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INFLUENZA VIRUS-DR.AKIF A.B
INFLUENZA VIRUS-Segmented RNA virus
- Helical symmetry
-Types :
1) Influenza A : MC cause of epidemics
- only cause of Pandemic
2) Influenza B
3) Influenza C : Not circulating currently
ANTIGENS OF INFLUENZA1) Haemagglutinin : Causes haemagglutination
2) Neuraminidase : Causes reversal of haemagglutination k/a Elution
Currently CirculatingINFLUENZA VIRUSES1) H1N1 = Swine Flu
2) H2N2
3) H3N2 =Seasonal flu
4) H5N1 = Bird Flu
5) H7N9
6) H5N6
7) TYPE - B
TYPE A
ANTIGENIC VARIATIONSANTIGENIC SHIFT ANTIGENIC DRIFT
Due to genetic Reassortment Due to point mutation
Occur in Type A Type A as well as in Type B
Pandemic and epidemics sporadic cases
Sudden onset Gradual onset
AVIAN INFLUENZA -Caused by H5N1 (MC Type)
H7N7 (Netherlands)
H9N2 (Hong Kong)
H7N9
-Bird Flu
-DOC : Oseltamavir 75mg bd for 5 days (C.I in Infants)
CLINICAL FEATURES-Incubation Period = 18-72hrs
-MC Presentation : Flu like symptoms
-MC complication : Bacterial Pneumonia (S.aureus> Pneumococci)
-Reye Syndrome : Common with Type B Influenza following Aspirin intake.
DIAGNOSIS-Most sensitive test = ELISA
-Most specific test = Neutralisation Test
VACCINES-Killed Vaccine
: 2doses, I.M route, 70-90% efficacy, last for 6-12months
-Life nasal Spray vaccine(Trivalent vaccine)
1) Influenza A (H1N1)
2) Influenza A (H3N2)
3) Influenza B
Influenza vaccine can lead to Guillian Barre Syndrome
SWINE FLU (H1N1)-Originated by genetic reassortment of four strains : 1 human
2 swine 1 avian
-Uncomplicated case presents with flu like symptoms (URTI)
-Complicated cases presents with pneumonia, dehydration, CNS involvement and multi-organ failure
SWINE FLU (H1N1)Risk factors for severe Disease
1) Infants and children <2yrs
2) Persons aged >65yrs
3) Pregnant females
4) COPD
5) Immunosuppressive diseases
6) Chronic cardiac disease
SWINE FLU (H1N1)DIAGNOSIS
1) RT-PCR : Most sensitive
2) Samples : Nasopharyngeal or throat swabs
-Patient to be isolated for 7days.
SWINE FLU (H1N1)TREATMENT
1) Oseltamavir 75mg bd for 5 days
2) Zanamavir 2 inhalations bd for 5 days
Prophylaxis : Oseltamavir 75mg once a day, duration depends on clinical settings.
PARAMYXOVIRUS- DR.AKIF A.B
PARA-INFLUENZAVIRUSES
-MC agent of Croup ( Acute Laryngo-Tracheo bronchitis)
-MC complication : Otitis media
EPIGLOTITIS
THUMB SIGN
Steeple sign
CROUP
MUMPS VIRUS-MC cause of Parotid Gland enlargement in children
-MC manifestation = Bilateral parotiris > Epididymo orchitis
-MC complication : Aseptic meningitis
-MC Complication in adolescent : Orchitis, Oopheritis
-Atypical Mumps : Patient directly presents with Aseptic Meningitis and parotitis is absent
-Once infected gets life long immunity
-Period of communicability : 4-5 days before to 7days after onset of symptoms.
- Vaccine : Live vaccine, Jeryll Lynn Strain
RUBELLA-Caused by Togavirus
-Also known as German Measles
-Incubation period = 14days
-Vaccine = RA 27/3 strain , Live vaccine, Subcutaneous
-Rubella vaccine is C.I in Pregnancy and if female is vaccinated she should be advised to prevent pregnancy for next 3 months
-Priority for vaccination:
1) 15-49 yrs reproductive age females
2) 1-14yrs children
CONGENITAL RUBELLASYNDROME
Infection in 1st trimester
Heart Disease (MC: PDA ) +Eye defect(MC: Salt and Pepper Retinopathy>Cataract)+Sensorineural deafness (MC)
- Blue berry muffin lesions
Infection in early part of 2nd trimester :
Only deafness
Infection after 16th week :
No abnormalities.
BLUE BERRY MUFFIN LESIONSRubella
Toxoplasmosis
Cytomegalovirus
Herpes simplex
Coxsackie virus
Parvovirus
Epstein Barr virus
Syphilis
Salt and Pepper Retinopathy
-Seen in
1) Syphilis
2) Rubella
3) NARP Syndrome
MEASLES-Rubeola
-Incubation period : 10-14 days
-No carriers
-Secondary attack rates : 80%
-MC complication : Otitis Media
-Koplik spots are present opposite 2nd upper molar
-Rarest but severe complication : Subacute Sclerosing Panencephalitis
-Cytopathic effect : Multinucleated Giant cells( Warthin Finkeldey cells) Containing both intra cytoplasmic and intranuclear inclusion bodies.
Fever + 3 C’sC- Coryza C- Cough C- Conjunctivitis
Warthin Finkeldey cells
MEASLESIncubation period (10days)
Fever(10days)
Koplik’s spots(12th day)
Rash( 14th day )
MEASLES
MEASLES VACCINES-Edmonston Zagreb strain
-Lyophilised form
-Reconstituted with distilled water
-Live vaccine, Sub cutaneous
-Given at 9months since that time maternal antibodies disappears by that time.
-Side effects : Toxic shock syndrome
-Measles immunoglobulin or vaccine can be given after exposure within 72days but should not be given together.
MEASLES ERADICATION1) Catch up : one time effort to vaccinate all children from 9months-10years
2) Keep up
3) Follow up : done every 2-yrs following catch up campaigns to vaccinate children of age >9months who were born after catch-up campaign
RESPIRATORY SYNCYTIALVIRUS
-MC cause of LRTI in Infants causing Bronchiolitis, Pneumonia and tracheobronchitis.
-Diagnosis :HeLa and Hep-2 are most sensitive cell lines used
- Treatment : Ribavirin
EXANTHEMATOUS DISEASES
Very Varicella Rash appears 1 day after fever
Sick Scarlet fever 2days
Patients Pox (smallpox0 3 days
Must Measles 4days
Take Typhus 5days
No no No
Double Diphtheria 7days
Treatment Typhoid 7days
Patient is infective from 24hrs prior to onset of fever.