The Fifth International Conference on Poliomyelitis was held
in Copenhagen, Denmark, from the 26th - 28th July 1960. Over a
thousand delegates from 47 countries attended this conference. It
might legitimately be asked why poliomyelitis alone among the virus
diseases has acquired this honour and importance when some other
diseases with greater morbidity and mortality rates have not been
deemed worthy of this distinction. The answer lies in the fact that
the changes in the pattern of this disease during the last hundred
years have caused great anxiety and concern in the minds of epidemiologists and public health authorities all over the world. The
relatively uncommon 'infantile paralysis' of the 19th century has
become the epidemic poliomyelitis of the 20th century. Contrary to
expectations and to the behaviour of most of the other intestinal
infections, epidemics of poliomyelitis began to appear after the role
of defective sanitation in the spread of enteric infections was
recognised. Where the new ideas of sanitation were put into effect
with much vigour, poliomyelitis epidemics became more frequent.
Thus poliomyelitis presents itself as a threat in epidemic form to
all countries which have and aspire to have improved standards of
hygiene and living conditions unknown in the early part of the
Besides this change from an endemic to an epidemic pattern, the
disease has evolved in another direction also. Over a hundred years
ago, as the name 'infantile paralysis' suggests, poliomyelitis was
mainly a disease of the lowest age group (under 5) in the community.
But a shift, showing a significant incidence of the disease in higher
age groups, with case -paralysis and case -mortality rates which are
very much more pronounced than among the under -five group, has occurred.
The inexorable tendency of notification figures to rise in almost
every country presents the disease as a menace of world-wide significance.