ENG-1973 — Page 126

74

HEALTH

section of the Urban Services Department. Clinical aspects of malaria control such as surveys and chemotherapy are the responsibility of the Medical and Health Department.

Although one case was reported during the year, diphtheria can be considered to have been eradicated from Hong Kong. The story of diphtheria control has been a fascinating one. In 1959, when mass inoculation against the disease started, 2,059 cases were notified. Since then there has been a steady decline in the number of cases each year culminating in the virtual absence of cases in 1973. But immunisation against the disease will have to be continued indefinitely as reduction in the immunity status of the population would result in its reintroduction.

Poliomyelitis has been brought under control since the introduction of the poliomyelitis vaccination programme in 1963. During the year only three cases were reported. Vaccine is offered free at government maternal and child health centres and a general immunisation campaign is mounted annually in January and March. Infants in hospitals and maternity homes are given one dose of Type 1 polio-vaccine soon after birth. This is followed by two doses of balanced trivalent vaccine at three and five months and a booster dose at 18 months. Epidemiological surveillance of the disease was maintained throughout the year. This included virological investiga- tion of laboratory specimens for polio-virus and the carrying out of a poliomyelitis faecal survey among normal children to find the distribution of polio-virus in the community.

Measles is most prevalent among children under the age of five years and epidemics are characteristically biennial. In Hong Kong during epidemics the disease is usually associated with high mortality due mainly to complications, such as bron- chopneumonia, encountered too late for treatment to be effective. Since December 1967 measles vaccine was included in the public health vaccination programme and the vaccine is now regularly available at government maternal and child health centres. Anti-measles campaigns are conducted throughout Hong Kong each year, and for 1973 the campaign was started in April, lasting about nine weeks. During the drive, measles vaccine was made available at all government dispensaries, clinics and health centres, and also in other inoculation posts set up in resettlement and low-cost housing estates, health offices and other areas. The disease incidence and its mortality have remained low in the last five years. However, in 1973 there was some evidence to suggest that the biennial occurrence of measles, a feature of the disease before the introduction of vaccination, was recurring.

Influenza occurred sporadically during the year. In conjunction with the World Health Organisation, the disease continued to be kept under a surveillance programme in which epidemiological and laboratory information about the disease is transmitted regularly overseas. The epidemiological information includes regular recording of influenza-like illness seen in the general outpatient departments of certain designated clinics, and also the recording of deaths from influenza, pneumonia and bronchitis.

Other communicable diseases remain at a low level, and do not constitute a major public health problem,