NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
Investigating, etc., of infectious disease.
A p p x . X I X .
APPENDIX XIX.
NOTES ON INVESTIGATING, REPORTING ON, AND
DEALING WITH OUTBREAKS OF INFECTIOUS
DISEASE.
1.—TABLE OF INCUBATION AND SEGREGATION PERIODS.
Disease.
INCUBATION PERIOD.
Segregation period.
Usual.
Ordinary
limits.
Scarlet Fever
.
. 2-3 days . 1-8 days . 10 days.
Measles .
.
. 14
,, . 6-18 „ . Contacts examined daily
between 7th and 14th
days.
Rubella . . .
15-18 „ . 10-23 „ .
Contacts examined daily
between 7th and 23rd
days.
Mumps .
.
.
. 18-21 „ . 12-28 „ . 22 days for non-immunes.
Small-pox .
.
. 12
, ,
. 8-17 ,, . Successful vaccination or
18 days.
Chicken-pox .
. .
12-14 „ . 12-21 „ . 18 days.
Influenza .
.
. 2
„ . 1-4
„ .
Whooping cough .
. 7-14 „ . 2-21 ,, .
16 days for non-immunes.
Diphtheria .
.
. 2-3
„ . 2-10 ,, .
Depends on bacteriological
examination.
Typhoid Fever
.
. 10-14 days . 8-21 days .
Paratyphoid Fever
. 10-14 „ . 8-21 „ .
Cholera . . . 1-3
„ . 1-8
„ . 8 days.
Bacillary Dysentery . 1-8
,, . 1-5
„ .
Plague .
.
.
. 3-5 days. 1-8 days. 5 days.
Typhus Fever
.
. 5-8
,, . 4-14 ,, . 14 days subsequent to era-
dication of lice.
Relapsing Fever .
. 8-10 ,, . 2-14 ,, . 10 days after disinfesta-
tion.
Trench fever . . .
5-9
„ . 5-21 „ .
Yellow Fever
.
. 3-4
„ . 2-5 ,, . 5-6 days.
Rabies .
.
. . 6 weeks
. 7 days to 6
months.
App. XIX.
Investigating, etc., of infectious disease.
2. Interchange of Information .—Medical officers should work in the
closest possible collaboration with the Deputy Assistant Directors of
Hygiene and of Pathology and officers in charge of brigade laboratories,
and should also maintain touch with the civil public health authorities
of their station or district. They should arrange with the latter for
the mutual exchange of information as to the occurrence of infectious
disease in their respective spheres.
3. Lines of investigation.—In investigating outbreaks of infectious
disease the main inquiry should be directed to the known routes of
infection for the particular disease concerned and to the discovery of
a possible " carrier ". The possibility of cases having been missed,
either through errors in diagnosis or through failure of the patient to
report sick, should be borne in mind. Early information should be
obtained as to the movements of the first patients during the three.
weeks immediately preceding the onset of their illness. The subsequent
series of cases and its connection with the first cases or with a common
cause should be carefully traced, recorded in detail, and plotted out
on a spot map. Attention should be directed to any sanitary defects,
in the camp, barracks or their surroundings. Investigations should
be made regarding food, water, milk and other supplies, both official
and private ; the method of disposal of refuse and excreta ; over-
crowding and ventilation ; the existence of breeding places of flies.
and other disease vectors, and their presence in excessive numbers.
In reporting on the outbreak, reference should be made to methods
adopted for the isolation of the sick, segregation and observation of
contacts, disinfection, and other general sanitary measures which
have been taken.
The early and accurate diagnosis of all cases of infectious disease,
and the isolation of patients, is of the utmost importance.
4. Disinfection.—As soon as possible after the removal of any case
of infectious disease, disinfection will be carried out as laid down in
paras. 533-554.
In cases where isolation of the patient is effected in quarters,.
disinfection will be carried out immediately after the disposal of the
case.
The following paragraphs give a synopsis of present knowledge
as to the methods of spread and necessary preventive measures in the
case of the principal diseases (arranged in alphabetical order).
ANTHRAX,
5. Spread.—By close association with infected cases, human or
animal, by carcases, hides, hair or bristles, by shaving or tooth brushes
containing spores. The route of invasion is commonly through
abrasions.
6. Preventive measures.—The patient should be isolated and
dis- infection carried out as indicated in para. 554.
246
Investigating, etc., of infectious disease.
Appx. XIX.
By co-operation with veterinary officers, early information should
be obtained of diagnosed and suspected cases of anthrax among
animals. Infected animals should be destroyed, and their carcases
burnt or deeply buried after being freely coated with quicklime ;
special care must be taken to prevent the ground being fouled by
blood and discharges. Infected ground should not be camped on.
(See K. R., paras. 1453, 1454).
Abrasions of all personnel engaged in attending animals of infected
units must be protected.
Shaving brushes before being taken in stock should be soaked for
four hours in a 10 per cent. solution of formalin.* The solution should
be kept at a temperature of 110 0 F. and the brush agitated so as to
bring the solution into contact with all hair and bristles.
Bacteriological examinations should be made of suspected shaving
brushes or tooth brushes. If proved to contain anthrax spores, they
must be destroyed, and the D. M. S. in India notified by telegram.
CEREBRO-SPINAL FEVER.
7. Spread.—Is closely associated with overcrowding ; conveyed
by " droplets " emitted by a carrier in coughing, sneezing or breathing.
The causal agent is a diplococcus found in the nasopharyngeal
mucosa, and present in a definite small percentage of the general
population, without necessarily implying any individual pathogenic
significance. Recruits and young soldiers are peculiarly liable to
attack. There is definite seasonal incidence. In temperate latitudes
the maximum incidence occurs during the humid months of spring and
in autumn ; in the tropics in the " cold " season when overcrowding
is greatest.
8. Preventive measures .—Avoidance of overcrowding : and free
ventilation. Disinfection should be carried out as indicated in para.
554. Isolation of the patient, segregation and bacteriological exami-
nation of contacts, segregation of attendants on the sick : gargling
or spraying the throats of troops.
Experience has shown that the disease will not occur in armies
if the established peace-time allotment of accommodation is not
departed from, if judicious spacing is maintained in sleeping rooms,
if men are prevented from over-crowding recreation rooms, dining
rooms, lecture halls and canteens, and if ventilation is established
and maintained in all rooms, more especially in sleeping rooms. In
cold weather, in the presence of an outbreak, a generous supply of
blankets should be issued to permit of thorough ventilation of sleeping
rooms. The temperature of the air affects the viability of the diplo-
coccus which has but a short life in cold freely moving air.
CHOLERA.
9. Spread.—By water, milk, cream, butter, uncooked vegetables,
salads, fruits, mineral water, etc., when any of these have become
infected by the discharges from a carrier or case of the disease.
* Formalin is a 40 per cent. solution of formaldehyde.
247
1 2
Appx. XIX.
Investigating, etc., of infectious disease.
10. Preventive measures.—Disinfection will be carried out as indi-
cated in para. 554. During outbreaks, special attention should be
paid to cases of diarrhoea and saline aperients should be avoided.
Bazaars and other places where cholera is present should be placed out
of bounds, and hawking of food and drink in barracks or camps pro-
hibited. All personnel employed on duties connected with food or
water should be medically examined daily, and instructed to report
sick immediately on the occurrence of diarrhoea ; the . sources of all
food supplies, including water and especially milk should be investigated
and strict measures employed to ensure freedom from contamination.
Bathing in pools and streams should be prohibited ; the . eating of un-
cooked vegetables and fruits should be forbidden. Communication
with places infected should be restricted as far as possible.
When tracing the source of an outbreak, valuable information
can sometimes be obtained at the commencement of an epidemic
by determining those articles of food or drink, the consumption of
which has been common to all persons attacked. As apparently
healthy men are occasionally found to harbour the germ during cholera.
epidemics, the arrangements for the disposal of faeces must be based
on the assumption that all troops are potentially infectious.Inocula-
tion with cholera vaccine has been shown to give . definite protection
for some months, and should be carried out when troops are exposed
to infection.
DENGUE.
11. Spread.—By mosquitoes (Aedes aegypti). A dengue patient
infects mosquitoes during the first three days of illness ; the infected
mosquito is able to transmit the virus eleven days after its infection ;
infected mosquitoes remain infective throughout life ; hereditary
transmission does not occur. A. aegypti is essentially a day-biter,
but may bite also by night : it breeds in collections of clear water
inside or close to human habitations: its eggs are very resistant and
retain their vitality after storage in a dry place for several months ;
the eggs hatch normally in 3 days and the adult mosquito emerges
ordinarily from 8 to 15 days later.
12. Prevention .—Patients should protect themselves by using
mosquito-nets by day and night. Non-immune persons should
avoid infected houses. Adult mosquitoes should be destroyed. Water
should not be left in uncovered receptacles, open cisterns, buckets,
etc., for more than 7 days.
DIPHTHERIA.
13. Spread.—By droplet infection, as in coughing and talking
occasionally infected articles, such as towels or pencils, may be respon-
sible.
A large proportion of individuals (about 50 per cent. of children
and 75-80 per cent. of adults) are permanently immune to diphtheria.
In the case of healthy carriers it is generally found that the condi-
tion lasts on the average for about 10 days.
248
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 rmbrane removed from the affected region with
st eri l e forceps. For, general use a non-absorbent cot t on-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
249
Appx. XIX.
Investigating, etc., of infectious disease.
be deemed necessary until adequate time has been allowed for sponta
-neous recovery.
17. Serum Treatment.—Subcutaneous injection is the easiest,
and is usually, though wrongly, believed to be safer than other methods.
In all other respects it is inferior to intravenous and intramuscular
injection.
In mild cases the intramuscular route may be employed: in severe
or late cases the intravenous route ought to be adopted, either alone
or in conjunction with intramuscular injection.
The following tables are a guide to the amount, in antitoxin units,
that should be given in the various types of cases:—
TABLE A.
—
Mild cases. Early moderate. Late moderate
and early
severe.
Severe and
malignant. –
Infants 10-30 lbs. in
weight; under 2
years.
2,000-3,000 3,000-5,000 5,000-10,000 7,500-10,000
Children 30-90 lbs. in
weight; under 15
years.
3,000-4,000 4,000-10,000 10,000-15,000 10,000-20,000
Adults 90 lbs. and over
in wei ght .
3,000-5,000. 5,000-10,000 10,000-20,000 20,000-50,000
Method of administra-
tion advised.
Intramuscular. Intramuscular. Intravenous. Intravenous.
TABLE B.
—
If treated on
1st day.
IF UNTREATED.
Until 2nd day. Until 3rd day. Unt i l 4t h day or l at er.
Mild faucial
. .
6,000
6,000
8,000
10,000
Moderate
. .
10,000
12,000
14,000
16,000
Severe, severe faucial,
and laryngeal.
20,000
24,000
30,000
30,000
Very severeal faucial
30,000
40,000
50,000
50,000
Laryngeal only .
18,000
18,000
18,000
18,000
Nasal only, but with
membrane. Con-
junctival only.
6,000
6,000
8,000
10,000
Principles of procedure.—It is essential that antitoxin treatment
be given early in the attack. If the patient is really ill, with symptoms
that are probably diphtheritic, it is imperative that antitoxin be
administered at once, without waiting for the bacteriological diagnosis.
250
Appx. XIX.
Investigating, etc., of infectious disease.
conservancy arrangements. Anti-fly measures are of special import-
ance. Patients suffering from diarrhoea or dysentery should, as far
as circumstances permit, be isolated from others. Stools of patients
must not be left exposed. If required for inspection or if sent to the
laboratory, they should be kept in fly-proof receptacles. Attendants
on the sick should pay strict attention to personal cleanliness, and
should be inspected frequently to ensure that they are not suffering
from irregular diarrhoea.
No one who has suffered from dysentery or is proved to be a dysen-
tery carrier will be employed in the preparation or handling of food
or drink. No member of the I. H. Corps will, however, be dis-
charged from the service as a carrier of amoebic dysentery unless the
finding of E. histolytica cysts has been confirmed in a district laboratory.
Routine examinations of all such individuals will be carried out as
laid down in paragraph 51 of Appendix XIX and paragraph 14 of
Appendix XXI.
A convalescent from bacillary dysentery may be considered " free "
if mucus is not found during eight careful consecutive daily naked-eye
examinations of the stools.
A convalescent from amoebic dysentery may be considered " free "
if six negative microscopic examinations of the stools, commencing
three days after the emetine course is completed, have been recorded.
Stools however should be sent for laboratory examination for cysts
once a week for 6 weeks after discharge from hospital.
COLLECTION AND DESPATCH OF DYSENTERY SPECIMENS FOR LABORATORY
EXAMINATION.
The methods to be employed by hospital staffs in connection with
the above are of the greatest importance as regards diagnosis. Detailed
instructions are given in Appendix XXI, and should be strictly
complied with,
ENCEPHALITIS LETHARGICA.
20. Spread.—Probably from mucosa to mucosa in the buccal
secretions in a similar manner to cerebro-spinal fever. Infectivity
is of a low grade, instances of multiple associated cases being rare in
comparison with individual sporadic cases. It may be inferred there-
fore that carriers of the infection, who either do not develop the disease
or who suffer with a mild unrecognised attack, are in far greater numbers
than the cases discovered.
21. Preventive measures. —The precautions prescribed for cerebro-
spinal fever should be adopted. Of first importance is the prevention
of overcrowding, and the continuous maintenance of free ventilation
in all rooms. The patient should be isolated ; immediate contacts
should be kept under surveillance for at least ten days ; disinfection
will be carried out as indicated in para. 554.
Oases of sore throat should be sought for and appropriately treeted.
252
Investigating, etc., of infectious disease.
Appx. XIX.
INFLUENZA.
22. Spread.—By " droplet" infection during speaking and cough--
ing, etc. The most important factors in the dissemination of the
disease are overcrowding and lack of efficient ventilation.
23. Preventive measures.—Disinfection will be carried out as indi
-cated in para. 554. Cases of the disease should be isolated. Over
- c r o w d i n g s h o u l d b e p r e v e n t e d i n b a r r a c k - r o o m s , e t c . C r o w d e d
places of public resort should be avoided. Insufflation of the naso--
pharynx with a week solution of permanganate of potash (1 part in
5 , 0 0 0 p a r t s o f 0 . 8 p e r c e n t . s o l u t i o n o f s o d i u m c h l o r i d e ) a p p e a r s t o b e
very useful i n prevent i ng at t acks. Cups and ot her dri nki ng ut ensi l s
in huts, messes, etc., should be sterilized. Promiscuous spitting must
be prevented. Where possible, during unusual prevalence of influenza,
the personnel of every unit should be medically inspected daily. There
is evidence that influenza vaccine provides protection and reduces the
liability to severe complications.
MALARIA.
24. Spread.—By infected anopheles mosquitoes.
Malaria is the principal cause of sickness amongst the troops in
India, and consequently of great financial loss to the State. Approxi
- m a t e l y 1 m a n i n 5 s u f f e r s f r o m i t e a c h y e a r .
Admissions to Hospital.
Year.
BRITISH TROOPS.
INDIAN TROOPS.
Fresh. Relapse. Total. Ratio per
1,000. Fresh. Relapse. Total. Ratio per
1,000.
1922 . . . 4,093 6,459 10,552 175.4 Not av ailable. 25,705 173.9
1923 . . . 4,910 5,965 10,875 172.2 5,042 17,604 22,646 158.1
1924 . . . 4,515 7,605 12,120 206.8 3,293 14,139 17,432 1 2 9 . 4
1925 . . . 3,064 6,060 9,124 159.0 2,616 9,219 11,835 86.7
1926 . . . 4,175 5,214 9,389 165.3 3,620 12,022 15,542 1 1 5 . 0
1927 . . . 2,934 4,789 7,723 138.8 3,075 10,036 13,111 98.5
25. Preventive measures.—An a n t i - m a l a r i a l m e d i c a l o f f i c e r w i l l b e
appointed by the A. D. M. S. at each station in which malaria is pre
- v a l e n t . H e s h o u l d h a v e c h a r g e o f a l l a n t i - m a l a r i a l m e a s u r e s a n d b e
responsible for the correctness of any malaria statistics and reports
that may be called for. Approved policy consists of the following
measures : —
I . Withdrawal of troops from malarious stations during the infective
season ("Cold Storage ").—This is an effective measure when facilities
253
Appx. XIX.
Investigating, etc., of infectious disease.
are available. Every effort should therefore be made that all hill
accommodation is used to the utmost and that troops do not return to
malarious stations until the infective season has passed.
II. Mosquito-proofing of barracks. —This is a very effective measure
and mosquito-proofing has now been accepted as an authorised work for
British barracks in all malarious stations.
III. Anti-larval measures.—The question of expense puts many of
these out of count, for example, extensive schemes of drainage. But
much can be done in lesser ways to diminish malarial incidence, e.g.,
by oiling, use of " Paris Green," filling up borrow-pits and depressions,
minor schemes of drainage, but to be effective all such measures should
be based on a malarial survey of the station.
Malaria spot maps should therefore be kept showing—
(1) breeding places of vectors.
(2) barrack or room in which fresh cases occur.
The making of borrow-pits in cantonments should be strictly for-
bidden.
IV. Matters of interior economy and discipline in units—
(1) Proper care and use of mosquito-nets.
(2) Full use of fans and punkhas to ensure that there is movement
of air inside the nets.
(3) Use of P.C. oil by men on guard and by men who, owing to
transport or other duties after sunset or before sunrise can-
not be protected otherwise. Whenever possible these men
shouldbe provided with mosquito veils and gloves.
(4) The wearing of proper clothes (not shorts) after sundown.
(5) The advisability of placing known infected areas out of bounds
should be considered.
V. Destruction of adult mosquitoes.— Effective fumigation in April-
May and again in September-October is of value and should be carried
out as thoroughly as funds will permit. Fumigation, however, is often
attended with considerable difficulty, e.g., in high-roofed barracks with
innumerable openings. In such cases spraying with a high-pressure
spray may be of benefit. Trapping and swatting should also be tried.
VI. Propaganda.—The Rockefeller cinematograph film on malaria
is circulated amongst malarious stations. The film shows in graphic
manner the whole mechanism of infection. All officers, other ranks and
families should be given an opportunity of seeing it.
Experiments have proved that individuals possessed of full know-
ledge of the method of transmission of malaria from man to man by the
bites of mosquitoes can make such effective use of methods of personal
protection as to remain free from infection.
It is therefore of great importance that all ranks should be educated
in this subject.
254