poliomyelitis basics
TRANSCRIPT
Picorna Viruses. EnteroViruses Present and
Isolated from Alimentary tract
Throat, Lower Intestine.
Rhino viruses
Present and isolated from
Nose, Throat
Picorna Viruses.
Entero viruses, Can produce Severe paralysis, Aseptic meningitis, Myocarditis, Vesicular and
Exanthematous skin lesions.
Most serious is Poliomyelitis.
Rhino virusMainly produces
Respiratory illness
Conjunctivitis,
Properties of Picorna Virus.
Smallest in Size, Icosahedral 28-30 nm in Diameter,
Contains 80 subunits. Single Stranded RNA virus Contains 4 major polypeptides. VP 1, 2, 3. and VP 4. Produce important Diseases like 1. Poliomyletis,Aspetic meningitis, and
Common Cold.
Structure of Picorna virus
Entero viruses
The Nomenclature has given Numbers, 1.Polio virus types 1 to 3. 2.Coxsasackie virus Group A. 1- 24. 3.Coxsasackie virus Group B. 1-6. 4.Echo virus type 1-33. Entero virus type 68-71.
Rhino Virus and others.
Rhino viruses 100 Antigenic types Common cold is produced Others, Hepatitis A Virus In Animals. Foot and Mouth Diseases..
POLIOMYLETIS.
Entero Virus Group.POLIOMYLETIS.
Involves CNS, produces serious Illness.
Causes Destruction of Motor Neurons in Spinal cord.
Produces FLACID PARALYSIS. India has still has many cases of
Poliomyelitis.
Poliomyelitis First described by Michael Underwood
in 1789 First outbreak described in U.S.
in 1843 21,000 paralytic cases reported in the
U. S. in 1952 Global eradication in near future
Classification of Polio virus.
Type 1 - Brunhilde and Mahoney.
Type 2- Lansing and Mefi.Type 3- Leon and Salkett.
Poliovirus Poliovirus is a member of the
enterovirus subgroup, family Picornaviridae. Enteroviruses are
transient inhabitants of the gastrointestinal tract, and are
stable at acid pH. Picornaviruses are small, ether-
insensitive viruses with an RNA genome.
Poliovirus There are three poliovirus serotypes
(P1, P2, and P3). There is minimal heterotypic
immunity between the three serotypes. That is, immunity to one
serotype does not produce significant immunity to the
other serotypes.
Properties of Polio virus. Typical Entero virus. Inactivated at 550 c for 30 mt. Chlorine at 0.1 ppm Ether is not effective. Animal susceptibility. Monkey brain Requires Primate specific membranes. Contains 3 Antigenic types 1,2,3Can be differentiated by ELISA and CF methods.
Other Properties of Polio virus,
Size is 27 nm Contains 4 viral proteins VP1 to VP 4 VP1 Carries the major antigenic
site, and combines with type specific neutralizing antibodies
Polio Infection. Incubation 3 – 21 days On average 14 days Predisposing factors. Severe muscular acitivity
can lead to paralysis, as it increases the blood flow
May produce paralysis in the limb or bulbar region
Injecting vaccines with adjuvant can predispose to paralysis
Patients who underwent tonsillectomy have higher incidence as Ig G secretion is reduced
Rarely oral Polio vaccine produces poliomyelitis.
Pathogenesis and pathology.
Enter through Mouth, Multiplies in Oropharynx tonsils and
Intestines, Excreted in Stool. Enters the CNS from Blood. Spread along the Axons of peripheral
nerves to CNS. Progress along the fibers of the lower
motor neurons spinal cord or brain.
Pathogenesis and pathology.
The virus enters through the mouth, and primary multiplicationof the virus occurs at the site of implantation in the pharynx and gastrointestinal tract. The virus is usually present in the throat and in the stool before the onset of illness
Pathogenesis and pathology.
One week after onset there is less virus in the throat, but virus continues to be excreted in the stool for several weeks. The virus invades local lymphoid tissue, enters the bloodstream, and then may infect cells of the central nervous system.
Replication of poliovirus in motor neurons of the anterior horn and brain stem results in cell destruction and causes the typical manifestations of poliomyelitis.
Pathology and Pathogenesis.
Destroy the Anterior horn cells of the Spinal Cord
Do not Multiply in Muscles only muscles manifest with weakness and flaccid paralysis result is secondary.
Occasionally produce Myocarditis, Lymphatic hyperplasia.
Symptoms There are three basic patterns of polio infection: subclinical infections, nonparalytic, and paralytic. Most people have subclinical infection, and may not have symptoms.
SUBCLINICAL INFECTION SYMPTOMS
General discomfort or uneasiness (malaise)
Headache Red throat Slight fever Sore throat Vomiting People with subclinical po
Clinical Manifestations.
In apparent, Only 1% manifest with clinical features.
Can lead to permanent paralysis. Incubation 7-14 days, ( 3-35 ) May be abortive Poliomyelitis, Only Fever, Malaise, Drowsiness,Non paralytic Poliomyelitis,Aseptic Meningitis.
0 20 40 60 80 100
Percent
Asymptomatic Minor non-CNS illness
Aseptic menigitis Paralytic
Outcomes of Poliovirus Infection
Paralytic Poliomyelitis. Manifest as Flaccid Paralysis.( Caused due to
damage to Lower Motor Neurons.) Partial recovery within 6 months. Patient may continue with life time disability Can involve Spinal cord, and Bulbo spinal
region Bulb spinal involvement can paralyze
respiratory muscle and lead to Respiratory failure
.
Laboratory Testing Viral Isolati
Poliovirus may be recovered from the stool, is less likely recovered from the pharynx, and only rarely recovered fromcerebrospinal fluid (CSF) or blood.
If poliovirus is isolated from a person with acute flaccid paralysis, it must be tested further, using reverse transcriptase - polymerase chain reaction (RT-PCR) or genomic sequencing, to determine
Laboratory Diagnosis. Viral isolation from Throat swabs, Rectal swabs. Stool specimens, Transported in frozen containers. Produce cytopathic effect on Human and Monkey
cells Produce cytopathic effects.
Viral Isolation From feces - present in 80% of cases
in 1st week In 50 % till 3rd week In 25 % till several weeks Collect the fecal sample at the earliest. Primary monkey kidney is the ideal cell
line for isolation of virus Viral isolation must be interpreted with
caution and clinical presentation
Use of serology in diagnosis
Serology may be helpful in establishing a diagnosis of disease if obtained early in the course of disease. Two specimens are needed, one early in the course of the illness and another three weeks later. A four-fold rise in the titersuggests poliovirus infection. Two specimens in which no antibody is detected may rule out poliovirus infection.
Cerebrospinal Fluid (CSF)
In poliovirus infection, the CSF usually contains an increased number of white blood cells (10–200 cells/mm3 primarily lymphocytes) and a mildly elevated protein (40–50mg/100 mL).
Laboratory Diagnosis (Serology )
Estimation of Antibodies Ig M
A paired sample is essential.
Immunity. Permanent type specific. 1 and 2 types have Heterotypic resistance.
Mother to Off spring immunity lasts for less than 6 months.
Epidemiology
Endemic Epidemic Hygiene plays in spread of
diseases. Children < 5 in Developing
countries.
Possible Complications
Aspiration pneumonia Cor pulmonale (a form of heart
failure found on the right side of the circulation system)
Lack of movement Lung problems Myocarditis
Paralytic ileus (loss of intestinal function)
Permanent muscle paralysis, disability, deformity
Pulmonary edema Shock Urinary tract infections
Treatment The goal of treatment is to control
symptoms while the infection runs its course as there are no specific treatment for this viral infection.
People with severe cases may need lifesaving measures, especially breathing help.
Symptoms are treated based on their severity. Treatment may include:
Treatment Antibiotics for urinary tract infections Moist heat (heating pads, warm towels) to
reduce muscle pain and spasms Painkillers to reduce headache, muscle pain,
and spasms (narcotics are not usually given because they increase the risk of breathing trouble)
Physical therapy, braces or corrective shoes, or orthopedic surgery to help recover muscle strength and function
PhysioTherapy Physical therapy,
braces or corrective shoes, or orthopedic surgery to help recover muscle strength and function,
Pioneers who Discovered Vaccine
Prevention and Control. (Vaccines) Sabin’s Live attenuated vaccine Grown in Monkey kidney cells, Human
Diploid cells. Preserved at 4 c Multiple doses are given Given as oral Drops At present only vaccine given in our
National Programme of Immunization Boosts Immunity with Production Ig G ,Ig
M And also Ig A Participate as participant in
Prevention.
Vaccination Sabin's- Oral Administration
Sabin’s vaccine is administered orally.
Contains Type 1 – 10 lakhs, Type 2- 2 lakhs Type 3- 3 Lakhs.The virus are stable with Mg cl.
Oral Polio Vaccine
Highly effective in producing immunity to poliovirus
50% immune after 1 dose >95% immune after 3 doses Immunity probably lifelong
Sabin's Vaccine
Vaccines ( Cont )
Salk Vaccine - A Killed Vaccine. Four Injections are administered in
a period of two years, Administration of periodic booster
recommended. Most of the Western Nations do use
it.
Salk giving Vaccine to a Child
Salk Vaccine ( Killed-Inject able)
Present prevalence of Polio attacks
Wild Poliovirus 2006
Factors Predisposing to Increased prevalence.
Infection during pregnancy, Tonsillectomy. Injection of Triple vaccine ( DPT )
Global Eradication
WHO target date year 2000 Yet in 2008 we get cases of Polio
cases
Global Eradication.
The Indian Programme of PULSE POLIO Immunization is a part of it to eradicate Polio
Recent resurgence in UP and Bihar is a threat to the desired Goal.
In spite of best efforts thousands occur globally in Africa and Indian subcontinent.
Pulse Polio Immunization
Let us be partners in Eradication of Polio
WISH TO SEE THE CHILD HEALTHY VACCINATE WITH POLIO IMMUNIZATION
PROGRAM CREATED BY DR.T.V.RAO MD FOR MEDICAL
STUDETNS IN THE DEVELOPING WORLD EMAIL