36 or 6.97. Most of the cases were recorded between the months of May and August. The number of deaths, however, ahowed a very marked drop from 37 to 4 giving a case fatality rate of 0.71%, the lowest on record since 1946. The percentage of children under 5 years of age who were affected remained high although it was lower than those of the previous 3 years. 540 or 96.4% of the cases were notified by Government institu- tions, and the remaining 20 by private practitioners. 29 dysentery carriers were discovered and dealt with during the
year.
38. There were 789 reported cases of enteric fever including 40 paratyhoid cases, during the year. There was an absence of a sharp incidence peak during the summer season in spite of water restrictions and an overcrowded population. The annual total, though higher than that of the preceding year, was lower than those of the previous five years, being 789 as against 735 in 1965. 48 deaths were recorded, giving a case fatality rate of 6.08%, which, being the lowest on record, followed the continuous downward trend of case fatality rates from 50.0% in 1946 to 21.8% in 1949, 12.8% in 1952 and 7.9% in 1965. The cases were well-distributed throughout the Colony with no explosive outbreak in any particular area. 327 or 41.4% occurred on the Island, 342 or 13.3% in Kowloon, 86 or 10.9% in New Territories and the remaining 34 or 4.3% mainly among the "floating" population and persons of no fixed abode.
39. An interesting feature in the age group distributions is the change in the incidence peak since 1968 from the 20-24 to the present 5-9 group. While the number of cases in most of the age groups has shown a tendency to decline or remain at about the same level, the 6-9 group has followed a steady upward trend from 7.52% of the total in 1951 to 20.78% in 1955 and 23.887 in 1956.
40. The preventive measures taken included a mass inocula- tion campaign, the supervision of eating establishments and their employees by the health staff of Urban Services Depart- ment, hospitalization of the sick, the exclusion of known carriers from employment as food handlers, and the education of the public in such matters as personal hygiene and the sanitary disposal of excreta. The annual T.A.B. inoculation campaign was launched during the second quarter of the year,
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the total number of inoculations carried out being 150,282 1st doses, 95,920 Zad doses and 137,292 booster doses,
184 or
41. 273 cases of chickenpox were reported in 1956. 67.4% of the cases were recorded in the first quarter of the year. The number of missed and hidden cases is considered high as is also the case with measles and whooping cough.
12. Diphtheria infection has continued its downward trend Bince 1954. A total of 714 incidence returns was received during the year, as compared with 840 in the preceding year, representing a drop of 126 or 15%. The number of deaths, however, was 4 more than that of 1955, being 75, giving a case fatality rate of 10.5% as compared with 2.5% in the previous year. The decline in incidence of this disease in the Colony can be attributed to the annual immunization campaigns, although the response from the public this year was not as satisfactory as in previous years. The inoculation figures for the whole year were 74,082 1st doses, 58, 197 2nd doses and 46,803 booster doses. It is apparent however that many very young children still escape immunization and fall victim to this disease. The routine investigation of reported cases and their contacts was carried out by the health staff. Altogether 12 carriers were discovered and dealt with in 1956.
43. Measles continued to be the principal cause of infant mortality among the notifiable diseases due to respiratory complications. Cases recorded during the year numbered 709 with 36 deaths as against 543 with 88 deaths in the preceding year. More than 600 cases have been reported in the first quarter of 1957 which is the highest figure on record for the first quarter of any year since 1946.
44, Poliomyelitis occurred sporadically in various parts of the Colony, indicating a wide spread infection with a higher incidence in Kowloon and the New Territories than on the Island. Cases reported during the year numbered 81 (with 3 deaths) as against 51 (with 3 deaths) in 1955, and 49 (with 9 deaths) in 1954. The incidence returns were highest in the third quarter when 21 or 67.74% of the total were recorded. Those affected were mainly infants. There were a few European adults who had recently arrived in the Colony, but there has been an appreciable drop in incidence among Europeans since the last half year of 1954. Of the cases reported, 23 were
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