Læknablaðið - 01.02.1976, Page 82

46
LÆKNABLAÐIÐ
temporary increase during the years of the
second world war, continued to fall rapidly
reaching 20 per 100.000 population in 1950. In
the period from 1930-50 the tuberculous death
rate thus dropped a little over 90 per cent.
In the year 1952, when speeific tuberculosis
medical treatment was initiated (streptomycin,
isoniazid and PAS) the death rate dropped to
14 per 100.000 population and the next year
further down to 9 and since 1956 it has never
exceeded 5 per 100.000. From the year 1962
the tuberculosis mortality has never been over
2 per 100.000 population.
The mortality rates have been broken down
to reveal the role of age and sex specific death
rates over some selected five year periods. Also
the rates are shown according to different
forms of the disease, pulmonary, meningeal
and other forms. The highest proportionate
mortality (60%) was observed in the 15-19
vear age group between 1926 and 1930. From
1911 to 1930 tuberculous meningitis caused a
remarkably high number of deaths, fluctuating
between 20 and 50 per 100.000 population.
Since 1956 not a single death from this forrn
of the disease has occurred. Up to that year
the highest meningitis death-rate consistently
occurred in infancy and early childhood.
Sex-specific tuberculosis death rates indicate
that in every age-group the disease is more
dangerous to women. Between 1941 and 1945.
when the combined mortalitv-rate began to
drop sharplv. it was the rate for males, which
was first affected.
Due to the very steen decline in tuberculosis
mortality especially from 1952 tuberculosis
mortality figures can no longer be considered
the right. criterion for the spread and course
of the disease. The infection and morbiditv
rates are from then on the best measures of
the prevalence and course of the disease.
Tuberculosis infection-rátes obtained throueb
tuberculin t.est'ng on a comoaratively broad
scale. esnecially in school children 7-13 years
of age, show a progressive reduction in tuber-
culosis infectinn in the country as a whole.
These tuberculin survevs on school children
were initiated by the districts health officers
in the second decade of the century and there-
fore now extend over 60 years. The procedure
of t.he tuberculin survevs and the methods
"sed are mentioned. The shortcomings of
t.hese surveys and their importance are dis-
cussed. Th" value of the ^urveys is con-
sidered doubtful as long as the examinations
are performed without anv guidance or co-
ordination. About the year 1930 the total per-
centage tubercidin t.ested in the age grouo
7-13 venrs was a little ov°r 10%. In the year
1935 the director of tubercuiosis control sent
all th“ health officers instructions on how to
perfo"m th« tuberculin testing and how to
interorete the reactions together with some
anoouragement to perform such survevs. That
v-'íir ahout 43 per cent of t.ho 7-13 years
populátion was tested and in 1945 the percent-
age was 75% Between 1965-1970 the attend-
ance percentage was 85%.
The tested 7-13 years age group showed in
1935 26,1 per cent positive reaction, in 1945
10,1 per cent, in 1955 5,3 per cent and in 1970
0,7 per cent. In 1970 0.2% of the 7 years old
children reacted positively and 1.1% of those
13 years of age. The decline of the infection
rate in this age group is remarkable. The very
few BCG vaccinated children were excluded
from the surveys.
In the tuberculosis surveys made in the
years 1940-1945 which covered 12 medical
districts or parts thereof extensive tuberculin
examinations were performed. The results of
these surveys showed that the infection rate
was higher among male adults than females.
This difference was notable after the age of
15 and especially in isolated and thinly popu-
lated rural districts. In urban and more thick-
ly populated rural districts the infection rate
was much higher.
BCG vaccination was first used in Iceland
in 1945. Only few persons were vaccinated the
first two years. In 1948 a systematic vaccina-
tion was proposed in the country to supplement
the tuberculosis-control plan. The vaccination
was particularv meant for the age group 12-29
where the risk of infection appeared to be
greatest. However, at the end of the year
1950 a total of only about 6900 persons had
been vaccinated mostly groups of school-
children, young adults and contacts of tuber-
culosis cases. Most of the children and adults
■'vere born between the years 1929 and 1936
but in none of these years did the vaccination
exceed 15 per cent of those borne in any one
of the vears concerned. Because of the ran'd
deciine in the tuberculosis infection rate, mor-
biditv and mortality in the country this vac-
cination nbn was abandoned and changed at
the cnd nf t.he year 1950. After that only few
groims of peonle were vaccinated i. e. tuber-
culos’s contacts. medical students. student
nurses. adu'ts studying abroad and persons
wbo asked for vaccinat'on.
Botween 1951 and 1970 only about 7000
neonie have been vaccinated. So tho tntal
number of BCG vaccinations un t.o the end of
1970 bas not exceeded 14000 in 1hé countrv.
Thereforc it seems most unlikely that. tb''
re'ativelv few BCG vaccinations. given in re-
r‘"'t ireara can b° exnected to have had mucb
inflimnce m sper-d'ng tbe downward trend nf
tim d’saas-' in the countrv. A careful recor.1
has been kent of tbe vaccinat.ions performca.
Ex"minations (tuberculin tests. microscomc
exam'natinns and cultures) have been madn b"
veterinarv surgeons and ohvsicians on catt.ie.
shoen and fowls. Accord’ng to thew find'ngs
tubeyculos's is very rare in domastic animalr.
The hovinc tvne of t.uberc"'osis has n“ver
b“en fmmd witb cert.aintv either io hum“n
beings n« i-. cattle. On the oth°r hmd the
avian tnv> has been found in fowls as well as
sheep. Tuberculous infection (based on positive