1 / 32

Measles, Mumps, Rubella, Varicella

Measles, Mumps, Rubella, Varicella. MedCh 401 Lecture 6. Measles, Mumps, Rubella. Common childhood diseases May be associated with severe complications/death More often in adults Measles - pneumonia, encephalitis Mumps - aseptic meningitis, deafness, orchitis

Olivia
Télécharger la présentation

Measles, Mumps, Rubella, Varicella

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Measles, Mumps, Rubella, Varicella MedCh 401 Lecture 6 KL Vadheim Lecture 6

  2. Measles, Mumps, Rubella • Common childhood diseases • May be associated with severe complications/death • More often in adults • Measles - pneumonia, encephalitis • Mumps - aseptic meningitis, deafness, orchitis • Rubella - congenital rubella syndrome • Respiratory transmission KL Vadheim Lecture 6

  3. Measles • 14-day incubation period for respiratory-acquired infections • 6-10 days if acquired parenterally • remains the leading cause of vaccine-preventable death in children KL Vadheim Lecture 6

  4. Measles virus attenuation • Start with attenuated Enders’attenuated Edmonston strain • Propagate in chick embryo cell culture KL Vadheim Lecture 6

  5. Measles vaccine efficacy • 1941 - 894,134 U.S. cases • 1995 - 288 U.S. cases KL Vadheim Lecture 6

  6. Vaccine failure • Infants vaccinated at <12m who were born to naturally-infected mothers may not develop sustained antibody levels when later revaccinated • Primary failure • No seroconversion • Secondary failure • Loss of protection after seroconversion KL Vadheim Lecture 6

  7. Mumps Pathogenesis • Viremia common, leading to organ involvement • salivary glands (parotitis), meningitis, orchitis, endolymph infection leading to deafness • A major cause of permanent, bilateral, sensorineural deafness in children • Virus shed in saliva and urine for long periods after infection KL Vadheim Lecture 6

  8. Mumps Pathogenesis • Reinfection occurs • usually asymptomatic KL Vadheim Lecture 6

  9. Mumps virus attenuation • Jeryl Lynn (B level) strain • Cultured from Jeryl Lynn Hilleman’s throat • Attenuated by serial passage in • embryonated hen’s eggs • chick embryo cell culture KL Vadheim Lecture 6

  10. Passive immunization against mumps • Immune globulin ineffective for postexposure prophylaxis • does not prevent disease or reduce complications • Transplacental maternal antibody appears to protect infants for first year of life KL Vadheim Lecture 6

  11. Mumps vaccine efficacy • 1968 - 152,209 U.S. cases • 1995 - 840 U.S. cases KL Vadheim Lecture 6

  12. Recent mumps outbreaks • Started in Dec. 2005 in Iowa • 2,597 cases Jan. 1- May 2, 2006 • 11 states, all ages affected • Vaccination clinics initiated KL Vadheim Lecture 6

  13. Theories on outbreak • College campuses are the perfect environment for spreading a disease transmitted through oral secretions • Only 25 states and DC require two doses of MMR for college admission KL Vadheim Lecture 6

  14. More theories • Delayed recognition and diagnosis of disease: • few younger MDs have seen the disease • Many would not consider the diagnosis in a vaccinated individual KL Vadheim Lecture 6

  15. UK Mumps epidemic, 2004-2005 • >70,000 cases in England and Wales • Increased susceptibility of unvaccinated cohorts who have less exposure to mumps because of a decrease in disease circulation after implementation of a childhood immunization program KL Vadheim Lecture 6

  16. UK Epidemic • Importance of ensuring high levels of immunity among other age groups when mumps vaccination is added to the routine immunization schedule for children. KL Vadheim Lecture 6

  17. Rubella • Aka ‘German’ measles • Discovered in 1841 • Virus isolated in 1941 by German scientists • Sudden pandemic in 1962-65 • Vaccine developed in 1960s • Vaccine licensed in 1970 (U.S.) KL Vadheim Lecture 6

  18. Congenital Rubella Syndrome • Infection in first trimester most dangerous • 90% of fetuses likely to have some type of abnormality • Virus disrupts organogenesis • plus more destructive on brain, cochlea, lens, etc. • Virus establishes chronic infection in many cells/organs • virus secretion may persist for years KL Vadheim Lecture 6

  19. Congenital Rubella Syndrome • Cataracts • Deafness • Heart malformation • Also: • microcephaly • autism • mental retardation • Diabetes • etc. KL Vadheim Lecture 6

  20. Mumps Pandemic 1962-65, Europe and U.S. • 12.5 million mumps cases • 20,000 cases CRS • 11,600 deaf • 3,580 blind • 1,800 mental retardation • 6,250 spontaneous abortions • 5,000 surgical abortions • 2,100 stillborn/neonatal deaths KL Vadheim Lecture 6

  21. Rubella vaccine • Mumps virus RA-27/3 isolated from an infected fetus in 1965 • Culture fluid passaged directly into WI-38 cells • 8 serial passages at 37C • Seven additional passages at 30C • human volunteer studies showed attenuation • Ten additional passages to further decrease pathogenicity KL Vadheim Lecture 6

  22. Rubella RA27/3 vaccine strain • Produced between 25th and 30th passage in human diploid cells • Relatively rapid attenuation due to: • cold adaptation (30C) • Retention of high immunogenicity due to: • relatively low passage number required for attenuation KL Vadheim Lecture 6

  23. Rubella points to remember • Clinical rubella has been demostrated in vaccinees and naturally infected, immune persons • Reinfection with fetal transmission of wild virus in presence of both natural and vaccine-induced immunity • can result in CRS KL Vadheim Lecture 6

  24. Rubella vaccine efficacy • 1969 - 57,686 U.S. cases • 1995 - 200 U.S. cases KL Vadheim Lecture 6

  25. MMR Vaccines • Live • Attenuated • Subcutaneous administration • Lyophilized presentation • Licensed 1971 KL Vadheim Lecture 6

  26. MMR Vaccines KL Vadheim Lecture 6

  27. Varicella zoster • Causes two separate diseases • chickenpox (varicella) • shingles (herpes zoster) • Generally a benign, self-limiting disease • Herpes virus • Highly communicable disease of all ages KL Vadheim Lecture 6

  28. Varicella Transmission • Airborne • Skin, Respiratory droplets through conjunctivae or mucosa of upper respiratory tract • Can transmit chickenpox to a susceptible person from a person with shingles KL Vadheim Lecture 6

  29. Varicella Pathogenicity • Usually a mild disease • can cause severe, life-threatening complications • 1st trimester infection can cause permanent CNS (and other) damage to fetus, or death • 3rd trimester infectionmay cause severe maternal infection, • Host range limited to humans and some primates KL Vadheim Lecture 6

  30. Varicella Pathogenicity • Latent infection of sensory nerve ganglia common • Some viral infection during latent stage • Suppression of VZV reactivation partially under immunological control KL Vadheim Lecture 6

  31. Varicella Vaccine • Lyophilized • Requires storage at +5F or below • Live, attenuated virus KL Vadheim Lecture 6

  32. Varicella attenuation process • Initial viral isolation from a child with varicella • Adapted to human embryonic lung cell cultures • Adapted to and propagated in embryonic guinea pig cell cultures • Propagated in human diploid cell cultures (WI-38) • Further passage in human diploid cell cultures (MRC-5) that are free of adventitious agents KL Vadheim Lecture 6

More Related