Infectious diseases Flashcards
What is sepsis?
SIRS + suspected/proven infection
What is SIRS?
Systemic inflammatory response syndrome: Fever/hypothermia Tachycardia Tachypnoea Leucocytosis or leucocytopenia
What is severe sepsis?
SEPSIS + multi-organ failure >2 of: - Respiratory failure - Renal failure - Neurologic failure - Haematological failure - Liver failure
What is ARDS?
Acute respiratory distress syndrome - inflammatory response of the lungs
Which sex des sepsis occur in more?
Male
What are the responsible pathogens of sepsis in neonates?
Group B streptococci
E.coli
Listeria monocytogenes
What are the responsible pathogens of sepsis in children?
Strep pneumoniae
Meningococci
Group A strep
Staph aureus
What are symptoms of paediatric sepsis?
Fever/hypothermia Cold hands/feet Mottled skin Prolonged cap refill time Chills/rigors Limb pain Vomiting/diarrhoea Muscle weakness Muscle/joint aches Skin rash Reduced urine output
What is probably the best sign of sepsis?
Tachycardia
What is the treatment for sepsis?
ABC
DEFG - don’t ever forget glucose
Antibiotics with broad-spectrum and CSF penetration
Cephalosporins
What blood investigations would you do for sepsis and the likely results?
FBC - leucocytosis, thrombocytopenia
CRP - elevated
Coag factors - deranged clotting due to DIC
U&Es, LFTs - renal and hepatic dysfunction
Blood gas - metabolic acidosis, raised lactate
Glucose - hypoglycaemia
Culture
What CSF investigations would you do for sepsis and what are the likely results?
Cell count & culture - increased WCC
Protein & glucose - increased protein level, low glucose
What other investigations would you do for sepsis?
Blood CSF Urine culture Skin biopsy culture Imaging: CT/MRI head
What are the responsible pathogens of meningitis in neonates?
Group B strep
E.coli
Listeria monocytogenes
What are the responsible pathogens of meningitis in children?
Strep pneumoniae
Meningococci
Haemophilus influenza
What are the symptoms of meningitis in children?
Nuchal rigidity Headaches, photophobia Diminished consciousness Focal neurological abnormalities Seizures
What are the symptoms of meningitis in neonates?
Lethargy, irritability Bulging fontanelle Seizures High temp Sleepy Breathing fast/difficulty breathing Shivering Vomiting/refusing to feed Blotchy skin Stiff body with jerky movements Cold hands/feet
What is the treatment of meningitis?
Chemoprophylaxis
Steroids
Where does strep pneumoniae colonize?
Upper airways
What is the transmission of strep pneumoniae?
Droplets
What are signs of pnuemococcal meningitis?
Brain damage
Hearing loss
Hydrocephalus
Is strep pneumoniae gram neg or pos?
Gram positive
Is haemophilus influenza type B gram pos or neg?
Gram negative
What can haemophilus influenza type B cause?
Bacteraemia
Meningitis
Pneumonia
Epiglottitis
What are long term complications for survivors of meningitis?
Amputation
Skin scarring
Cognitive impairment/epilepsy/hearing loss
What are vaccine preventable diseases?
Meningococcal disease
Haemophilus influenzae B Pneumococcal disease
What are the first signs of scarlet fever after 2-4 days?
Malaise
Fever
Flu-like symptoms
Pharyngitis
If progressive strep infection what is the next sign after flu-like symptoms?
Rash
What happens to the tongue in scarlet fever
Strawberry tongue
What can happen to hands and fingers in scarlet fever?
Peeling
What time of year is scarlet fever most common?
Winter
When can Group A strep cause complicated presentations?
Immunosuppressed
Chickenpox
What is the treatment for scarlet fever?
Penicillin 10 days
What are some complications of scarlet fever?
Impetigo Necrotising fasciitis Erysipelas Rheumatic fever Glomerulonephritis
What infections can staph aureus cause?
Impetigo Cellulitis Infected eczema Ulceration Staph scalded skin syndrome Toxic shock syndrome
Is streptococci gram positive or gram negative?
Gram positive
What is streptococci treated with?
Penicillin
Does streptococci have resistance issues?
Not usually
Is staphylococci gram positive or gram negative?
Gram positive
What is staphylococci treated with?
Flucloxacillin
Does staphylococci have resistance issues?
Yes - resistance big issue e.g. MRSA
What is impetigo caused by usually?
S. Pyogenes
S. Aureus
How does impetigo present?
‘Golden’ sores and blisters
No systemic symptoms
What is SSSS usually caused by?
S. Aureus
How does SSSS usually present?
Fever
Widespread redness
Fluid-filled blisters - rupture easily, especially in skin folds
What is TSS usually caused by?
S. Pyogenes
S. Aureus
How does TSS present?
Widespread redness, desquamation, multi-organ involvement
What is Kawasaki disease?
Self-limited vasculitis of medium-sized arteries
What is the leading cause of acquired heart disease in developed world?
Kawasaki disease
What are the signs/symptoms of Kawasaki disease?
Fever for 5 days plus:
- bilateral conjunctival injection
- cracked lips/strawberry tongue
- cervical lymphadenopathy >1.5cm
- polymorphus rash
- changes of the extremities
What is the diagnostic test for Kawasaki disease?
None - exclude differentials
Throat swab/microbiology
What is the main acquired heart disease caused by Kawasaki disease?
Coronary aneurysm
What is the aim of Kawasaki disease treatment?
Aim to prevent complications
What is the treatment of Kawasaki disease?
Immunoglobulins Aspirin Steroids Immunosuppressive agents Cardiology assessment
What are examples of persistant fever and rashes?
Henoch-Schonlein purpura
Vasculitis
What are three categories of rash?
Erthematous maculopapulous
Vesiculobullous
Petechial and purpuric
What viruses may present with an erythematous maculopapulous rash?
Measles Rubella Enterovirus Cytomegalovirus Human herpesvirus 6 Human herpesvirus 7 Parvovirus B19 Epstein-Barr virus
How does a erythematous maculopapulous rash appear?
Red, patchy rash, often raised
What viruses may present with a vesticulobullous rash?
VZV
Herpes simplex virus
Enterovirus
How does a vesiculobullous rash appear?
Small vesicles, fluid/pus filled, or bullous
What viruses may present with a petechial or purpuric rash?
Rubella (congential)
Cytomegalovirus (congenital)
Enterovirus
What are the types of VZV infections?
Primary infection: varicella, chickenpox
Recurrent infection: zoster
What is the incubation period for VZV infections?
14 (10-21) days
What are the clinical signs of chickenpox?
Mild malaise Fever Generally not unwell Itchy Exanthema
What is the natural history of exanthema in chickenpox?
Papules -> vesicles -> pustules -> crustae -> scarring ‘cropping’
What are the complications of chickenpox?
Secondary strep/staph infections of skin
Meingoencephalitis
Cerebellitis
Arthritis
What is the therapy for chickenpox?
None
Aciclovir if immunosuppressed
When is a VZV infection more fatal?
<1yr
T-cell deficiencies
What are the warning signs of a more fatal VZV infection?
High fever
New lesions >day 10
Inflammed lesions
General malaise
What are signs of HSV infection?
Herpes stomatitis
Whitlow’s on fingertips
Which type of herpes is HSV 1?
Oral
Which type of herpes is HSV 2?
Genital
What is the primary symptom of HSV 1?
Stomatitis - recurrent cold sores
What are serious complications of HSV?
Keratoconjunctivitis
Encephalitis
Systemic neonatal infections
What is the therapy for HSV infections?
Self-limiting
Aciclovir
How can HSV infections be spread to neonates?
Birth canal/direct contact
Why are HSV infections serious in neonates?
Not great immune system, disseminates
What disseminated infections can HSV cause in neonates?
Sepsis
Meningoencephalitis
Hepatitis
Skin/eye/mouth (SEM) disease
What is the treatment for neonates with HSV infection?
Acyclovir
What is the usual cause of hand-foot-mouth disease?
Enteroviruses
What age group is most susceptible to hand-foot-mouth disease?
<10yrs
When is hand-foot-mouth disease most prevalent?
Summer and early autumn
What is the incubation period for hand-foot-mouth disease?
3-6 days
What is clinical presentation of hand-foot-mouth disease?
Exanthema
Painful lesions
What type of bacteria is usually responsible for scarlet fever?
Group A strep (GAS)
What are primary immunodeficiencies caused by?
Missing or improper function of body’s immune system//single genetic defects
What is more common: primary or secondary immunodeficiencies?
Secondary immunodeficiencies
What is the most common cause of secondary immunodeficiency?
Prolonged steroid use
What are warning signs that it could be a primary immunodeficiency?
Serious Persistent Unusual Recurrent FH
What investigations should you do if you suspect a primary immunodeficiency?
FBC Immunoglobulins HIV test Functional antibodies Lymphocyte subsets NBT - Nitroblue tetrazolium blood test Complement
What does the Nitroblue tetrazolium blood test check for?
Screen for Chronic Granulomatous Disease (CGD)
What are different causes of immunodeficiency?
Antibody deficiencies
Cellular immunodeficiencies
Innate immune disorders
What is transmission for most paediatric HIV cases?
Vertical transmission
What is the main risk factor for vertical transmission of HIV?
High viral load
What is the treatment postnatally for HIV?
Mother - ART
Baby - prophylaxis until further testing, no breastfeeding
What is the treatment for children with HIV?
ART