Case 9 - Infection and Vaccination Flashcards
Examples of virus’ transmitted by direct contact
HSV Varicella Zoster Virus (chicken pox) Epstein Barr Cytomegalovirus HPV
Examples of vector-borne virus’ and their reservoir species
Influenza - poultry
hantavirus’ - deer mouse
Monkey pox - rodents
Yellow fever - mosquitoes
What is antibody enhancement
Antibodies made from contracting a different strain of the same virus enhance the pathogenicity of the newly contracted strain. This prevents vaccines from being developed because it would have to protect against all of the strains
Examples of airborne virus’
Influenza
Common cold
RSV
SARS-Cov2
What is antigenic drift
Progressive small changes in envelope proteins through mutations
What is antigenic shift
Sudden massive changes in the envelope protein through reassortment by changing genome
Examples of blood-borne virus’
HBV
HCV
HIV
Physical barriers from pathogens
epithelial cells with tight junctions mucus and cilia tears low stomach pH surfactant
What are the three stages of an immune response
Detection
Communication
Disposal
Which cells are involved in detecting a pathogenic presence
Macrophage
Dendritic
Langerhans cells
Which cells are involved in communication in an immune response
Macrophages
dendritic cell
What cytokines do macrophages produce and what is their effect
IL-6, TNF-alpha, IL-1-beta = pyrogens - induce fever
IL-12 = activates natural killer cells
What do virally infected cells produce to make natural killer cells more responsive
interferons
What is the role of a plasmacytoid dendritic cell
Produces large amounts of interferons to make natural killer cells more responsive
What is the role of a conventional dendritic cell in adaptive immunity
Transport surface antigens from the pathogen to secondary lymphoid tissues and present the antigens to naive t cells
What activates immature conventional dendritic cells
PAMPs (pathogen associated molecular pattern cells)
What part of the conventional dendritic cell loads up with pathogenic antigens
MHC class I receptors
What are the two types of t cells
CD4+
CD8+
How do virus’ try to impair antigen presentation
By activating genes that actively work against it
What are CD8+ t cells activated to become
cytotoxic killer t cells
What induces the proliferation CD8+ cells
IL-2
How do cytotoxic killer t cells induce apoptosis
Recognise and binds to virus-infected cell
Programs target cell for death by inducing DNA fragmentation
Cell migrates to new target
Target cell dies by apoptosis
What do CD4+ cells differentiate into
t helper cells
What are the two types of t helper cells and where are they based
virus-specific t cells - leave lymph
follicular helper t cells - stay in lymph
What is the purpose of follicular helper t cells
They induce the expression of activation-induced cytidine deaminase by which allows for class switching recombination in the B cell
What does class switching recombination in the B cells achieve
Increased binding affinity between pathogen and B cell
Allows for change in antibody production to a potentially more efficient type ie, from IgM to IgG
What four modalities are measured in child development
gross motor skills
fine motor skills
hearing and vision
communication and social
What factors can affect child development
Hereditary Genetic factors Pre-natal factors Perinatal events Post-natal factors
Examples of newborn reflexes
grasp reflex
crawl reflex
step reflex
tonic neck reflex
How does an antibody test work
This test looks for antibodies to a specific viral infection. It is generally done on a blood sample. If the antibody is found, this test can show whether a person was infected recently or in the past.
How does a viral antigen test work
A viral antigen detection test is done on a sample of tissue that might be infected. Specially tagged (with dye or a tracer) antibodies that attach to those viral antigens are mixed with the sample. The tagged antibodies can be seen by using a special light (or other method). If the tagged antibodies are attached to the cells, the cells are infected with the virus.
How does a viral culture test
A sample of body fluid or tissue is added to certain cells used to grow a virus. If no virus infects the cells, the culture is negative. If a virus that can cause infection infects the cells, the culture is positive. A viral culture may take several weeks to show results.
How does a viral PCR test work
Using a sample of tissue or blood or other fluid (such as spinal fluid), this type of test looks for the genetic material (DNA or RNA) of a specific virus. This test can show the exact virus causing an infection
Stages of a viral life cycle
Attachment Penetration Uncoating Biosynthesis Assembly Release
How can DNA virus’ be classed
Single vs double stranded
Enveloped or non-enveloped
How can RNA virus’ be classed
+/-
enveloped vs non-enveloped vs double capsid
What is the difference between a +ve and -ve RNA virus
+ve can use host ribosomes to directly copy RNA and acts like regular mRNA.
Features of non-enveloped virus’
They display excellent heat-resistant properties, and moreover, can easily withstand a dry and acidic environment. In fact, the virus is more powerful and proliferates rapidly in an acidic environment. They can also survive in some disinfection processes. This essentially means that the virus remains active and infectious in these harsh conditions too.
Features of enveloped virus’
They cannot tolerate hot temperatures or acidic environment. Moreover, they are also sensitive to dry conditions. This means that they no longer remain active in these conditions.
Symptoms and transmission of measles
Symptoms:
• cold-like symptoms, such as a runny nose, sneezing and a cough
• sore, red eyes that may be sensitive to light
• a high temperature (fever), which may reach around 40C
• small greyish-white spots on the inside of the cheeks
Spread by:
• breathing in droplets
• touching a surface the droplets have settled on and then placing your hands near your nose or mouth (the virus can survive on surfaces for a few hours)
Complications of measles
Common complications:
• diarrhoea and vomiting, which can lead to dehydration
• middle ear infection (otitis media), which can cause earache
• eye infection (conjunctivitis)
• inflammation of the voice box (laryngitis)
• infections of the airways and lungs (such as pneumonia, bronchitis and croup)
• fits caused by a fever (febrile seizures)
Uncommon complications:
• liver infection (hepatitis)
• misalignment of the eyes (squint) if the virus affects the nerves and muscles of the eye
• infection of the membranes surrounding the brain and spinal cord (meningitis) or infection of the brain itself (encephalitis)
Rare complications:
• serious eye disorders, such as an infection of the optic nerve, the nerve that transmits information from the eye to the brain (this is known as optic neuritis and can lead to vision loss)
• heart and nervous system problems
• a fatal brain complication known as subacute sclerosing panencephalitis (SSPE), which can occur several years after measles (this is very rare, occurring in only 1 in every 25,000 cases)
Symptoms of mumps
- Swelling of the parotid glands is the most common symptom of mumps, along with:
- headache
- joint pain
- feeling sick
- dry mouth
- mild abdominal pain
- feeling tired
- loss of appetite
- a high temperature (fever) of 38C (100.4F), or above
Complications of mumps
Complications: • Swollen testicles • Swollen ovaries • Viral meningitis • Pancreatitis
Rare complications:
• Encephalitis
• Hearing loss
Symptoms of rubella
Symptoms: • Rash • aching fingers, wrists or knees • a high temperature of 38C or above • coughs • sneezing and a runny nose • headaches • a sore throat • sore, red eyes
Risks of rubella in pregnancy
- loss of the baby (miscarriage)
* serious problems after the baby is born – such as problems with their sight, hearing, heart, or brain
Complications of rubella
- Bleeding problems
- Testicular swelling
- Inflammation of nerves
- Some women with rubella experience arthritis
- Rubella may cause ear infection and encephalitis
Contraindications for vaccines
Allergies Refusal Poor immune system Pregnancy Religion/cultural
Signs of autism in young children
- not responding to their name
- avoiding eye contact
- not smiling when you smile at them
- getting very upset if they do not like a certain taste, smell or sound
- repetitive movements, such as flapping their hands, flicking their fingers or rocking their body
- not talking as much as other children
- repeating the same phrases
Signs of autism of older children
- not seeming to understand what others are thinking or feeling
- finding it hard to say how they feel
- liking a strict daily routine and getting very upset if it changes
- having a very keen interest in certain subjects or activities
- getting very upset if you ask them to do something
- finding it hard to make friends or preferring to be on their own
- taking things very literally – for example, they may not understand phrases like “break a leg”
Travel vaccines and where you need them for
- Cholera (sub-Saharan Africa, Caribbean, Middle East and South East Asia)
- Hep A (sub-Saharan Africa, Asia, Middle East, Central and South America)
- Hep B (Africa, Asia, Middle East, Eastern Europe)
- Japanese Encephalitis (not just found in Japan, mostly East Asia)
- Rabies (if going to countries with lots of wild rabid animals or you plan to do lots of outdoor activity)
- Tic borne encephalitis (forested areas in spring-summer)
- TB (Indian Subcontinent, Africa, South East Asia, South and Central America, Middle East)
- Typhoid - (Indian Subcontinent, Africa, South East Asia, South and Central America, Middle East)
- Yellow Fever (tropical Africa and Central and South America)
What is an erythematous rash and what is it indicative of
exhibiting abnormal redness of the skin or mucous membranes due to the accumulation of blood in dilated capillaries
Scarlet fever
Toxic shock syndrome
Kawasaki disease
Alcohol poisoning
What is a vesiculobullous rash and what is it indicative of
A vesiculobullous disease is a type of mucocutaneous disease characterized by vesicles and bullae (i.e. blisters). Both vesicles and bullae are fluid-filled lesions, and they are distinguished by size (vesicles being less than 5–10 mm and bulla being larger than 5–10 mm, depending upon which definition is used)
Hand, food and mouth Varicella Smallpox Necrotising fasciitis Shingles Atopic dermatitis
What is a Petechial-Purpuric rash and what is it indicative of
The rash is basically a number of small red or purple spots in the skin. The size of the spots is on average 1 to 2 mm or about one half inch or less.
Endocarditis
Vasculitis
ITP (Immune thrombocytopenia)
What is a maculopapular rash and what is it indicative of
A maculopapular rash is a type of rash characterized by a flat, red area on the skin that is covered with small confluent bumps. It may only appear red in lighter-skinned people.
Scabies Eczema Psoriasis Lyme disease Drug reaction
Conditions causing developmental delay in children
- autism spectrum disorders (ASDs)
- cerebral palsy
- fetal alcohol spectrum disorders
- Landau Kleffner syndrome
- myopathies, including muscular dystrophies
- genetic disorders, such as Down syndrome and fragile X syndrome
