Infectious Diseases Flashcards
(32 cards)
TB risk factors
- HIV
- immunosuppression
- overcrowed living
- ethnic minorities
- malnutrition
- IVDU
- chronic lung disease
TB pulmonary presentation
- constitutional symptoms (weight loss, night sweats, fatigue, fever and chills)
- lymphadenopathy
- Cough ± haemoptysis
- SOB
- chest pain
Extra-pulmonary symptoms of TB
Neuro: meningisms
Opthalmology: blurred vision, red eyes
GU: dysuria, haematuria
GI: abdo pain, abdo mass
rheum: arthritis
osteo: osteomyelitis
How is TB diagnosed
- Sputum sample alcohol and acid fast bacilli (AAFB)
- Rapid PCR - immediate confirmation of species and early implication of rifampicin sensitivity
- Nucleic acid amplification tests (NAAT) rapid diagnosis of mycobacterium complex
What is the management of TB
Rifampicin 6/12 *red urine, CI OC*
Isoniazid 6/12 *perupheral neuropathy*
Pyrazinamide 2/12 *liver toxicity*
Ethambutol 2/12 *optic neuritis*
Contact screening
- mantoux test or interferon gamma release assay
- if +ve -> CXR
- if -ve 3/12 prophylaxis
what is multi-drug resistant TB
TB that is resistant to at least izoniazid and rifampicin normally due to poor compliance or incomplete courses
how is multi-drug resistant TB managed
combo of 5-8 drugs for up to 2 years
HIV transmission
- sexual
- vertical
- untreated risk 25-40%
- treated risk <1%
- C-section if mother has detectable viral load at birth
- needles
- blood products
HIV pathology
*RNA retrovirus*
- virus becomes part of host cell
- transcriptase enzyme transcripts RNA-> DNA
- Integrase integrates virus DNA into hosts
- host cells produces/releases virons (cleaved by protease)
- Virons infect any cells with CD4 receptor by binding with GP120 glycoprotein
- CD4 receptor cells now release virons
- infection progressed, CD4 cells destroyed, reduced host immune system
Which cells have CD4 receptors?
T cells, macrophages, monocytes, neurons
How is HIV diagnosed?
- serology for antibodies and antigens at 4 weeks (2-3 weeks where tests will be -ve because no Ab response yet)
- P24 antigen
- IgG and IgM
HIV monitoring
CD4 normal range 450-1600
Viral Load = quantity of virus in serum
Undetectable VL = Untransmittable disease
HIV Management
2 NRTI + NNRTI OR PI
NRTI (nucleoside reverse transcriptase inhib)- zidovudine, abacavir
NNRTI (non-NRTI)- nevirapine, etravirine
PI (protease inhib)- indinavir, lopinavir
HIV prophylaxis
PrEP - pre exposure prophylaxis
- Truvada
- daily or when needed 12 hours before sex
PEP - post exposure prophylaxis
- Truvada
- given to pt after high risk exposure for 4 weeks
- follow up test
What is truvada
tenofovir and emtricitabine
When does a person have AIDS
when their CD4 count is less than 200 or presence of an aids defining condition
AIDS defining conditions
Resp: TB, PCP
Gastro: persistent cryptosporidiosis
opthal: CMV retinitis
Malig: Kaposis sarcoma, non-hodgkins lymphoma, cervical cancer
Neuro
- cerebral toxoplasmosis
- primary cerebral lymphoma
- crytococcal meningitis
- progressive multifocus leucoencephalopathy
AIDS management
Co-trimazole - PCP, toxoplasma, bacterial infection
pentamidine - PCP
azithromycin - Mycobacterium Avium Intracellulare
ganciclovir - CMV
Hepatitis transmission
B- vertical, sexual, blood, needles
D- blood and body fluids
C- blood and body fluids
A - faeco-oral
E- faeco-oral (water)
Hep B presentation
fever
malaise
upper abdo discomfort
jaundice
can be asymp then cirrhosis and liver failure
Hep C presentation
85% asymptomatic/mild symptoms forllowing infection (develop chronic HCV: also asymptomatic or nonspecifc - malaise, fatigue, RUQ pain)
15% malaise, nausea, RUQ pain, jaundice (more likely to clear disease)
Presentatio of Hep A
anorexia, nausea, jaundice
presentation of hep E
abdo pain, jaundice, fever, fatigue
Diagnosis of hep C
enzyme immunoassay -> immunoblot assay
if +ve confirmed by HCV RNA test by PCR
