Introduction
Finland is one of the few European countries where neonatal BCG (Bacille
Calmette-Guérin) vaccination is still universally implemented.
Sweden, which is culturally and geographically our nearest neighbour,
moved to a selective programme in the 1970s [1]. Finland has a low incidence
of tuberculosis (TB), and has met the International Union Against Tuberculosis
and Lung Disease (IATLD) criteria for discontinuing a universal BCG programme
in countries with a low prevalence of TB [2]. Following a change in vaccine
strain, an increase of vaccination complications has been seen. The National
Vaccination Advisory Board has recently recommended changing the policy
to targeting risk groups, and it is planned that the new programme will
begin in January 2008. New official recommendations are being prepared
but are not yet available.
Background
The newborn BCG vaccination programme was begun in Finland in the 1940s.
It is administered by physicians (mostly pae-diatricians) in maternity
hospitals and uptake of the vaccine is high, with over 98% of newborns
being vaccinated. Tubercu-lin testing and revaccination of tuberculin-negative
schoolchildren was practised until 1990. In 2001, the newborn vaccina-tion
programme was evaluated by Tala-Heikkilä et al [3]. This evaluation
concluded that a selective BCG vaccination strat-egy would be a safe
and cost-effective approach in preventing tuberculosis in Finland,
if the identification of high-risk groups were successful. A transition
period was recommended to identify the risk groups and to prepare for
the change.
From 1971 to 1978, when Finland used the Gothenburg BCG strain, the frequency
of BCG osteitis was very high, at 36.9/100 000 vaccinated. It decreased
to 6.4/100 000 after changing the vaccine to the Glaxo-Evans strain and
decreasing the dose to 0.05 ml [4]. In August 2002 the vaccine strain
had to be changed at short notice. Due to concerns about reduced potency
of the Evans vaccine, it was withdrawn by the manufacturer. Since August
2002, the vaccine produced by Den-mark’s Statens Serum Institut
(SSI) has been used in Finland.
Following the change of the vaccine strain to BCG SSI, a sharp rise in
the incidence of inguinal lymphadenitis was noted, from about 8/100 000
with the Evans strain to 285/100 000 in the months immediately following
the change [5]. An increase in the rate of BCG lymphadenitis was also
noted in London (Royal London Hospital) after the same change in vaccine
strain, although the application method was also changed at the same
time from percutaneous to intradermal route [6]. The initial increase
of reported lymphadenitis has settled in Finland to 140/100000 (Marko
Luhtala, National Public Health Institute, KTL, personal communication).
Milstein et al noted clusters of increased reported adverse reactions
to BCG vaccine follow-ing a change in the vaccine strain in different
populations or settings [7]. Until 2002, only one to two cases of BCG
osteitis per year were notified in Finland [5]. Six cases of BCG osteitis
have been notified in children vaccinated in 2003, [8, Marko Luhtala,
KTL, personal communication]. The increase in adverse reactions to BCG
SSI is also a factor influencing the view of both the medical faculty
and the public about universal neonatal BCG vaccination. As the incidence
of TB has decreased, the complications are no longer considered acceptable.
Factors considered during the preparation of the new programme
Demographics of TB patients
In the Finnish BCG debate, Finland has been repeatedly compared with
Sweden, where mass BCG vaccination was stopped in 1975, when TB incidence
in Sweden was 18/100 000 [3]. In comparison, the annual incidence of
TB in Finland is cur-rently lower at 6.6/100 000 in 2004, and has continued
to decline steadily [9].
The difference between Finland and the other Nordic countries is the
population in which new cases are detected. In Den-mark, Norway and Sweden
the majority (60 to 80%) of TB cases are detected in individuals born
abroad [10], whereas in Finland the proportion of TB cases in foreign-born
people was only 12% in 2004, although this proportion has been increas-ing
on an annual basis, (5.6% in 1995 and 8.4% in 2000) [9].
In 1960 the incidence of TB in Finland was high at 172/100 000 [3]. As
a consequence, many of those aged 65 years and older had contracted TB
infection in their youth. The incidence of TB is highest in the oldest
age group, those over 75 years [9] [FIGURE]. However, the most significant
decline in the number of cases has also been seen in this group, possibly
due to a reduction of the exposed people in the age group. Childhood
TB is very rare in Finland, with an annual average of four cases registered
in children in the whole country [9].
Geography
Finland shares a large border with Russia, where the notification rate
for TB was 106/100 000 in 2003, and the proportion of multidrug resistant
(MDR) TB is high, 6.7% in new cases in 1999 [9], compared with Finland
where no MDR cases were notified in 2004. In addition, the Russian
Federation has one of the highest rates of HIV infection in all of
Europe, with St. Petersburg and the Leningrad Oblast being heavily
affected [11]. In recent years, there has been an increase in migration
from Russia to Finland. Communication across the border is frequent,
and trade and commercial cooperation is increasing. Despite this, no
increase in the incidence of TB among Finnish-born people living near
the Russian border has been noted to date, but the situation will continue
to be monitored.
Finland has also frequent interactions with Estonia, with several boats
making the journey between Helsinki and Tallinn daily. In Estonia, the
proportion of MDR-TB is high, 12% [10]. The HIV epidemic in Estonia also
continues to expand. The possibility that MDR-TB may spread to Finland
has been a cause of concern, although one which has so far not been real-ised.
There have been a few separate cases but no outbreaks detected.
Inoculation site
BCG in Finland is administered intradermally in the left thigh, as originally
described by Wallgren [12]. Among active par-ent groups in particular,
concern has been raised about the possible contribution of the vaccine
site to the frequency of com-plications. In Sweden, the thigh was also
used until the 1970s. However, when the mass BCG vaccination changed
to a se-lective immunisation programme, it was decided that the inoculation
site should be changed from the thigh to the left upper arm (Victoria
Romanus, personal communication). The manufacturer of the current vaccine,
SSI, recommends the left thigh as the inoculation site. The only article
found comparing these two sites was published by Gaisford and Giffiths
in 1954 [13]. The study is not randomised but observational and describes
the decreasing frequency of regional lymphadenitis as the au-thors
decreased the dose and changed the site to the upper arm. The authors
recommend inoculation in the arm, but their results may have been influenced
by the different dosages of the vaccine, different strains used and
the growing skill of the vaccinators.
When asked about their BCG scars, English children found them unsightly
and showed a preference for other sites than the outer arm [14]. These
children were vaccinated at age 11 to 13, and their reaction might have
been different if they had grown up with an old scar acquired as infants.
WHO recommends vaccinations in the upper arm, and by convention BCG scars
are looked for over the left arm everywhere else in the world but Finland.
As it is better to have an internationally rec-ognised token of a successful
vaccination, it is recommended that the vaccination site be changed to
the upper arm when the vaccination programme changes in 2008.
Age at vaccination
In Finland, there has been public discussion about the age of BCG administration,
with parents expressing their concern for the young age of the vaccinees,
and demanding the vaccination to be postponed to several weeks or months
of age. BCG is most effective in preventing cases of severe TB, such
as meningitis and miliary TB, in small children [15]. For maximum benefit
children should be vaccinated soon after birth. On the other hand,
severe immune deficiencies such as severe com-bined immune deficiency
(SCID) may not be evident at birth, exposing the children to severe
complications of BCG, a rea-son why Sweden defers BCG vaccine until
six months of age. Although the incidence of SCID is unknown, a recent
review estimated that it is at least 1/100 000 [16]. If this figure
is correct, with targeted BCG vaccination a newborn child with SCID
would receive BCG in Finland once in 30 years. HIV screening is offered
to all pregnant mothers in Finland, with coverage of over 99%. Children
of HIV positive mothers are offered BCG only after they have been found
not to have contracted the virus, so the risk of vaccinating an HIV
positive child is low.
Vaccination centres
The rate of BCG complications has been observed to be influenced by the
training and skills of the vaccinator [7].
With fewer children being vaccinated, vaccinating expertise will gradually
decline. To ensure adequate skills the number of vaccinating centres
needs to be limited. Almost all children in Finland are born in hospitals
and it is recommended that the paediatricians will continue the vaccination
of newborns. However, there is controversy about who should vaccinate
older children, and the discussion is ongoing.
Recommendations
Target groups
Newborns to be vaccinated are those corresponding to the following definitions:
(1) Children of immigrant families, with parents or grandparents originating
from countries with a high incidence of TB, or with a member of the household
from a high incidence country
(2) Children of Finnish-born parents with a first or second-degree relative
(parent, grandparent, sibling or parent’s sib-ling) who has or
has had TB
(3) Children of families planning to stay for a prolonged period in a
high-incidence country
(4) Children of families requesting BCG for their child.
Using these target groups, the estimated annual number of newborns eligible
for BCG is between around 3000 and 3500, or 5%-6% of this age cohort.
Older children
Older immigrant children from high-incidence countries who have not yet
started school should be offered BCG if they have not been previously
vaccinated and are tuberculin negative. Another group of older children
to be vaccinated is unvaccinated contacts of detected cases of infectious
TB who are healthy and tuberculin negative. The annual number of these
children needing vaccination is calculated to be between 200 and 500.
Identifying newborns who need to be vaccinated
The need for BCG in a newborn should be ascertained before delivery.
Finland has a well-functioning system of public ma-ternity clinics
with almost universal attendance by pregnant mothers. A questionnaire
to be used by midwives at maternity clinics is currently being tested
with the guidance of the National Public Health Institute (Kansanterveyslaitos,
KTL). When the questionnaire has been evaluated, training will take
place to prepare for its implementation in all maternity clinics.
Training and education
As childhood TB is very rare in Finland [9], physicians’ ability
to suspect and diagnose it has declined. Very few paediatri-cians have
ever seen a child with miliary TB or tuberculous meningitis. During the
last 10 years, there has been only one case of paediatric tuberculous
meningitis in Finland detected in an immigrant child [17]. With universal
BCG, the risk of an infected child developing serious disease has been
small. The medical community must be alerted to the real risk of TB in
exposed unvaccinated children and the need for vigorous contact tracing.
Implementation of the new programme
The Ministry of Social Affairs and Health (Sosiaali-ja terveysministeriö)
and KTL have agreed that KTL will take the lead in the preparation for
the change to the targeted BCG programme. New official recommendations
are being prepared but are not yet available.
A committee organised by the Finnish Lung Health Association (Filha ry),
cooperating with the KTL and supported by the Ministry for Social Affairs
and Health, has been preparing a new tuberculosis control programme for
Finland. Several parts of the guideline have already been published in
the national medical journal Suomen Lääkärilehti and are
also available online [18]. The guidelines will be completed in 2006.
While enhancing awareness and knowledge of TB the guidelines will support
the preparation for the change to the new BCG programme.
Correction
In the section 'Factors considered during the preparation of the
new programme', 'Geography', paragraph 2, sentence 3, should
read: The HIV epidemic in Estonia also continues to expand.
This change was posted online on 27 March 2006.
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