used in Hong Kong. Occasional shipments were made avail- able to neighbouring governments or agencies when requested.
INDUSTRIAL HEALTH
118. The health of workers in factories and industrial undertakings is the statutory responsibility of the Commissioner of Labour. The industrial health division of the Labour Department, staffed by officers seconded from the Medical and Health Department, is responsible for advising the Commissioner on all matters affecting the health and welfare of industrial workers, and providing an advisory service on the medical aspects of industrial problems. The division's main functions are to prevent occupational diseases and to promote health at work. The inspection of industrial undertakings by medical officers, the monitoring of the working environment by the laboratory staff, and the investgiation of notified occupational diseases and medical surveil- lance of special groups of workers, are the principal ways in which these functions are carried out. Professional and technical staff of the division lecture labour officers, assistant factory inspectors and labour inspectors under training, medical students of Hong Kong University, students health visitors, health inspectors and health auxiliaries,
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