| BCG (Bacillus Calmette-Guerin) vaccine was developed
from an attenuated strain of Mycobacterium bovis at the beginning of the
twentieth century. Its widespread use as a vaccine against tuberculosis
spread in Europe, and subsequently globally, over the next 50 years. It
remains one of the most frequently administered vaccines in the world.
It has also been one of the most controversial. Widely differing estimates
of the effectiveness of BCG at protecting against different forms of tuberculosis
in different population subgroups in different settings have been published
[1]. Some countries, with a low incidence of tuberculosis, did not adopt
the use of BCG vaccine at all and some others abandoned its use at a later
stage. In addition, great variation developed in national programmes for
the administration of BCG including the age(s) at which it should be given,
whether or not its administration should be preceded by tuberculin sensitivity
testing, and whether repeat vaccinations with BCG should be given.
In recent decades, some consensus has been reached about the role of
BCG vaccination in populations where it appears to offer some protection.
Protection appears to be greatest in infants and children and against
the early primary progressive forms of disease (including disseminated
disease and meningitis) [2,3]. Protection against disease resulting from
secondary reactivation, particularly pulmonary disease in adults, appears
to be much more limited. As this is the group of cases responsible for
most transmission of infection, BCG vaccination probably has very limited
impact on controlling the incidence of new infections in the community.
In addition, the evidence that repeat vaccination offers additional protection
is very limited.
It is therefore timely that, on World TB Day, this edition of Eurosurveillance
brings together a series of articles on the use of BCG vaccination in
Europe demonstrating not only the continued variation in policies for
the use of BCG, sometimes in otherwise very similar epidemiological settings,
but also the growing number of countries reviewing and revising their
national policies in the light of the growing consensus on its role and
the local pattern of occurrence of TB.
Andrea Infuso and Dennis Falzon, on behalf of the EuroTB network (www.eurotb.org),
have surveyed national policies on BCG vaccination in Europe [4]. Most
(83%) countries responded to reveal policies that varied from no use
of BCG vaccine at all, through use of vaccine in neonates and infants
in population groups assessed to be at high risk of infection, to vaccination
of all children at birth, in infancy, at school entry or in later school
years. Routine revaccination, with or without prior tuberculin sensitivity
testing, is recommended in four countries – in one instance, for
all children at four separate ages. In 12 countries, the current policy
was reported to be under review with a shift from universal vaccination
to selective vaccination of children at risk being the most common proposal.
Limited data on BCG vaccine uptake levels or information on the occurrence
of adverse effects was available and the authors conclude by calling
for more systematic collection of comparable data between countries,
as well as the discontinuation of routine revaccination. The availability
of comparable data on the occurrence of TB in different countries and
an understanding of current policies for BCG vaccine use and its uptake,
contribute usefully to discussions within individual countries about
future policy.
France is one such country that is currently reviewing its approach
to the use of BCG vaccine. Daniel Levy-Bruhl reports that revaccination
with BCG has ceased from 2004 in France [5]. Moreover, the Conseil Supérieur
d’Hygiène Publique de France (the national high committee
of public hygiene) has recommended the discontinuation of routine vaccination
of all schoolchildren, in favour of a more targeted approach, but only
when other measures to strengthen control measures to decrease the risk
of infection in children have been implemented. In Finland too, where
all newborns have routinely been offered BCG vaccination with an uptake
rate of 98%, Eeva Salo reports that the national policy has recently
been revised so as to offer BCG only to risk groups [6]. A similar review
and revision of BCG policy in the United Kingdom has also taken place
in July 2005, with the implementation of selective vaccination and abandonment
of the universal schools BCG programme in place since the 1950s [7].
Sweden, by contrast, abandoned its policy of universal BCG vaccination
in 1975 while retaining selective vaccination for high risk groups [8].
Victoria Romanus reports that the incidence in indigenous Swedish born
children, which was already very low in the 1970s, has remained low.
High uptake of BCG vaccination, however, has been achieved in the high
risk groups. Despite the low incidence in Sweden, outbreaks occasionally
occur in vulnerable groups such as young children in association with
delayed diagnosis, providing a reminder of the need to identify and institute
treatment in active cases early as well as to screen contacts who may
have been exposed.
Another benefit of the collaboration of all European countries in the
EuroTB surveillance network has been the opportunity to collate information
on the outcome of treatment in patients with tuberculosis. This is not
without difficulty as assessment of treatment outcome in individuals
within countries involves decisions about which cases to include, how
to classify various categories of failure to complete standard treatment
and how to deal with cases on which there is only partial or complete
absence of information on outcome. To collate these data from different
countries and provide information that can usefully be compared between
countries is an even greater challenge. Dennis Falzon and colleagues
[9], on behalf of EuroTB, have gone along to achieving this through the
development of standardised outcome categories, and definitions of disease
type and population subgroups to be included (all confirmed pulmonary
cases with or without previous treatment). Forty-two of 51 eligible European
countries submitted results and completeness of reporting was reported
to be very high in most countries (at least 98% of originally notified
cases in 35 countries). Despite generally high levels of reported successful
treatment completion, problems with the interpretation of outcome categories
such as ‘defaulted’, ‘transferred’ and ‘unknown’ continue
to complicate the interpretation of the outcome in those in whom treatment
has probably not been successful. The authors conclude that further simplification
of outcome categories combined with standardisation of the application
of the definitions will lead to more robust and comparable data.
Finally two reports from TB trouble spots, Latvia and London, illustrate
the different tuberculosis problems in those widely different settings
and the challenges to achieving effective control of tuberculosis. Vaira
Lemaine from Latvia [10] describes the high incidence of disease, including
high prevalence of multi-drug resistance (MDR), that has emerged since
the early 1990s with the socio-economic disruption and health system
reform that followed the political changes of that period. The implementation
of a new national tuberculosis programme in 1996 with adoption of the
WHO Directly Observed Therapy Short-course (DOTS) strategy for all new
cases and, in 1999, the addition of the WHO DOTS-Plus strategy for individualised
management of MDR tuberculosis, has led to great progress in reducing
case numbers. Much remains to be done, however, and progress to date
is threatened by a developing HIV epidemic. In London, as Delphine Antoine
and colleagues report [11], tuberculosis is not under control and case
numbers continue to increase, though not at the levels reported from
Latvia. Particular problems are identified with tuberculosis in the homeless,
drug users and alcoholics. The authors call for greater adaptation of
treatment and care services in London to cater for the special needs
of those at greatest risk of tuberculosis in the capital including greater
use of DOT (especially in the intensive phase) and greater support for
patients during treatment.
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