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.
