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.