On the occurrence of the first clinical case of cholera on the 22nd August, 1962 a twenty-four hour cholera diagnostic service was established at the Institute in Sai Ying Pun and in the Kowloon Hospital branch of the Institute for the investigation of all cases of gastro- enteritis and suspected cholera.
255. Table 23 details the examinations for vibrios carried out during the year from sources other than patients and their contacts,
Water from sea
Water from wells
TABLE 23
same as in previous surveys. The findings again showed that polio-virus and other entero-viruses are distributed widely in the normal child population. Type I poliovirus was the only type found in these surveys, while in 1961 Types I and III were prevalent. The results of the surveys carried out between June 1961 and June 1962 are shown in Table 25.
TABLE 25
POLIOVIRUS AND OTHER ENTERO-VIRUSES IN THE 0-5 AGE GROUP 1961-62
615 1.079
Due
Ntomber examined
Negative
Positive Poliovirus Type 1 Type 1 Type III
Total
Pendrive other enter
Tap water
Swimming pools
7
June 1961
258
143
TO
-
133
Pond water for fish fry
10
August 1981
247
116
14
6
34 (9.3%)
91 (33.3%)
11 (4.4%)
120 (48,6%)
Sewer swabs
186
November 1961
238
198
2(0.8%)
·
Fresh water from local junks
591
January 1962
201
190
30,3%)
38 (15.9%)
16(75%)
Fresh water from incoming junks
445
April 1962
207
168
5 (2.4%)
34 (164%)
Vegetables and fruits
916
June 1962
261
170
15
15 (5.6%)
78 (25.0%)
Fish and sh swabs
63
Nightsoil and manurc Cooked food Others
11.489
9
338
Total
15,881
256. Of the 3,754 specimens taken from patients and contacts, the following were positive for P. cholerae. (Table 24).
TABLE 24
Faeces
Hasientr
10
Comeet
21
2
Specimen collected from patients' domNES Night- Kitchen defiae, Roff wtensit swabg
16
Nighsoil collected by U.S.D.
27
Total
146
257. Non-agglutinable vibrios were isolated during the period August to December. 1962 in 29 instances.
Virus Laboratory
258. The Virus Laboratory is equipped mainly for diagnostic and survey work in connexion with entero-viruses. During the year, three faecal surveys were carried out in the months of January, April and June. Specimens of faeces were taken from Chinese children under the age of five years, the methods of sampling and examination being the
2.59. In conjunction with the International Social Service and the Lederle Corporation, children in Hong Kong orphanages destined for adoption into families outside Hong Kong were given trivalent oral poliomyelitis vaccine. A total of 912 children were fed the vaccine in two doses at an interval of 6 to 12 weeks.
260. In order to assess the antibody response to the vaccine, samples of sera were collected from 69 children before the first feeding and again four weeks after the second feeding. Rectal swabs were also taken from this control group prior to the first dose and again four weeks after each feeding. Prior to feeding, poliovirus type I was isolated in 3 cases, and other enteroviruses in 7 cases, the remainder being negative. The virus excretor rate 4 weeks after the first feeding was found to be 31.6%. being equally shared by poliovirus types I and III: 4 weeks after the second feeding the excretor rate was 3.4% for type II only. A total of 69 serum examinations carried out prior to vaccination showed the pres- ence of type I antibody in 92.7% of the children, type II in 18.8%, type III in 52.1% and only 3 children were negative for all these types of antibody; 41 Sera tested four weeks after the second feeding showed a high conversion rate to all three types of antibody. The results are shown in Figure 1.
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