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In 1996, 315 892 cases
of tuberculosis were notified in 50 countries of the WHO European
Region (Table 3). The notification
rate varied between countries from 0 in Monaco and San Marino
to 195 in Georgia (Box 5) with a median of 26 cases per 100 000 population.The
notification rate was lower than 20 per 100 000 in 21 countries,
all of which are situated in the western part of Europe except
for the Czech Republic and Israel. In 11 of these countries,
the rate was less than 10 per 100 000. The rate was 20 cases
per 100 000 or over in 29 countries located in the eastern
part of Europe, except for Portugal and Spain (Map).Comparison
of tuberculosis notification rates in 1995 and in 1996 was
possible for all countries providing the number of cases notified
in 1996, except for Andorra, Georgia and Ukraine (Table
3). The distribution of countries by notification rate
(under 20 cases, 20 cases and over per 100 000 population)
was similar in 1995 and in 1996. Between 1995 and 1996, the
notification rate decreased in 18 countries, remained stable
in five and increased in 24. The rate increased by more than
10% in 12 countries (Armenia, Azerbaijan, Belarus, Estonia,
Kazakstan, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Malta,
Russian Federation, Uzbekistan), eight of which (all republics
of the former USSR) reported over 50 cases per 100 000 in 1996.
These trends should be interpreted with caution, particularly
since they are based on two years only. Data on tuberculosis
cases are dependent on the notification procedure of a country
as well as on its health care system. Changes in notification
rates may be related to the epidemiological context, but also
to changes in patterns of reporting or in diagnostic procedures.
For example, the decrease in Tajikistan between 1995 and 1996
may be explained by the reporting of cases in 1995 which had
not been reported in previous years due to the disruption of
the health services (Prof. Sirodjidinova, personal communication).
Likewise, a similar overreporting of cases which had not been
reported or diagnosed because of the disruption of the tuberculosis
control programme in 1991-1995 may account for the particularly
high 1996 notification rate in Georgia (Prof. Khechinachvili,
personal communication).In the 37 countries with available
information on previous tuberculosis history (Table
4), the overall proportion of new cases was 88%. The proportion
of recurrent cases was 11% ranging from 0 to 35% (median 9%).
Comparisons between countries should be made with caution however,
considering the differences in the definition of recurrent
cases.
Age and sex
Overall, among the 38
countries with information available on sex (Table
5), 1.8 times more male than female tuberculosis patients
were reported. The sex ratio ranged from 0.8 to 2.9 (median
1.6). The age distribution of all new and recurrent cases could
be described according to recommended age groups in 35 countries
reporting a total of 122 799 cases (Box
6). Patients younger than 15 years of age accounted for
5% of the cases (children under 5 for 2%). About half of the
cases (49%) were found in the 15-44 year age group, 28% in
the 45-64 year age group and 18% in those aged over 64.
The age distribution
varied across countries (country profiles). The proportion of patients
in the 15-44 year age group was lower in countries with a lower
notification rate (under 20 per 100 000) than in countries
with notification rate of 20 and over (41% versus 53%) while
the proportion of patients aged 65 years or more was higher
(29% versus 13%).The age and sex-specific tuberculosis notification
rate also varied across countries (Box 7, 8 & 9).
The rate was similar in males and females until the age of
15, but was higher in males in all age groups thereafter, with
larger sex differences in countries with a notification rate
of 20 and over. In countries with a notification rate under
20 (Box 7), the rate increased with
age for both sexes. Age-specific rates in males increased rapidly
until age 25-34, remained stable until age 55-64 and increased
again in the older age group. In females, the rate peaked at
25-34, decreased slightly until age 55-64 and then increased
again. The peaks observed for both sexes in the age group 25-34
were suppressed when age-specific rates were calculated using
cases in nationals only as numerators (data not shown). In
countries with a notification rate of 20 and over (Box
8 & 9), age-specific rate in
males increased with age until age 35 - 44. Above age 44, the
rate reached a plateau in countries with a notification rate
from 20 to 49 (Box 8). In countries
with a notification rate of 50 and over (Box
9), the age specific rate in females peaked earlier (at
25-34), but generally followed the male trend at a lower level.
Children under 5 years of age have a much higher risk of developing
tuberculosis after infection than older children [9].
The notification rate in children under 5 was higher than that
in children aged 5 to 14 in countries with a notification rate
under 20, but not in countries with a notification rate of
20 and over. This suggests possible underreporting of cases
in children under 5 in some countries.
Geographic origin
Information on geographic
origin was available in 23 countries, based on birth place
(as recommended) in 18 and citizenship in eight, with three
countries (France, Luxembourg and Switzerland) providing information
on both birth place and citizenship (Table
8). The proportion of cases with missing information on
birth place was greater than 20% in three countries (Croatia,
France and Switzerland). The proportion of missing information
on citizenship was 3% or less, except in France (12%).The proportion
of cases in foreign-born patients ranged from 0% in Czech Republic
to 83% in Israel. In countries providing information on geographic
origin based on citizenship, the proportion of cases in foreigners
varied from 24% in Austria and France to 61% in Luxembourg.
Comparisons of the proportion of patients of foreign origin
across countries should however be made with caution, because
of differences in notification of some population groups (e.g.
asylum seekers, illegal immigrants), various policies regarding
immigration and acquisition of nationality, and potential differences
in tuberculosis screening programmes for immigrants.The proportion
of patients of foreign origin in 1995 and in 1996 was fairly
stable in the 16 countries providing this information in both
years using the same definition.
Data on the continent
of origin of the patients are presented in Table
9 for 15 of the 16 countries which provided this information
(Croatia is excluded because of a large proportion (41%) of
cases with missing information on geographic origin). For France
and Switzerland, which provided data both on birth place and
citizenship, data on citizenship were used because this information
was more complete. The distribution by continent of origin
may be compared in 1995 and in 1996 for the 12 countries providing
the information in both years using the same definition. In
1996, 27% of the patients of foreign origin originated from
Europe, 26% from Asia and 39% from Africa, similar to the proportions
observed in 1995 (29%, 26% and 40%, respectively). Because
several non-European countries (Armenia, Azerbaijan, Georgia,
Israel, Kazakstan, Kyrgyzstan, Tajikistan, Turkey, Turkmenistan
and Uzbekistan) are part of the WHO European Region, the proportion
of cases in immigrants from within the WHO European Region
is higher than that of patients coming from the European continent
only (34% compared with 27% in 1996).The specific country of
origin of the patients was available in 14 countries in 1996:
Austria, Belgium, Denmark, Estonia, Finland, Iceland, Italy,
Luxembourg, Malta, Netherlands, Slovakia, Slovenia, Sweden
and Switzerland. Among the 11 countries which had provided
the same information in 1995 (all but Estonia, Slovakia and
Sweden), the origin of the patients was diverse, but five countries
together accounted for more than 45% of the patients of foreign
origin each year:
- Somalia: 13% in 1995 and in 1996
- Morocco: 12% in 1995 and in 1996
- Yugoslavia: 11 % in 1995 and 10%
in 1996
- Turkey: 7% in 1995 and 8% in 1996.
- Bosnia-Herzegovina: 6% in 1995 and
5% in 1996
Site of disease
Site of disease was
reported in 38 countries for all new and recurrent cases (N=
138 951 cases): 11 countries provided detailed information
on major and minor site of disease from which it was possible
to classify cases as pulmonary or extra-pulmonary; 13 provided
information based on the pulmonary classification; 14 provided
information by classifying cases as respiratory or extra-respiratory
(Table 10). In all 38 countries, the proportion of
cases with unknown site of disease was at most 3%. Among the
countries providing information based on detailed site or on
pulmonary classification, 77% of the cases were pulmonary.
In the countries providing information based on respiratory
classification, the proportion of respiratory tuberculosis
was 90%.Pulmonary tuberculosis could be reported as a major
site only, whereas extra-pulmonary localisations could be reported
either as major sites (if not associated with pulmonary tuberculosis)
or as minor sites (if associated with another localisation).
Among the 11 countries (Austria, Belgium, Estonia, Iceland,
Luxembourg, Malta, Norway, Romania, Slovakia, Slovenia and
Switzerland) providing detailed information on major and minor
site of disease (Box 10), 82% of the
patients had pulmonary tuberculosis. Pleural tuberculosis was
reported in 12% of the patients. All other sites were reported
in less than 3% of the patients. A minor site of disease was
reported for 1267 patients (4%), of which 1177 also had pulmonary
tuberculosis. Among those 1177 patients, 605 (51%) had pleural
tuberculosis, 251 (21%) had disseminated tuberculosis and 122
(10%) had intrathoracic lymphatic tuberculosis.Sites of disease
were distributed differently according to age (Box
10). Extra- pulmonary tuberculosis without pulmonary tuberculosis
was more frequent among children (less than 15 years of age)
than in adults aged 15 years or more (52% versus16%). Several
localisations, associated or not with pulmonary tuberculosis,
were reported more frequently in children than in adults:
- intrathoracic lymphatic (34% versus < 1%);
- extrathoracic lymphatic (5% versus
2%);
- meningeal (4% versus < 1%);
- disseminated (3% versus < 1%).
All children with disseminated
tuberculosis were reported with a pulmonary localisation, most
probably corresponding to miliary tuberculosis.Pleural tuberculosis
was rarely reported among children under 5 years of age (2%).
The proportion of cases with pleural tuberculosis was the highest
among children aged 5 to 14 (18%) and in the 15-24 year age
group (20%). Above 24 years of age, the proportion of cases
with pleural tuberculosis decreased with age (13% in patients
aged 25-34, 11% in patients aged 35-44, 9% in patients aged
45 or more). The distribution of the sites of disease in 1995
and in 1996 was similar overall and by age group in the seven
countries providing data in both years (Austria, Iceland, Luxembourg,
Malta, Romania, Slovenia and Switzerland).
Bacteriological confirmation
Bacteriological confirmation
of the cases was available in 34 countries (Table
11): based on positive culture, as recommended, in 12 countries,
and based on positive culture or positive sputum smear in 22,
including two countries (Armenia and Georgia) for which confirmation
was based on sputum smear only. The median proportion of bacteriologically
confirmed cases was 62% in the first group of countries (range
43% to 88%) and 50% in the second group (range 17% to 67%).
In 12 countries, the proportion of cases without bacteriological
confirmation (non confirmed or unknown) was over 50% regardless
of the type of confirmation.
Culture
In 1996, information
on culture was available in 18 countries providing individual
data. The median proportion of cases with a positive culture
was 54% (range 20% to 88%). The median proportion of cases
for which culture was reported as performed was 80%. The proportion
of cases with unknown culture results ranged from 2% to 76%
and was mainly due to cases with no information about culture,
except in some countries (e.g. France, Romania) where a substantial
proportion of the cases had a culture done but the results
were unknown.The average proportion of cases with a positive
culture was higher among cases with pulmonary/respiratory tuberculosis
than among cases with extra-pulmonary/extra-respiratory tuberculosis
(37% versus 19%) and increased with age: 13% among children
under 15, 31% among patients aged 15 to 44 years, 37% among
patients aged 45 and over. Among the 14 countries providing
information on culture both in 1995 and in 1996, the median
proportion of cases with a positive culture was stable in both
years (59% in 1995 and 60% in 1996). The average proportion
of cases with a positive culture was lower in 1996 (34%) than
in 1995 (41%), mainly because of a decrease in this proportion
in Romania (23% versus 37% in 1995). As in 1995, large differences
between countries were observed. All countries stated that
culture was available for all suspect tuberculosis cases in
the whole country in 1996. However, differences in diagnostic
practices and in reporting patterns may exist between countries.
For example, some countries (Denmark, Finland, Norway) report
information on positive cultures only. The countries stated
that culture was available for all suspect tuberculosis cases
in the whole country in 1996. However, differences in diagnostic
practices and in reporting patterns may exist between countries.
For example, some countries (Denmark, Finland, Norway) report
information on positive cultures only. The completeness of
information and the proportion of cases with positive culture
was higher in countries where culture positivity is required
to classify a case as definite.
Sputum smear results
Information on sputum
smear results was available in 31 countries (Table
13). The European recommendations specify that only the
results of smear examination performed on spontaneously produced
or induced sputum should be reported [3,4]. Among the 31 countries
reporting smear results, 7 followed this recommendation, 17
included also results of examination of broncho-alveolar or
gastric lavage and 7 included results of smears performed on
specimens not taken from the lung. The median proportion of
smear positive cases was 40% (range 14% to 60%) among the pulmonary
cases and 37% (range 9 to 58%) among the respiratory cases.
In 17 countries, the proportion of pulmonary/respiratory cases
with negative or unknown smear results was over 60%. Individual
information on smears was provided by 16 countries. The median
proportion of smear positive cases among pulmonary cases (among
respiratory cases in the Czech Republic) was 37% (range 14%
to 57%). The median proportion of pulmonary or respiratory
cases for which smear examination was reported as performed
was 90%. The proportion of pulmonary or respiratory cases with
unknown smear results ranged from 0% to 49%. Unknown smear
results could be due to the smear being reported as performed
but results being unknown, to the smear not being performed,
or to a complete absence of information. The average proportion
of pulmonary/ respiratory tuberculosis cases with a positive
smear was lower in children under 15 years of age (13%) than
in adults (55% in patients aged 15 to 44 years, 47% in patients
aged 45 years and over). Among the 14 countries providing individual
information on smears both in 1995 and in 1996 (Austria, Belgium,
Czech Republic, Estonia, Finland, France, Iceland, Italy, Malta,
Netherlands, Romania, Slovenia, Sweden and Switzerland), the
proportion of smear positive cases among pulmonary or respiratory
cases was similar in both years. |
