Viruses “an intracellular, infectious parasite capable of living and replicating only in living cells”

Viruses Page 386 can infect almost any living cell a piece of genetic material wrapped in protein contain either DNA or RNA (not both) replicate inside living cells and use cell’s own structures to reproduce more infected cells some of the smallest human pathogens lack enzymes such as ATP for producing energy

Inactivation of Viruses some are sensitive to disinfectants due to lipids in their coverings detergents and ether dissolve their lipid coverings e.g. HIV can be inactivated by a solution of 10% sodium hypochlorite (household bleach) in water

Dermatropic (Skin) Diseases Page 387 Smallpox: vaccination ended in the 1970s Monkeypox: Page 389 Figure Measles: Page 390 Readings question #1: What is the virus responsible for measles? What is the only reservoir for this virus? MMR vaccine (measles, mumps, rubella)

Dermatropic Diseases (cont’d) German Measles: Page 390 Readings question #2: What is the virus that is responsible for the disease known as German measles? How is it spread? Color Plate 61 Chickenpox and Shingles: Page 392 Color Plate 62 Shingles rarely occurs in people under the age of 20 and highest incidence is in the elderly Color Plate 63

Reye’s Syndrome severe complication of chickenpox, influenza and some other viral diseases persistent vomiting signs of brain dysfunction coma and death survivors: neurological damage children and teenagers use of aspirin to lower fever in chickenpox and influenza increases chance of acquiring this

Dermatropic Diseases (cont’d) Herpes Simplex 1 and 2: Page 392 Readings question #3: What is caused by the Herpes Simplex 1 virus and how is it transmitted? What is caused by the Herpes Simplex 2 virus and how is it transmitted? Color Plate 64 Figure

Pneumotropic (URT) Diseases Page 394 Influenza: strains are “antigenic shifts” - vaccines are usually “multivalent” - pandemic new drugs: zanamivir (Relenza) oseltamivir phosphate (Tamiflu)

Pneumotropic Diseases (cont’d) Common Cold: Hantavirus Pulmonary Syndrome (HPS): – Rodents especially mice Severe Acute Respiratory Syndrome (SARS): – Asia, North American and Europe – fever greater than degrees – close person-to-person contact, resp. droplets

Neurotropic (CNS) Diseases Page 396 Rabies: rhabodovirus – shaped like a bullet – spread by “bite” or “aerosols” – colonizes in skeletal muscle and connective tissue – immune system cannot suppress infection because lymph does not circulate in the brain and spinal cord (CSF) – “hydrophobia”

Neurotropic Diseases (cont’d) Poliomyelitis: (polio virus) Page 396 ingestion of feces contaminated water path of the poliovirus once it is ingested: – throat – small intestine- lymph nodes (neck and ileum) – blood (viremia) – final stages: CNS vaccines: Salk (injection) and Sabin (oral)

Neurotropic Diseases (cont’d) Viral Encephalitis: Page inflammation of the brain -arthropod-borne arbovirus (mosquitoes) -EEE (Eastern Equine Encephalitis); WEE (Western Equine Encephalitis); SLE; CE; LCE etc. -control of large populations of mosquitoes to decrease spread

Neurotropic Diseases (cont’d) West Nile Virus: Page 397 – can infect humans, birds, mosquitoes, horses etc. – causes mild flu-like disease with no long- term health effects – spread limited through mosquito control – Elderly: can cause fatal encephalitis or polio-paralysis

Viscerotropic (Visceral) Diseases Hepatitis:Hepatitis A (HAV) “infectious” Hepatitis B (HBV) “serum” Readings question #4: According to OSHA’s Blood-borne Pathogen Rule, what are the rights of funeral home employees regarding the HBV vaccine? Hepatitis C (HCV): “silent epidemic” – 100,000 people infected/year in the U.S.

Viscerotropic Disease (cont’d) Infectious Mononucleosis: Page 400 Epstein-Barr virus (EBV) through transfer of saliva replicates in parotid salivary glands Cytomegalovirus: “inclusion bodies” “owls eyes” Shed in body secretions 80% of population are carriers Common in day-care settings Epidemic Parotitis (Mumps) Figures 27 – 9 and

Immunological Disease Page 402 HIV (Human Immunodeficiency Virus) – transmitted in bodily fluids; multi-drug resistant – affects “T” cells within the immune system – “opportunistic infections” Readings question #5: What is the major threat to embalmers when embalming AIDS victims? What can the embalmer do to protect him/herself?