Effecting liver viruses & Hepatitis‘B’virus infection

                          Effecting liver viruses & Hepatitis‘B’virus infection

        Ans :  The following viruses affect liver.

                                 I.            Yellow fever virus ( Arbo virus ).

                               II.            Lyssa fever virus.

                             III.            Merbury virus.

                            IV.            EB virus ( Epstin bar virus ).

                              V.            CXytomegalo virus.

                            VI.            Herpes virus.

                           VII.            Rubella virus.

                         VIII.            Coxsackie virus.

                             IX.            Hepatitis-A virus.

                               X.            Hepatatis-B virus

                             XI.            Hepatitis-C,D &E virus.

 

Ø  Laboratory diagnosis of Hepatitis ‘B’ virus:

                                  I.             Demostration of virus by using immune electron microscope from fecal specimen.

                                 II.            CIE ( Counter in immune electrophoresis ).

                               III.            RIA & ELISA technique are done:-

                              IV.            The following serological and viral marker are done.

a.       Detection of HBSAg – Appears early in blod vafter 6 weeks.

b.       Demonstration of Anti –HBS – Appears after 3 months against HBSAg in serum.

c.       Detection of HBEAg – Derived core protein.

d.       Anti HBe – Appears after disappearencer of HBeAg.

e.       Anti HBc – Detection in serum of Acute hepatitis-B.

f.        HBV DNA – Detected by southeron blot technique present in acute stage.

                                V.            Isolation of virus on tissue culture.

Describe of diphtheria.

 

                                  Describe lab diagnosis of diphtheria.

Causative organism of diphtheria is coryn bacterium It is gram positive, non-motile, rod shaped, non-acid fast bacilli, non-sporing and pleomorphic. Average size Is 3 µ /0.3 µ.

1. Examination of throat swab or laryngcal swab for albert staining.

Ø  Prepare smear from throat swab or laryngeal swab.

Ø  Dry air and fix over flame.

Ø  Pour albert-I for 5-7 mints.

Ø  Blot anmd dry with the help of filter paper.

Ø  Add Albert-II stain keep it for 3-5 mints.

Ø  Wash under tap water.

Ø  Diptheria bacilli shows met achromatic dot two pole of bacillius.

2. Culture from throat swab or laryngeal swab on. Loefflers serom agar and Tellurite blood agar.

Ø  Loefflers serum agar shows gram positive bacilli with metachromatic granule in 6-8 hours.

Ø  Tellurite blood agar shows three diphtheria bacillius (Gravis, Intermedius, mitis)

Ø  Gravis shows Daisy head colonies.

Ø  Intermedius shows frog egg colonies.

Ø  Mitis shows poached egg colony.

3. Virulence test by animal inoculation. Either subcutaneously or intradermal.

Ø  Both emulsion of the culture on loefflers shope is emulsified in 2-5 ml both and 0.8ml of emulsion injected sub-cutaneously in two guinea pig. 1^st Guniea pig gives 500units of antitoxin of C. diphtheria present, 2^nd Guniea pig will die in 54 days.

4. Eleks gel preparation test.

5. Culture on HELA Cell line:- Bacteria is identified by death of cells on cell line.

6. Schick test :- Skin test 0.2 ml of diphtheria toxin injected intradermaly on left for arm and similar does of toxin inactivated by heating at 70 ˚c of 30 mints injection.

Classification of virus

 

                                               Classification of virus

On the basis of type of nucleic acids , viruses are classified into two group:-

v  Ribo virus or RNA virus→contains RNA.

v  DeoxyRibo virus or DNA virus →contains DNA.

ü  RNA virus

                 A) Picorana virus (20-30)

Eg→ a) Entero virus

       b) Rhino virus

       c) Rhro virus

       d) Hepato virus (HAV)

               B) Orthomyxo virus ( 80-120nm )

                   Eg:- a) Influenza virus

                C) Paramyxo virus (100-130nm)

                    Eg:- mumps, rubella viruses.

                 D) Arbo virus

                     Eg:- chickengunya , Denque , sendfly fever

                  E) Rhabdo virus (75-180nm)

                     Eg:- Lyssa virus (Rabies virus)

                  F) Reo virus

                  G) Corana virus

                  H) Hepatities – A virus

v  DNA virus

 a) pox virus → Infect vertibrates , birds and insects.

   Eg:- Small pox , cow pox , monkey pox.

                          b) Herpes virus (100- 200)

Eg:- Herpes simplex ( Infect only man) Varicella / chicken pox ( by varicella zoster )                                CVM .        

                          c) Adeno virus

                           d) Papovo virus

                           e) Parvo virus

                           f) Hepatitis – B virus

v  Polio virus

Morphology :- Spherical particle , 30 nm in size , icosahedral symmetry . It can be crystallised which can be seen in infected cell. It is RNA virus belong to family picrona virus.

Antigen:- Three distinct types:

   Type 1 or Brunhillda , Type 2 or Lansing , Type 3 or Leon. Type 1 is most virulent and couse most epidemics , Type 2 causes endemic infection & Type 3 causes epidemic occasionally.

        Transmission :- The virus enter in the body by ingestion or inhalation of contaminated food or drink . They muttifly in Lymphatic tissue of alimentary canal, from the tonsil to the peyer`s patches and enters the regional lymphatics . Then these viruses reaches blood , then spinal cord and then to CNS . In CNS they multiply in neurons and destroy them.

                                                                              The earliest change is the degeneration of Nissle bodies (chromatolysis) Necrotic cell lysis .  lesions are mostly in the anterior horn of spinal cord, causing flaccid paralysis but posterior horns and intermediate column may also be involved . In same cases it causes Encephalitis.

            Lab diagnosis :-

              1) Isolation of virus from threat swab in early stage , virus is grown in Robertson cooked meat media.

               2) Cultivation of virus in tissue culture , cytopathic effect is seen in 3 days . Virus is Identify by Neutralization test.

                3) Cultivation of virus from stool in late stage of disease on Robertson cooked meat media.

                4) Serological  diagnosis by Neutralization or complement fixation test.