Lecture 38: Fever and Headache

Question 1

Pathogenic causes of meningitis: viral; bacterial; fungi; protozoa; other

Answer 1

• Viral: Common, enteroviruses, influenza, HSV2
• Bacterial: N. meningitidis, strep pneumoniae. RARE: haemophilus infulenzae; mycobacterium tuberculosis; listeria monocytogenes
• Fungi: rare, AIDS in cancer. Cryptococcus neoformans
• Protozoa: rare, angiostrongylus cantonensis. Pacific. eosiniophilic
• other: drugs, trauma, neurosurgery, cancer

Question 2

Meningeal inflammation and symptoms

Answer 2

Headache; photophobia; neck stifffness, drowsiness
Systemic response: fever, drowsiness, septic shock; rash (neisseria)

SORE BACK OF LEGS

Question 3

What is bacterial meningitis preceded by

Answer 3

Nasopharyngeal colonisation by N. meningitidis

Question 4

How to diagnose meningitis

Answer 4

CSF; blood cultures; throat swab; blood to detect bacterial DNA by PCR

Question 5

Kernig’s sign

Answer 5

Flex the hip and extend the knee. + when there is pain in doing so. Indicates meningitis or subarachnoid haemorrhage

Not due to hamstring stretch, makes headache worse. Stretching cauda equina

Not tell tale

Question 6

CSF findings for viral and bacterial meningitis

L4/5, cauda equina

Answer 6

Viral:
glucose: normal; protein (Ig): high/normal; WBC: high; cells: lymphocytes; gram stain: -ve; culture:-
Bacterial: glucose: low (bacteria and neutrophils respiring); protein: high; WBC: high; cells: neutrophils; gram stain: +/-: culture: ++/-

Question 7

Meningitis and rash. If no rash what do you do?

Answer 7

Meningococcal meningitis! Petechiae, Neisseria

No rash: all effort to find aetiology, to exclude meningococcal disease. If CSF gram -:
Antigen test strep pneumoniae; CSF PCR (amplifies nucleic acid sequences to be seen, uses primers) for causes; blood PCR; throat swab

Question 8

Streptococcal antigen test

Answer 8

CSF, urine or blood put on a card

If strep. pneumoniae antigens present, will move on blotting paper. Antibodies react with antigen and colour change

Question 9

PCR

Answer 9

Strands displaced, specific primers to DNA form organisms added.Cooled down to anneal the primers..
Heat back up to allow DNA polymerase to lengthen then strands.
Visualised with a fluorescent tag added. Will double every time new strands are made

Question 10

Meningitis epidemiology

Answer 10

5% death rate
Most common in winter
Most common in very young
Maori pacific children common

Question 11

How does neisseria meningitidis evade complement

Gram __ ___. Often ____, spheres Stain with ___ and red
Thick polysaccharide ___ to stop _____ and ___ formation
Protein that binds human ___ _, which ____ regulates complement
___ that bind ___, preventing C3 from breaking
___ similar to blood group antigens so ignored. (Level of LPS determines ____ of disease/ symptoms), releases ___ into blood stream

Answer 11

Gram - coccus. Often diplocci, spheres Stain with saffron and red
Thick polysaccharide capsule to stop opsonisation and MAC formation
Protein that binds human factor H, which down regulates complement
Pilli that bind C4, preventing C3 from breaking
LPS similar to blood group antigens so ignored. (Level of LPS determines extent of disease/ symptoms), releases extra into blood stream

Question 12

Neutrophil traps and septic shock charcateristics

Answer 12

When LPS/ bacterial load is very high, neutrophils release DNA into capillaries.
Clogs these, sticky and traps bacteria, RBC’s and platelets. Platelets cause
Due to blockage, reduces blood flow and oxygen, causing shock.
Shock: lowBP, tachycardia, reduced organ perfusion= organ failure

Question 13

Bacterial meningitis treatment

Answer 13

If in progress, dexamethasone before penicllin?? at hosp
IV antibiotics (penicillin)
resuscitate
blood cultures
transfer to hosp
pain relief, fluids, IV antibiotics
Droplet precautions

Question 14

Viral meningitis treatment

Answer 14

Analgesia and rest