View report page

6
(3) The gradual change in the distribution of the population from rural to rural has been a
outstanding development of the life of England and Wales during the nineteenth century. Thus, In 1810,
it is calculated that only about 20% of the population was classified as urban, whereas in 1910, the
proportion rose to something like 80% of the population. The theory here is that the liability to absorb
small doses of tubercle bacilli increases with the prevalence of the disease and the density of the
population. Therefore during this period there was going on, pari passu as it were, an increase in the
prevalence of the disease and a corresponding increase of the minimal immunising doses of infection from
the tuberculous to the non.tuberculous population.
This process while it is suggested by advocates of the theory that it greatly increased the amount
and the fatality of the disease in the early part of the last century (1800.1850) led later on to an increase
in the resisting power of the succeeding generations and so in the second half of the century to a decrease
in the prevalence and fatality of the disease. If this is a correct theory then the decline in the prevalence
may lead to a point where there will also be a corresponding decline in the immunising'process and in time
this would be followed by a rise in the prevalence and mortality of the disease, unless we can by other
means stem the rise of the tide. Thus the rate of mortality from tuberculosis may be subject to rhythmic
changes of the natural curve of the rate extending over a long series of years, and we may be simply
passing through a low port on of one of these waves.
(4) Improvement of social conditions.—Nearly all authorities are agreed that probably the most
powerful factors in influencing the decline of the death rate from tuberculosis are those which are summed
up in the words " improvement of social conditions of the people," but they differ as to their relative
importance. Amongst the many factors which are included in this category are the following—
(a) Removal of damp, dirty, insanitary houses, including narrow streets, alleys, cul.de.sacs,
etc.—all the conditions of housing in fact which constitute what are termed Insanitary Areas,
large and small.
(b) Improved conditions of occupation, including shorter working hours, higher wages,
better and more abundant food supply, etc.
(c) Improvement of the milk supply.
(d) Removal of sub.soil dampness, etc.
Although all the factors included in the term " improvement of social conditions " have been
actively at work now for many years and it is admitted that they must have done much to reduce the
mortality from tuberculosis, yet it is certain that they cannot be the only forces at work, otherwise, as
pointed out by Sir William Broadbent, tuberculosis should never occur among the rich. It is probable,
therefore, that other direct factors have been at work, and Newsholme, after investigating all the suggestions
which had been brought forward to explain the fall in the death rate, arrived at the conclusion—
(5) That the influence which, concurrently with all those referred to above, has been exercising the
predominant, though unrecognised, influence, " is the segregation of consumptives. especially of advanced cases,
in general hospitals, poor law infirmaries, asylums and other public institutions." This statement strongly
urged also by Koch, has been vigorously opposed by Bulstrode, who gives the following reasons for
disagreeing with Newsholme's conclusion :—
Extract from Report on " Tuberculosis " by Bulstrode to the Local Government Board, 1907.—
(a) " This theory assumes for phthisis a degree of infectivity which the evidence available does not in the
opinion of many epidemiologists justify.
(b) " No definite effect of the very general and, it may be added, complete isolation—during
the whole period of illness and convalescence—of such a highly communicable disease as scarlet fever
is conclusively demonstrable. Accordingly it was not to be anticipated that the partial segregation of
phthisis, along with non.phthisis cases, during a small portion only of the whole infectious period of
the disease should yield such satisfactory results as those claimed as a result of the process.
(c) " It is not improbable that for a considerable interval prior to the removal of any given
patient to an infirmary or workhouse, such patient has already exercised the major part of the total
influence qua infection, of which he or she is capable, a circumstance which, if true, would tend to diminish
the influence of segregation in Poor Law institutions.
(d) " The charts furnished elsewhere in this report (Chapter XXL and Part III.) although purely
provisional and preliminary, do not, so far as they go, suggest that segregation is likely to be attended
with very obvious satisfactory results.
(e) " If the average duration of stay of the phthisical patient in Poor Law institutions bears any
direct relation to the average stay of all patients in such institutions, the total period would hardly seem
sufficient for the exercise of a very material influence of such sojourn in preventing the spread of the
disease. For instance, during 1897, the average stay, in days, in certain provincial infirmaries was as
follows—Salford, 97 ; Leeds, 95 ; Croydon 86 ; Birmingham, 74 ; West Derby, CO.
" A stay of three months or so out of a total infective period of probably very many months,
perhaps years, hardly appears likely, having regard to what is known as to the hospital influence in scarlet
fever, to exercise a very great salutary effect, more especially when it is borne In mind that many workhouse
patients go home to die. It would seem, indeed, that the majority are discharged alive to return
to their homes where they have again opportunities for spreading infection.
" As Dr. Niven observes, it is necessary to bear in mind the fact that no inconsiderable section of
infirmary and work.house cases have received repeated treatment, and there is no reason to suppose that
these persons have produced much less harm at home than they would have done had they not been in
hospital. He also points out that as precautions as regards expectoration were not taken until a recent
period, segregation may not improbably have acted rather in spreading the disease than in reducing it.