Infection 1 Flashcards
HHV types?
1 and 2 are HSV1/2. 3 = VSV 4 = EBV 5 = CMV 6/7 are 6/7 8 = 8
What can HSV-1 Cause?
Gingiovstomatitis, keratoconjunctivitis, herpes labialis, temporal lobe encephalitis.
ECZEMA Herpticum and herpteic whitlow
HSV-2 Presentation?
Gential herpes (lifelong) -> flu like prodrome -> vesicles papules around gentials and anus Shallow ulcers Urethral discharge Dysuria Fever and Malaise
How does acyclovir work?
Guanosine analogue that inhibits viral DNA polymerase as anaologue of dGTP. Absence or 3’hydroxyl group prevents nucleoside attachment
HSV investigations and treatment?
Clinical diagnosis but mayb viral culture or HSV PCR
Topical, oral or IV acyclovir
Varicella Zoster incidence?
Is in dorsal root ganglia.
Chickenpox = 4-10
Shingles =>50 YO
90% adults VSV IgG +ve
Presentation of chickenpox?
Prodromal malaise Mild pyrexia Generalised pruritic vesicular rash Maculopapular Contagious from 48hours until all vesicles crusted (7-10 days)
Shingles presentation?
May occur due to stress and tingling in dermatomal distribution followed by painful vesicular skin lesions. recovery 10-14 days
Investigations and Pox managment?
Clinical diagnosis, maybe PCR, viral culture or ELISA.
Chldren = treat symptoms with calamine otion, analgesia and antihisamines
Treatment and prevention of shingles?
1st line = valaciclovir or famciclovir
2ns line = acyclovir if within 72hours of appearance of rash.
VZIG for immunosuppressed and pregnant women exposed
Complications of VSV?
kids: bacterual sepsis, pneumonia, encephalitis and haemorrhagic complication
Adults: POSTHERPETIC NEURALGIA
Also: menigoencephalitis, myeltis, cranial nerve palsy, vasculopathy, GI ulcers, pancreatitis and hepatitis
EBV names and aetiology?
infectious mononucleosis and glandular fever.
90-95% of eople at some point and spread by saliva droplets.
Infects B lymphocytes and incorporation of viral DNA into host DNA
EBV presentation?
Fever, hepatosplenomegaly (jaundice), pharyngitis (tonsillar exudates) and lymphadenopathy (posterior cervical)
ATYPICAL LYMPHOCYTOSIS
EBV Investigations?
1) FBC (lymphocytosis) highest in week 2-3
2) Blood film - ^
3) Heterophile Abs
4) EBV Specific Abs
5) Rea time PCR for EBV DNA detection
EBV management?
Supportive care (antiinflammatory and analgesics) Corticosteroids if severe
AMOXICILLIN or ampicllin is contraindicated fue to widespread maculopapular rash
throat swab to exclude Group A strep
Components of EBV specific Abs?
IgM, IgG and EBNA. None = no infection IgM = early infection IgG+IgM = acute primary infection IgG+EBNA = past infection
Difference in presentation fro EBV and Strep pyogenes?
Strep has anterior cervical lymphadenopathy and no splenomgealy
Causative organism for purple, purpural lesion on nose?
HHV-8 (Kaposis)
HIV features?
Pneumocystic pneumonia
How does HIV work?
Retrovirus (+sense RNA)
1) Enters CD4 lmphocytes via gp120 and chemokine receptor
2) Reverse transcriptase RNA to DNA
3) Viral DNA incoporated
4) Dissemination of virions leads to cell death
5) Eventually to T-cell depletion
Methods of HIV transmission?
Sexual contact, pregnancy, childbrith and breastfeeding, occupational exposure, blood transfusion or organ transplant and injection drug use
Stages of untreated HIV?
4F’s
1) Flu-like
2) Feeling Fine
3) Falling count and FInal crisis in AIDS
Capsulated organisms in HIV presentation?
Strep pneumoniae
Haemophilus influenzae
Bacterial presentation for HIV?
Mycobacteria (lungs GI skin), staphylococci, salmonella, capsulated organisms