Infectious Disease Flashcards
What is HIV and when was it first recognised?
Human immunodeficiency virus
1984
When has treatment for HIV been available since?
1996
How many people are living with HIV now worldwide?
37 million people
How many people are living with HIV in the UK now? How many are undiagnosed?
100 000
18000 undiagnosed
How many new diagnoses of HIV are made each year in the uk?
6000 a year, mainly 20-39 year olds
What is the mortality of HIV if diagnosed late when CD4 count is less than 100?
8% at 1 year
What is the mortality rate of HIV when diagnosed early, when CD4 count is more than 200?
0.5% mortality at 1 year
What is normal CD4+ T cell levels and what is it when opportunistic infections arise?
500+ normal
When should you be tested again for HIV if risk of exposure?
Test when exposed and 3 months after
Who should be routinely tested for HIV?
Men who have sex with men IV drug users Pregnant women Anyone with another STI/partner has STI From a country of high prevalence or partner from that country
Indicators for HIV testing?
Any opportunistic infection Pneumonia Blood disorders Weight loss Shingles Lymphadenopathy
Name the 5 most common opportunistic infections
Seroconversion illness Pneumocystis jirroveci pneumonia (PCP) Toxoplasmosis gondii Kaposi's sarcoma Tuberculosis
What is seroconversion illness also called?
Acute HIV syndrome
Similar to glandular fever
Can drop CD4+ counts low enough to get infections
What is the commonest opportunistic infection in the UK?
Pneumocystis Jirroveci pneumonia
Signs and symptoms of PCP pneumonia? Treatment?
Subacute insidious onset of breathlessness, fever, cough
Progressive hypoxia
Treatment= co-trimoxazole +/- steroids
Toxoplasmosis gondii
Protozoan parasite
May be latent and reactivated when immunocompromised
Space occupying lesion in brain
Treated with sulfadiazine and pyrimethamine
Kaposi’s sarcoma
AIDS associated cancer
Vascular tumour of spindle cells -> dark red pigmented lesions
Skin and viscera
Driven by co-infection with HHV-8
What is the most common complication of HIV worldwide?
TB
Who should be giver ART?
All people with HIV at any CD4+ count
-> prevents onward transmission, extends life and improve health
What is PrEP and who should be on it?
Pre-exposure prophylaxis
Anyone at substantial risk of HIV
(serodiscordant couples, sex workers, injecting drug users, men who have sex with men/transgender women, transgender people, prisoners)
What is a community acquired infection?
An infection contracted outside of a healthcare setting, or present
Why is it important to know if an infection is community or hospital acquired?
Different organisms and resistance patterns
Community cases are a potential marker for developing outbreaks
What is the most common community and hospital acquired cause for pneumonia?
Comm: Strep pneumonia
Hosp: Gram -ve E.coli/Klebsiella
What is the most common community and hospital acquired cause for meningitis?
Comm: Strep pneumonia
Hosp: Gram -ve E.Coli/Klebsiella
What is the most common community and hospital acquired cause for UTI?
Comm: E.coli
Hosp: E. coli
What are the main infective organisms for hospital acquired infections?
Gram -ve E.coli and Klebsiella
Pseudomonas
Staph aureus
What are the 2 main infective organisms for community acquired infections?
Strep pneumoniae
Haemophilus influenzae
Signs and symptoms of meningitis
Headache, neck stiffness, photophobia CSF raised WCC and raised protein Meningeal enhancement on CT Sepsis? Rash (in neisseria meningitis)
What is the most common cause of meningitis in the young versus old
Viral in young
meningococcal if older
Why is travel history useful in meningitis presentation?
Tick borne encephalitis
West nile virus
Lyme’s disease
Treatment of meningitis?
Stabilise airway, breathing, circulation Intensive care? Senior review? GCS documented Blood cultures and nasopharyngeal swab LP if not shock or sever sepsis Start treatment (antibiotics) Fluid resus if septic
If CSF us cloudy/purulent, what is likely?
Bacterial meningitis
If CSF is viscous and clear/opaque what is likely?
TB meningitis
If CSF is clear, what is likely?
Viral meningitis
If CSF >90% neutrophils present and low protein, what is likely?
Bacterial meningitis
If CSF has few neutrophils plus low protein what is likely?
Viral meningitis
if CSF has high protein and low glucose, what is likely?
TB meningitis
What antibiotics usually treat bacterial meningitis?
Ceftriaxone/Cefoxione IV
If meningitis is penicillin resistant pneumococci?
Add vancomycin IV
Complication of meningitis infection?
Subdural empyema
Seizures
Hydrocephalus
Central venous sinus thrombosis
