Viruses Flashcards
Cytomegalovirus (type, appearance, patterns):
- herpesvirus
- typically only disease causing in immunocompromised
- owl’s eye appearance (intranuclear inclusion bodies)
- congenital, mononucleosis, retinitis, encephalopathy, pneumonitis, colitis
Congenital CMV infection:
- growth retardation
- pinpoint petechial blueberry muffin skin lesions
- microcephaly
- sensorineural deafness
- encephalitis (seizures)
- hepatosplenomegaly
CMV mononucleosis:
- infectious mono like illness
- may develop in immunocompetent
CMV retinitis:
- common in HIV patients
- visual impairment e.g. blurred vision, fundoscopy: retinal haemorrhages and necrosis (pizza retina)
Dengue fever (transmission, incubation, features, management)
- viral haemorrhage fever
- transmitted by Aedes Aegypti mosquito
- incubation 7 days
- form of DIC - dengue shock syndrome
- headache, fever, myalgia, pleuritic pain, facial flushing, maculopapular rash, reduced platelet, increased ALT
- manage symptomatically, no antivirals
Ebola (virus type, locations, transmission, incubation)
- Filoviridae family
- West Africa - Guinea, Sierra Leone, Liberia
- human to human direct contact transmission
- incubation: 2-21 days
- not infectious until symptomatic
Features of ebola:
- sudden onset fever, fatigue, myalgia, headache, sore throat
- vomiting, diarrhoea, rash
- impaired liver and kidney
- internal and external bleeding
Malignancies associated with EBV:
- Burkitt’s lymphoma
- Hodgkin’s lymphoma
- nasopharyngeal carcinoma
- HIV - associated CNS lymphoma
Non-malignant association with EBV:
harry leukoplakia - indicative of HIV
Infectious mononucleosis causes and features:
- HHV4, CMV, HHV6
- triad: sore throat, lymphadenopathy, pyrexia
- malaise, anorexia, headache
- palatal petechiae
- splenomegaly (rare splenic rupture)
- hepatitis (transient increase ALT)
- lymphocytosis
- haemolytic anaemia secondary to cold agglutinins IgM
- maculopapular pruritic rash if ampicillin/amoxicillin whilst having mono
Diagnosis of infectious mononucleosis:
heterophil Ab test (monospot) - second week illness
What needs to be avoided with infectious mono?
contact sports 8 weeks after
Mumps virus type, spread, features, management:
- RNA paramyxovirus
- spread by droplets
- infective 7 days before and 9 days after parotid swelling starts
- incubation period: 14-21 days
- MMR vaccine
- fever, malaise, muscular pain, parotitis (unilateral initially becomes bilateral in 70%)
- manage with paracetamol, notifiable disease
Complications of mumps:
- orchitis - uncommon pre-pubertal males (4-5 days after start of parotitis)
- hearing loss - unilateral and transient
- meningoencephalitis
- pancreatitis
Norovirus (type, symptoms, transmission, diagnosis)
- most common cause gastroenteritis
- range of non encapsulated RNA virus species
- symptoms: 15-20 hours
- nausea, vomiting, diarrhoea, headaches, low grade fever, myalgia
- faeco-oral route
- virus enters cell via host receptor mediated endocytosis and replicates in small intestine
- diagnose with stool culture viral PCR