Infection and Immunity Flashcards
What counselling should be given to parents with an unvaccinated children?
- Understand why they have not vaccinated – let them talk for however long they need
- Give examples of how the infections can cause long-term morbidity/mortality
- Mumps → infertile boys, deafness
- Rubella → severe deformities to pregnancy
- Measles → death
- Polio → massive respiratory problems
What are the long-term morbidity/mortality of mumps?
- Infertility in boys
- Deafness
What are the long-term morbidity/mortality of measles?
Death
What are the long-term morbidity/mortality of rubella?
Severe deformities to pregnancy
What are the long-term morbidity/mortality of polio?
Massive respiratory problems
What are the congenital and neonatal infections?
- Toxoplasmosis
- Other - Syphilis, Parvovirus, VZV, HIV, HBV
- Rubella
- CMV
- HSV
What is the management of toxoplasmosis in a child?
- 1st line = Pyrimethamine + Sulfadiazine for 1 year
- Adjunct = Prednisolone
What is the management of syphilis in a child?
- IM benzathine penicillin
What is the management of syphilis in a child?
- IM benzathine penicillin
What is the management of CMV in a child?
- IV ganciclovir
- Oral valganciclovir
What is the management of herpes simplex virus in a child?
-
Aciclovir (400mg, TDS) if neonate exposed on delivery
- If not nothing is needed
What can GBS cause in a neonate?
- Pneumonia
- Meningitis
- Septicaemia
What is the management of sepsis in a neonate?
- Early onset <72 hours = IV cefotaxime + amikacin + ampicillin
- Late onset >72 hours = IV meropenem + amikacin + ampicillin
What is the management of GBS in an adult?
- Only for women in labour → IV benzylpenicillin
How does a mother pass listeria monocytogenes to a child?
- Passes to child in placenta → mother has a mild influenza-like illness
What are the consequences of listeria in a mother?
- Spontaneous abortion
- PTL
- Neonatal sepsis
What are the signs and symptoms of listeria monocytogenes?
- Meconium staining of liquor in pre-term infant
- Widespread rash
- Sepsis
- Pneumonia
- Meningitis
- Mortality 30%
What is the management of listeria monocytogenes?
- IV amoxicillin/ampicillin OR Co-trimoxazole
- If systemic infection = IV benzylpenicillin + gentamicin
Define Kawasaki Disease.
Systemic vasculitis in a child under the age of 4/5 years old.
What are the risk factors for Kawasaki disease?
- Ethnicity - Japanese, Black-Caribbean
- Peak at 1yo
What are the signs and symptoms of Kawasaki disease?
-
Fever for over 5 days +4/5 of the following CRASH symptoms
- Conjunctivitis
- Rash - polymorphous; begins hands/feet
- Adenopathy = Cervical lymphadenopathy
- Strawberry tongue = Mucous membrane changes
- Hands & feet swollen - desquamate/peel
What are the complications of Kawasaki disease?
- Cardiovascular
- Gallop rhythm
- Myocarditis
- Pericarditis
- Coronary aneurysms → require long-term warfarin and close follow-up
- Sudden death
What are the appropriate investigations for suspected Kawasaki disease?
- Diagnosis on clinical findings (no test)
- Bloods - FBC (inc. platelets), CRP, ESR
- Echocardiography - check cardiac function
What is the management of Kawasaki disease?
- Admission
- IVIG (within 10 days)
-
High-dose aspirin - reduce thrombosis risk
- Other = corticosteroids, infliximab/ciclosporin and plasmapheresis if persistent inflammation and fever
What causes malaria?
- Protozoa Plasmodium
- Falciparum most fatal
- Ovale, Malariae and Vivax
- Spread by female Anopheles mosquito
What are the signs and symptoms of malaria?
- Onset 7-10 days after inoculation (<1yr)
- Cyclical fever
- Diahorrea and vomting
- Flu-like symptoms - shaking, chills, night sweats, headache, myalgia
- Jaundice
- Anaemia
- Thrombocytopaenia
What are the appropriate investigations for suspected malaria?
-
3 thick and thin blood films
- Thick = parasite
- Thin = species, parasitaemia
- Malaria rapid antigen detection tests - plasmodial HRP-II, parasite LDH
What is the prevention of malaria?
- Anti-malarial prophylaxis with quinine
- Bite prevention – repellent and nets
What is the management of malaria?
- Arrange immediate admission → Medical emergency
- Notify PHE (can have a RAPID deterioration)
- Treatment
- Non-falciparum = Chloroquinine
- Mild falciparum (not vomiting, parasitaemia <2% and ambulant)
- 1st line = ACT (Artemisinin Combination Therapy)
- 2nd line = Atovaquone-proguanil (cannot give doxycycline to age <12yo)
- Severe/complicated falciparum
- 1st line = IV Artesunate
- 2nd line = IV Quinine
- Primaquine for eradication of hypnozoites - dormant parasites in liver in vivax and ovale
What can anti-malarial drugs precipitate?
G6PDD
What are the causes of typhoid fever?
- Salmonella typhi
- Paratyphoid
- Both via faeco-oral transmission
What are the complications of typhoid fever?
- GI perforation
- Myocarditis
- Hepatitis
- Nephritis
What are the signs and symptoms of typhoid fever?
- Fever
- Bradycardia
- Headache
- Travel history
- Dry cough
- Weight loss/Anorexia
- Malaise
- Myalgia
- GI symptoms - diarrhoea or constipation
- Splenomegaly
- Bradycardia
- Rose-spots on trunk
What are the appropriate investigations for suspected typhoid fever?
- Blood culture = Diagnostic
- Bloods – FBC, LFTs, stool culture
What is the cause of Dengue fever?
Dengue arbovirus
What are the signs and symptoms of dengue fever?
- Primary infection:
- Headache (retro-orbital)
- Fine erythematous sunburn-like rash (50%)
- High fever and myalgia
- Recent ravel history - 5 day incubation period
- Hepatomegaly
- Abdominal distension
- Severe = Haemorrhage
What is Dengue haemorrhagic fever?
-
Secondary infection
- Previously infected child → subsequent infection with a different strain → severe capillary leak, hypotension, haemorrhagic manifestations
- Treatment = fluid resuscitation usually helps a lot
- Due to partially effective host immune response augmenting the severity of the infection
What are the appropriate investigations for suspected dengue fever?
- Gold standard = PCR viral antigen, serology IgM
- bloods
- FBC - low WCC, low platelets, low Hb → espe in severe
- LFTs
- Serum albumin
What is the management of dengue fever?
- Supportive → fluids and monitoring
- ITU - if increased deterioration
How is mumps transmitted?
- Transmission by respiratory secretions
- Long incubation period (15-24 days)
What are the signs and symptoms of mumps?
- Asymptomatic (in 30% of cases)
- Parotid swelling - infectious 5 days before and after
- Headache
- Fever
- Pancreatitis
- Neuritis
- Arthritis
- Mastitis
- Nephritis
- Thyroiditis
- Pericarditis