Saturday, January 24, 2009

Hepatitis B Vaccine And Its Significance

Hepatitis B vaccine

Why hepatitis B virus is more dangerous than HIV?

Hepatitis B virus ( HBV) causes hepatitis (liver inflammation). This can lead to liver cirrhosis (small shrunken liver) and cancer.
HBV is transmitted very easily through blood, body fluids and this is an important cause of morbidity and mortality. It kills more people in the world per year than HIV. This can be easily transmitted from mother to baby at birth.

As HBV can survive adverse atmospheric conditions, this is a of more concern than HIV. This HBV is more dangerous than HIV as rapid death can occur within a few days due to “ fulminant liver (hepatic) failure”. Development of Hepatitis B vaccine proved to be a major milestone as it has helped in preventing deaths due to liver cirrhosis and cancer. Once fulminant liver (hepatic) failure develops, liver transplantation remains as a trial Rx which may help

Magnitude of the problem

More than 2 billion people worldwide have been infected with the virus and 600 000 persons die each year due to the complications of hepatitis B.

Dose Schedule

Doses are given at 0, 1 , 6 months. 0 means the day when 1st dose is given. Booster doses are recommended after every 5 year

Dosage

The standard adult dose is 1 ml.
The standard pediatric dose is 0.5 ml.

Market Preparations

It is available as

1. Genetically engineered vaccine ( engerix, shanvac)

2. Derived from human sera of infected people

Genetically engineered recombinant hepatitis B vaccine is preferable as it doesn’t have the risk of transmitting infection from 1 person to the other. Serum derived vaccines can transmit infection like HIV though this is very rare. Hepatitis-B surface Antigen (HBsAg) is produced in genetically engineered yeast cells of Pichia pastoris which carry the gene that codes for the major surface antigen protein of the hepatitis-B virus.
It is available with following brand names

1. Engerix

2. Shanvac

3. REVAC-Bmcf - This is free of Thiomersol (Mercury) and Cesium Chloride

Vaccine is available in single-dose and multi-dose vials.

Careful maintenance of the cold chain ( proper temperature while storage) is the most important precaution for all vaccines.

When Hepatitis B vaccine Is Recommended

1. All healthcare workers ( doctors, Pathology laboratory staff) who handle blood and blood products should get vaccinated. Many healthcare workers hav got infected and some of them have expired.

2. If a lady with active hepatitis B infection delivers a baby, baby has a risk of getting infection. In all such cases, Baby should be vaccinated within 48 hours of birth. Also we have to give hepatitis B immunoglobulins to baby.

How To Check Response to Vaccination?

Blood testing is recommended 1-4 after vaccination to determine antibody titres. If antibody levels are above 100 mIU/ml, its considered as satisfactory response. If levels are less, additional 1 dose is recommended.

Booster Dosage

After a lot of controversial reports, UK guidelines now suggest that for initial responders who require lifelong protection, such as for healthcare workers, only a single booster is recommended at 5 years.

Efficacy

It is 95% effective in preventing HBV infection.

How It Is Given?

HepB vaccine is given by intramuscular injection in the anterolateral aspect of the thigh (infants) or deltoid muscle (older children). It can safely be given at the same time as other vaccines, such as DTP,Hib, measles, OPV, BCG, and yellow fever vaccines. If more than one injection is given at the same time, separate injection sites should be used.

Risks and Complications associated with Vaccination

This is not common. Sometimes child may develop reaction in the form of fever, swelling, etc.at injection site.
Its a very safe vaccine. The only concern was an increased risk of multiple sclerosis. But now it has been proved that HBV vaccine doesn’t lead to an increased risk of multiple sclerosis.

Read more at

Vaccination Schedule for Child

Vaccination for baby - Protection against childhood Infectious diseases

Child's Vaccination
. One should take all precautions to prevent this disease.

1 Avoid unprotected intercourse with commercial sex workers.Use of condoms is recommended


2 Make it sure that all blood products have been checked for HIV before transfusion

3 Licencing & screening of commercial sex workers by Govt will be very helpful

4 Start sex education in schools after std 8th

5 Use disposable needles, blades.Proper sterilization of instruments in hospitals before surgery

6 Avoid sharing of needles in case of intravenous drug abusers

Infectious Diseases And Vaccination (Immunisation) Schedule for Child And Its Significance

Child birth in any family brings a lot of happiness for the family. At the same time, it brings a lot of responsibilities for parents. One should have a healthy child as children are building blocks of a family and nation when they become adults. All parents should be aware of Vaccination Schedule for child

Vaccination (Immunisation) gives immunity to fight against various infections by building immunity. Vaccines may be containing either live or inactivated organisms (attenuated vaccine) organisms
One has to be very careful during early neonatal and infancy as child is more susceptible for some diseases due to inadequate immunity. Breast-fed infants have better immunity as they get antibodies from mother

Vaccination is very important in prevention of childhood diseases and some vaccines give lifelong immunity against certain diseases. Some vaccines need booster doses after a certain interval. Certain vaccines are live while others are inactive.

BCG- Bacille Calmitte Guerine

This gives protection against tuberculosis ( TB). TB is a very common health problem in developing countries like India. It is said that almost every Indian gets exposed to TB organisms (mycobacterium tuberculosis). It affects lungs & possibility of any other organ involvement is there (like kidney, skin, etc). If organ other than lung is involved, its called as extra-pulmonary TB. So this vaccine is given as early as possible after birth preferably within 1st 2 days when delivered lady is still hospitalized. In spite of Vaccination, person can develop TB in future life

MMR

It consists of 3 vaccines- Mumps, Measles, Rubella


Mumps -

This is caused by a virus. It is manifested as epidemic parotitis ( Painful swelling of the salivary glands). Mumps virus was the leading cause of viral meningoencephalitis earlier.
Fever, headache, parotitis(salivary gland inflammation in which cheeks appear swollen), malaise and anorexia are other constitutional symptoms.

Generally it will subside slowly but sometimes it may cause complications like
1. Orchitis ( inflammation of testes in which testes appear swollen) in a male baby which may lead to infertility..
2. Viral meningoencephalitis
Live, attenuated mumps virus vaccine is used as it gives a longterm immunity. The vaccine may be given separately or as part of the MMR . The mumps vaccine has helped a lot in achieving a decrease in the incidence of mumps

Measles –

Measles comes in the category of “ exanthematous fevers”.
The word "exanthem" is a Greek word meaning “ skin rash”. Measles is a highly contagious viral disease that primarily affects children.
It is characterized by fever, cough, cold,, red eyes and a generalized, maculopapular, erythematous rash.
3 “C”s help in diagnosing measles- Cough, coryza , Conjunctivitis.
Koplik's spots are seen inside the mouth . These are pathognomonic for measles but are not seen commonly.
Measles can lead to serious complications sometimes like

Complications Of Measles



1.“ Subacute sclerosing panencephalitis ( SSPE)”
2. Corneal ulceration leading to corneal scarring

Thanks to the efforts of UNICEF, measles deaths worldwide have dropped by 74 percent since 2000. UNICEF is the global leader in vaccine supply, supplying 50% of the world’s need.

Rubella-

This is given at 9 months of age.

In US and UK, rubella vaccine is given compulsorily for all adolescent girls. If girl affected by rubella gets pregnant, child can develop some serious congenital anomalies called as “ Congenital Rubella Syndrome”. This vaccine gives protection.

Congenital Rubella Syndrome

Child develops various abnormalities like
1. Cardiac ( heart related)- Patent ductus arteriosus
2. Defective dentition
3. Deafness
4. Salt pepper fundus or Rubella retinopathy – an abnormality of retina

American Academy of Pediatrics recommends administration of MMR vaccine at the age of 12-15 months and at 4-6 years.
Efficacy of the vaccine is usually around 80%.

Reye's syndrome

Aspirin use is discouraged in young children with viral fever due to chances of Reye’s syndrome. In this syndrome, many abnormalities are seen like brain related abnormalities, mental retardation. Paracetamol, acetaminophen or ibuprofen can be used.

Chicken Pox

This is caused by the varicella-zoster virus (VZV) also known as human herpes virus 3 (HHV-3). It is very contagious from about 2 days before the rash appears and lasts until all the blisters are crusted over. It is acquired by the inhalation droplets from an infected host.

Vaccine

American Academy of Pediatrics (AAP) recommends the vaccine for all children and adults with no history of the disease
From 12 months to 12 years of age – 1 dose.
13 years and above – 2 doses with an interval of 6-10 weeks.

How the vaccine is given

The vaccine is given subcutaneously.

When the vaccine should not be given? What information to be given to doctor

1. Immuno-compromised people
2. Anybody suffering from acute severe febrile illness.
3. Pregnant women
4. Any reaction to previous vaccine
5. If one is taking any drugs like steroids, inform doctor.

OPV ( Oral Polio Vaccine )

Pulse polio programme is going on all over the world to eradicate this disease. India is participating actively in this. Generally OPV is given in December or Jan months on selected days at the same time all over India.
In earlier days, polio used to be seen commonly and it used to make children handicapped. We see many children with lower limb (leg) abnormalities. Nowadays with aggressive vaccination, polio is almost eradicated.

Hepatitis B vaccine

Hepatitis B virus ( HBV) causes hepatitis. This can lead to liver cirrhosis and cancer.
HBV is transmitted very easily through blood and this is an important cause of morbidity and mortality. As HBV can survive adverse atmospheric conditions, this is a of more concern than HIV. This HBV is more dangerous than HIV as death can occur within a few days due to
“ fulminant hepatic failure”

Doses are given at 0, 1 , 6 months. 0 means the day when 1st dose is given. Booster doses are recommended after every 1 year

It is available as
3. Genetically engineered vaccine
4. Derived from human sera of infected people

Genetically engineered vaccine is preferable as it doesn’t have the risk of transmitting infection from 1 person to the other.
It is available with following brand names
1. Engerix
2. Shanvac
.


Tetanus toxoid

Tetanus

This is caused by Clostridium tetani, an anaerobic organism. Unhealthy wound is a risk factor. Tetanus means lock jaw due to muscle spasm. This is an acute fatal disease.

CLOSTRIDIUM TETANI And PATHOGENESIS



Organism enters the body through wound and produces toxin which reaches
central nervous system . This leads to muscle spasms and other signs and symptoms.

Incubation period

Ranges from 3 days to 3 weeks.

Complications



1. Asphyxia

2. Laryngospasm

3. Convulsions related injuries- fractures

4. Death

Tetanus toxoid

It is a formaldehyde treated toxin. Adsorbed toxoid is preferred as it gives long lasting immunity.
This is given to all children between 2 months and 6 years of age to protect (immunize) against tetanus infection .
Schedule For DtaP primary vaccination
1st at 2 months
2nd at 4 months
3rd at 6 months
4th 15 – 18 months

Booster Doses

May be needed at the time of injury

Where It is Given

Upper arm intramuscular deltoid muscle is the commonest site.

What adverse effects can occur?

These are generally mild.

Local adverse effects

1. Irritation

2. Swelling,

3. Redness

4. Bruising with pain

5. Lump at the injection site

6. Itching

Systemic side effects

1. Malaise

2. Low grade fever

3. Itching.

DPT Vaccine



Diphtheria
Pertussis
Tetanus

DTaP Vaccine



Diphtheria
Acellular Pertussis
Tetanus

Management Of Tetanus



1. Wound cleaning and surgical debridement is extremely important.

2. Metronidazole and penicillin treatment are useful to some extent.


Rx Of Mild tetanus

1. Tetanus immuno-globulins IV ( intravenous) or IM ( intramuscular)

2. Tetanus toxoid

3. Metronidazole intravenous

4. Sedation to prevent injuries due to convulsions

Rx Of Severe tetanus

1. Hospitalisation

2. Tetanus immuno-globulins intrathecally

3. Tracheostomy and artificial ventilation

4. Sedation

Myths About Tetanus

Laymen often think that rust on an iron surface causes tetanus if one gets injured with such an object. Actually any injury whether it is due to a rusty nail or normal nail can cause tetanus as it breaches the skin and anaerobic organisms can get penetrated.

Read more about vaccines at
Hepatitis-B-vaccine

Sunday, January 4, 2009

What are the consequences of ROP- Causes of childhood blindness

Your child's eye are precious. Take care


1. Myopia (refractive error, near-sightedness)- High minus power glasses which makes life difficult for child
2. Squint- both eyes are not parallel to each other & appear deviated ( cross eyes)
3. Poor vision- Amblyopia
4. Retinal detachment & blindness - This can occur in 1 eye or both eyes. Retina is like curtain situated at the back side of eye where image is created & then image is transferred to brain via nerves

Saturday, October 11, 2008

Retinopathy of prematurity (ROP)- A Blinding Disease During Infancy (Childhood)

Retinopathy of prematurity(ROP) is emerging as a major health problem in premature,low birth weight infants.
In this condition abnormal blood vasculature occurs in retina which can cause bleeding inside eye, tractional retinal detachment(TRD).
Who are at risk?
1)premature,low birth weight infants.
2)very sick infants who had respiratory distress syndrome & who were kept in neonatal intensive care unit (NICU) for longer duration
3)Infants who were given oxygen for a longer duration
4)Infants who were given surfactant & steroids for maturation of lungs in case of respiratory distress syndrome where lungs are immature at birth
Initially a ridge forms in peripheral retina.Then popcorn vessels form.If we diagnose the condition at early stage,laser Rx is to be done as early as possible.Laser burns are placed as confluent.After this ROP may regress
Retinopathy of prematurity (ROP) may regress completely or leave sequelae ranging from mild myopia ,squint to bilateral total blindness due to TRD or combined RD.Premature babies with ROP have higher rates of myopia and strabismus than those without ROP. Long-term follow-up of these babies is important for early detection and treatment of these ocular problems. TIMELY RECOGNITION AND TREATMENT OF retinopathy of prematurity (ROP) is the cornerstone to improving chances for preserving vision in premature infants.Neonatologists, ophthalmologists, and their patients will have to work in coordination to detect ROP babies & treat them.
Neonatologists should monitor oxygen strictly in NICU(Neonatal ICU).
Blockage of the renin-angiotensin system (RAS) during pregnancy can cause serious dysfunction of many organs of the foetus and newborn. Angiotensin II is an angiogenic factor and angiotensin-converting enzyme (ACE) inhibitors prevent retinal neovascularisation and their use in preventing proliferative retinopathy of prematurity has been suggested
Intravitreal injection of bevacizumab,pegaptanib seems to be associated with reduced neovascularization & trials are going on