Poliomyelitis and Polioencephalitis.—These names describe two types of infection by the same
virus : In the former the spinal cord is chiefly affected, and in the latter the brain bears the brunt of the
Though poliomyelitis was apparently known to the ancients, the first account of paralysis associated
with fever in young children was published towards the end of the 18th century. While scattered cases
were reported in Europe and North America it was not till 1870 that the disease was recognised as occurring
in epidemic form. These epidemics made their appearance first in Scandinavia, then in United States,
and then in Australia. In these countries epidemics involving thousands of persons began to be more
frequent, while small outbreaks occurred in England and elsewhere in Europe. Since 1936 there has been
an increase in epidemics in Europe, though their distribution has been patchy. The disease has been
notifiable in England since 1912, but there has been no epidemic comparable to that of 1947. Though
final figures are not available the incidence was about 20 per 100,000 population. This incidence is about
the same as in the United States epidemic of 1916, but much less than in the 1941 epidemic in Norway
and Sweden or in the 1944 epidemic in Switzerland. With the development of the disease to epidemic
proportions the age incidence has altered. Originally the disease occurred chiefly in young children—
hence the name, infantile paralysis—but in recent years an increasing proportion of adolescents and young
adults have been affected. Accompanying this age incidence change there has been a change in the type
of disease resulting in an increase of non-paralytic cases. Poliomyelitis has been reported from all parts
of the world, but a peculiar feature is that epidemics appear and recur in countries where sanitation and
hygiene are at a high level. Though the virus can be demonstrated in the excreta of patients and contacts
there is no sound evidence to warrant considering the disease to be transmitted by water, food or flies.
The disease is thought to spread by person-to-person contact, but in what way is still unknown. The
current view is that for every person showing clinical signs of the disease many are infected, but show
few or no symptoms. Doctor Horstmann of Yale University summarised the position as follows in the
Lancet early in 1948:—"In spite of all the information collected by many investigators in many lands
we still cannot say why poliomyelitis suddenly became epidemic almost sixty years ago, why it is increasing
rather than decreasing like other infectious diseases, why it is a summer disease with a preference for
certain lands, how it is spread or how it may be prevented."
The early symptoms of the disease are almost indistinguishable from those of any febrile disease
and doctors were encouraged to arrange admission to hospital on any suspicion that an illness might be
poliomyelitis. The diagnosis was confirmed in 44 cases out of 61 notified. One case, a patient in West
Middlesex Hospital, was not a resident of the Borough. Of the 43 Borough cases 3 died, 21 made a
complete recovery and the remaining 19 were transferred to orthopaedic hospitals or clinics for treatment
of the residual paralysis. The age distribution of the cases is shown in Table V. In one household 3 cases
occurred, in another household 2 cases, but the other cases occurred singly. The ward distribution of the
cases was as follows:—Heston, 8; Hounslow Central, 2; Hounslow West, 2; Hounslow South, 3;
Hounslow Heath, 12; Isleworth North, 6; Isleworth South, 7; Spring Grove, 3. Apart from multiple
cases in the same household direct contact between cases was traced in one instance only.
No closure of schools, swimming baths, children's cinema, etc. was undertaken with a view to
controlling the spread of infection.
Typhoid and Paratyphoid Fevers.—No case of paratyphoid fever and only one case of typhoid
fever was notified during 1947. The source of infection of this one case was not traced.
Dysentery.—No case of dysentery was notified during the year.
Tuberculosis.—The notifications of pulmonary tuberculosis weie 40 less than in 1946, but there was an increase of 3 in the notification of non-pulmonary tuberculosis.