ENG-1956 — Page 164

130

HONG KONG ANNUAL REPORT

non-Chinese with residence of short duration in the Colony- there were 8 cases, all under 25 years of age, from among the Armed Services and their families during the year.

Poliomyelitis has been notifiable as an infectious disease since July 1948, the first full year for reports being 1949. Only paralytic cases are usually notified and all figures given are for such cases, with the exception of 7 cases in 1954 which were non-paralytic. No virus laboratory is available nearer than Singapore, and few serological tests to confirm diagnoses have been made.

Infection chiefly affects two quite specific groups, namely, infants and young children both Chinese and Non- Chinese; and

(a)

(b) young Non-Chinese adults particularly those who have

recently arrived in the Colony.

The first group (under 5 years of age) have accounted for 54% of all cases notified from 1949 to 1956; the majority have been Chinese but it is to be noted that the ratio of Chinese to Non-Chinese in the population is approximately 100 to 1. The second group of young European adults appear to be especially at risk within the first year or so of arrival, and a large number of the cases occurring in this group have been among British servicemen and their families; visiting United States Navy personnel have also been affected. The disease is also more fatal in this group with a tendency to a rapidly ascending paralysis causing death within one or two days of onset. There appears to be no real sex difference in the infantile group. The young adult group naturally shows more males affected since the servicemen at risk are pre- dominantly male. As regards season of the year, cases have occurred at random throughout the whole year with the exception of 1955 when 26 cases were reported in June. There has been no apparent association between and incidence of cases and immunological procedures-particularly anti- diphtheria inoculations though several hundred thousand of