X1000306-1965-66_Part01 — Page 9

Chickenpox

19. An increase in the annual incidence of this disease was recorded as a resuk of an outbreak which occurred in the first quarter of 1965. No death was recorded.

Diphtheria

20. As demonstrated in Figure 3, diphtheria incidence has shown a continuous decline since the commencement of an intensive and year- reund immunization campaign in 1959. Although somewhat disrupted by the cholera and poliomyelitis immunization campaigns of recent years, this programme continues to give encouraging results. During the first three months of the year the incidence of diphtheria was somewhat higher than anticipated. However with the onset of cooler weather in October the usual sharp rise in the number of cases did not occur so that taking the year as a whole the annual incidence of the disease showed a further decrease. C. diphtheriae mitis remained the predominant organism; consequently most cases presented with laryngeal symptoms. Approximately 56% of cases occurred in children under the age of ten. The case fatality rate in 1965 was 6.4 per cent, partly due to the fact that a number of cases do not seek immediate medical treatment, and patients admitted into Government hospitals often give a bistory of having been treated by herbalists in the first instance.

21. A total of 101 carriers was discovered amongst contacts of reported cases; each was treated and, if necessary, isolated until proved free of infection.

Enteric Fever

22. Typhoid fever showed a very considerable decrease compared with 1964 and preceding years. This disease in Hong Kong is generally associated with neglect in personal and community hygiene and its decrease is probably connected with the continuous water supply available throughout the year. Free inoculation is offered and the usual control measures are enforced with special attention to the detec tion of carriers among food handlers.

Measles

23. In Hong Kong, as in nearby countries, this disease occurs in large numbers. The incidence of the disease tends to rise every two years as a wave of infection spreading throughout susceptible children

aged 0-2 years. Such a wave of infection was experienced during the winter months of 1964-65, commencing in December 1964 and reaching a peak in January and February of 1965. Thereafter incidence of the disease began to decline. The mortality, due to complicating advanced bronchopneumonia, remained relatively low. The true value of the recorded mortality is difficult to assess as related to incidence, as notification tends to be limited to those severe cases which merit hospital admission. Furthermore a proportion of such cases only enter hospital after the onset of complications.

Poliomyelitis

24. This disease, which had shown a low incidence since a wide- spread immunization campaign using oral vaccine was carried out early in 1963, increased during the year. The increase was largely due to an outbreak of Type I infection which occurred mainly in the northern part of Kowloon and in Tsuen Wan during March. April and May (Fig. 4). Approximately half of all children born between the age of 3 months and 1 year received anti-poliomyelitis vaccine at Maternal and Child Health Centres and general campaigns are held yearly in an attempt to immunize the remainder,

CASES NOTIFIED

40

30-

10-

FIGURE 4

POLIOMYELITIS 1959-1965

AVERAGE 1959–1963

1964

1945

0

Jan

Feb Mar Apr May Jun

7

Jul

Aug Sep Oct

Nov Dec