X1000306-1968-69_Part01 — Page 10

Enteric Fever

23. Typhoid fever showed a slight increase in incidence during the summer months. The disease in Hong Kong is generally mild and the case fatality ratio is less than 2%. Transmission of infection is frequently associated with neglect in personal and food hygiene. As elsewhere the peak incidence occurred in children of school age and young adolescents. Free inoculation was offered and the usual preventive measures en- forced with special attention to environmental and food hygiene and the control of food premises.

Adalaria

24. The incidence of malaria showed a notable reduction during the year, only 17 fresh cases of infection being reported and the disease being restricted mainly to the Tai Po Area of the New Territories, Of the 3 fresh cases reported from the urban areas, 2 were due to blood transfusion while in the remaining case the infection was probably con- tracted in the New Territories where the affected person had recently stayed. Plasmodium vivax remained the predominant parasite responsi- ble for infection.

Measles

25. As shown in Figure 5, measles in Hong Kong has shown a distinct biennial pattern with exacerbation of the disease every alternate winter and spring. The last epidemic occurred in the winter months of 1966-67 and reached its peak in the first three months of 1967. There- after the incidence of the disease began to decline and the disease has since remained at a low ebb.

26. At the end of December, 1967, measles vaccine was made available at all Government Maternal and Child Health Centres to children aged between 6 and 48 months, the reason for the selection of this age group being that the disease in Hong Kong affects predom- inantly children under the age of 4 years and that in this age group there is a high mortality associated with the disease, the mortality being due mainly to complications, particularly broncho-pneumonia, develop- ing as a result of delay in seeking medical attention. In the summer of 1968, the vaccine was also made available to the public through mobile clinics visiting resettlement estates, tenement areas, New Terri- tories villages, and other areas. At the end of the year a total of 83,107 children had been vaccinated and, although coverage was little more than 50% of all those infants and children in the 6 months to 4 years

B

age group likely not to have had measles and to be susceptible to it, the outbreak of measles expected in the winter of 1968-69 did not occur. The measles vaccination drive was still in progress at the end of the year.

Poliomyelitis

FIGURE S

MONTHLY MEASLES NOTIFICATIONS & DEATHS JANUARY 1960 - MARCH 1969.

PRATIA / PHKUPRIN

MCLERGIA,

TE--

27. Fifteen cases of poliomyelitis were reported during the year, as compared with 5 cases in 1967. The rise in the number of cases reported is not considered to be significant. Variations in incidence must be expected when it reaches a low level and the disease continues to be satisfactorily controlled. The success in the control of the disease has been due to the continuing vaccination programme, consisting of giving one dose of Type 1 polio-vaccine, soon after birth, followed by 2 doses of "balanced" trivalent vaccine at three and five months of age. Approxi- mately 77% of infants received one dose of Type 1 polio-vaccine soon after birth and 64% of children received two doses of the trivalent vaccine at Maternal and Child Health Cenures. A general campaign is mounted annually in an attempt to immunize the remainder.