Investigating, etc., of infectious disease.
Appx.xix.
14. Preventive measures.— The prevention of diphtheria depends
on prompt early recognition of cases and isolation of them.
In the majority of cases in which infection is not due to contact
with a recognised acute case, it is contracted from a recent undiagnosed
case, from a carrier or from a still infectious convalescent case. One
or more mild cases of sore throat or enlarged cervical glands, or of
other catarrhal infection (not diagnosed as diphtheria), often precede
the first recognised case of the disease.
Two cases of diphtheria should be regarded as constituting an
outbreak, and as requiring vigorous steps to trace the origin and
prevent the spread of the disease.
In dealing with an outbreak any recent cases of sore throat, tonsil-
litis, enlarged glands in the neck, nasal or aural discharge, also con-
valescents from scarlet fever or diphtheria, should be isolated and
investigated and should, if possible, remain isolated.
A chronological list of all diagnosed and suspicious cases, giving
particulars as to dates, quarters, barrack-rooms, dining tables, etc.,
may give useful information.
Isolation. —Convalescents from this disease should not be dis-
charged from hospital until they have clinically recovered, are free
from nasal discharge, have normal throats and are no longer carriers
of virulent bacilli, as shown by the results of examination of throat
swabs.
3 negative swabs, taken at least 12 hours after any medication to
the throat, at 3 day intervals are required before a case or a carrier
can be considered " free".
15.Material for examination.— The best material for examination
is a portion of r
sterile forceps. For, general use a non-absorbent cotton-wool swab
on a stout wire, sterilized by dry heat (and enclosed in a test-tube
till required) is effective and reliable. The swab should be seen to
come into actual contact with the faucial exudate and should be
used with such gentle force as to remove some of it. In the case of
contacts and in laryngeal diphtheria the swab should be rubbed tho-
roughly over the fauces. In obtaining material from the nose the
swab should be so introduced as to reach the turbinal bones, as these
are the usual seat of membrane. In no case should any antiseptic
have been recently applied to the affected area.
16. Disinfection.— (i) Of room and objects as in para. 554.
The bacillus has little power of resistance: it is killed in 20 seconds
by 1: 1,000 corrosive sublimate or 5 per cent. carbolic acid, and in 10
minutes by1 per cent. lysol. The thermal death point is low (58° C.).
The articles actually used by the patient can thus be easily disinfected.
Pencils and pens should not be overlooked.
(ii) Of carriers—
Local antiseptic treatment has been used with effect. Removal
of infected tonsils and adenoids has decisive results, but should not
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