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Vaccine Preventable diseases
By
Prof. Dr. Asmaa AbelAziz
Dr. Alaa Hassan
Vaccine Preventable diseases
• Measles• German Measles• Mumps• Poliomyelitis• Whooping Cough • Diphtheria • Tetanus• Chicken Pox
Measles (Rubeola)Standard case definition:
A) Suspected case:
Any child suffering from the following symptoms
•Fever (38.5 and lasting for >=3 days).
•Maculopapular rash
•Cough, Coryza (i.e. running nose) or
•Conjunctivitis .
B) Confirmed Case :
A confirmed case is one in which suspected
case is confirmed by laboratory( virus isolation or
antibody elevation) .
Maculopapular Rash of Measles
Place :
Countries in which measles vaccine is
widely used are already experiencing a marked
decrease in the incidence of the disease.
Time:
The seasonal trend that is observed in winter
months.
Epidemic cyclic rhythm in the pre-vaccination
era was 2-3 years according to accumulation
of susceptibles.
Person:
Age and sex:
Measles is mainly a disease of children.
The incidence is equal in both sex.
Following the widespread use of measles vaccine,
the disease is now seen in older age-groups and
the incidence increases in adults
Nutrition:
Measles tends to be very severe in the
malnourished child
Mode of transmission:
Measles is highly communicable diseases.
It can be transmitted by:
- Droplet spread
- Direct contact with nasal or throat
secretions of infected persons.
- Less commonly it is spread by air born
mode or indirect contact
Inlet:
Nose and mouth.
Susceptibility :
Practically all persons who have not had the disease or
been immunized are susceptible.
•Acquired natural immunity: is permanent.
•Acquired passive immunity: Infants born to mothers
who have had the disease are immune for the first 6-9
month or more depending on the amount of residual
maternal antibody at the time of pregnancy.
• Artificial passive immunization (Immunoglobulin)
•Artificial active immunity ( Vaccination)
Vaccination• The vaccine is presented as freeze-dried product.
•It is stable, stored at refrigerator temperature (0-8C).
•The vaccine is either monovalent or in combined form
measles, rubella, and mumps – MMR – without loss of
potency of any antigen.
•Dosage: Single subcutaneous dose of 0.5ml of the
reconstituted vaccine given into the arm.
•According to the Schedule in KSA ,MMR is given in Two
doses ( at 12th months & at 4-6th Years)
•Immunity: Immunity develops eight days after
vaccination. One dose of the vaccine appears to protect
95% of recipients.
•Side effects: Mild fever (7 days after vaccine receiving)
Contraindications:
I. Measles vaccine should not be given to Children with
impaired immune systems ( leukemia, lymphoma,
generalized malignancy, immune deficiency diseases or
immunosuppressive therapy.)
II. Pregnant women.
III. Person suffering from an acute illness and active T.B.
IV. Recipients of blood or blood products ( immune globulin,
whole blood or packed red blood cells). They neutralize
the measles vaccine. Administration of measles vaccine to
blood recipients should be postponed 2-3 weeks after
receiving the blood
Period of communicability:
The period of communicability is four days before and four
days after the appearance of the rash.
The vaccine virus has not been shown to be
communicable
Prevention:1. Apply basic measures for prevention of respiratory tract
infection .
2. Vaccination.
3. Immunoglobulin: The need for immunoglobulin is now
much reduced because of the availability of an effective
live attenuated vaccine. It is given to exposed children
whom the vaccine is contraindicated
To be effective, passive immunity must be given within three
days following an exposure, administration after three
days is not effective Why?.
Measles elimination program:Measles like small pox, has several favorable factors
that make it a suitable candidate for eradication.
The virus exists in a single serotype that is of
antigenicaly stable
Absence of nonhuman reservoir
The disease provides durable immunity.,
Available effective live vaccine stable and
produces durable immunity.
Characteristics of measles that makes the disease more
resistant to eradication. I. Measles has very high secondary attack rate; (i.e. highly
communicable ) .. It is necessary to maintain nearly 100%
coverage with vaccine to prevent transmission.
II. Measles is transmitted mainly by direct contact with
infectious droplets or less commonly by air borne spread. Air
borne transmission of measles increases the contact rate
between the index case and susceptible.
III. Because measles patients are contagious for 4 days
before rash onset they transmit the infection before their
discovery.
The strategies recommended for achieving measles
elimination and mortality reduction include:
1-Maintain high vaccination coverage rate
for measles vaccine
2-Enhancing measles surveillance
systems.
3-Improve management of complicated
cases of measles.
4-Provide Vit. A supplementation
German Measles (Rubella)
Standard case definition:a) Suspected case :
Any patient with the following :1.Fever (>37.2C) 2.Generalized maculopapular rash.3.Lymphadenopathy.
b) Confirmed case :
A confirmed case is one in which the suspected case is confirmed by laboratory (virus isolation or antibody elevation ) or epidemiological.
Manifestations of congenital rubella
Ear :Deafness
Eyes : cataracts, glaucoma, retinopathy and microophthalmia
Heart : patent ductus arteriosus, ventricular septal defect, pulmonary
stenosis
Neurologic : microcephaly and mental retardation
Others:
bone lesions, splenomegaly, hepatitis, and thrombocytopenia with
purpura may occur.
These congenital malformations and even fetal death may occur
following either clinically manifest or inapparent rubella infection during
early pregnancy.
Descriptive Epidemiology:Place :
Worldwide, universally endemic
Time:
The disease is prevalent in winter and spring.
Person:
Age and sex:
•In unvaccinated population, rubella is primarily a
disease of childhood and young adults.
•In communities where children are well
immunized, adolescent infection become more
important.
•Both sexes are susceptible.
Mode of transmission:
•Droplet spread.
•Direct contact with patients.
-Indirect contact with articles freshly soiled with
discharges from nose and throat,
-Air borne transmission
-Transplacental.
Inlet:
Nose and mouth.
Susceptibility :
1. Infants borne to immune mothers are protected for 6-9
months.
2. Active immunity acquired by natural infection is
permanent
3. Immunity after vaccination:
A single dose of live attenuated rubella virus vaccine
elicits a significant antibody response.
According to the Schedule in KSA ,MMR is given in Two
doses ( at 12th months & at 4-6th Years)
Duration of immunity: Rubella antibody persists for a
long period after vaccination.
Vaccine and pregnancy:
Because vaccine virus theoretically might infect the
fetus and cause congenital defects if given to
susceptible women early in pregnancy, immunization of
women known to be pregnant is contraindicated.
Pregnancy is to be avoided for 3 month after
vaccination.
4 - Immunoglobulin: is given to women exposed
during early pregnancy
Mumps
Standard case definition:A) Suspected case :
An acute illness of unilateral or bilateral tender self limited swelling of parotid or other salivary glands.
B) Confirmed case :All of the above and isolation of the virus from salivary secretion of the case or by serological testing for mumps specific antibodies.
Complications :
The complications occur more in teenage children and adults than in infants and young children. These include:
• Orchitis: sterility is rare because the condition is unilateral
• Oophoritis , mastitis and myocarditis, Pancreatitis• Neurological : meningitis and meningoencephalitis.• Congenital anomalies involving the heart if the
infection occurs during pregnancy.
Descriptive Epidemiology:
• Place :Mumps is rarely an endemic disease . Outbreaks are associated with overcrowding .
• Time:Winter is the season of greatest incidence.
• Person:Age: It affects any age if there is no previous immunity. The disease tends to be more severe in adults than in children, with more frequent complications.
Cycle of infection:
• Agent:Mumps virus.• Reservoir:
Man in the form of clinical and sub clinical infection.The source of infection is the saliva of infected person.• Exit:
Mouth.• Mode of transmission:• Droplet contact.• Direct contact with saliva of an infected person.• Indirect contact with articles soiled with nose& throat discharge
• Inlet:Nose and mouth.
• Susceptibility :
• Susceptibility is general .
• Post infection immunity is generally life long and develops after subclinical as well as clinical attacks..
• Vaccination: Live attenuated vaccine in combination with Measles & german measles vaccine (MMR)
Prevention:
1-Apply basic measures for prevention of respiratory tract infection
2-Vaccination: live attenuated vaccine The vaccine is available as combined vaccine (combined measles – mumps – rubella vaccine) MMR. In KSA, 2 doses of MMR are given in the 12th & at 4-6 years of age.
Whooping cough(Pertussis)
Standard Case definition: Suspected case: A person with a cough at least 2 weeks with one of the
following:-Paroxysms of coughing or.-Inspiratory whoop or.-Post-tussive vomiting (ie vomiting immediately after
coughing) and without other apparent cause. Confirmed case:
A confirmed case is a suspected case that is laboratory confirmed.
-By isolation of Bordetella pertussis. - Serologically
Complications
Complications of whooping cough include
- Hernia, – Prolapsed rectum, – Sub-conjunctival haemorrhage, – Encephalopathy, – Pneumonia and bronchiectasis.
Descriptive epidemiology:
• Person:
Age and sex: Whooping cough is a disease of infants and pre-school children.
• Place
Whooping cough occurs in all countries. During the past four decades, a marked decline has occurred in incidence and mortality rates, chiefly in countries with active immunization programs.
• Time
It occurs more in winter.
Cycle of infection:• Causative agent Bordetella pertussis bacilli. • ReservoirMan in the form of cases. There is no evidence that the infection is subclinical.There is no carriers in whooping cough ( bacteriologically free before the clinical cure)Sources of infection: Nasopharyngeal and bronchial
secretions.• ExitNose and mouth.• Mode of transmission
Direct contact andDroplet contact .The role of indirect & air borne transmission is less important.
• Inlet Nose and mouth.
Susceptibility :
• Susceptibility to the disease is general.
• There is no passive maternal immunity even if the mother is immune.
• Post-infection immunity is long lasting.
• There is no evidence of the efficacy of hyper-immune globulin in pertussis prophylaxis.
• The efficacy of the vaccine in children who have received 3 doses is estimated to be 80%.
Vaccination:1.Whole cell pertussis vaccine:
•It is a killed vaccine given in combination with diphtheria
and tetanus toxoids (DPT) in three intra-muscular
injections at 2, 4, 6 months old. Two booster dose at 18th
months & 4-6 years of age.
Side effects of Whole cell pertussis vaccine is
local adverse events (eg. Erythema, swelling & pain at the
injection site.), fever, drowsiness & anorexia.
Systemic events ( Convulsions, encephalopathy, shock.)
occur less frequently. This calls for the development of
more purified (acellular pertussis vaccines) that are
associated with a lower frequency of adverse events.
2.Acellular pertussis vaccine (DTaP):
• It contains purified, components inactivated toxin and filamentous haemagglutinin of bordetella pertussis cells.
• Certain types of DTaP have been licensed only for administration of the fourth and fifth doses in the series to children aged 15 months to 6 years who previously had received 3 doses of DPT vaccine.
• In general, pertussis vaccine is not given to person 7 years of age or older since the disease is usually milder and the reaction to the vaccine may be increased in older children and adults.
Diphtheria
Standard Case definition:A) Suspected case :
A patient is suffering from an illness characterized by adherent membrane on the tonsils, pharynx and or nose and any one of the following: Pharyngitis, laryngitis or tonsillitis.
B) Confirmed case:
Is a suspected case, laboratory confirmed by one of the following:
- Isolation of corynebacterium diphtheriae from throat swab.
- A rise in the serum antibody.
Complications
1-Cardiovascular complications:– Peripheral circulatory failure due to diffuse
toxic changes in all organs including the adrenals and the vascular endothelium.
– Myocarditis and congestive heart failure.
2-Paralysis .
Case fatality rate ranges from 5-10%.
Cycle of infection :
• Causative agent:• Corynebacterium diphtheriae , it produces a powerful
exotoxin. • Reservoir:• Man in the form of cases (clinical and sub-clinical)
and carriers. • Carriers may be temporary or chronic, contact or
incubatory, nasal or throat carriers.• Source of infection:• Discharges from the nose and throat.• Exit• Nose and mouth.
• Mode of transmission:
• Contact transmission : direct, indirect and droplet.
• Air-borne transmission by droplet nuclei.
• A common vehicle (raw milk).
Inlet
• Upper respiratory tract.
• Susceptibility :• Infants born to immune mothers are relatively
immune for the first six months. Post-infection immunity is specific and long-lasting.
• Active artificial immunity can be induced by toxoid vaccine (DPT).
• Short passive artificial immunity (2-3 weeks) can be gained by administration of antitoxin.
Vaccination• Active immunization with diphtheria toxoid.
• Immunization is initiated in infancy with a formalin
inactivated diphtheria toxoid, tetanus toxoid & cellular
or acellular pertussis vaccine ( DPT ).
• In KSA DPT vaccine is given by IM injection at two,
four and six months of age and booster doses at 18-
24 months & at 4-6 years.
• If the pertussis component is contraindicated (DT),
should be substituted.
•For persons 7 years of age and older, a reduced
concentration of diphtheria toxoid (adult Td) is
used for a previously unimmunized individual, a
primary series of 3 doses is given. The first 2
doses are given at 4-8 weeks intervals and the
third dose 6 months to 1 year after the second
dose.
•Administration of a dose of Td every 10 years
thereafter for persons who are at higher risk of
patient exposure, such as health workers
Poliomyelitis
Standard case definition:A) Suspected case• Any child under 15 years of age with acute,
flaccid paralysis (AFP).• Any person- at any age- with paralytic illness
when polio is suspected.B) Confirmed case• A suspected case is confirmed with isolation of
wild poliovirus from the stools of either the case or its contacts.
Complications :-Permanent muscle paralysis, disability,
deformity.
-Respiratory muscle involvement & death
-Post-polio syndrome (PPS) : muscle pain
and weaknesses or paralysis. It occurs after
30 to 40 years, in 25%-40% of individuals
who contract paralytic poliomyelitis in
childhood.
• Time
Poliovirus infection typically peaks in the summer months.
Cycle of infectionAgent
Poliovirus : three serotypes (P1, P2, P3) with different
antigenicity
The virus can live in water for three months and in the faeces for
six months.
The poliovirus is rapidly inactivated by heat, formaldehyde,
chlorine and ultraviolet light.
Reservoir
Cases : clinical & subclinical plays a role in the spread of infection
Carriers: faecal temporary. There is no chronic carrier.Source of infection:Faeces and pharyngeal secretions of the infected person
Mode of transmission
1-Feaces (feco-oral): in areas with lack of personal hygiene
especially in young children in developing countries. It results in
infection not paralysis.
2-Droplet : in developed countries with high standard of
sanitation, droplet is common mode of transmission during the
acute phase of the disease when the virus is in the throat.
3-Direct contact with respiratory discharge
4- Common vehicle: ingestion of food or drink contaminated with
faeces
5- Indirect contact with articles contaminated with pharyngeal
discharge of infected person. InletThe mouth and nose
Vaccination:
• There are 2 types of vaccines
– Sabin; live attenuated oral polio virus vaccine (OPV)
– Salk; inactivated poliovirus vaccine (IPV)
IPV (Salk) OPV (Sabin)
Type of vaccine
Killed formalin inactivated contains the 3 strains .
Live attenuated contains the 3 strains
Mode of administration & number of doses
Subcutaneous or IM, 2-3 doses in first year of life and 1 booster commonly given in 4-6 years.
Oral ,5 doses 2nd , 4th, 6th, 18th months& 4- 6th years
Differences between IPV and OPV vaccines
Preventive measures
• Vaccination
• Educating the public regarding the benefits of immunization in early childhood and personal hygiene
Epidemic measures
In countries undertaking polio eradication, a
single case of poliomyelitis is considered a
public health emergency.
Polio eradication program:
• In 1988 the WHO adopted the goal of global eradication of polio virus by the year 2000.
• Although substantial progress has been made the goal was not achieved .
Polio is suitable to be eradicated for the following reasons
• Polio only affects humans, there are no known animal reservoirs
• An effective, inexpensive vaccine is available: Oral Polio Vaccine (OPV)
• Immunity is life long
• There are no chronic carriers
Strategies of polio eradication
There are four core strategies to stop transmission of the wild poliovirus
A-Routine immunization of infants
B-Supplementary immunizationNational immunization days ( EPI)
Mopping up immunization ( EPI)
C- Surveillance Acute flaccid paralysis.
D-An effective virological laboratory
ChickenpoxVaricella
• Case definition• Chickenpox is an acute highly infectious
disease, characterized by vesicular rash, mild fever and mild constitutional symptoms.
• Herpes zoster is a local manifestation of reactivation of latent varicella infection in the dorsal root ganglia. It occurs in 15% of normal immune adults.
Descriptive epidemiology • Person:• Age and sex• Chickenpox occurs primarily among children
under 10 years of age. • Few persons escape infection until adulthood. • The disease can be severe in normal adults.• No sex difference has been reported.• Place:• Chickenpox has a worldwide distribution.• Time: • Chickenpox occurs most frequently in winter
Cycle of infection:
• Causative agent
• Varicella zoster virus, which is a member of herpes virus group.
• Reservoir
• Man in the form of cases.
Source of infection
Discharges of respiratory tract of infected persons and fluid of vesicles before they become dry (scabs are not infective).
• Exit• Upper respiratory tract and lesions of the
skin and mucosa.• Mode if transmission• Contact, direct, indirect and droplet.• Air borne transmission by droplet nuclei.• Transplacental.The virus can cross the
placenta and may result in a condition known as congenital varicella.
• Inlet • Upper respiratory tract and skin.
• Susceptibility • Susceptibility to chickenpox is general among
non-immune individuals. • Infection usually confers Long lasting
immunity. • The viral infection may remain latent, and
disease may recur years later as herpes zoster in about 15% of older adults.
• Varicella zoster immune-globulin is effective in modifying or preventing disease if given within 96 hours after exposure.
• Infants born to immune mothers have passive immunity for the first 6 months of their life.
Varicella vaccine
• It is a live-attenuated vaccine. • It was licensed for use since 1995. • A single 0.5 ml subcutaneous dose is recommended for routine
immunization of children aged 18 months and for immunization of children up to 12 years of age who have not had varicella.
• The vaccine effectiveness ranged from 85-90% for prevention of all disease
• If vaccine given within 3 days of exposure, it prevents the disease.
• Varicella vaccine is recommended for susceptible persons more than 13 years old e.g. health workers. They require 2 doses of vaccine 4-8 weeks apart.
Some may not recommend varicella vaccination because:
• Chicken pox is a mild illness there is no need for the vaccine .
• It may be risk if chicken pox is postponed for childhood (where it is mild) to adulthood where it is more severe with more complications.
• Live vaccine may establish latent infection this may produce zoster in later years or in a more severe form than natural disease.
Tetanus (Lock jaw)
An acute disease induced by the tetanus bacillus which grows anaerobically at the site of an injury and produces a neurotoxin. There are two types of tetanus:
• Adult Tetanus
tetanus
A-Adult Tetanus
It is characterized by: Painful muscular contractions of the masseter muscles (lock jaw or trismus) and neck muscles, then the trunk muscles and the muscles of the face causing risus sardonicus. The first sign of tetanus is abnormal rigidity at the region of injury.
Generalized spasms induced by sensory stimuli. The adult tetanus usually follows an injury or surgical operation, delivery or abortion. However, history of an injury or apparent portal of entry is often lacking.
Types of Adult tetanus:Traumatic tetanus : due to injuriesPuerperal tetanus: following abortion or
labor.Surgical tetanus: following a surgical
operation.Otogenic tetanus: as a result of introducing
foreign bodies in the ear (pencils, matches)Idiopathic: where no definite history of
trauma, yet, usually due to minor microscopic injuries which are missed.
B-Neonatal tetanus: (NT)Case definition (NT):A) Suspected case:Any death of unknown cause between 3 to 28 days of life.B) Confirmed cases:NT is diagnosed on clinical findings and does not
depend on laboratory confirmationA confirmed case is
– An infant is able to suck and cry normally during the first 2 days of life ,he becomes unable to feed or suck between the ages of 3 and 28 days
– He has episodes of convulsions
Case fatality:-
• Neonatal tetanus (NT) is always fatal (>90%).
• Other types of tetanus range from 30-90% depending on age, severity of injury, immune status and time of intervention (diagnosis and treatment).
Descriptive epidemiology
• Place:
It is world wide disease, occurs sporadically, it is more common in agricultural regions and in underdeveloped areas, where contact with animal excreta is more likely and immunization is inadequate.
Neonatal tetanus is common in areas where birth is traditional particularly in the rural areas.
Parenteral use of drugs by addicts results in individual cases or occasional circumscribed outbreaks.
• Person:
Age and sex:
Tetanus affects all ages especially under 15
years. In the agricultural It areas affects
adult males.
Neonatal tetanus affects the newborn.
Time:
In Summer especially when humidity is high.
Incubation period:
• In adult tetanus it is 4-21 days, it depends on character, extent and location of wound; average ten days.
• In neonatal tetanus, the incubation period is usually two days (after birth).
The prognosis is very poor in those with early onset, and favorable in those with late onset.
Cycle of infection
• Agent:Clostridium tetani,( the tetanus bacillus). The
vegetative form of the organism is fragile, but under unfavorable conditions changes to spores which are highly resistant,
• Reservoir :• The soil and intestinal tract of animals specially
horses and cattle in which the organism is harmless normal inhabitant.
• Source of infection: is the soil or street dust containing the spores.• Exit :• The stools of animals specially horses.
•Mode of transmission:
• Tetanus spores introduced into the body during • injury, contaminated with soil, street dust or
animal faeces, • laceration, burns and unnoticed wounds.
• Neonatal tetanus occurs through infection of the unhealed umbilicus, during cutting, ligature or dressing of the umbilical cord under septic technique.
• Inlet :
Wounds, puncture, burns or umbilical cord
stump.
•Susceptibility
Susceptibility is general. • The presence of necrotic tissue or foreign bodies favors the growth of anaerobic pathogens. • Second attack may occur because protective
post infection immunity is absent.
• Vaccination with Tetanus toxoid (TT) produces a long active immunity.
• Tetanus antitoxin or tetanus immunoglobulin produces passive immunity
Period of communicability:
The disease is not communicable from man to man.
Prevention:
1.Active immunization with tetanus toxoid gives solid protection:
a. In infancy: it is given with diphtheria and whooping cough vaccine (DPT) at the end of second, fourth, and sixth month of age and a booster dose at 18 months & 4-6 years of age.
• Booster dose is needed every 10 years (Td).
b. Tetanus toxoid can be given at any age, for workers in contact with soil, sewage or domestic animals, members of military forces, policemen and others with greater than usual risk of traumatic injury.
The schedule for previously non immunized individuals (>7years) a primary series of 3 doses of (TD) is given. The first 2 doses are given at 4-8 weeks interval and a third dose 6-12 months after the 2nd dose.
Prevention of neonatal tetanus:
Immunization schedule for women in the
reproductive period has been recommended.
It consists of five doses of tetanus toxoid (TT),
respecting the minimum interval between
doses will provide immunity through a
woman's childbearing years.
TT1: At first contact or as early as possible during pregnancy.
TT2: 4 weeks after TT1.
TT3: 6 months after TT2 or during the second pregnancy.
TT4: 1 year after TT3 or during next pregnancy.
TT5: 1 year after TT4 or during next pregnancy.
There is no evidence for contraindications of TT immunization of pregnant women at any time during pregnancy
Control:1- Reporting to local health authority.
2-Isolation of the patient in a hospital for the benefit of the patient 3-Treatment:• Tetanus immunoglobulin (TIG) IM, if not available, intravenous tetanus antitoxin • Penicillin in large doses intravenous. • The wound should be excised if possible, if not it should be
infiltrated with TIG.• Maintain an adequate airways; and sedation if indicated; • muscle relaxants together with tracheostomy 4-Active immunization should be initiated concurrently with
therapy.5-Disinfection: not applied.
6-Contacts: Nothing.