Infectious diseases I Flashcards
Name the different human herpesviruses
HHV-1 = HSV1 HHV-2 = HSV2 HHV-3 = VZV HHV-4 = EBV HHV-8 = HHV-8; Kaposi's sarcoma (purple, purpural lesion)
Compare the presentations of HSV1 and HSV2
HSV1
= cold sores (herpes labialis), herpetic whitlow (lesion on finger), systemic inflammation
= keratoconjuctivitis, herpes simplex meningitis/encephalitis
HSV2
= life long genital herpes, flu-like prodrome, shallow ulcers, urethral discharge, dysuria, fever + malaise
Chicken pox summary card
Primary infection of varicella zoster, typically occurs in children
= prodromal malaise, mild pyrexia, generalised pruritic vesicle rash (mainly face and trunk), contagious from 48hr before rash and until all vesicles crusted over (7-10 days)
= children mx w/ calamine lotion, analgesia, antihistamines
= adults mx w/ acyclovir/valacyclovir/famciclovir if < 24 hr onset
= can lead to bacterial sepsis, pneumonia, encephalitis, haemorrhagic complications
Shingles summary card
Reactivation of varicellar zoster, typically occurs in elderly
= occur due to stress, tingling in dermatomal distribution, followed by painful skin lesions, recover 10-14 days
= 1st line: valacyclovir/famciclovir
= 2nd line: acyclovir if < 72 hr of appearance of rash for 7 days
= can lead to myelitis, meningoencephalitis, cranial nerve palsies, vasculopathy, GI ulcers, pancreatitis, hepatitis
Presentation of infectious mononucleosis
Glandular fever: primary EBV, proliferation of B lymphocytes as incorporation of viral DNA into host DNA
= lymphadenopathy (posterior cervical chain), fever, pharyngitis (tonsillar exudates), hepatosplenomegaly; jaundice
= most pts make uncomplicated recovery in 3-21 days
Ix and mx for mono
Ix
- FBC, blood film (atypical lymphocytes), heterophile antibodies (monospot test), EBV specific antibodies, PCR_EBV DNA detection
Mx
- Supportive care; anti-inflammatories, analgesia
- Corticosteroids; if severe case (haemolytic anaemia, obstructive pharyngitis, severe tonsillar swelling)
*amoxicillin/ampicillin CONTRAINDICATED as leads to widespread maculopapular rash
Which EBV specific antibodies would be present for the following:
a) -ve EBV status
b) early primary infection
c) acute primary infection
d) past infection
a) no antibodies present
b) EBV VCA IgM present
= viral capsid antigen, IgMnow (like meow)
c) EBV VCA IgM, EBV VCA IgG
= viral capsid antigen, IgMnow
= viral capsid antigen, IgGone
d) EBV VCA IgG, EBNA
= viral capsid antigen, IgGone
= nuclear antigen (6-12 weeks after onset)
Presentation of HIV
Normally due to the complications from reduced CD4+ T-cells
= bacterial infection (staphylococci, mycobacteria, salmonella, strep., H. influenzae)
= viral infection (CMV, HSV, HPV, VZV, EBV)
= fungal infection (invasive aspergollis, pneumocystic pneumonia, candida)
= protozoa infection (toxoplasmosis, microconidia, crypto)
HIV associated tumours
Kaposi’s sarcoma
= AIDS-defining, HHV-8, pink/purple patch on skin/in mouth
SqCC
= anal/cervical due to HPV
Lymphoma
How is HIV transmitted and what are its stages of infection?
Sexual contact, pregnancy/childbirth and breastfeeding, IVDU, occupational exposure, blood transfusion/organ transplant
- Flu-like
- Feeling fine
- Falling count (CD4+ T cells)
- Final crisis (AIDS)
Ix for HIV
1st line = ELISA, confirm w/ Western Blot = serum HIV rapid test = serum HIV DIVA PCR in infants = CD4+ count = serum viral load (HIV RNA)
Other tests
= drug resistance test to determine therapy
= screen for Hep B + C
= screen for syphilis (Treponema pallidum)
= screen for TB (tuberculin skin test)
= FBC, U&Es, LFTs etc.
What is hairy leukoplaki associated with?
Irregular, white, painless plaques form on lateral tongue and cannot be scraped off
EBV-mediated in HIV + organ transplant pts
Candidiasis summary card
Thrush; candida albicans
= oral: dysphagia
= vaginal/balanitis: thick discharge, itching, redness, soreness
= disseminated fever, hypotension +/- leucocytosis
= associated w/ diaper rashes, infective endocarditis
Ix are not routine, clinical diagnosis but may want to exclude:
= UTI (urinalysis)
= Diabetes (fasting/random glucose, glucose tolerance test)
= STIs (vaginal pH test)
= HIV (antibody test)
Types of candidiasis and pts they’re associated with
Oral candidiasis and oesophageal thrush
= immunocompromised
Vulvovaginitis
= diabetics, use of Abx
Disseminated candidiasis
= neutropenic pts
Tonsillitis summary card
Acute infection of parenchyma of palantine tonsils
= pain on swallowing, fever > 38, tonsillar exudate, sudden onset sore throat, tonsillar erythema and enlargement, anterior cervical lymphadenopathy
= viral: rhinovirus, coronavirus, adenovirus, EBV
= bacterial: group A strep, mycoplasma pneumoniae, Neisseria gonorrhoea
Ix: rapid strep antigen test, throat culture
Common cold summary card
Clinical diagnosis, consider FBC, throat swab, sputum cultures, CRP, CXR if v v v bad
Causes include rhinovirus (50%), coronavirus (20%), influenza, parainfluenza, respiratory syncytical virus
Present w/ malaise, fever, headache, cough, sore throat, sneezing, runny/blocked nose
Needs supportive care, clears within 7-10 days but common complications include sinusitis, LRTI, acute otitis media
How may an abscess present?
Collection of pus built witin tissue, organ or confined space walled off by fibrosis
External
= skin (subcutaenous/cutaenous)
= erythema, pain, oedema, hot, loss of function
Internal
= perianal, incisional, lungs, brain, kidneys, tonsils etc
= systemically unwell, pain, fever
Ix and mx of abscess
Ix
= Hx, examination, obs, clinical diagnosis (skin), USS (internal)
Mx if uncomplicated skin/soft tissue
= aspiration, incision and drainage, no need for Abx
Mx if severe, multiple site, rapid disease progression, cellulitis, sepsis
= Abx (Staph. aureus main culprit), incision and drainage, excision in severe cases
A 30 yo lady on the HIV ward has white plaques all over her tongue that extend into her throat. She says it’s very painful to swallow. What is the most likely causative organism?
A Candida albicans B Epstein-Barr virus C Herpes Simplex Virus D Streptococcal throat infection E Human Herpes Virus 8
A Candida albicans
A 50 year old homeless man presents to A&E with purple purpural lesions on his back and on his gums. What is the most likely causative organism?
A HHV-2 B HHV-4 C HHV-5 D HHV-7 E HHV-8
E HHV-8
A 26 year old architect presents to GP with a history of sharp tingling around his lips followed by a painful ulcer on the side of his mouth. O/E he has cervical lymphadenopathy and a blister on his finger. What is the pathogen?
A Varicella Zoster Virus B Epstein-Barr Virus C Herpes Simplex Virus 1 D Herpes Simplex Virus 2 E Cytomegalovirus
C Herpes Simplex Virus 1
A 20 year old medical student presents with sore throat, headache, myalgia and coryzal symptoms. O/E she has cervical lymphadenopathy, enlarged exudative tonsils and splenomegaly. What is the most likely diagnosis?
A Varicella Zoster Virus B Epstein-Barr Virus C Herpes Simplex Virus 1 D Herpes Simplex Virus 2 E Cytomegalovirus
B Epstein-Barr Virus
A 20 year old medical student presents with sore throat, headache, myalgia and coryzal symptoms. O/E he has cervical lymphadenopathy, enlarged exudative tonsils and splenomegaly.
What is the most appropriate management?
A Rest at home, paracetamol B Amoxicillin C Acyclovir D Ceftriaxone E Vancomycin
A Rest at home, paracetamol
A 15 year old female patient presents to A&E with difficulty speaking. 4 days ago she experienced a sore throat, which progressively got worse. It’s now difficult for her to speak or swallow. She has not had a cough or cold recently.
O/E there is bilateral tonsillar exudate and the oropharynx is not erythematous. There are 3 tender swellings on the anterior border of the sternocleidomastoid muscle.
Her observations are: T 39.1, HR 90, BP 113/68, SpO2 97%
What is the most likely diagnosis? A Infectious mononucleosis B Viral tonsillitis C Common cold D Bacterial tonsillitis E Chickenpox
D Bacterial tonsillitis
- exudate present
Which of the following is the most common cause for herpes labialis?
A HSV-1 B HSV-2 C VZV D EBV E CMV
A HSV-1
A 6-year old girl presents with a fever of 38.5, fatigue and a maculopapular rash on her face and trunk. Other children at school present with similar symptoms. How should this patient be managed?
A Hydration and NSAIDs.
B Give oral acyclovir
C Consider oral valaciclovir if within 24 h of rash onset
D Paracetamol and Calamine lotion
E Vaccinate with Varicella Immunoglobulin
D Paracetamol and Calamine lotion
A 50-year-old man presents with a rash as seen in this photo. (dermatomal, vesicular rash)
Which of the following is NOT true?
A This condition is Shingles B May occur due to stress C The rash may present bilaterally D Tingling in a dermatomal distribution E The rash is painful
C The rash may present bilaterally
A wild medical student presents with sore throat and tonsillar exudates, posterior cervical lymphadenopathy and his basic observations are 38.9oC, HR is 90bpm and oxygen saturation on air is 99%. On examination there is splenomegaly. His condition is most likely due to which of the following?
A EBV B Streptococcus pyogenes C Adenovirus D Covid-19 E Candida
A EBV
A 42-year-old man, previously treated for pneumocystic pneumonia and oral ulcers, presents with a purple, purpural lesion on his nose. Which is the causative organism for this skin lesion?
A Staphylococcus Aureus B Malignant Melanoma C Human Immunodeficiency Virus D Human herpesvirus 6 E Human Herpesvirus 8
E Human Herpesvirus 8
A 47-year-old HIV positive patient presents with weakness of his right leg, headaches, fever and confusion that have been getting worse for the last week. CT head shows multiple ring-enhancing lesions. Which is the causative organism?
A Plasmodium falciparum B Neisseria meningitidis C Toxoplasma gondii D Herpes Simplex Encephalitis E Pox virus
C Toxoplasma gondii
- associated w/ cats
- occurs in immunocompromised
What is the most common causative agent for someone with a runny nose, sneezing and coughing (not during a pandemic)?
A Rhinoviruses B Coronavirus C Influenza D Parainfluenza E Respiratory syncytial virus
A Rhinoviruses
A 37-year-old presents with a lump on the posterior of his neck that is hot erythematous and painful. What is the most likely causative agent?
A Streptococcus pyogenes B Staphylococcus aureus C Mycobacterium Tuberculosis D Parasitic infection E Pseudomonas Aeruginosa
B Staphylococcus aureus
