Microbiology/Immunology Flashcards
What are the two main plasmodium species that cause malaria?
Which one causes the bulk of disease?
What stage is the immune response against?
P. Falciparum *causes bulk of disease
P. Vivax
Merozoites in Blood stage
What organs does malaria effect?
What is the difference between mild and severe
What is the antimalarial used?
Brain, lungs and placenta
Mild just flu like symptoms
Severe get anaemia, cerebral affects, rest distress etc.
Artemisinin used to treat
How do antibodies help clear malaria?
However how is the overall immune response?
Bind to sporozoites to stop them entering liver
Bind to Merozoites to stop them entering RBC
Bind to infected RBC (parasite antigen on surface)
Opsonise them so they can be phagocytosed
But overall immune response bad for a variety of reasons (such as antigenic diversity), takes a few exposures to acquire immunity
*note T cell response to hepatocytes is much smaller
What is the biggest cause of osteomyelitis?
What are two ways it can get in?
What are some bacterial causes in neonates?
Staph aureus
Through the blood (more common in children)
Direct contamination through trauma or surgery (more common in adults)
Group B strep
Gram negs
H. Influenza
What are some clinical symptoms of osteomyelitis?
What do we treat osteomyelitis with?
What do we add in neonates?
Tenderness, warmth, swelling over site and diminished ROM. fever.
Flucoxacillin
Add ceflotaxime in neonates
What is the difference in blood supply to long bones between neonates, children and adults? How does this affect risk of osteoarthritis and septic arthritis?
In neonates vessels penetrate growth plate from metaphysics into epiphysis. Can spread from epiphysis into articular surface and into joint causing septic arthritis (more common in them then in adults)
In children growth plate is a barrier between metaphysis and epiphysis so generally get metaphysis infection which spreads subperiostally as periosteum is weakly attached to easy to form abscess there.
In adults the metaphyseal vessel reunite with epiphyseal as growth plate closure. Means once again can get spread of infection into epiphysis and into joint.
The looped capillaries and slow flow venous sinusoids as well as poor immune system access make infection easier
What defines PUO?
Pyrexia of unknown origin;
- Prolonged illness (2-3 weeks)
- Fever above 38.3 on multiple occasions
- No diagnosis after intelligent investigations
Most acute fevers are from self limiting infections, what are some warning bells of something more serious?
What is the management?
- Rapid onset
- Rigors
- Altered conscious state
- Rash
- Vomiting
- Headache
- Muscle pains
- Jaundice
Empirical IV antibiotics if think its bacterial, blood work and observe.
What are the differentials for PUO?
- Infection; eg SBE and TB, HIV opportunistic
- Malignancy; eg lymphoma, hepatoma
- Connective tissue disorder; eg PMR, thyroiditis, lupus, crohns.
- Other (drugs, factious)
What can pooled and hyperimmune antiserums be used for?
They provide passive immunity.
Eg pooled can be used for hypogammaglobulinemia and immunodef kids for measles
Hyperimmune for more specific such as prevention and treatment of diphtheria and tetanus, rabies and hep B
What is 4 virus and one bacteria that empirically attenuated vaccines have been used for?
Sabin OPV, measles, mumps, rubella
BCG for TB
What are two ways apart from attenuation live vaccines can be administered? give examples.
Reassortment vaccines- Rotavirus (rotateq)
Antigens on living vectors- VSV-ZEBOV
What is the difference between a Salk and Sabin vaccine?
Sabin is a living attenuated vaccine given orally
Salk is an inactive vaccine
What two routine vaccinations are component vaccines?
Hep-B and HPV
why does conjugation improve efficacy? Why does it make it possible to immunise babies?
- Polysaccarides alone only stimulate a T cell independent response, so no memory and only lasts a few years in adults. In children under 2 there is no T cell independent response so it doesn’t work.
Pneumococcal
- Use a capsular polysaccaride antigen from a bunch of different serotypes - Works in the healthy and recommended for elderly to stop pneumonia - However in children under 2 the response is poor as the IgG class of antibody which predominates in response to CHO antigens develops late, so they get a T-cell independent response. - So we conjugate it to a protein carrier which allows T cells to participate and use it in infants.
