THE MASS BCG VACCINATION CAMPAIGN IN JAMAICA*? (October 1951-June 1953) 1. THE CAMPAIGN 1. The Joinf Agreement between WHO, UNICEF and the Govemment of Jamaica for a Mas-s BCG Caynpaign Early in 1951 it mas agreed between repre- sentatives of the Jamaican Government, the World Health Organization and the United Nations Children’s Fund (UNICEF) that a tuberculin testing and BCG vaccina- tion campa@ should be started in Jamaica during 1951. An agreement was reached concerning details about the objectives of the project, the organization, method and extent, the training of personnel and the proposed commitments of WHO, UNICEF and the Government of Jamaica. The campaign was expected to cover the whole island and to last for at least two years. The population LO be examined was hmited to persons O-20 years of age in the urban areas and O-30 years of age in the rural areas. The field work was planned to be done by four teams, each consisting of one doctor, two nurses and one driver. It was estimated that about 600,000 persons would thus be examined in the campaign. Name-lists of the positive tuber- culin reactors should be made for the local health authorities’ use in their case-finding programmes. 2. Training, Personnel and O$îce In February 1951, Dr. R. G. Lampart and two nurses, Miss P. Manahan and Miss V. Skeffery, mere sent on a three months * Campa@ carried out under the joint auspices of the Government of Jamaica, World Health Organization and the United Nations Children’s Yc Fund. This report-mas prepared under the direc- tion of Dr. J. 1. Rerrie, Tuberculosis Officer, ’ Jamaica, with the assistance of Mr. Truls Zeiner- Hendriksen, Statistician, World Health Organisa- tion. t Manuscript received in July, 1956. WHO scholarship to Ecuador for training with the “International Tuberculosis Cam- paign” BCG vaccination teams in that country. In September 1951 they, in turn, trained four junior medical officers and eight nurses in Jamaica. At the onset of the programme, Dr. Knut Osvik, WHO Regional BCG adviser, was present during one month to instruct and advise the local personnel. The chief of the campaign was Dr. J. 1. Rerrie, Chief of Tuberculosis Division, Island Medical Department, Jamaica. Cam- paign organizer was Dr. R. G. Lampart, Jamaica. Four teams, each consisting of one as- sistant medical officer and two nurses plus a chauffeur, were working during the whole campaign. During June 1952 two of the doctors working as team leaders were re- placed by the two senior nurses who were trained in Ecuador and two new nurses were appointed. The personnel in the central BCG Office in Kingston were one supply officer, one statistician, two clerks, a chauf- feur and a messenger. The Office consisted of three rooms plus a store room. A team consisting of one doctor and two nurses arrived in November 1951 from Trinidad for two months’ training in BCG work. A similar team from Paraguay arrived one month later for a short visit. 3. Equipment All the equipment: 6 Willys station wag- ons, vaccination kits, propaganda material, etc., was supplied by UNICEF and arrived in July 1951 in good condition. The tuber- culin and vaccine were paid for by UKICEF and sent weekly by air-freight from Mexico City to Kingston. 4. Propaganda and Planning During September and October 1951 extensive propaganda was carried out 61
Transcript
THE MASS BCG VACCINATION CAMPAIGN IN JAMAICA*?
(October 1951-June 1953)
1. THE CAMPAIGN
1. The Joinf Agreement between WHO, UNICEF and the Govemment of Jamaica for a Mas-s BCG Caynpaign
Early in 1951 it mas agreed between repre- sentatives of the Jamaican Government, the World Health Organization and the United Nations Children’s Fund (UNICEF) that a tuberculin testing and BCG vaccina- tion campa@ should be started in Jamaica during 1951. An agreement was reached concerning details about the objectives of the project, the organization, method and extent, the training of personnel and the proposed commitments of WHO, UNICEF and the Government of Jamaica.
The campaign was expected to cover the whole island and to last for at least two years. The population LO be examined was hmited to persons O-20 years of age in the urban areas and O-30 years of age in the rural areas. The field work was planned to be done by four teams, each consisting of one doctor, two nurses and one driver.
It was estimated that about 600,000 persons would thus be examined in the campaign. Name-lists of the positive tuber- culin reactors should be made for the local health authorities’ use in their case-finding programmes.
2. Training, Personnel and O$îce
In February 1951, Dr. R. G. Lampart and two nurses, Miss P. Manahan and Miss V. Skeffery, mere sent on a three months
* Campa@ carried out under the joint auspices of the Government of Jamaica, World Health Organization and the United Nations Children’s
Yc
Fund. This report-mas prepared under the direc- tion of Dr. J. 1. Rerrie, Tuberculosis Officer,
’ Jamaica, with the assistance of Mr. Truls Zeiner- Hendriksen, Statistician, World Health Organisa- tion.
t Manuscript received in July, 1956.
WHO scholarship to Ecuador for training with the “International Tuberculosis Cam- paign” BCG vaccination teams in that country. In September 1951 they, in turn, trained four junior medical officers and eight nurses in Jamaica. At the onset of the programme, Dr. Knut Osvik, WHO Regional BCG adviser, was present during one month to instruct and advise the local personnel.
The chief of the campaign was Dr. J. 1. Rerrie, Chief of Tuberculosis Division, Island Medical Department, Jamaica. Cam- paign organizer was Dr. R. G. Lampart, Jamaica.
Four teams, each consisting of one as- sistant medical officer and two nurses plus a chauffeur, were working during the whole campaign. During June 1952 two of the doctors working as team leaders were re- placed by the two senior nurses who were trained in Ecuador and two new nurses were appointed. The personnel in the central BCG Office in Kingston were one supply officer, one statistician, two clerks, a chauf- feur and a messenger. The Office consisted of three rooms plus a store room.
A team consisting of one doctor and two nurses arrived in November 1951 from Trinidad for two months’ training in BCG work. A similar team from Paraguay arrived one month later for a short visit.
3. Equipment
All the equipment: 6 Willys station wag- ons, vaccination kits, propaganda material, etc., was supplied by UNICEF and arrived in July 1951 in good condition. The tuber- culin and vaccine were paid for by UKICEF and sent weekly by air-freight from Mexico City to Kingston.
4. Propaganda and Planning
During September and October 1951 extensive propaganda was carried out
61
through press and radio and public meetings. tested even though they were over 30 years Before the campaign teams were scheduled of age. Refusal to test such persons was diffi- to arrive in a district, meetings were held cult and perhaps unnecessary. Accordingly, with local doctors, health workers, sc&hool- almost everyone up t’o about 50 years of age teachers and other authorities, pamphlets who carne to the vaccination centres was distributed and propaganda films with accept’ed. It was derided not to test or popular lectures shown for the public. The vaccinate babies under one year of age in schools were visited, and sites were selected the campaign, because of t,he often difficult as vaccination centres. Before and during working ronditions for at,tending new-borns the examinations, loud-speaker propaganda in the field. was made from the team cars. This proved Name-lists of positive reactors were pre- to be very effective, and good contact was pared for the lora1 health authorities. obtained with the public. Table 1 shows the progress of the cam-
5. Progress of Worlc paign in terms of the number of persons tested and the number vaccinated each
The vaccination teams generally worked month from October 1951 through June together in the same district and covered 1953. one entire parish before proceeding to another. 6. Tuberculin Testing and BCG Vaccination
The campaign started in Kingston on 22 B single 5 T‘C’ intradermal tuberculin test October 1951, with vaccination in schools was used throughout the rampaign. This and later in some offices and factories. The meant that people only had to be seen twice: four teams continued to work in Kingston once to be given the test and a second time and St. Andrew parish through November, three days later to have the reaction read December and January. The next parishes and to be vaccinated, if considered “nega- to be covered were St. Thomas and Portland tive”. With few except’ions the tuberculin in the eastern part of the island. In April tests were given on Mondays, Tuesdays and 1952 the campaign proceeded to the parish Wednesdays; the reactions were read and of St. Mary. During May, June and July the “negatives” were vaccinated on Thurs- the parishes of St. Mary, St. Ann and days, Fridays and Saturdays. Trelawny, al1 on the north coast, were Tuberculin for the campaign was the covered. St. James and Hanover in the purified protein derivative (PPD) identified north-western part of the island were cov- as RT XX11 from the State Serum Institute, ered in September; Westmoreland and St. Copenhagen. Stock solutions sent from Elizabeth in the south-western part of the Copenhagen were diluted at the Laboratorio island in November and December. In del BCG in Mexico City, and the ready-to- January 1953, the campaign had reached use dilutions were forwarded weekly (as a Manchester and proceeded to Clarendon, rule), by air, in 100 CC. bottles packed in where vaccination was done until May. The specially const,ructed ice-containers. The parish of St. Catherine was also finished tuberculin test’ mas given by intradermal during May. In June some additional injection of approximately 0.1 CC. of the 5 vaccination was done in Kingston, and one TU dilution into t,he dorsal aspect of the team was sent to the island of Grand Cay- left forearm. man where vaccination was done until the Reactions with indurations measuring 6 end of June 1953. mm. or more in transverse diameter were
The age-range considered in the campaign considered “positive”, those with indura- was changed from what had been set out in tions of 5 mm. or less were considered the agreement. It was found difficult to hold “negative”. Only persons with “negative” the oldest age limit, as adults coming to reactions were offered BCG vaccination. the centres with their children wanted to be The time interval between injecting the
62 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
July 195?] BCG VACCINATION IN JAMAICA 63
TABLE I.-Number of persons tuberculin-tested and vaccinated with BCG during October 1951-June . . 1953, by month.
Month and year
October 1951 November 1951.. December 1951 : : January 1952.. February 1952.. March 1952.. April 1952.. : : May 1952, June 1952. July 1952.. : : : : August 1952.. September 1952 October1952.. -1” . . November 1952.. December 1952 January 1953.. : : : February 1953.. March 1953. April 1953.. . May 1953. June 1953.
* In addition to this 117 persons were vaccinated without previous testing.
tuberculin and reading the reaction was usually three days, in a few cases two or four days. The vaccination was made by injecting approximately 0.1 CC. of BCG vaccine intradermally into the deltoid region of the left shoulder.
Vaccine for the campaign was prepared at the Laboratorio del BCG in Mexico City and sent by air, together with the tuber- culin, packed in ice-containers. The tuber- culin and the vaccine were stored in refriger- ators either at the BCG Office in Kingston or at the temporary field stations. Vaccine lot numbers 141 to 216 were used during the campaign. *
7. Post-Vaccination Testing
For the purpose of getting some informa- tion about the allergy obtained after the mass vaccination, two post-vaccination
* The following lots were not used: 150, 151, 161, 166, 170, 181, 182, 195, 199, 201-204, 208, 212.
tuberculin testing programmes were carried out: the first from 2 June to ll July 1952, the second from 8 September to 15 October 1953. Under the supervision of WHO per- sonnel, both programmes were done in selected school-groups vaccinated with dif- ferent lots of vaccine at different periods in different parts of the island (see section IV: Post-Vaccination Testing).
8. Continuation of BCG Vaccination
Final decisions regarding the continuation of BCG vaccination under national auspices had not yet been made when the campaign ended in June 1953. Instruction and training of public health nurses in the different par- ishes were to be done by a BCG nurse during the first months of 1954, and plans had been made to obtain necessary equipment for supplying the public health nurses through- out the island so that BCG vaccination could become a part of the parish public
64 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA .
health nurses’ routine programme in the by t,he WHO Tuberculosis Research Office School Health Service. Vaccination is to be in 1951 for WHO/UNICEF mass BCG given to the lower classes in the schools, and vaccination campaigns. According to this it is hoped that by 1955 the BCG programme system, three kinds of statistical record will be organized throughout the island. forms are used:
(a) an individual card for selected groups; II. THE STATISTICAL MATERIAL (b) a group card for recording the daily
1. Method counts of the tested and vaccinated; Records of tuberculin tests and BCG (c) a monthly statistical report form.
vaccinations were made in accordance with The individual card (Fig. 1) is used only a simplified statistical system recommended for “selected groups” such as schools, etc.,
FIG. l.-Individual card
1 SURNAME 3 DATE OF BIRTH 1
! ’
4 AQE 9 INSTITUTION DhY MOHTH; YE*I IN YEARS
/Is_
2 FIRST NAME 5 SEX
MALE q FEMALE q
6 House NO.. STREET
7 TOWN/VILLAGE
13 RE-TESTINQ
15 RE.YACCINATION
DATE q CG NO.
1
VACCIN*TOR
I
REMARKS
July 19573 BCG VACCINATION IN JAMAICA 65
where details of identification can be ob- tained with a view to possible follow-up examinations. Space is provided for identi- fication data, tuberculin test results, BCG vaccination (if given) and, on the reverse side, details about post-vaccination exami- nations.
The group card (Fig. 2) is designed to
provide records of the campaign in the general population and is not intended as a basis for follow-up examinations. It is filled out each day by the teams, giving informa- tion about the location of the group exam- ined, the vaccine lot used, date of testing and reading; records of the total number of persons with test given, “positives”, vacci-
66 BOLETIN DI? LA OFlCIN.4 SANITARIA PANAMERICANA
FIG. 3.-Monthly statislical report form
MONTHLY STATISTICAL REPORT Country. District Month
_.
-.
_.
-.
_.
-.
195 Tuberculin test & dose used. Form filled by
----------
___-------
--l---I-----
-1-1-1-l-/7-l ,
---_ mi l I nated, and “negatives not vaccinated” by the three age-groups: O-6,7-14 and 15 years and more are collected by tallying in the space provided for this purpose. Totals and identification information for the “selected groups” are also filled in on group cards after counting of the individual cards.
The monthly stalistical repart form (Fig. 3) gives summary data on the number of persons tested and vaccinated by the three age-groups and by place of examination, in correspondence with the group cards.
With few exceptions, the schools al1 over the island were examined as “selected groups” with individual cards. Individual cards were also used for some other institu- tions and for some factories and offices in Kingston. Results in al1 other groups, re- ferred to as the “general population”, were recorded by tallying directly on the group card.
Records of the testing and vaccination were made by the teams in the field. The identification information for the school- children was, as a rule, filled in on the indi- vidual cards by the teachers before the first visit of the vaccination team.
The monthly statistical report was drafted by the field personnel and forwarded to the
-
_.
_.
-.
_.
-.
_.
----_ ~___--
----_- -
----___--___
-__------_-
----_--
----___
local statistician at the central BCG Office along with group cards and individual cards. After the statistician had verified the data, the report was typed and sent to the WHO Regional Office in Washington through the WHO Caribbean Field Office, to UNICEF Area Office in Guatemala, and to the Tuber- culosis Research Office in Copenhagen. A copy was also given to the Director of Medical Services, Kingston, Jamaica.
A “summary report” with monthly totals and accumulated t’otals was sent regularly to the same institutions plus the WHO Tuberculosis Section, Geneva, the WHO Caribbean Field Office, and the WHO Regional BCG Statistician.
The WHO Tuberculosis Research Office in Copenhagen has reviewed the monthly stat’istical reports, caomputed the records by month and parish, and puhlished the monthly and accumulated totals.
2. Completeness and Accuracy of the Material
The same products of tuberculin and vaccine and a uniform technique of testing and vaccination were used during the whole campaign. The readings of the tests were always done by the campaign doctors or nurses. The measurements of indurations in
TABLE II.-Number oj persons tuberculin-tested and vaccinated with BCG by age-group and parish.
Number of persons -
T With test read Positive Vaccinated Parish -
/ I Age ~roup (years) Age group (years)
Total Total - Total O-6 1-14 15+ O-6 1-14 15+ O-6 7-14 15+
9 St. Elizabeth. St. James.. St. Mary. , St. Thomas Clarendon. Hanover . Manchester., Portland. : Trelawny Westmoreland . Grand Cayman. . . .
Total. 635,421
* In addition to this, 117 persons were vaccinated without previous testing.
68 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
FIG. 4.-Number of persons with test read and number vaccinated in each of the three age-groups: l-6 years, 7-14 years and 15 years and more.
AGE IN YEARS
mm. for the “selected groups” were done carefully. However, many different nurses and doctors made the readings, and personal errors in the measurements are likely to have occurred.
In the “general population” the persons were asked their age on the first and again on the second visit in case it was not obvious to which of the three broad age-groups they belonged. Persons of 5-7 and 14-16 years may have been grouped in different cate- gories on the two visits, with some small discrepancies between the numbers tested and read in each age-group as a result. For ‘(general population” in the cities some persons may have had their reactions read twice, or a person may have had his reaction read in another examination centre than the one where he was tested. For the school- children age information was generally taken from the school registers.
Only the selected group material contains information about sex and sizes of reactions in mm. Tabulation by sex is not included in this report.
III. RESULTS OF STATISTICAL TABULATION
AND ANALYSIS
1. The Population Tested and Vaccinated
In al1 635,421 persons carne for a tuber- culin test and 586,014 (92%) returned for the second visit to have the test read. Of these 40.4 % were considered “positive”. A total of 347,660 persons or 99.6 % of the “negatives” were BCG vaccinated. The persons with test read had the following age-distribution: l-6 years 15.9 %, 7-14 years 30.9 % and 15 years and more 53.2 %. The vaccinated had the following age-dis- tribution l-6 years 25.3 %, 7-14 years 42.4 % and 15 years and more 32.3 %.
Total figures for tested and vaccinated by the three age-groups and by parishes are given in table II; see also Fig. 4.
2. Completeness of Testing and Vaccination
The last census in Jamaica was in 1943, but population figures for 31 December 1952 have been calculated from birth, death and migration since the census and may be used for making rough estimates of the complete- ness of the campaign. (A sample census in 1953 is not yet published, but the first results indicate that the calculated figures for 1952 are usable.)
The total number of persons with test read is close to 40 % of the total 31 December 1952 population (1,478,078). Including those who were given test but did not return for the reading the percentage is 43. This is a high coverage compared with similar cam- paigns in many other countries (1). For the three age-groups the proportion of persons with test read among the estimated total population of the same age-groups is 37% (l-6 years), 65 % (7-14 years) and 35 % (15 years and more) .*
The adult population seems to have been covered almost as well as the population of children under 6 years of age, but the cover-
* Population in the three age-groups is esti- mated as 17, 19 and 60.5yo of the total population figures, as obtained from a modification of the age distribution in the 1943 census.
Juìy 19571 BCG VACCINATION IN JAMAICA 69
age was highest in the school-aged group. All the schools on the island were visited by the campaign-teams, and many school-age children were also examined in the “general population” at the vaccination centres.
Population coverage in the different par- ishes varies, as shown in table III giving figures for the number of persons with test read and the estimated population, by parish.
The campaign worked all over the island, including small villages with difficult com- munications from the main routes. The only parish where the population appeared to offer some resistance to the campaign was Portland; this parish shows the lowest percentage, only 29.0 %, of the population to have completed test. The next lowest percentage is found in St. Andrew Rural, but this may in fact reflect some error in the population figures, as Urban St. Andrew is included with Kingston, and only a rough estimate of the St. Andrew urban and rural population has been available. The parish of St. Catherine had a coverage percentage of only 30.6 and this may be because the
TABLE III.-Number of persons with test read in percentage of total population, by parish.
Parish
Kingston and St Andrew Urban
St. Andrew Rural.. St. Thomas. Portland. St. Mary. St. Ann.. Trelawny St. James _. Hanover Westmoreland.. St. Elizabeth. Manchester. CIarendon. St. Catherine. Grand Cayman
TABLE IV.-“Positive” reactors (6 mm. or more induration to 6 TU) in percentage of the total num- ber of persons with test read (positive plus negative reactors) by age-group and parish.
Parish Age-group (years)
-
Kingston and St. An. drewurban. ,._ _,
St. Andrew Rural St. Thomas. Portland. St. Mary. St. Ann. Trelawny St. James. Hanover . Westmoreland St. Elizabeth. Manchester. Clarendon St. Catherine.. Grand Cayman
parish was reached in the last months of the campaign when the work was somewhat rushed. For all the other parishes the per- centage participation is between 37 and 45, except for the island of Grand Cayman where 57 % of the population were tested and read.
One of the difficulties in a mass BCG campaign is to get persons to return for the second visit for reading of the tuberculin test and for vaccination. Yet the percentage of persons who were tuberculin tested and returned for the reading was 92.2, in average, for the entire campaign. The parish of Portland, which showed the lowest coverage of the population, also had the lowest percentage of tested persons returning for the secoqd visit. The highest percentage (95.1%) was on the island of Grand Cayman.
3. Tuberculin Sensitivity
The statistical material givés the number of “positives” and “negatives” by three
70 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
age-groups, for each locality and group of persons examined. The percentages of “positive” reactors (6 mm. or more of indura- tion to 5 TU) of the total number with test read (positives plus negatives) for each of the 14 parishes and the island of Grand Cay- man are given in table IV.
These percentages are calculated from the total number of persons (selected groups and general groups) with test read during the entire campaign.
Kingston, including St. Andrew Urban, has the highest percentage of “positives” in each age-group, and St. Catherine has the next highest. Clarendon, the parish west of St. Catherine, ranks as number three in the age-groups l-6 and 7-14 years, and as number four, after St. Thomas, in the oldest age-group. The lowest percentages of “positives” are found in the parishes of Trelawny, St. Ann, Hanover, St. Elizabeth and the island of Grand Cayman. The high- est percentages in the three age-groups, represented by Kingston, are: 8.5, 31.4, 73.4 while the lowest on the island of Jamaica are 2.2, 9.0, 51.8 represented by the parish of Trelawny. The average percentages of “positives” among school-aged children (7-14 years) in the different parishes are illustrated in Fig. 5.
The parishes are rather large units for computing percentages of “positives”, and much variation is found when different
districts and groups within the same parisl-c are compared. Some of the variation may, of course, reflect differences in age-distribu- tions, especially within the youngest and oldest age-groups. For parish to parish comparisons, however, the variation in age distributions within the three age-groups should be rather small and of little impor- tance.
Tabulation of percentage of “positives” by age in single years has been done for a group of schools where the children were retested in 1952. For 12 schools in Kingston (4,902 tested and read), 6 schools in St. Andrew (1,075 tested and read) and 6 schools in St. Thomas (3,861 tested and read), the percentages of ‘Lpositives” for ages 7-14 are illustrated in Fig. 6. The tuberculin sensitivity increases with increas- ing age.
For the same schools the distributions of the sizes (in mm.) of induration to 5 TU are given in table V. See also Fig. 7.
The distributions show quite high pro- portions of small reactions and do not show the two fairly distinct concentrations of reactions reported from European countries. Similar distributions may be found in other districts in Jamaica, though only samples of the statistical material have been analysed in this respect. Accumulations of reactions read as “round” numbers, as 10, 12, 15 and 20 mm., are also quite obvious-an indica-
FIG. 5.-Geographical distribution by parishes of percentages of “positives” (persons reacting with 6 mm. or more induration to Mantoux 6 (TU) among unvaccinated persons r-14 years old examined during the mass campaign.
July 19571 BCG VACCINATION IN JAMAICA 71
tion that the reactions were not measured too carefully in the mass campaign. More- over, there is an accumulation on 6 mm. probably owing to a tendency to read doubtful small reactions as 6 mm. to avoid the possible vaccination of naturally infected persons.
There are other limitations in using the percentage of “positives” as an expression of the prevalence of tuberculosis infection. It ís doubtfu1 what proportion of the small but definite indurations to 5 TU may repre- sent specific tuberculosis infection or a non- specific kind of sensitivity: the larger non- specific reactions cannot be distinguished from the smaller specific reactions with the tuberculin products in use today. Although very little is known about the presente or prevalence of non-specific tuberculin sensi- tivity in Jamaica, it is likely that a substan- tial proportion of the “10~ allergy reactors” among the “positives” have not had a virulen‘t tuberculosis infection.
IV. POST-VACCINATIOR’ TESTING
1. Method
Two post-vaccination tuberculin testing projects were carried out to obtain informa- tion about the allergy developed among those vaccinated ín the campaign. The first project was in June and July 1952, after the campaign had been in progress for nine months; the second in September and Octo- ber 1953 after the finish of the campaign.
Retesting was done in samples of the vaccinated school population. Various vac- cine lots used for vaccination in different parts of the island were selected. About 300-500 children, preferably from severa1 schools, were retested for each vaccine lot; the retesting was also intended to cover vaccination done by the different teams in schools including both sexes, rural and urban populations and differing living conditions. But practica1 considerations regarding trans- portation, co-operation and attendance in the schools had, of course, to be made.
Most of the groups retested were govern-
FIG. 6.-Percentages oj “positives” (persons re- acting with 6 mm. or more induration to Mantoux 6 TU) among groups oj unvaccinated school children in Kingston, St. Andrew and St. Thomas parishes, by single years of age.
- KINGSTON
30 - ---- ST ANDREW
w ---- ST THOMAS
2 5 20.
E ti!
10 - z i’ r._cI/-x,
.*‘,’ /’
N.’ /
Oo-7 8 9 10 II 12 13 14 AGE IN YEARS
FIG. 7.-Freguency distributions by size oj in- duration of reactions to Mantoux 5 TU among groups of unvaccinated school children in Kingston, St. Andrew and St. Thomas parishes.
W ” 4 t- z ” 0 05 w CL
KINGSTON
NUMBER. 4,902
819 ST. ANDREW
NUMBER: 1,075
76.2 ST. THOMAS
NUMBER: 1,861
4 8 12 16 20 24 28 Z3C INDURATION in mm.
ment schools, generally comprising boys and girls 6-14 years old, although some
72 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
TABLE V.--Size of induration of reactions to Mantoux 6 TU test among unvaccinated school chil- dren examined in Kingston, St. Andrew and St. Thomas, October 1961 to March 1962.
kindergarten and higher schools were also included. With very few exceptions, al1 the vaccinated pupils present in school during the retesting visits were tested. In severa1 schools, tuberculin tests were also given to children whose reactions had been “positive” or “not read” according to the mass cam- paign secords, as well as to new pupils who had entered school since the time of the campaign. Children in the latter group were considered non-vaccinated if no BCG scar
could be found. Tuberculin testing of the non-vaccinated was done in order to get some information about the allergy among natural reactors and at the same time to obtain a mixed group of vaccinated and unvaccinated to obtain biased readings. The nurse reading the reactions did not see the individual cards and therefore could not know the child’s vaccination status.
Al1 post-vaccination tuberculin tests were made with 5 TU of the same tuberculin used for the mass campaign: the PPD iden- tified as RT XX11 from the State Serum Institute, Copenhagen, diluted at the Labo- ratorio del BCG in Mexico City and used within a month of preparation. The tuber- culin injection technique, the reading of reactions and the statistical recordings were done in a uniform manner throughout the retesting programme and were similar to the procedures used in the campaign, with the following exceptions :
In 1953, the reactions were read after two days instead of after three days. This was of considerable practica1 advantage for the work, and comparative readings in two schools of second and third day reactions had shown that the difference in reaction sise on the two days was very small. This is also in accordance with studies reported by the Tuberculosis Research Office (2). The retest examinations were recorded on the same individual cards that had been used in the vaccination campaign. In 1952 these cards were forwarded together with pro- visional tabulations and work reports to TRO for punching and tabulating; in 1953 complete tabulations were made with the help of the Medical Department in Kings- ton.
Everyone retested was also examined for vaccination lesion, and the measured sise of the.lesion (scar) was noted on the individ- ual card.
The 1952 retesting team comprised the WHO Regional BCG Adviser, Dr. K. Osvik, the WHO Regional BCG Statistician, Mr. T. Zeiner-Henriksen, and one of the nurses from the mass campaign, Miss A. Thompson.
July 19573 BCG VACCINATION IN JAMAICA 73
In 1953 Mr. Zeiner-Henriksen and two campaign nurses, Miss P. Manahan, and Miss 1. Jones, made up the team. Both retesting projects were set up in co-operation with the Campaign Organizer, Dr R. G. Lampart. The work, which was planned in accordance with suggestions made by the WHO Tuberculosis Research Office, was done carefully and with special attention to accurate measurements of reactions.
2. Resulta
The main statistics for the retesting pro- gramme are given in table VI. A total of 6,000 children attending 43 schools, repre- senting BCG vaccination with 16 different lots of Mexican vaccine, completed retest during the two projects. Thus, 1.7% of al1 those vaccinated during the campaign and 4.1% of those vaccinated in the age-group 7-14 years were retested. In addition to the examination of children vaccinated in the mass campaign, 640 previously “positive”, 250 previously “not read” and 1,300 new pupils were also retested.
In most of the schools where retesting was done, the children had been vaccinated early in the campaign: 26 of the 43 before March 1952. Only in 12 schools had mass vaccination been done after June 1952. Most of the schools were located in Kingston and the surroundings of Kingston, but re- testing was done al1 over the island, covering schools in the mountainous area as well as the coast and swamp land. The campaign records showed that 10,5UO children had been vaccinated in the 43 schools. Of these, about 70 % were given a tuberculin test by the retesting team, but some 1,300 failed to return to have the test read. Retesting was thus completed in 58 % of those vaccinated in the 43 schools selected for the retesting programme. Many pupils had left school since the vaccination campaign, and many were absent: during the retesting in 1953 heavy rains during the last two weeks re- duced the school attendance and in 1952 the “mango season” had the same effect.
Results of BCG vaccination have often
been expressed as the percentage of persons with a tuberculin reaction larger than a certain sise (usually 5 mm. of induration). This implies that a reaction of 5 mm. or more indicates a successful vaccination, a smaller reaction an unsuccessful vaccination. More- over, the percentage of “positives” after vaccination gives little information about the degree of tuberculin sensitivity induced by the vaccine. On the other hand, in every part of the world, vaccinated groups tested for post-vaccination allergy show unimodal distributions by size of induration (3). The arithmetic mean (average) of al1 the reac- tions in a group is, therefore, a meaningful expression of the allergy produced by the vaccination and may be used for comparing results from one group to another.
The distributions of post-vaccination 5 TU reactions by size of induration are shown in Fig. 8A for the schools retested in 1952 and in Fig. 8B for the schools retested in 1953. Both distributions form a smooth, fairly symmetrical dome-shaped curve-the uni- modal curve commonly found in vaccinated groups. The reactions in both distributions cover about the same range on the size scale and have about the same mean value: ll.4 mm. for the groups retested in 1952 and 10.5 mm. for those retested in 1953. Children in three schools vaccinated in Kingston during the first month of the mass campaign and retested in 1952 showed a high proportion (more than 10%) of reac- tions at 0 mm., although the bulk of re- actions centered at lo-12 mm.
When the results are analysed according to vaccine lot number, some variations among the various lots are found, as shown by the unweighted averages for each lot in table VI. The mean size of reactions by lot varies from a low average of 8.8 mm. of induration obtained with lot 143 to a high average of 16.0 mm. with lot 156. The children in the two schools vaccinated with lot 156 had higher means than found from any of the other vaccine lots retested. The vaccination scars were also considerably larger (7-8 mm. as compared to 3-6 mm.
74 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
TABLE VI.-Results of testing children vaccinated in the mass campaign with 6 TU, by school and vaccine lot.
Gordon Town Mannings Hill Stony Hill Mt. Fletcher gh&ent Gap
W&e Hall Wilmington Cedar Valley Yallahs Aeolus Valley Highgate G. Carron Hall G. Carron H. J. Port Maria Hillside Falmouth Clarks Town Granville Lances Bay Green Island Lucea Ballards Valley Mayfie!d Tneyoy
1
1
,
1
,
,
1
,
-
Total. -
* Unweighted average.
for 80 % of the schools), which suggests that vaccine lot given to children in different this lot has in fact been stronger than the schools in the same area at the same time the others. Variability within the same was also found. Lot 141, for example, pro-
July 1957] BCG VACCINATION IN JAMAICA 75
FIG. 8.-Frequency distributions by size of induration of reactions to Mantoux 6 TU among BCG vac- inated children.
A: Al1 groups (24 schools) retested in 1952 B: All groups (25 schools) retested in 1953 c: Groups (6 schools) retested both in 1952 and 1953; results 1952 D: Same groups as C; results 1953
- 8. RETEST 1953
25 SCHOOLS t 7-23 MONTHS AFTER
VACCINATION ‘OI-
NUMBER. 2,758 MEAN: 10.5
l-----T- Z”
C. 6 SCHOOLS RETESTED 1952-1953 NUMBER. 1,308
RESULTS 1952 r MEAN, 10.4
6-8 MONTHS AFTER Io VACCINATION w
a
2 = 0 w ”
E 20 p.
1 D SAME GROUP AS C NUMBER. 635 MEAN: 9.8 I RESULTS 1953 I
duced mean reactions ranging from 7.7 to 14.2 mm. of induration; and mean reactions to lot 154 ranged from 7.4 to 13.7 mm. This indicates that variation in the strength of the different vaccine lots is not the only cause of the varying results obtained in the retesting programme.
Four of the schools with lowest post-
vaccination allergy were vaccinated in the first months of the campaign when the destructive effect of sunlight on BCG vaccine had not yet been brought to the attention of the teams. In two of these schools (Rous- seau and Calabar), it was learned that vaccination was in fact done outdoors and the exposure to sunshine may thereby have
76 BOLETIN DE LA OFICINA SANITARIA PANAMERICANA
reduced the vaccine’s allergy-producing potency. Children in schools vaccinated after the first months of the mass campaign show very few instances of a mean post- vaccination allergy of less than 10 mm. of induration. In about 33 % of al1 the schools the children retested showed mean reactions of 11-12 mm., and about 40 % had mean reactions of more than 12 mm.
In six schools, retesting was done in 1952, and repeated 15 months later during the retesting project in 1953. The distributions of the reactions for both retestings are illustrated in Fig. 8C and 8D, where the mean siee of induration for the 1952 retest is 10.4 mm, for the 1953 retest 9.8 mm. The reactions are a little larger for St. George school in 1953 than in 1952, unchanged for schools Rousseau and Alpha Infant, and somewhat smaller in average sizes for the other three schools, Alvernia, Windward Road and Rollington. 635 children were retested both in 1952 and again in 1953, giving mean sizes of induration of 10.9 and 9.8 mm. There is, however, no indication
of any fading with time of the allergy in- duced by BCG vaccination ; the somewhat lower average for the 1953 retesting may reflect diff erences in various technical factors in the vaccination.
Unvaccinated persons-new pupils, stu- dents with reactions previously “not read” or “positive’‘-were retested together with the vaccinated persons. The degree of allergy found among the naturally positive, presum- ably tuberculosis-infected children could thus be compared with the degree of BCG- induced allergy in the vaccinated. The 640 previously positive persons had an average reaction of 14.5 mm. of induration; of the 500 unvaccinated new pupils, the 280 react- ing with 8 mm. or more of induration had an average reaction of 13.6 mm. These figures show that although some vaccinated groups have an allergy comparable to that of the natural reactors, on the average the tuberculin allergy induced by BCG vaccina- tion in Jamaica is 33 mm. smaller than that of the natural positives.
REFERENCES
(1) Mass BCG Vaccination Campaigns 1948-1961. lin reaction size on five consecutive days. (Reports from 17 countries.) The Interna- Bull. Wld. Hlth. Org. 12:189-196, 1954.
tional Tuberculosis Campaign, Copenhagen, (3) WHO Tuberculosis Research Office. Further
1954. studies of geographic variation in naturally acquired tuberculin sensitivity. Bull. Wld.
(2) WHO Tuberculosis Research Office. Tubercu- Hlth. Org. 12:63-83, 1954.
