"1nv Weekly

"1nv Weekly
Canada Diseases
Rapport hebdomadaire des
Weekly Report
maladies au Canada
Date of publication:
Date de publication:
CONTAINED IN THIS ISSUE:
CONTENU DU PREsENT NUMERO:
Rubella Outbreak Among Unimmunized 'v\ale
High School Students in Wabush/Labrador
City - Newfoundland . . . . . . . . . .
Flambee de rubeole chez des garc;ons non
immunises frequentant l'ecole secondaire
Wabush/Labrador City - Terre-Neuve. . • .
Vol. 13-lflf
a
199
199
RUBELLA OUTBREAK AMONG UNIMMUNIZED
MALE HIGH SCHOOL STUDENTS IN
WABUSH/LABRADOR CITY - NEWFOUNDLAND
FLAMBEE DE RUBEOLE CHEZ DES GAR(:ONS NON
IMMUNISES FREQUENT ANT L'ECOLE SECOND AIRE
A. WABUSH/LABRADOR CITY - TERRE-NEUVE
Introduction: On 11 April l 986, the Medical Officer of
Health for the Grenfell Regional Health Services was
notified of a suspected outbreak of rubella in Labrador
City. Approximately 8 individuals had presented with
typical signs and symptoms of rubella in the previous 4
days. This was significant because there had been only a
few sporadic cases reported in the province during the
previous 3 years. The suspected diagnosis was confirmed
serologically and it was apparent that a large outbreak
was occurring among unimmunized males between the
ages of 15 and 18 years who were attending high scho.ols
in Wabush/Labrador City. Health authorities decided to
institute a 'crash' vaccination program among susceptible
high school students in the community to reduce spread to
un-immunized female students and pregnant women.
Although Wabush/Labrador City is located in an isolated
part of the province, it was feared that the disease would
spread to other parts of the province through air travel.
It was also hoped that Public Health Units throughout the
province would review their immunization records and
offer immunization to susceptible female teenagers.
Introduction: Le 11 avril 1986, le medecin-hygieniste des
services de sante regionaux Grenfell est avise d'une flambee
possible de rubeole
Labrador City OU quelque 8 sujets
avaient affiche !es signes et symptomes typiques de la
rubeole au cours des 4 jours precedents. Cette constatation
etait significative car la province n'avait enregistre que de
rares cas sporadiques au cours des trois dernieres annees. Le
diagnostic presomptif est confirme par serologie et ii devient
manifeste qu'une flambee importante frappe Jes garc;ons non
immunises ages de 15
18 ans et frequentant une ecole
secondaire a Wabush/Labrador City. Afin de limiter le risque
de transmission de la maladie
des adolescentes non
immunisees et
des femmes enceintes, Jes autorites
sanitaires decident d'instituer un programme de vaccination
d'urgence des eleves receptifs. Bien que Wabush/Labrador
City soit situee dans une region isolee de la province, on
craint une transmission eventuelle de la maladie par Jes
deplacements par avian. On espere aussi que Jes services de
sante publique de la province revoient leurs registres
d'immunisation et offrent le vaccin aux adolescentes
receptives.
In the Province of Newfoundland and Labrador,
rubella vaccine was first offered to l 0-year-old females
in September 1971. In October 1972, measles/rubella
vaccine became available and was given to both sexes age
l year. In December 1974, MMR vaccine, manufactured
by Merck Sharp and Dohme, became available and was
isiven to all children at l year of age. Thus, males born
before October l 971 would not have been vaccinated
against rubella.
In theory, all females born after
September 1961 should have been protected against the
disease.
Le vaccin antirubeoleux est offert aux fillettes de l O ans
depuis septembre 1971 a Terre-Neuve et au Labrador. Le
vaccin combine contre la rougeole et la rubeole est disponible
depuis octobre 1972 et est offert
tous les enfants
I an.
Le ROR, vaccin fabrique par Merck, Sharp et Dohme, est
disponible depuis decembre 1974 et administre
tous !es
enfants
1 an. I! se peut done que Jes garc;ons nes avant
octobre 1971 n'aient pas ete immunises contre la rubeole. En
theorie, toutes Jes femmes nees apres septembre 1961
devraient etre protegees contre cette maladie.
The Outbreak: Figure 1, showing the number of cases by
date of diagnosis and sex, indicates that the outbreak
occurred between 8 April and 25 July l 986, with the
greatest number of cases being diagnosed between 16 and
18 April.
Following completion of the immunization
program on 15 May, only 18 more cases were diagnosed;
half of these were females.
The total number of
confirmed and suspected cases was 64; 55 of these were
males.
La flambee: La Figure l donnant le nombre de cas selon la
date du diagnostic et le sexe, la flambee se serait produite
entre le 8 avril 1986 et le 25 juillet 1986, le plus grand
nombre de cas etant diagnostiques du 16 au 18 avril. Apres
l'achevement du programme d'immunisation le 15 mai, on ne
diagnostiqua que 18 cas additionnels, la moitie chez des
sujets de sexe feminin.
En tout, 64 cas presumes ou
confirmes ont ete enregistres, dont 55 chez des sujets de sexe
masculin.
lsecond Ch=i;s Ii.all Redstrat.ion Ho. S670!
I
"1nv
November 7, 1987
7 novembre l 987
ISSN 0382-232X
( )/
·1 3 mB7
Health and Welfare
Sante et Bien-etre social
Canada
Canada
a
a
a
a
a
a
a
a
Courrler de la deux1eae claue - Jforl! ht.rl!llll!nt: n
- 199 -
67
Canada
Figure I. Suspected/Confirmed Cases of Rubella By Date of Diagnosis* and Sex, Wabush/Labrador City, Newfoundland, 1986/
Figure 1. Cas presumes et confirmes de rubeole selon la date du diagnostic* et le sexe, Wabush/Labrador City (Terre-Neuve), 1986
12
~
-
MALE I HOMME
I-
10
UJ
FEMALE I FE MME
w
UJ UJ
<t <t
B
uo
*
u. w
oc
6
"'"'
:; :;
3-day intervals
de 3 jours
1 intervalle
a: w
w a:
I
4
:::io
22
2
0
2 5
81114 1720232629 2
5
APRIL/AVRIL
8 11141720232629 1 4
MAY I MAI
Figure 2 shows that the disease occurred predominately
in males born between 1968 and 1971. In fact, 44 (69%) of
the suspected/confirmed cases occurred in this group. Of
the 64 clinically suspected cases, 16 were confirmed
serologically and 8 did not reveal a diagnostic antibody
increase.
7 10 1318192225 28 1 4
JUNEIJUIN
71013 161922 25
JULV/JUILLET
La Figure 2 montre que la maladie a frappe surtout des garc;:ons
nes entre 1968 et 1971. En fait, 44 (69%) des cas presumes OU
confirmes ont ete notes chez ce groupe. Des 64 presumes selon des
signes cliniques, 16 ont ete confirmes par serologie et 8 n'ont pas
affiche une augmentation des titres d'anticorps permettant de poser
un diagnostic.
Figure 2. Suspected/Confirmed Cases of Rubella By Year of Birth, Wabush/Labrador City, Newfoundland, 1986/
Figure 2. Cas presumes et confirmes de rubeole selon l'annee de naissance, Wabush/Labrador City (Terre-Neuve), 1986
16
(/)
14
w
(/) (/)
<( <(
(.) (.)
D
12
•
10
u. w
oc
8
a:: w
w a::
6
co CJJ
:? :?
4
::::>O
22
2
•
FEMALE MALE
FEMME HOMME
•
...
...
...
r.l - Suspected Rubella
L:.l
Rub~ole presumee
r:;,:1
Confirmed Rubella
L.::..I -Rubeole conlirmee
... ...
( lgG/ lgM posit!vjl
( lgG / lgM pos1t1f
A
r;i
Clinically Susp.:ct (Serologically tlegative)
L:J-Cas clinique suspect (Serologie negative)
.
..
......
.........
.........
... ... ...
.........
... ... ...
0
19 5 0
194 0
DATE
OF
BIRTH
- 200 -
1970
19 6 0
I
ANNEE
DE
NAI SS ANCE
A partir des registres des infirmieres-hygienistes, il a ete
possible d'estimer le taux d'atteinte pour les deux sexes selon l'annee
de naissance. Les resultats indioues au Tableau l revelent un taux
d'atteinte beaucoup plus eleve chez Jes gan;:ons nes au cours des
trois annees de 1969 a 1971 que chez ceux nes en 1972. 11 y avait
egalement une difference importante entre Jes taux notes chez Jes
deux sexes pour ces trois annees.
Based on public health nursing records, it was possible
to estimate the attack rate for both sexes by year of birth.
The results, shown in Table l, indicate much higher attack
rates in the males for the 3 years 1969-1971 compared to
1972. There was also a dramatic difference between the
rates for the 2 sexes for these 3 years.
Table l. Wabush/Labrador City Rubella Outbreak: Attack Rates by Age and Sex for Selected Years/
Tableau 1. Flambee de rubeole Wabush/Labrador City: Taux d'atteinte selon l'age et le sexe pour des annees donnees
a
Birth Year/
Annee de naissance
1969
1970
1971
1972
Number Ill/Total Population/
Nombre de malades/Population totale
Attack Rate (No. per 1000)/
Taux d'atteinte (Nombre pour 1000)
Male/Gar~ons
Female/Filles
Male/Gar~ons
Female/Filles
16/ 116
11/122
12/ 118
0
0
0
3/62
138
90
102
19
0
0
0
48
l/53
Control Measures: The vaccination program was not
initiated until 24 April, 13 days after the Public Health Unit
became aware of the outbreak. This was attributed to the
rather remote location of the community and the fact that
it was quite difficult to find sufficient vaccine stocks so
quickly. However, good publicity and public relations on
behalf of the local Public Health Nurses and physicians
ensured a high acceptance rate of 90%. Only 29 of 309
susceptible male students refused to be vaccinated. The
acceptance rate for females was much lower. Of the 64
females identified as being susceptible to rubella, only 30
had received vaccine by the end of October 1986. This was
due in part to the Public Health Nurses requesting parental
approval for vaccination, as well as a negative pregnancy
test. In many of the females believed to be susceptible,
immunization records were incomplete and serology was
also requested prior to vaccination. As well, a significant
proportion of parents had expressed some previous concerns
about the value of immunization.
This resulted in a
significant delay and a number of refusals which could not
be fully overcome, despite intensive promotional efforts. It
is, therefore, not surorising that the epidemic did not fully
abate until August, because of the small but significant
continuing population of susceptibles within the community.
Mesures de Jutte contre Ja maJadie: Le programme de vaccination
n'a ete amorce que le 24 avril, soit 13 jours apres que le service de
sante publique ait ete avise d'une flambee. On attribue ce delai a
l'eloignement de la collectivite visee ainsi qu'au fait qu'il s'est
revele assez difficile de trouver suffisamment de preparations
vaccinales pour reagir rapidement. Toutefois, grace aux efforts de
sensibilisation du public et de relations publiques de la part des
infirmieres et des medecins de sante publique de la collectivite, le
programme a connu un taux d'acceptation eleve (90%). Seulement
29 des 309 eleves de sexe masculin receptifs ont refuse de se faire
vacciner. Le taux d'acceptation etait beaucoup plus faible chez Jes
filles. Des 64 filles trouvees receptives, seulement 30 avaient re<;:u
le vaccin a la fin d'octobre 1986. On attribue cette constatation en
partie au fait que les infirmieres-hygienistes demandaient le
consentement des parents avant de proceder a la vaccination, ainsi
que la preuve d'un test de grossesse negatif. Comme les dossiers
d'immunisation de bon nombre des sujets feminins juges receptifs
etaient incomplets, on a demande en outre de proceder a des
analyses serologiques avant !'immunisation. Enfin, une proportion
significative de parents avaient exprime leurs reserves quant a la
valeur de !'immunisation, ce qui avait entra!ne un retard important
et donne lieu a un certain nombre de refus categoriques, malgre une
promotion intensive. II n'est done pas surprenant que l'epidemie
1
n'ait pu etre jugulee avant le mois d'aoOt,
cause du nombre
significatif bien que restreint, de sujets receptifs dans la
collectiv i te.
I
a
The control measures instituted and the publicity
generated confined the outbreak to Wabush/Labrador City.
There was no spread to other parts of the island. Perhaps
most importantly, there was no subsequent case of
congenital rubella syndrome.
Les mesures de lutte anti-infectieuse instituees ainsi que Jes
efforts de sensibilisation du public ont circonscrit la flambee a la
region de Wabush/Labrador City. II n'y a pas eu transmission a
d'autres parties de l'lle. Fait important, il n'y a pas eu de cas
subsequent de rubeole congenitale.
Discussion: This outbreak of rubella in Labrador City was
the first epidemic of the disease in Newfoundland since
1qg2(0, It demonstrates once again that rubella, a vaccinepreventable viral illness, is still prevalent in Canada.
Despite routine wide-scale immunization programs for
children, a small group of susceptible individuals, primarily
male high school students, were affected in the outbreak.
This observation has been previously reported in the
literature(2,3). In this particular situation, the fact that the
susceptibles happened to be high school students confined to
classrooms for a large portion of the day undoubtedly helped
spread the infection. Where other susceptible individuals
are in close proximity to each other, the same result no,
doubt will occur again. This would appear to be the case I
even though the overall immunity of the population, through
previous vaccination and natural infection, was high.
Discussion: La flambee de rubeole enregistree a Labrador City
constituait la premiere epidemie de cette maladie a Terre-Neuve
depuis 1982(1). C'est une autre preuve du fait que la rubeole,
maladie d'origine virale qu'il est possible de prevenir par une
vaccination, sevit toujours au Canada. Malgre des programmes
d'immunisation systematique des enfants, cette flambee a touche un
petit groupe de sujets receptifs, pour la plupart des gar<;:ons
frequentant l'ecole secondaire. Cette observation avait deja ete
mentionnee dans la presse specialisee(2,3), Dans le cas qui nous
interesse, le fait que !es sujets receptifs etaient des eleves du
secondaire, confines dans des salles de cours pendant une bonne
partie de la journee, a sans nu! doute facilite la propagation de
!'infection. Une telle situation pourra certainement se reproduire si
d'autres receptifs viennent en contact etroit. C'est ce qui sernble
s'etre produit dans une collectivite ou le taux global d'immunisation
etait eleve, que Ce so it par vaccination OU infection na turelle.
- 201 -
Le programme de vaccination institue a permis jusqu'a un
The vaccination control program that was instituted
was partially successful in controlling the outbreak. Two certain point de circonscrire la flambee. Deux cent soixante-dixhundred and seventy-eight susceptible males attending high huit gan;:ons receptifs frequentant l'ecole secondaire dans la
school in the community received the vaccine. Most of collectivite ont ete vaccines. La plupart n'ont pas ete touches par
these dicf not get the disease, as is indicated by the la maladie, comme en temoigne le taux d'atteinte relativement
relatively low attack rate. It was unfortunate that it proved faible. II est toutefois malheureux que la vaccination des filles
more
difficult
to
vaccinate
susceptible
females. receptives se soit revelee plus difficile. La vaccination chez les
Vaccinating both sexes in this age group resulted in a deux sexes dans ce groupe d'age a occasionne divers effets
variety of adverse effects, involving approximately 10-15% secondaires touchant environ 10 15% des sujets. Les reactions Jes
of all those receiving the vaccine. The most common plus
frequentes
etaient
la
fievre,
un
erytheme,
une
Deux sujets
reactions were fever, rash, lymphadenopathy and a feeling lymphadenopathie et une impression de malaise.
of malaise. In only 2 individuals, males aged 17 and 18, seulement, des gan;ons de 17 et 18 ans, ont eprouve des effets
were the side effects severe enough to require close secondaires suffisamment graves pour necessiter une supervision
physician supervision and extended absence from school. medicale etroite et une absence scolaire prolongee. Le programme
The control program confined the outbreak to the one de Jutte anti-infectieuse a permis de circonscrire la flambee a une
community. It also gave provincial Public Health officials seule localite. En outre, Jes autorites provinciales de sante publique
time to notify staff so that appropriate records could be ont eu le temps d'aviser les emoloyes competents afin de faire
reviewed and susceptible females be offered rubella revoir les dossiers d'immunisation et d'offrir le vaccin aux filles
Toutefois, d'autres flarnbees de rubeole ont ete
vaccine. However, other outbreaks of rubella were reported receptives.
in the province. By the end of 1986, 208 cases had been signalees dans la province. Vers la fin de 1986, 208 cas avaient ete
notified from various parts of the province, and up to the recenses dans diverses regions de la province et en date de la fin de
mai 1987, 214 cas additionnels avaient ete signales.
end of May 1987, 214 additional cases had been reported.
a
I
The epidemic in Wabush/Labrador City conclusively
demonstrated only one case of vaccine failure.
This
occurred in a previously immunized 14-year-old female.
Acknowledgements: This study could not have been
completed without the cooperation of Public Health Nursing
and support staff in Wabush/Labrador City, personnel at the
Captain William Jackman Memorial Hospital Laboratory in
Labrador City, personnel at the Public Health Laboratories
in St. John's, Newfoundland, and physicians working in
Wabush/Labrador City, particularly Drs. Costello and Foley.
2.
3.
Newfoundland Communicable Disease Report:
summary, 9 October 1981.
Izumi T. CDWR 1987; 13:83-84.
CDC. MMWR 1986; 35:770-779.
SOURCE:
L'epidemie de Wabush/Labrador City n'a permis de documenter
fa<;:on categorique qu'un seul cas d'echec vaccinal, chez une
adolescente de 14 ans.
i1 Remerciements: La presente etude n'aurait pas ete possible sans la
collaboration des infirmieres et du personnel de soutien des services
de sante publique de Wabush/Labrador City, du personnel de
laboratoire du Captain William Jackman Memorial Hospital de
Labrador City, du personnel des laboratoires de sante publique de
Saint-Jean (Terre-Neuve), ainsi que des medecins exer<;:ant
Wabush/Labrador City, notamment Jes ors Costello et Foley.
a
References:
References:
l.
I de
Weekly
M Bokhout, MD, (formerly) lvledical Officer of
Health, Gren[ ell Regional Health Services,
St. Anthony, Newfoundland.
l.
2.
3.
Newfoundland Communicable
Summary, 9 octobre 1981.
Izumi T. RHMC 1987; 13:83-84.
CDC. MMWR 1986; 35:770-779.
SOURCE:
Disease
Report:
vr M Bokhout, (anciennement) Medecin-hygiifoiste,
Services regionaux de sante Gren[ ell, St. Anthony
(T erre-N euve).
The Canedo Dlseesea Weekly Report pre..,nts current lnlormellon on lnfecllouo
and other dlseoees for surveillance purpose• end la evolleble free of charge upon
request. Many of the article• contain prellmlnnry lnformollon end further
conflrrnetlon mey be obtained from the BOUJ'C<!B quoted. The Department of
Netlonel Health end Welfare does not assume reopomlblllty for occumcy or
authenticity. Contribution• ere welcome On the official langUB<J• of your
choice) from anyone working In tho health flold and will not preclude
publication eloewhere.
Le Rapport hebdomedelre deo meledle• eu Conede, qui foumlt des donn~ea pertlnentee sur le•
maladies lnfectleusea ot lea autres maledieo dens le but do feclliter leur surveillance, peul
~tre obtenu gratultement aur demende. Un grand nombre d'erllclee ne contiennent que des
donmfoe rommnlres male den reneelgnements compl~mentolrett peuvent Mre obtenus en
o'adressent eux 60urcea clt~ea.. Le miniot~re de In Sant~ notionole el du Bien·~tre social ne
peut atre tenu responooble da l1exoctitude, nl de l'outhenticit~ des articles. Toute personne
oeuvront dens le domelne de le sant~ est lnvlt~e ~ collaborer (den• le langue officlelle de son
cholx) et la publlcatlon d'un article dona le pr~sent Rapport n'en emp~che pa• le publication
ellleura.
Edlton Dr. S.E. Acre• (613) 957-0325
Meneqlng Edlton Eleanor Peuloon (61J) 957-1788
Cln:uletlonl Dolly Rl~qln• (613) 957·0841
R~dacteur
R~dacteur
en cheh or 5£, Acres (613) 957-0325
edrnlnlatmtlh Eleonor Paulson (613) 957-1768
Dlatrlbutlon: Dolly Rlgglnn (613) 957-0841
Burenu of Communicable Dloeaoe Epldemloloqy
Laboratory Centre for Dlsenoe Control
Tunney's Pasture
OTTAWA, Ontario
Canedo KlA !L2
Bureau d'~plMmlologle den maladies trensmleslbla•
Lehoretolre de lull• contra le maledle
Pare Tunney
Ottawa (Ontario)
Canada KlA !L2
- 202 -
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising