View report page

130
Annual Report of the London County Council, 1911.
quent knowledge, the events illustrating the spread of an outbreak. It then became evident that closure
of schools was not the cause of the stoppage of an outbreak, but that this would have occurred spontaneously
without closure.
The futility of closure for measles is exemplified by the following diagram, which I made in
connection with the closure of a school, which was carried out against my advice by a former medical
Figure 8.—Showing typical school outbreak of measles in reference to school closure.
officer of health for Hampstead. When the question of closure was considered, seven cases were known
and it was concluded from their distribution that a larger number were already infected : subsequent
events showed that 88 additional cases had been already infected when the presence of the disease was
first announced, and that nine cases more may have been subsequently infected. The day after these 113
cases had all ceased attendance the medical officer of health insisted on closure. No subsequent case
occurred. This was not the result of the closure, but because no case in the school had become infected
during a fortnight before the date when closure had been insisted on.
From observation of classes it appears necessary for at least one-third of the children to be
susceptible before measles spreads. Our analyses showed that whilst scarlatina, which is rarely school
distributed on any extensive scale, usually presented itself as isolated cases in several classes, measles
(more frequently school distributed) showed itself mainly in single classes. Before the recent epidemic
measles outbreaks have been to some extent altered to approximate more and more to the scarlatinal
type of distribution through the effect of our regulations in the past five years. The first case in an
infant class is carefully watched for, and a list having been prepared of those who have not had
measles, all these children are excluded from the class from the ninth till the fourteenth day after the
last attendance of this first case. All infected children are thus excluded before being infectious to
others in the class. The first crop of cases is frequently arrested, putting an end to the outbreak for
the time being. If the first crop has not been arrested any further attempt to restrict the class outbreak
is futile, and, as Fig. 8 demonstrates, closure is useless.
Sometimes all children under five are excluded. If the list of children who have already suffered
has been prepared there is no reason to exclude them, whatever their age.
In the "Woolwich enquiry, class closure was rigorously enforced on every possible occasion in the
eastern portion of the borough, whilst there was no closure in the western portion. No difference
resulted in the prevalence of the disease, but class closure cost a loss of 135 attendances per case notified,
whilst individual exclusions cost 63 attendances, less than half.
Experience showed that measles only spread in infants' schools, that the liability to extension
existed when from 30 to 40 per cent, of the children were unprotected by previous attack, and ceased
when only 15 to 20 per cent, remained susceptible. Children in the standards were not liable to school
spread of the disease. Incidentally, this is suggestive as to the cause of the continued escape of the
partially protected population from serious small-pox outbreaks.
Rules were framed on these observations, viz. (1) to warn the parents of "unprotected" children
in the class where a case of measles occurs, by means of advice cards describing symptoms, etc., to watch
their children closely, (2) to exclude where necessary the "unprotected" upon the notification of the
first case of measles, (3) to prevent intimate mixing and massing of children when the disease is prevalent,
and (4) to allow children from houses where measles exists to attend boys' or girls' departments if they
themselves have already suffered measles.