Infectious Diseases Flashcards
If a fever has lasted longer than 5 days what do you think of?
Kawasaki
If the febrile illness arises days before a rash what is viral cause?
VZV
History questions in sick child presentation?
How long
Chronology
Immunisations
Infected contacts
immunosuppression
Exposure - animals, travel, school, food/drink
Treatment already given - meningitis/penumonia
What temperature would be immediately high risk in a baby under 3 months and a child 3-6 months?
under 3 months = over 38
3-6 months = over 39
Child presenting with cough, conjunctivitis, coryzal rash on face and ears now around bottom, what are differentials?
Scarlet fever
Signs of scarlet fever?
sandpaper rash, strawberry red tongue, pastias lines
Symptoms of Meningitis in children?
Photophobia, neck stiffness, bulging fontanelle, rash, headache, seizures, sepsis, altered GCS
What investigations are needed into suspected meningitis?
Blood culture and LP
What does lumbar puncture look at for meningitis investigation?
Glucose, protein, WCC, microscopy, gram stain, molecular testing
How will CSF present in TB?
yellow with raised WCC, marked raise in protein and very low glucose
What sign is positive for meningitis?
Kernigs
8 causative organisms for meningitis?
Neisseria meningitidis Haemophillus influenza type b Streptococcus pneumoniae group B strep E.Coli TB Fungi Parasites
Treatment for CNS infections?
3rd gen cef = cefotaxime or ceftriaxone
Steroids (HiB)
What follow up is needed in meningitis?
Audiology
clinical
What do steroids allow in meningitis treatment?
reduced hearing loss
Define encephalitis?
Inflammation of brain parenchyma
What 6 viral illnesses can then proceed to encephalitis?
CMV, enteroviruses, HSV, adenovirus, jap encephalitis, arboviruses
Why does HSV encephalitis have unique presentation and what is it?
Temporal region effected following tracking back from temporal lobe ganglion
Presents with haemorrhagic encephalitis
Treatment of HSV encephalitis?
Aciclovir
In encephalitis what investigations on CSF are looked at?
PCR
Serology - arboviruses, lyme disease
Examine - RBCs, protein, oligoclonal bands, pleocytosis
What is ADEM spectrum and when does it occur?
Acute demyelinating encephaliting spectrum in post infectious CNS
What 3 organisms most likely to cause post-infectious encephalitis?
HSV
VZV
Mycoplasma
6 common viral pathogens causing URTI?
RSV Rhinovirus Adenovirus Parainfluenza Influenza Coronavirus
Viral pathogens most likely to cause LRTI?
RSV parainfluenza influenza Adenovirus Metapneumovirus
Bacterial pathogens most likely to cause LRTI?
mycoplasma
strep. pneumoniae
haemophillus
Staph aureus
Tests for moderate to severe pneumoniae?
Blood culture
Nasopharyngeal aspirate - PCR, FISH for virus
Sputum culture - bacterial
Pleural fluid
When is CXR indicated in pneumonia?
When it is very severe with complications or diagnostic doubt
Treatment of CAP? what is added if not effective?
Amoxicillin
Macrolide
What is Pertussis known as? Presents as?
Whooping cough
URTI, rhinorrhoea, cough with whoop, apnoea, vomiting, conjunctival haemorrhages
100 day cough
How is diagnosis of pertussis made?
Nasopharyngeal swab for PCR and culture
lymphocytosis
What drug class is given in pertussis to reduce transmissibility?
Macrolide - clarithromycin, azithromycin
What does the cocooning strategy of pertussis vaccination refer to?
Vaccinating whole household of newborn infant
Primary causative viral agent of gastroenteritis? 2 other viral causes?
Rotavirus
Adenovirus
Norovirus
5 main bacterial causes of gastroenteritis?
Shigella salmonella e.coli campylobacter c. diff
Management of Gastroenteritis?
Supportive
Fluid and electrolyte replacement
Rotavirus vaccine
2 big MSK infections to be aware of?
Septic arthritis
Acute haemotogenous osteomyelitis
Septic arthritis symptoms?
Joint swelling
Fever
limitation of movement
Most common pathogens causing septic arthritis?
S. aureus Group A strep Hib Pneumococcus Kingella Kingae
Symptoms of acute haematogenous osteomyelitis?
pain
fever
swelling
Organisms most likely to cause acute haematogenous osteomyelitis?
Staph aureus Group A strep Hib Pneumococcus Kingella Kingae
Treatment of MSK infection?
Flucloxicillin (more broad spec in younger)
What is it important to clarify in a history of GI upset?
Travel history
Travellers diarrhoea may need short course of what 2 antibiotics?
Ciprofloxacin
Azithromycin
Most common 4 agents of travellers diarrhoea?
Shigella
E.Coli
Salmonella
Parasites
Malaria symptoms in children, test and what test looks for?
Fever, rigors, headache
Antigen test for malaria
Looks at viral load and species of plasmodium
Increasing symptoms of typhoid fever in first 3 weeks?
Treatment with what 2 drugs?
Fever GI pain Rash - rose spots 2nd week - gastro perforation 3rd week - encephalopathy broad spec ceph and azithromycin
What is the infection known as break down fever? symtpoms?
Dengue fever, high temp and severe bone pain
2 illnesses you can get from ticks?
Typhus
Lyme disease
At 2 months old, what 3 injections are given? What oral drug?
1 - diptheria, polio, tetanus, pertussis
2 - penumococcus
3 - Hib
Oral - rotavirus
At 3 months old what 2 injections are given? what oral drug?
1 - (second) diptheria, tetanus, polio, pertussis
2 - Men C
Oral - rotavirus
At 4 months old what 3 injections are given?
- (third) tetanus, polio, diptheria, pertussis
- (second) Hib
- (second) Pneumococcus
At age 1 what 3 vaccines do you receive?
- MMR
- Pneumococcus
- Hib and Men C
At age 3 what 2 vaccines do you get?
- MMR
2. (fourth) tetanus, polio, pertussis, diptheria
Girls age 12/13 get what vaccine
HPV
If a mother is identified as having hep B, what is the child vaccination management plan?
Birth ( potentially Ig too) 1 month 2 months 1 year 5 years
Who is the BCG vaccine given to and what does it protect against?
TB Children in high risk areas Parents from high risk countries Travel Recent contact
What should you ask about in a CNS infection history?
Travel Work Sex Contacts Epidemics Animal contacts Vaccinations
Clinical features of meningitis?
Headache Photophobia Decreased consiousness Bulging fontanelle Vomiting Fever Positive Kernigs sign Rash Lethargy Irritable High pitched cry in babies Poor feeding
Comment on the lymphocytes, neutrophils, glucose, protein, gram and ziehl neelson in CSF of pyogenic, viral, TB infections?
Pyogenic = normal, very raised, very low, high, positive, negative Viral = raised, normal, normal, raised, negative, negative TB = raised, normal, low, very high, negative, positive
Which bacterial agent of meningitis initially invades intracellularly and which invades intercellularly
Neisseria meningitis is intracellularly
Haemophillus influenzae is intercellularly
How are meningitis agents able to invade the CNS undetected?
Evade the complement system and therefore no Ig are produced allowing unimpeded growth
What 3 components of bacterial cell walls are released in meningitis ?
IL 1
IL6
TNF
3 most common pathogenic causes of meningitis in infants?
Group B strep
E. Coli
Listeria monocytogenes
3 most common pathogenic causes of meningitis in toddlers?
N. meningitidis
Hib
Strep. pneumoniae
What is neisseria meningitidis sensitive to? type of bacteria? How is it grown and identified?
penicillin
Gram negative diplococci
Sugar fermentation of maltose and glucose
Haemophillus influenzae sensitive?
Grown on what?
Type of bacteria?
Beta lactamase positive meaning usually penicillin resistant
Grown on chocolate agar with factor X and V
Gram negative rod
2 drugs used to treat children with meningitis?
Ampicillin and cefotaxime
1 drug used to treat toddlers and adults with meningitis?
Ceftriaxone
When is dexmethasone used before treating meningitis?
Before beta lactam antibiotics to treat cerebral oedema
For Hib as reduces changes of deafness
What are the 2 protein carriers for Hib vaccine?
tetanus, diptheria
Which strain of neisseria meningitidis has a vaccine and which doesnt?
Strain B doesnt, strain C does
If someone in the house had Hib what are the rest prophylactically treated with?
Rifampicin
If someone has neisseria meningitidis what 2 things are the rest of the household treated with prophylactically
Rifampicin or ciprofloxacin
What viral cause of meningitis is most common? other agents
Enterovirus 80% CMV VZV HSV Adenovirus Japanese encephalitis HIV Mumps
Different presentations of viral meningitis?
URTI Conjunctivitis pharyngitsis pneumonia myopericarditis gastroenteritis Neuro
Other causes of meningitis besides bacterial and viral
Fungi TB Helminths Protozoa Mycoplasma Brucella Syphillis
How many months after initial infection does TB meningitis present?
3-6 months
50% of TB meningitis is what type?
miliary
Symptoms of TB meningitis?
Drowsy Headache Neck stiffness Photophobia Irritable Personality changes decreased consiousness cranial nerve involvement
How do you diagnose TB meningitis?
positive tuberculin test (man 2 test), gastric washings
What is the 4 fold treatment of TB meningitis?
Rifampicin Isoniazid Pyrazinamide Aminoglycoside/ethambutol all for 2 months Continue rifampicin and isoniazid up to 9-12 months
2 forms of meningitis most prevalent in the immunocompromised?
Listeria monocytogenes
Crytococcus (yeast)
Most common viral cause of encephalitis? % get long term complications?
HSV 1
50%
Fever, headache, decreased consciousness, confusion, dysphasia
non-viral causes of encephalitis?
Neisseria meningitis listeria monocytogenes Scrup typhus Leptospirosis Melioidosis Malaria TB Borrelia Brucella
Before youve got samples back for encephalitis what do you start?
high dose aciclovir and antibiotics
What investigations are done into encephalitis?
Throat sample Stool sample CSF Neuroimaging EEG
What can develop immediately after infection by measles?
Post-infection encephalitis
What can develop 1-6 months after infection with measles? prognosis?
measles inclusion body encephalitis
Fatal
What can develop years after a measles infection? prognosis?
Subacute sclerosing panencephalitis
Fatal
Progressive multifocal encephalopathy occurs in the immunosuppressed due to what virus?
JC virus
Symptoms of a brain abscess?
Fatigue stupor Seizures Headache confusion ataxia sensory or motor impairments focal to the lesion Nausea Vomiting Papilloedema
3 different ways in which brain abscess’ can develop?
Contiguous suppurative focus
trauma
haematogenous spread
What is an example of contiguous suppurative spread that causes a brain abscess?
Otitis media
Most common organisms that are involved in brain abscess development?
Staph aureus Strep - aerobic and anaerobic Bacteroides Prevotella Fusobacterium Enterobacteriaceae Pseudomonas
When treating a brain abscess blindly what 3 medications do you use?
Penicillin G and 3rd gen cephalosporin (ceftriaxone, cephalosporin)
Metronidazole to cover anything penicillin resistant
After brain surgery or trauma what bacteria is suspected to cause a brain abscess? 2 medications that cover this?
Staphlococcus aureus
Vancomycin and nafcillin
If pseudomonas aeruginosa is suspected as a causative agent for brain abscess what 2 medications are used to treat?
cefepime or ceftazidime
If a HIV patient develops a brain abscess, what infection are you worried about?
Toxoplasmosis
What are prion diseases also known as?
Transmissible spongiform encephalopathies
Sporadic CJD symptoms? diagnosed how?
Ataxia, myoclonus, dementia
14-3-3 protein in CSF
Familial form of transmissible spongiform encephalopathy? inheritance pattern?
Familial TSE
Autosomal dominant
Variant CJD is also known as what? Presentation? 2 proteins in CSF?
Bovine Spongiform Encephalopathy
Psychiatric symptoms
Proteins - 14-3-3 and Tau
