X1000306-1968-69_Part01 — Page 9

CASĘS REPORTED

FLOURE 4

INCIDENCE OF MAJOR INFECTIOUS DISEASES 1954 - 1965

DIPHITHIEMA

A

M10

1500

Cholera

500

CECILLARY DIS:NJERY

56

SA

EQ

YEAR

ENTERFO FEVER

POLKUTELINS

**

EA

15. Hong Kong was last declared free from cholera infection on 5th December, 1966. Since then no further case of the disease has been reported though it continues to be prevalent in nearby countries which are in regular air and sea communication with Hong Kong. Special preventive measures were continued and strict quarantine restrictions were maintained in respect of neighbouring countries declared infected.

16. Routine sampling of nightsoil was carried out throughout the year as part of Hong Kong's anti-cholera surveillance programme. This measure now provides very useful epidemiological information about the presence or absence of infection in Hong Kong, the locality likely to be infected and the possible extent of infection. Other public health preventive measures taken routinely throughout the year included the routine bacteriological investigation of specimens sent to the Medical and Health Department pathology laboratories of cases of gastro- enteritis as well as the sampling of well water and of food stuffs liable to be involved in the transmission of the vibrio. No positive samples

were obtained from these investigations. As in previous years a mass immunization campaign against cholera was commenced in April and by the end of the year a total of 1,385,272 inoculations had been given.

Amoebiasis

17. This disease continued to occur endemically, being most prevalent in the overcrowded urban areas. A total of 117 cases were notified. The disease remained predominantly one of adult males,

Bacillary Dysentery

18. A total of 869 cases were notified, this being the third successive year in which a slight increase in the number of notifications was recorded. The disease occurs at all ages, but 37.2% of the notifications were in respect of children under the age of 5 years. Shigella flexneri and Shigella sonoci remained the predominant organisms isolated.

19. Transmissions of infection among families and in institutions is a feature of the disease and very often a number of symptomless carriers are detected among members of the same family or inmates of the same institution. To all a total of 427 carriers were discovered during investigations of reported cases. All were given appropriate treatment.

Chickenpox

20. This is a very common disease among children, 98% of the cases reported being under 15 years of age. The seasonal prevalence of the disease is in winter and spring and hence the earlier part of the year saw an increase in the number of notifications.

Diphtheria

21. As a result of annual immunization drives which have been in progress since 1959, the incidence of the disease has shown a con- tinuous and sleady decline falling from 73.01 per 100,000 population in 1959 to 2.9 in 1968. The disease affects largely children and 73.4% of the cases were under the age of 10 years. The case fatality ratio in 1968 was 8.8% and death occurred primarily among the unimmunized children. Corynebacterium diphtheriae mitis remained the predominant organism isolated in clinical cases.

22. A total of 25 carriers was discovered among contacts of reported cases. Each was treated and, if necessary, isolated until proved free of infection.

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