Viral Diseases of Man

2. Diseases of the Skin Warts (p. 587) Smallpox (p. 587) Chickenpox -Shingles (p. 588) Herpes Simples I (p. 590) Measles (p. 590) Rubella (p. 591)

3. Warts Papillomaviruses ssDNA virus naked, polyhedral Incubation -months benign growth Genital forms can go malignant - STD Treatment- laser or electro- removal, cryosurgery.

4. Smallpox Variola major DNA virus -large Transmitted via respiratory -spreads to organs and skin. Dermal lesions Very infectious first symptoms of smallpox include fever, malaise, head and body aches, and sometimes vomiting.

5. Smallpox rash emerges first as small red spots on the tongue and in the mouth. At this time, the person becomes most contagious. a rash appears on the skin, starting on the face and spreading to the arms and legs and then to the hands and feet. Usually the rash spreads to all parts of the body within 24 hours. As the rash appears, the fever usually falls and the person may start to feel better. By the 3rd day of the rash, the rash becomes raised bumps.

6. Smallpox By the 4th day, the bumps fill with a thick, opaque fluid and often have a depression in the center that looks like a bellybutton. (This is a major distinguishing characteristic of smallpox.) Fever often will rise again at this time and remain high until scabs form over the bumps. The bumps become pustules —sharply raised, usually round and firm to the touch as if there’s a small round object under the skin.

7. Smallpox The pustules begin to form a crust and then scab .By the end of the second week after the rash appears, most of the sores have scabbed over. Most scabs will have fallen off 3 weeks after the rash appears. The person is contagious to others until all of the scabs have fallen off. Scabs have fallen off. Person is no longer contagious.

8. Chickenpox Herpes zoster DNA virus Respiratory - 2 weeks Skin vesicles erupt. Virus infects peripherial nerves. Mortality low but higher in adults.

9. Chickenpox-Shingles Herpes zoster Virus infects peripheral nerves migrates to CNS. Remains latent (characteristic of Herpes). Later in life (decades) can migrate back down nerve and cause skin eruptions - shingles.

10. Chickenpox-Shingles Shingles.

11. Herpes Simplex Cold sores HSV1 DNA Transmission during infancy from relative. Similar to zoster infects peripheral nerves - latency. Always erupts at the same spot. Treatment- acyclovir, OTC ointments.

12. Measles Rubeola RNA Entry respiratory Incubation 10-12 days. Koplick’s spots in mouth. Red rash spreads from arms to trunk and face, then legs. 1 in 1000 develops encephalitis - 50% die.

13. Measles Rubeola Childhood vaccinations have greatly reduced incidence. Vaccine 95% effective. < 100 cases / yr.

14. Rubella German (3 day) Measles ssRNA Much milder and shorter in duration Congenital form more serious - causes serious birth defects. If in 1st trimester can lead to heart defects, mental retardation, or death. Vaccine introduced in 1969 to prevent congenital form.

15. Diseases of the Nervous System Polio (p. 611) Rabies (p. 613) Arboviral Encephalitis (p. 615)

16. Poliomyelitis Picornavirus Enterovirus: oral-fecal route Symptoms like summer flu- headache, sore throat, fever Mild if very young or infant. As age increases becomes more severe. 1% of adolescents develop severe symptoms.

17. Poliomyelitis Virus enters intestine then circulatory system- viremia. If viremia persists, enters CNS where manifestations can be severe. Infects motor neurons causing paralysis. Death due to respiratory failure. Iron Lung.

18. Poliomyelitis Vaccine Salk - inactivated virus - protects but does not stop spread. Sabine- attenuated virus - stimulates IgA antibodies and thus protects plus stops spread.

19. Rabies Rhabdovirus Rabies - L. Madness exist >2500 yrs - Aristotle Bite from infected animal. Incubation - 21+ days. ssRNA Virus - bullet shaped Furious rabies & dumb rabies. Furious very excitable, fever headache, difficulty swallowing, followed by coma and death. Dumb - paralytic, quiet sedate.

20. Rabies Rhabdovirus Virus first replicates in muscle then infects peripheral nerves to CNS. Eventually infects brain and causes encephalitis. Vaccine- can give post exposure, but before symptoms arise. Vaccine virus from human cell cultures (HDCV); 4 - 6 doses. Can also administer anti-sera (humans or MAb) against virus.

21. Arboviral Encephalitis Arthropod borne- mosquitoes. ssRNA, 300 SLE, WEE, EEE, WNV 35% mortality Domestic animals reservoir (horses) Headache, fever, chills, coma, death. Treatment - convalescence seizure treatment.

22. Viral Diseases of Cardiovascular System Infectious Mononucleosis Hemorrhagic Fevers

23. Mononucleosis Epstein Barr virus DNA Oral transmission -kissing Incubation 4 - 7 weeks. Infects B-cells, causes them to proliferate, illicit T cell response. Self- limiting - rest, gamma globulin.

24. Hemorrhagic Fevers Zoonotic -monkeys, rodents Ebola, Yellow Fever, Lassa Fever, Dengue, Hantavirus. Fever, chills, headache, nausea, vomiting. Liver damage causes yellowing of skin in YF.

25. Viral Diseases of Respiratory System Viral Pneumonia (p. 672) Can result from influenza, measles, chickenpox. If no bacteria is cultured, and Mycoplasma ruled out. The Common Cold (p.662) Influenza (p. 672 - 3)

26. Common Cold Caused by many viruses 50% Rhinovirus 15-20% Coronavirus 40% unidentified Sneezing, runny nose, headache, congestion. Spread aerosols, direct contact, fomites.

27. Influenza True Influenza Fever, headache, muscular aches. No diarrhea- “stomach flu” RNA virus- enveloped 2 spikes - hemagglutinin (H) neuraminidase (N) H recognizes cell receptors.

29. Influenza Antigenic Shift H and N antigens change - causes people to lose immunity. Genetic recombin-ation via animals. Major shift in 1918 ~25-40 million deaths in Pandemic. Types A, B, & C Spread by respiratory route.

30. Influenza Virus replication peaks 48-60 hrs after infection - acute. Complications due to bacterial infections. Virus inhibits PMNs and Macs ability to respond to chemotaxis. Annual vaccination recommended for very young and old. Due to antigenic drift.

31. Viral Diseases of Digestive System Mumps (p. 699) Hepatitis (p. 701) Viral Gastroenteritis (p. 705)

32. Mumps Paramyxovirus (RNA) Respiratory and oral transmission. Can also cause orchitis (testis swelling) esp in older individuals Vaccination- MMR Self limiting.

33. Hepatitis Inflammation of the liver. Types A, B, C, D, E HAV - ssRNA HBV - DNA enveloped

34. Hepatitis Types A, B, C, D, E

35. Hepatitis

36. Hepatitis

37. Gastroenteritis “Stomach flu” Rotavirus - Norwalk Oral- fecal route Low grade fever, vomiting, diarrhea Norwalk- cramps 3-4 days- week. Self-limiting

38. Viral Diseases of Reproductive System Genital Herpes (p. 733) Genital Warts (p. 734) AIDS (p. 535 - 544)

39. Herpes Simplex 2 DNA virus- enveloped Spread direct contact (usually sexual)

40. Herpes Simplex 2 DNA virus- enveloped Spread direct contact (usually sexual) Large fluid filled pocks, Infected for life -no vaccine. Virus enters neurons- latent phases.

41. Herpes Simplex 2 Neonatal transmission- Caesarian birth. Can cross placenta and infect fetus - birth defects. Treat symptoms - acyclovir ; anti-virals. HSV1 can also be found in genital infections.

42. Herpes simplex 2

43. Genital Warts Papilloma virus Condyloma acuminata Causes external warts and leads to an increase in cervical cancer in women.

44. Genital Warts No cure.

45. AIDS HIV Covered in Immunology section