Infectious diseases 1 Flashcards
Give the transmission route and clinical presentations of the following Human herpes viruses
- Herpes Simplex V1
- Herpes simplex V2
- HSV1: respiratory, saliva: gingivostomatitis, keratoconjunctivitis, herpes labialis, temporal lobe encephalitis
- HSV2: Sexual contact, perinatal: genital herpes, neonatal herpes
Give the transmission route and clinical presentations of the following Human herpes viruses:
- Varicella Zoster
- Epstein-Barr
- Cytomegalovirus
- HHV-8
- VZV: Respiratory: chicken pox, shingles
- EBV: saliva-“kissing disease”: mononucleosis (associated with lymphomas, nasopharyngeal carcinoma).
- CMV: congenital, sexual, saliva: mononucleosis (immunocompromised)
- HHV-8: sexual contact: Kaposi sarcoma (immunocompromised patients).
Give 6 features of HSV-1 presentation.
- Gingivostomatitis, cold sores (herpes labialis): ulcers with yellow slough near mouth
- Herpetic whitlow: blisters on fingers
- Eczema herpeticum
- Herpes simplex meningitis, encephalitis
- Systemic infection: fever, sore throat, lymphadenopathy
- Keratoconjunctivitis: watering eyes, photophobia
Give 5 features of HSV2 presentation.
- genital herpes- chronic, life long: flu-like prodrome, vesicles/ papule around genitals, anus
- Shallow ulcers
- urethral discharge
- dysuria
- fever and malaise
HSV has a latent phase and a lytic phase.
When may herpes simplex virus reactivation occur?
What is the management of HSV?
- Stress and immunosuppression.
- Topical, oral or IV acyclovir
What time period is someone with chickenpox contagious?
- Give 3 features of of shingles presentation.
- Contagious from 48h before rash and until all vesicles have crusted over (7-10 days)
Shingles: - Shingles may occur due to stress.
- Initial tingling in dermatomal distribution
- Followed by painful skin lesions
Give 3 symptomatic treatments for chickenpox in children.
Give 1st and 2nd line treatment for shingles if within 72 hours of rash appearance.
Chicken pox: 3 As
- calamine lotion- alleviate itch.
- Analgesia
- Antihistamines
Shingles;
- 1st: Valaciclovir or famciclovir
- 2nd: acivlovir
Which virus causes infectious mononucleosis aka glandular fever.
Give 4 features of infectious mononucleosis presentation.
- EBV
- Fever
- Hepatosplenomegaly- jaundice
- Pharyngitis- tonsilar exudates
- lymphadenopathy- posterior cervical nodes.
What is the pathogenesis of infectious mononucleosis?
- EBV attaches to throat epithelium, causing pharyngitis
- Virions escape lymph nodes, travel to blood stream
- Either productively infect or latently infect B cells
- Infected B lymphocytes actively replicate, produce random immunoglobulins including heterophile antibody
- T cells destroy lymphocytes replicating EBV but not latently infected cells.
What would be seen in the following investigations for infectious mononucleosis?
- FBC
- Blood film
- Monospot test
- Antibodies
- real time PCR
- FBC: lymphocytosis highest in week 2-3
- Blood film: atypical lymphocytosis
- Monospot test: heterophile antibodies
- EBV specific antibodies
- PCR: EBV DNA
Give 2 management steps and 1 contraindication in treatment of infectious mononucleosis.
- Supportive care: paracetamol or ibuprofen
- Corticosteroids for severe cases, e.g. haemolytic anaemia, tonsillar swelling, obstructive pharyngitis.
- Amoxicillin or ampicillin is CONTRAINDICATED due to widespread maculopapular rash.
Most cases make uncomplicated recovery 3 days- 3 weeks
Differentiate the following EBV specific antibody tests:
- VCA IgM positive
- VCA IgM and IgG positive
- VCA IgG and EBNA IgG positive
Early primary infection: VCA IgM positive
Acute primary infection: VCA IgM and IgG positive
Past infection: VCA IgG and EBNA IgG positive.
IgG: GONE. IgM: NOW.
VCA: viral capsid antigen
EBNA: Epstein Barr nuclear antigen
Which group of micro-organisms does HIV infection give susceptibility to?
- What is hairy leukoplakia?
- Encapsulated organisms: streptococcus pneumonia and haemophilus influenzae
- Hairy leukoplakia: irregular white painless plaques on lateral tongue, cannot be scraped off. HBV mediated. Occurs in HIV positive patients, organ transplant recipients.
What types of candidiasis are caused by the following risk factors?
- Immunocompromised
- Diabetes, use of antibiotics
- Babies
- IV drug users
- Neutropenic patients
- Oral candidiasis and oesophageal thrush- immunocompromised.
- Vulvovaginitis- diabetes, use of antibiotics
- Diaper rash- babies
- Infective endocarditis- IV drug users
- Disseminated candidiasis (systemic)- neutropenic patients
Give 3 features of disseminated candidiasis.
What locations is it disseminated to?
Why are swabs not recommended for Candida Albicans?
- Fever, hypotension, leucocytosis.
- Retina, CNS, liver, spleen, bones, kidney
- Candidal organisms found in healthy people- 30-45% if adults. 45-65% healthy children.
What is the management for oral candida?
What the management for vulvovaginitis?
- Miconazole and nystatin suspension.
- Intravaginal anti fungal cream- azole or oral antifungal.
Which virus is Kaposi’s sarcoma caused by?
Which condition is it indicative of?
How does it present?
- Caused by HHV8
- It is an AIDS defining condition.
- Pink/ violaceous (purple) patch on skin or in mouth.
Which cancers is HPV linked to?
- How is HPV spread?
- How does it present in most people?
Give 1 other HIV associated tumour other than Kaposi’s sarcoma.
- Cervical and anal squamous cell carcinoma
- Sexual contact
- Genital warts in most people.
Lymphoma
Give first 3 first line investigations for HIV.
What CD4 count defines AIDs?
What serum viral load is diagnosis of HIV?
What is the most commonly used assay to investigate HIV?
- ELISA confirmed with Western blot.
- Serum HIV rapid test
- Serum HIV DNA PCR- infants- more expensive.
CD4 <200 cells/ml
Viral load >1000 copies/mL is confirmed diagnosis.
Combined HIV antibody and p24 antigen assay: tests for HIV-1, HIV-2 and HIV p24 antigen
Give the 3 most common viral causes of tonsillitis.
Give 3 bacterial causes of tonsillitis.
Give 2 extra-oral signs of tonsillitis.
- Rhinovirus, coronavirus, adenovirus.
- Group A streptococci, Mycoplasma pneumoniae, Neisseria Gonorrhoea.
- Anterior cervical lymphadenopathy, fever >38.
Give 3 complications of the common cold.
Give 3 most common viruses that cause common cold.
Give 3 common respiratory tract bacteria.
- Lower respiratory tract infection, sinusitis, acute otitis media.
- Rhinovirus (50%), Coronavirus (10-15%), Influenza (5-15%).
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
What is most common causative pathogen of abscesses?
What are the 3 management steps of uncomplicated skin/ soft tissues abscess?
What are 4 management steps of severe abscess/ multiple sites of infection etc.
Staphylococcus aureus.
- AID: Aspiration, incision and drainage.
- AIDES: Antibiotics, incision and drainage, excision in severe cases.
Give examples of the following
- Gram positive cocci (3)
- Gram positive bacilli (2)
- Gram negative cocci (2)
- Gram negative bacilli
Gram positive cocci: Streptococcus, Staphylococcus, Enterococcus
Gram positive bacilli: Clostridium, Listeria
Gram negative cocci: Neisseria, Haemophilus
Gram negative bacilli: Most EMQ bacteria not already mentioned (Salmonella, Shigella, Pseudomonas, Legionella, Vibrio
Give 5 major nosocomial infections.
- MRSA
- VRE: Vancomycin resistant enterococcus
- ESBL: extended spectrum beta-lactamase producing bacteria. E. Coli and Klebsiella
- Pseudomonas
- Acinetobacter
