Prevention and control measures in particularly dangerous and quarantine infections

1. Prevention and control measures in particularly dangerous and quarantine infections

2. Plan of lecture

Epidemiology features and prophylaxis of hemorrhagic fevers of Lassa,
Marburg,
Ebola
Measures in an epidemic focus
Measures of concern a patient
Measures concerning the persons having contacts with patients
Measures concerning a situation
Methods of control of cholera
Prophylaxis anthrax
Prophylaxis plaque

3. EPIDEMIOLOGY FEATURES AND PROPHYLAXIS OF HAEMORRAGIC FEVERS OF LASSA, MARBURG, EBOLA

The haemorrhagic Lassa, Marburg, Ebola fevers are the
zoonosis natural-antropurgenic viral infectious diseases
characterized by the expressed haemorrhagical
syndrome.
The haemorrhagic Lassa fever was first reveling in the
north-eastern part of Nigeria in 1969 and got the name at
the place of hospitalization of diseased (Lassa).
The outbreaks of the Marburg fever in 1967 appeared
simultaneously among the employees of the biological
laboratories in Germany (Marburg) and Yugoslavia
(Belgrade), in 1976 in Zaire there was the outbreak
caused by the related virus of Ebola; 358 persons
became ill, from which 326 died.

4. Etiology

Causative agents are RNA-containing viruses.
The virus of the Lassa fever is related to the
Arenaviridae family,
causative agents of the Marburg and Ebola fevers
– to the Filoviridae family. Viruses are sensible to
the action of chlorinated preparations, ether,
chloroform

5. Clinical manifestation

A latent period at the Lassa and Ebola fevers is from
2 to 21 days, at the Marburg fever – from 3 to 9 days.
The beginning of the diseases is acute, a temperature rises
to 38-40°C, severe headache, myalgias, nausea appears;
at the Lassa fever is ulcerous-necrotic pharyngitis,
tonsillitis, lymphadenitis;
at the Ebola fever is quinsy, affection of lungs; at the
Marburg fever is vomiting, frequent watery stool with
blood.

6.

The haemorrhagical syndrome appears from the
3-7th day of illness: petechias on a skin and
mucous, spotted or maculo-papular rash; nasal,
gastric, uterine bleedings.
An acute period at the Lassa fever lasts for 3-4
weeks, the edemas, ascites, toxic shock, acute
kidney insufficiency, develop in the seriously cases,
lethality is up 20-50%.
The Marburg and Ebola fevers last for 6-14 days,
at the unfavorable cases the death comes from
toxic shock, cardiac weakness, cerebral disorders,
lethality is from 30 to 90%.

7. The diagnostics

Laboratory diagnostics is based on the selection of virus from
the blood, washings from nosopharynx, pleura exudation.
A virus is selected by the infection in the brain of the newborn white miсe and culture of cells.
From serological methods it is used on research of pair serum
of blood.
Taking and sending of material from patients or suspicious for
these diseases is done with the observance of rules of the
antiepidemic mode (sterility, hermetically packing, sending
with the special messenger on a separate transport),
research of this material is carried out in the special virology
laboratories with the maximal degree of protection of
personnel.

8. Prophylaxis

Prophylactic measures are directed to the warning of
penetration of causative agent of infection from abroad,
reduction of epizootic activity of natural focus and
prevention of people’s diseases in these focuses.
Protection of food and water from contamination with
animal’s urine and saliva is important in natural focuses.
The sanitary guard rules of territory foresee the receipt
and analysis of information about epizootic and epidemic
situations in different would countries;
The medico-sanitary examination of transport coming, for
example, from the focuses of the Lassa fever; revealing,
isolation and treatment of patients; disinfection and, if
necessary, deratization treatment of transport

9.

At the revealing of patient with the hemorrhagic fevers the
Lassa, Marburg and Ebola medical worker must work in the
antiplague closing of the I-st type (before receive of protective
clothing it is necessary to close a mouth and nose with a towel
or mask).
Closing of the I-st type (complete protective closing) consists
of: pyjamas and overalls, hood or large triangular bandage,
antiplague gown, cotton-gauze mask, glasses, rubber gloves,
oilskin sleeve protectors, oilskin apron, socks, knee-boot and
towel.
An antiplague closing of I-st type is put, not taking
off own clothes (except contamination by patient’s
excretions).

10.

Before dressing of protective closing it is necessary to
process the opened parts of body with a 0,5-1%
chloramines' solution or 70° spirits.
Order of putting on the articles of clothing is strictly
kept, and after the work the articles of antiplague
clothing is had to be take off in accordance with
established procedure and fold so that their “dirty”
surfaces were turned inward.
Duration of continuous work in the protective
clothing of the I type must not be more 3 hours (in
hot time of the year – 2 hours), after it an interval for
1 hour is needed.

11. Measures in an epidemic focus Measures of concern a patient:

1.
2.
The primary signaling about the revealing of patient (dead
body) is carried out in three main directions: to the chief
doctor of treatment-and-prophylactics establishment, the
station of medical first-aid and the doctor of the proper
Epidemiological station.
The medical worker revealing a patient, stay in the
apartment (before arrival of evacuation team), where a
patient is revealed:
by phone or through the special messenger not being in
touch with a patient, informs the chief doctor of the
establishment about the revealing patient and his state;
inquires the proper medicines, packing the protective
clothing, means of the personal prophylaxis.

12.

For evacuation of one patient evacuation team is needed,
consisting of a doctor and two helpers (doctor’s assistant,
hospital orderly). Accompaniment of patient with relatives or
acquaintances is forbidden. The employees of evacuation team
must work in the protective clothing of the I-st type.
Hospitalization of a patient is conducted in the boxes of
infectious hospitals with providing of hermetic condition and
disconnection of ventilation. Medicare is rendered by the
specially trained personnel in the protective clothing of the I-st
type with the observance of the rules of the antiepidemic mode
(as at the pulmonary form of plague).
The material from the patients is taken only at the place of
hospitalization by the specialists of laboratories doing these
examinations. Dissection of dead body and taking material
from a dead body for laboratory examination is not conducted
in connection with the large risk of infection. A dead body
should be buried or burnt in a crematorium.

13. II Measures concerning the persons having contacts with patients:

A medical personnel and other persons being in the direct
contact with a patient is isolated in the hermetic apartment
with the disconnected ventilation to the moment of the
establishment of final diagnosis or on a term equal to
incubation (on the 21 day – at the Lassa and Ebola fevers; on
the 9 days – at the Marburg fever).
Persons being in the direct contact with a patient have to take
measures of the personal prophylaxis:
1. mucous of the mouth, nose to process by a 0,05% solution of
permanganate of potassium, to wash eyes with a 1% solution
of boric acid, begin to drip a 1% solution of nitric acid silver in
eyes, in a nose – 1% solution of protargol;
2. additionally to rinse mouth and throat by a 70° spirits or 1%
solution of boric acid.

14.

With the purpose of urgent prophylaxis serum of convalescent
is used.
Persons not being in the direct contact with a patient (for
example, members of evacuation team, working in the
protective clothing of the I-st type), do not undergo isolations,
but are subjected to the medical observation during a maximal
latent period (for 21 days – at the Lassa and Ebola fevers; for 9
days – at the Marburg fever) at the place of work or place of
residence.

15. III Measures concerning a situation:

After hospitalization of patient final disinfection is
conducted in a focus.
Evacuation team, after delivery of patient to the
hospital has territory of hospital the complete sanitary
treatment with disinfection of protective clothing.
A car, articles of care, of patient is exposed to final
disinfection by forces of brigades of disinfectant.
Disinfection brigades must consist of a doctor and
two disinfectors working in the protective clothing of
the I-st type. All not valuable articles of everyday life
are placed in dense plastic or paper sacks for further
burning, remaining things are subjected to chamber
treatment in steam-formalin or steam-air chambers.

16.

For disinfection of the apartment, articles of care of patient,
protective clothing are used a 3% chloramines solution.
At disinfection the apartment must be hermetically closed. In
every apartment from a doorstep, not entering the room, a
floor and air by disinfectant solution have to be irrigated.
The articles of care of patient are double wiped by a 6%
peroxide of hydrogen solution, and then wet in a 3%
chloramines solution for 120 minutes; a protective clothing is
boiled in a 2% soda solution, then 5 l/kg is wet in a 3%
chloramines solution for 120 min.

17. Methods of control of cholerae A. Preventive measures:

Two oral vaccines that provide significant protection
for several months against cholera caused by 01
strains have become available in a number of
countries.
One is a single-dose live vaccine (strain CVD 103HgR, available under the trade names Orahol® in
Europe and Mutacol in Canada, SSVI);
the other is a nonliving vaccine consisting of
inactivated vibrios plus R-subunit of the cholera
toxin, given on a 2-dose schedule (Dukoral, SBL).

18.

Measures that inhibit or otherwise compromise the
movement of people, foods or other goods are not justified.
B. Control of patient contacts and the immediate environment
1.
2.
3.
Report to local health authority: Case report universally
required by International Health Regulations (1969).
Isolation of the patient and vibriocarrier. To discharge from
hospital after admission and 3-th negative bacteriological
tests of feces. For the special contingent necessarily negative
bacteriological test of bile.
Concurrent disinfection: Of feces and vomitus and of linens
and articles used by patients, by heat, carbolic acid or other
disinfectant. Terminal cleaning.

19.

Quarantine: None. Can introduce restrictive
measures. Monitoring of water supply and catering.
Management of contacts: Surveillance of persons
who shared food and drink with a cholera patient for
5 days from last exposure. If there is evidence or high
likelihood of secondary transmission within
households, household members should be given
chemoprophylaxis; in adults, tetracycline (500 mg 4
times daily) or doxycycline (a single daily dose of
300 mg) for 3 days, unless local strains are known or
believed to be tetracycline resistant.

20.

Children may also be given tetracycline (50
mg/kg/day in 4 divided closes) or doxycycline (a
single dose of 6 mg/kg) for 3 days; with such short
courses of tetracyclines, staining of teeth is not a
problem.
Alternative prophylactic agents that may be useful
where V. cholerae 01 strains are resistant to
tetracycline include: furazolidone ( Furox-one®)
(100 mg 4 times daily for adults and 1.25 mg/kg 4
times daily for children); erythromycin (pediatric
dosage 40 mg/kg/ day in 4 divided doses; adult
dosage 250 mg 4 times daily);

21.

Investigation of contacts and source of infection:
Investigate possibilities of infection from polluted
drinking water and contaminated food.
Meal companions for the 5 days prior to onset should
be interviewed.
A search by stool culture for unreported cases is
recommended only among household members or
those exposed to a possible common source in a
previously uninfected area.

22.

Specific treatment:
These are three mainstays in the treatment
of patients with cholera:
aggressive rehydration therapy;
2) administration of effective antibiotics;
3) treatment of complications.
1)

23. C. Epidemic measures:

1) Educate the population at risk concerning the need
to seek appropriate treatment without delay.
2) Provide effective treatment facilities.
3) Adopt emergency measures to ensure a safe water
supply. Chlorinate public water supplies, even if the
source water appears to be uncontamination.
Chlorinate or boil water used for drinking, cooking
and washing dishes and food containers unless the
water supply is adequately chlorinated and subsequently protected from contamination.

24.

4) Ensure careful preparation and supervision of food
and drinks. After cooking or boiling, protect against
contamination by flies and unsanitary handling;
Persons with diarrhea should not prepare food or haul
water for others.
5) Initiate a thorough investigation designed to find
the vehicle and circumstances (time, place, person) of
transmission, and plan control measures accordingly.
6) Provide appropriate safe facilities for sewage
disposal.
7) Parenteral whole cell vaccine is not recommended.

25. Prophylaxis anthrax:

Prevention of human anthrax is mainly by
general methods, such as improvement of
factory hygiene and proper sterilization of
animal products like hides and wool.
Carcasses of animals suspected to have died
of anthrax are buried deep in quicklime or
cremated to prevent soil contamination.

26.

Prevention of anthrax in animals is aided by active
immunization. The original Pasteur's anthrax vaccine
is of great historical importance. Pasteur’s vaccine
was the anthrax bacillus attenuated by growth at 4243 C.
As the spore is the common infective form in nature,
vaccines consisting of spores of attenuated strains
were developed.
The Stene vaccine contained spores of a
noncapsulated avirulent mutant strain. The Mazucchi
vaccine contained spores of stable attenuated
Carbazoo strain in 2 % saponin.
The spore vaccines have been used extensively in
animals with good results. They give protection for a
year following a single injection.

27.

Alum precipitated toxoid prepared from the
protective antigen has been shown to be a safe
and effective vaccine for human use. It has
been used in persons occupationally exposed
to anthrax infection.
Three doses given intramuscularly at intervals
of six weeks between first and second, and six
months between second and third doses induce
good immunity, which can be reinforced if
necessary with annual booster injections.

28. Prophylaxis plaque:

Dispensary observation during 3 months is necessary
for convalescence with obligatory bacteriological
researching from mucosa of pharynx and sputum.
It is necessary to protect people from expansion of
plague diseases. This work is carried out by workers
of sanitation center, ambulatory-polyclinic network
and antiplague establishments. Plague is the
quarantine disease, so the international medicosanitary rules (WHO, 1969) are distributed on it.

29.

Workers of the general medical network observe
health of the population with the purpose of early
revealing the patients on plague. Each medical
worker should know the basic signs of disease, the
rules of personal prophylaxis, be able to carry out
initial antiepidemic actions.
At presence of epizooty among rats and diseases of
camels vaccination of the population by local services
under the control of antiplague establishment will be
carried out.

30.

At occurrence of a plague among the population the
antiepidemic actions are carried out which are directed on
localization and liquidation of epidemic pesthole.
They include: revealing of patients and their hospitalization in
special hospitals in isolation wards with severe antiepidemic
regime; and establishment of territorial quarantine: revealing
and isolation of all persons which was in contact with patients,
they must be isolated for 6 days.
undergo emergency prophylaxis with antibiotics streptomycinum 0.5 gm 2 times per day in muscle or
tetracyclinum - 0.5 gm 3 times a day per os, during 6 days;

31.

revealing the patients with fever and their hospitalization in
special departments;
final disinfections, and also disinfectations and deratization on
territory of settlement and around it. Invaluable things are
liable to destruction;
The personnel should be work in antiplague suit. Persons who
need to leave zone of quarantine, will undergo medical
observation..