The London Vaccination returns give food for thought and
apprehension; as legislation made it more and more easy to obtain
exemption from vaccination, the unvaccinated children (including
cases postponed) were to be expected to increase.
The Vaccination Returns for England and Wales for 1909, when
compared with the Returns for 1908, show a considerable increase in
the percentage proportion of children born who remain unvaccinated.
It is cause for considerable anxiety to Medical Officers of Health that
the country threatens to become a practically unvaccinated community;
and that many of the children who are nominally vaccinated
are but very imperfectly protected by the growing practice of one-mark
vaccination. It is often contended that our sanitary administration
has reached such a stage of efficiency that we have little to fear from
Small-pox, but our comparatively recent experience in London taught us
that the notification of the disease (including the temporary notification
of Chicken-pox), and our arrangements for vaccinating contacts
and promptly isolating sufferers, did not suffice to prevent a considerable
amount of spread of the disease, a great dislocation of trade, and
an enormous expense to the community. Moreover, the Increasing
number of children who are unvaccinated at school ages must have
the effect of considerably increasing the danger of the spread of the
disease by school attendance.
THE DANGERS OF RATS.
Wide epidemics of plague in man are always associated with
epidemic plague in rats. Epidemic plague among rats provides a
large number of infected rat fleas, and, owing to the mortality among
the rats, these fleas come on to human beings in the absence of their
natural host. The essential part which these fleas play in the transmission
of disease is demonstrated by the fact that if plague-infected
rats are kept in close confinement along with healthy rats, no epidemic
of the disease occurs in the absence of fleas; but in the presence of
rat fleas the disease spreads from the infected to the healthy animals,