1) Symptoms, epidemiology pathogenesis, prevention and treatment
- Symptoms: Fever, headache, dry cough, Stomach symptoms (nausea, vomiting), runny nose, muscle aches
- Epidemiology: common in young and old and ppl with certain health conditions
- Pathogenesis: WILD birds are the natural reservoir for all subtypes of Influenza Type A….found in pigs, humans, seals, horses and whales. Influenza B circulate widely ONLY among humans
- Prevention: Flu SHOT(only work against Type A & B), Cover mouth & nose, Wash hands often, get rest & drink plenty of fluids
- Treatment: Flu SHOT, AntiVIRAL drugs
- Type: ENVELOPED ssRNA virus. 3 Types, A, B & C (causes mild respitory illness)
2) Influenza: mode of transmission, types of flu.
- Pass from person person through COUGHING or SNEEZING
- Also through touching something with flu & then touching mouth or nose.
- Types of flu: Seasonal flu and Pandemic flu
3) Can antibiotics work against Influenza
NO, as this is a viral infection..not a bacterial infection.
Antigenicity involves antigens H and N, with the antibodies binding to them. There are 15 different H subtypes and 9 different N subtypes…so there needs to be antibodies for each different one, which is determined by the developers of the flu vaccine.
4) Antigenic shift, antigenic drift, genetic plasticity
- Antigenic Drift: a Small change that occurs continuously over time. It produces a new virus (type A or B) strain that may not recognize the body’s immune system. This is why people can develop the flu more than once.
- Antigenic SHIFT: abrupt change in Influenza A virus (not type B) that results in a new subtype. Is result of a big mutation (ie deletion). No immunity against the new virus.
- Genetic Plasticity: If a host is simultaneously infected by 2 different strains of Influenza virus, each strain has 8 pieces of RNA that are now able to go through reassortment and form a hybrid strain.
5) What does a flu shot contain?
- It contains a live attenuated virus of a variation of Type A and B viruses, which allow the body to develop an immune response to this, so when they encounter the flu they will be able to combat it.
- The flu shot does not protect against Type C. There are also inactivated flu shots that contain killed viruses as above.
6) Is the flu shot effective in preventing us from getting sick? How is it possible to make flu shot that works to boost our immunity even though the virus is changing at a higher rate?
Yes, it is effective in preventing us from getting sick, as when the shot is administered we develop the immune response of a possible virus. However, the flu virus may vary a bit from the shot given that season, so it may not always be effective in promoting an immune response.
7) Is pandemic flu a real possibility?
Yes, it is, although it is more rare than seasonal flu. The most disasterous was in 1918-Spanish Flu. If H5N1 (avian virus) adapts to allow human-human transmission, a PANDEMIC could occur.
8) Explain reassortment of influenza viral genome.
Pigs can be infected with swine, human and/or avian strains @ the SAME time, allowing 2 unrelated viruses to reassort their RNA segments (genetic plasticity), leading to a NEW STRAIN that infects humans. There is NO PRE-EXISTING immunity for humans.
9) Differences between seasonal and pandemic flu
- Seasonal flu: ppl have some natural immunity to this (vaccine is also available for these). There is usually adequate supply of antiviral drugs and healthcare needs are usually met. Outbreaks follow predictable seasonal patterns
- Pandemic: which there is no immunity, allowing it to spread more easily from person-person. More serious symptoms and can cause a major impact on society and the economy (ie from school and work closings). Healthcare system can be overwhelmed and the vaccine would probably not be available during the early stages. Outbreaks are rare, but serious.
10) Bird flu: know the subtype
H5N1 is the type, called avian flu virus. Transfers from avian host to humans. It is highly pathogenic to humans and domestic fowel.
11) Is Avian flu a threat to humans?
Yes, it is deadly to humans, very pathogenic
12) Different levels of preparedness to combat the pandemic avian flu if it arises.
- Develop pre-pandemic vaccines based on lethal strains of H5N1 & Collaborate w/Industry to INCREASe VACCINE production
- Conduct research into developments of NEW VACCINE types
13)How can avian flu virus change and become a threat to us?
If H5N1 (avian virus) adapts to allow human-human transmission, a PANDEMIC could occur.