MANI'S MICROBIOLOGY

  VARICELLA-ZOSTER VIRUS ·        VZV causes chickenpox (varicella) upon recurrence, and causes herpes zoster, or shingles . ·        As an alphaherpesvirus, VZV shares many characteristics with HSV. ·        Causes Clinical chicken pox (primary infection). ·        90% of cases before age 10, peak incidence 2-8 years. ·        Recurrent infection - shingles (herpes zoster) in adults. ·        VZV is seen worldwide and is highly infectious, ·        Human is the only natural host of the virus. 1. Virus transmission and Structure ·        Virus entry through inhalation – airborne transmission. ·        Direct contact. ·        Vesicle fluids. ·        Viral ...

  HUMAN HERPESVIRUSES Ø   Infect only humans. Ø   Herpesviridae family contains enveloped , double-stranded DNA viruses with large complex genomes. Ø   They replicate in the nucleus of a wide range of vertebrate hosts. ·        Of the more than 100 known herpesviruses, 8 routinely I.          STRUCTURE OF HERPESVIRUSES Ø   The herpes viruses are large, enveloped viruses that contain double-stranded DNA. Ø   The virion is 150 nm in diameter. Ø   The DNA core is surrounded by an icosadeltahedral capsid containing 162 capsomeres. Ø   This capsid is enclosed by a glycoprotein-containing envelope. Ø   Encode several glycoproteins for viral attachment, fusion, and for escaping immune control. Ø   As enveloped viruses, the herpesviruses are sensitive to acid, solvents, detergents, and drying. II. ...