Lecture 5 Flashcards
Ziika Virus
Entebbe, Uganda
Rhesus Monkeys - Yellow fever
Take virus and Filter as to Trap Bacteria. Therefore Filtrate was sterile except for Viruses and proteins.= Proof that there were viruses in monkey 766’s Blood.
Filtrate then injected into mice. 6/7 fell sick. = Proof viruses were Transmissible and cause illness in mice
Thought was yellow fever, but came and went quickly.
If same mice were injected with blood, Stopped mice get sick second time round. Antibodies. - developed immunity. Didnt protect form Yellow fever.
Looks same as yellow fever- rounded circles.
Ebola: long worm like.
Studies in other parts of Africa and Asia found Zika infected mosquitos
People in Africa and Asia often had antibodies against zika virus
Yap Island Ziika outbreak: Many people had antibodies but no recollection of illness (1 illness:4.4 asymptomatic/subclinical)
-symptoms(minor, short lived, flu like) through to arise as a result of immune system REACTING to ziika infection (not due to virus destroying tissue)
-Aedes mosquitos, widespread, Flave viruses
Endemic: Africa and Asia- disease always present
Microcephaly incidence 20x (rates or new cases) - correlation between zika and microcephaly. Head circumference of new born baby, can be normal or can have limited development and learning disabilities
Virus
Infect living things- including bacteria
Array of shapes and sizes (Looks same as yellow fever- rounded circles.
Ebola: long worm like.)
1. All viruses are a piece of Nucleic Acid (RNA or DNA) - single or double stranded. Replicates.
2. All Capsid: Virus protein coat. (proteins that are encoded by viral nucleic acid)
3. Some Envelope: Derived from host cell. -piece of Plant cell if plant virus. Virus proteins embedded on the envelope
What are the requirements to Define a virus official?
- Compatible symptoms
- Detection of virus RNA in blood by PCR (virus RNA only replicating if you have the virus)
- detection of immune antibodies specific for zika
Microbe
a microscopic entity
virus, bacteria, fungus, animal
Pathogen
Entity something capable of generating disease
- usually a microbe((sub)microscopic entity)
- macroscopic pathogen = worms. scabies.
Endemic
something/disease regularily found in a place or population
Epidemic
more illness than before
-usually an infection
Pandemic
an epidemic spread across vast reaches/continents
Infection
the new presence of a microbe
- colonisation subclinical disease
- doesnt have to end up in disease. could just be temporary colonisation (staphylococcus aureus: 15% of population always lives on those people(colonisation) - strain which causes colonisation changes a few times a year)
Infectious disease
Symptomatic illness/disease caused by a pathogen
interaction with a microbe that causes damage to the host
asymptomatic(immune system fighting back) or symptomatic
-most are a combination of the two
Endogenous
originates within an organism
-appendicitis
Infectious disease arises from colonising pathogen or flora
-urinary tract infection.bacteria living in gut. crawls into bladder and causes infection
-infections of abdomen (appendicitis, gall bladder infection, colonsisitis, liver abcess)
Exogenous
present but originated outside an organism
- Tuberculosis
- flu/influenza cough and inhale (comes from environment or another person)
Subclinical
infectious disease that triggers the immune system
-but doesn’t cause symptoms
Transmission
manner of spread of a microbe
-direct or indirect
Flavivirus
a type of RNA virus that causes a wide range of diseases, often spread by Pedes genus mosquitoes/ Yellow fever Dengue Zika Hepatitis C)
Arbovirus
Virus spread by an insect vector
Arthrepod Borne Virus
Epidemiology
the study of a disease (usually in a population)
-Yap islande
Fever
the clinical measurement of a febrile response - poorly defined as:
an elevation of body temperature, or a temperature above the normal range
Antibody
an immune protein (immunoglobulin) that binds to an antigen
Antigen
Antibody generator
-often a protein or carbohydrate from non-self, although sometimes part of one’s self
Serology
the study of blood (serum)
-in this case the examination of serum to detect foreign antigens or antibodies specific for foreign antibodies
Seroconversion
development of antibody during an infectious disease OR change in type of antibody during an infectious disease, sometimes seroconversion leads to symptoms/illness
PCR
polymerase chain reaction
-learn how these are performed
Filter Sterilisation
Use of a filter to remove bacteria yeast cells etc
Febrile Infant
Febrile = fever
Normal body temp =36.5 -37
Birth-year 1 yr 1/2 huge changes
Urination rate change possibilities: dehydration, urine infection, kidneys
Common possibilities of infections:
1. Upper respiratory tract infections
2. Acute Otitis media (ear infection)
3. Influenza
4. Gastroenteritis
5. Urinary Tract Infection
6. Bacterial Pneumonia
What causes her to have symptoms? Febrile (feverish), Lethargic, Drowsy, Muscle aches, Tender joints, Back pain, Hyperalgesia (sensitive to touch). Body’s attempt to deal with infection often results in these symptoms
What determines recovery? inflammatory response and ability of immune system
Why doesn’t everyone catch it? Antibodies
Immune system: variety of things. Responsible for symptoms, determine susceptibility and are involved in recovery
What are the levels of susceptibility throughout NZ?
Unequal burden of infectious disease on Maori
Why is there vaccination?
Vaccination to prevent infectious disease in childhood and ability to check National Immunisation Register
What are the 3x main Categories of Microbes and how can they be recognised?
- Viruses: a. Virus particle capsid shapes, immune system can distinguish between virus A and B. b. Cells damaged by infection. (c.f. inflammation). c. Virus infected cells. -bits of virus on surface
- encapsulated nucleic acids. require host cell machinery to replicate. either bud off and infect other cells, or lyse cells and release viral structures to infect other cells. - Bacteria and Fungi. Free living cellular organisms. Most live extra-cellularily on surfaces(not inside cells). a. Cell surface shapes. b. Cells damaged by infection.inflammatory immune response triggers c. Bacterial/fungal metabolites during living process triggering inflammatory/immune response. Bacteria themselves arent that harmful, but these exotoxins produced are incredibly harmful. Need immune system to develop against these
- Parasites. Multicellular organisms, complex. a) Surface shapes (can be recognised). b) Cells damaged by infection- inflammatory mediated activation. c) Life-cycle changes in parasite structure. antigens/shapes change and immune system has to recognise, respond and then keep adapting.
Child with Respiratory disease
Difficulty breathing
Low grade fever- mildly elevated fever
5th attack cough and wheeze
-asthma. repeated attacks: child’s immune system isn’t coping in the manner a normal health child’s immune system would-congenital immunodeficiency (born with inability to make certain parts of immune system)
-most likely to have infection. Initially most likely to be virus or bacteria cause
Bordetella Petussis bacterial infection- Whooping cough
Childhood illness with Paroxysms of coughing, plus whoop(cough air out and then try get air back in), apnoea and vomiting
Typically lasts 6 weeks
Why are children more susceptible that adults?
- Immune system still developing
- Havent had much exposure
- immune system has fundamental quality of adaptation - Exposed to new environments
- More exposure leads to recovery and memory
- vaccination turns on this memory cycle
Fever and Adenopathy
lymphadenopathy: lymph nodes have swollen and are now palpable
Hepatosplenomegaly: liver and spleen aren’t enlarged
Fever-associated with infections often
Sweat- temperature raised
Could be associated with infection but could be other possibilities
High temp and sweating: Immune system response is triggering change in physiology.
Sore throat: inflammed, redness, swelling, higher temp in area, pain, loss of function
Swollen lymph node: Inflammatory response and immune system in response to the infection.
-could also not be infection related.
Colonisation
Infection with microbe fora varying period.
No host immune response
(often there is a host immune response)
could just be temporary colonisation (staphylococcus aureus: 15% of population always lives on those people(colonisation) - strain which causes colonisation changes a few times a year)
