At the British Congress'on Tuberculosis held in
London in 1901, Koch announced that human tuberculosis
was distinct from bovine tuberculosis and could not
be transmitted to cattle. He went further and, on
the analogy of his experimental failure to infect
calvos and sviine with progressive tuberculosis by
inoculation with the human bacillus, he assumed as a
corollary that the bovine tubercle bacillus must be
harmless for man.
This assertion was contested and investigations
were instituted in this country and abroad to inquire
into the relations of human and animal tuberculosis.
In 1911 a Royal Commission in L]ngland reported the
results of official investigations; extensive
corroboration of the findings from other home and
foreign workers proved conclusively that Koch was
wrong in his opinion that the bovine tubercle bacillus
was a negligible factor in human tuberculosis.
Interest in Scotland has been centred mainly in
the incidence in human tuberculosis of the different
types of tubercle bacillus. Fraser (1912) examined
67 cases of bone and joint tuberculosis in children
and found that 61.2% were infected with bovine bacilli.
Wang (1917) reported 55% of bovine infections in 20
children under sixteen years of age and 10.3% in 68
adults in the Edinburgh district. Munro and Cumming
(1926) found bovine bacilli in 36.4% of 55 cases of
surgical tuberculosis in the East of Scotland.
Blacklock (1936) isolated the bovine bacillus from
82.2% of 73 children with primary abdominal
tuberculosis and from 63.3% of 30 patients with
cervical gland tuberculosis. He noted a higher
incidence of bovine bacilli in country than in
Glasgow children. Blacklock and Griffen (1935)
found that 22% of cases of cerebral tuberculosis in
children in the same West of Scotland area were due
to the bovine bacillus.
The importance of factors other than the type of
organism had become manifest for it was obvious that
the proportional frequency of the type of infecting
organism varied greatly in different districts.
Griffith (1934), in surveying the results of
typing 265 strains of tubercle bacilli isolated from
cases of tuberculous meningitis occurring between
1905 and 1933 and derived from widely separated areas
throughout the United Kingdom, noted that the
incidence of bovine infection was higher, in general,
in country places and rural towns than it was in
cities. Munro and Scott (1936) reviewed the
relative frequency of human and bovine bacilli
recovered from cerebro-spinal fluids in patients from
the East of Scotland and concluded that bovine
infection was an urgent rural problem as, in the
series examined, the incidence of this type was three
times greater in rural areas than it was in cities.
This conclusion was supported by the work of
Macgregor and Green (1937) who found 2% of bovine
infections in 68 cases of tuberculous meningitis
occurring in the City of Edinburgh and 25 in 29
cases from the adjoining country districts.
The importance of raw milk was stressed by these
workers as a possible reason for the rural preponderance of the bovine type of tubercle bacillus, however,
in an investigation of 91 patients suffering from
pulmonary tuberculosis and residing in the rural areas
and small towns in the North East of Scotland,
Griffith and Smith (1935) found 14.45 with bovine
tubercle bacilli in the sputum. The possibility of
infection of susceptibles with the bovine organism
by such persons is a factor that cannot be overlooked.
Wright and Wright (1942) discussed the influence
of social conditions on illness in childhood in
London Boroughs. They analysed statistical data of
the morbidity and mortality of diphtheria, measles,
whooping cough and tuberculosis for the period 1924 - 1938 and, by comparing with data for social conditions
in the same area, they determined the correlation
between illness and social factors. The effects of
substandard housing and of the deprivation of many
of the amenities of life - food, heat and clothing - through deficient economic resources were noted as
important factors in the distribution of tuberculosis
among young children; the authors concluded that it
would be unwise to infer how poverty operates in
addition to the increased physical proximity of overcrowding.
