Infectious Diseases Flashcards
By which means can HIV be transmitted?
Sexual fluids
Blood
Breast milk
How can HIV be prevented?
Condom use
Post exposure Prophylaxis:
- short term antiviral therapy given immediately after exposure. Given up to 72 hours.
Pre exposure prophylaxis:
use of antiretrovirals in high risk groups
Antiviral use in pregnancy to avoid vertical transmission
How does primary HIV infection usually present?
2-12 weeks following exposure.
- flu like symptoms
- erythematous/ maculopapular rash
- lymphadenopathy
- pharyngitis
- Diarrhea
How is HIV tested for?
ELSIA for p24 antigen
ELSIA for HIV antibody
**both these are diagnostic
Rapid point of care testing: swap from mouth or finger prick
- require serological confirmation
Viral load
PCR of viral load
CD4 count
- this is not diagnostic but is used as marker to establish how the immune system is coping.
<200 is AID defining
If an asymptomatic patient has a negative result for HIV, what should be done next?
A repeat of test 12 weeks later
- by 3 months a 99% of people with HIV will have created antibodies towards the virus
What are some of the common opportunistic infections in HIV?
Pneumocystis Jirovecii
- progressive SOB
- Dry cough
- co-trimoxazole
Candidiasis
- odynophagia
- dysphagia
- fluconazole
Cryptococcus Neoformans
- meningitis
- molluscum papules
- lung disease
- Amphotericin
Toxoplasma Gondii
- intracranial mass
CMV
- retinitis
- encephalitis
- G.I disease
Cryptosporidium
- watery diarrhoea
- Pancreatitis
- Cholangitis
- supportive
Kaposi Sarcoma:
- HHV-8
- chemotherapy
Lymphoma
- Burkitt’s’
In which disease should an HIV test also be done?
TB
Hep B and C
Lymphoma - namely NHL
What are some differentials for HIV?
infectious mononucleosis
- EBV
Secondary syphilis
Viral infections
Drug allergy
Which sexually transmitted infections do not cause discharge but only a lesson, and divide these into painful and painless lesions:
Painless
- treponema pallidum - chancre lesions
- Condyloma accumulata (HPV virus)
- Granulomatosis inguinal (Klebsiella)
Painful:
- herpes
- lymphogranulomatous venereum
What are the stages of treponema pallidum:
Primary Syphilis:
- painless chancre
- high infectious
Secondary dissemination
- maculopapular rash - palms and central body
- condyloma lata (raised pale plaques)
- fever
- headache
Tertiary:
- neurosyphilis
- aortitis
- Argyll robertson pupil
What are the swollen lymph nodes in lymphogranulomatous venereum called?
Bubo’s nodes
- swollen abscess nodes that can burst
How is bacterial vaginosis diagnosed and what is the bacteria?
Gardnerella Vaginosis
Gram staining:
- clue cells
pH >4.5
Treatment:
metronidazole
What types of antiretroviral treatment is available for HIV? and when should it be started?
CCR5 antagonist
Nucleotide reverse transcript inhibitors
Non - Nucleotide reverse transcript inhibitors
Protease inhibitors
Integrase inhibitors
**everyone HIV positive should be started on HAART regardless of CD4 count.
What does a septic screen all include?
FBC Inflammatory markers - ESR, CRP Urine cultures Sputum Blood cultures Microbiological swaps CXR
- stop all biotics if possible before doing so
- echo if new murmur
- check sickle cell status
- LP if CNS symptoms
Which extremely infectious disease is characterised by greyish white spots on the buccal mucosa? and what are these lesions called?
Measles
Koplik spots
What are some complications of measles?
Otitis media
Pneumonia
Acute Demyelinating Encephalitis
Conjunctivitis
> 10 years later:
- Subactue sclerosing panencepahalitis
Scarlet fever, name some of the characteristic findings, complications and how is it treated?
Scarlet fever
- caused by strep pyogenes (group A)
Symptoms:
- pharyngitis
- Maculopapular rash starting on the neck and spreading across body predominantly affecting flexures (spares palms and soles)
- White coat with large papilla seen on tongue (strawberry tongue)
Complications include:
- glomerulonephritis - Post strep
- Peritonsillar abscess
- Rheumatic fever
- Otitis media (and its complications)
Treatment:
Penicillin V
What high contagious infection which presents with erythematous macular rash and lymphadenopathy can be dangerous to pregnant women? what are the complications in pregnancy?
Rubella
Highly dangerous during the 1st trimester
Congenital rubella syndrome:
- neurosensory deafness
- cataract formation
- congenital heart disease - patent ductus arterioles
What is the classification system used for cellulitis and when should surgery be indicated?
Enron classification
1 - no signs of systemic toxicity and controlled comorbidities
2 - systemically unwell or as comorbidities which may complicate
3 - Shock or comorbidities which are interfering with treatment
4 - Septic or Nec Fas
*Eron Classification 4 = surgery
What investigations should be done into cellulitis?
Bloods:
- FBC
- CRP
- Blood cultures (if pyrexial)
- D-dimer? - not so useful in acute infections often
Skin swabs
- MRSA
Ultrasound
- exclude DVT
What is the broad management of Necrotising fasciitis?
IV antibiotics
Urgent surgical review
What is the antibiotic management for cellulitis?
Enron <2
Oral:
- Flucloxacillin
or if penicillin allergic: Doxycycline
Enron >2
- IV Flucloxacillin
or
- Vancomycin
What must be present for a diagnosis of acne vulgaris to be made?
Comedones Papules Pustules \+ Erythema
Severe:
Nodules
Cysts
Which pneumonia presents with flu like symptoms and a dry cough, and on bloods may demonstrate hyponatremia?
Legionella
If a pregnant woman has positive urine cultures but is asymptomatic what is the management?
Antibiotic therapy
- always treat a pregnant female. it can quickly progress to pyelonephritis
Nitrofurantoin is the antibiotic of choice.
If a pregnant woman had pyelonephritis it would be co-amoxiclav
If a pregnant woman comes into contact with some with erythema infectiosum what should be done, what is this disease also known as and what are the typical appearances?
Also known as fifths disease, or slapped cheek syndrome.
Pregnant woman:
Immediate IgM and IgG antibodies in the mother.
USS of foetus
- fetus hydrops
- increased risk of spontaneous miscarriage
Signs of a child with erythema infectiosum:
- fever
- bright red cheeks
What are the anti-malaria regimes that can be given?
Atovaquone + Malarone = 7 days before
Chloroquine = 4 weeks before
Doxycycline = 4 weeks before
Mefloquine = 4 weeks before
Name some hospital acquired pneumonia causing bacteria:
E. Coli
Klebsiella pneumonia
Acinetobacter species
Staph aureus
When is staph aureus most likely to cause pneumonia?
Following Influenzas infection
ICU patients
How does Pneumocystis jiroveci present?
Dry cough
High fever
Breathlessness
Big drop in saturations during exercise
*with a clear chest
What organisms can cause TB?
Mycobacterium tuberculosis
Mycobacterium Bovis
Mycobacterium Africanum
Mycobacterium microti
What skin manifestations can be seen with TB?
Lupus Vulgaris
Erythema nodosum
Scrofuloderma
A patient receives treatment for syphilis, and shortly after develops a fever, rash and becomes tachy. there is no wheeze or sign of airway disruption. what has happened?
Jarisch-Herxheimer reaction
- release of endotoxins
What is the new guidelines with regards to gonorrhea treatment?
IM ceftriaxone
Which infectious diseases can cause low platelets?
malaria
Dengue fever
HIV
Typhoid
Severe sepsis
Which patients are at risk of developing staph aureus bacteremia?
IVDUs
Indwelling IV lines
- cannulas
Patient’s with complicated skin disorders
What is the definition of septic shock?
Sepsis induced hypotension requiring Inotropic support that is unresponsive to adequate fluid resuscitation within 1 hour.
Systolic <90mmHg
or
Reduction of >40mmHg from baseline
How quickly should neutropenic patients be assessed once presenting?
Within 15 mins
What antibiotics should be given for ascending cholangitis?
Amoxicillin \+ Gentamicin \+ Metronidazole
What extrapulmonary symptoms may be present in TB?
Systemic features
Gastro-intestinal:
- coliky pain
- Adhesions/ bowel obstructions
Lymphadenopathy:
- painless cervical enlargement
- sinus formation
CNS TB:
- focal neurological signs
Skin:
- Lupus vulgaris - apple jelly nodules
Miliary TB:
Millet formation throughout the lung
What are the risk factors for TB?
Being around someone with TB
HIV infection
TNF alpha inhibitors
Overcrowding
- prisons
Homeless
What are the two tests that can be done to diagnose latent TB?
Mantoux test
Interferon Gamma Release Assays
- used to confirm
What drug should be prescribed alongside the treatment for TB?
Pyridoxine
- vitamin B6
this is to help protect against the adverse effects of isoniazid
How is pneumocystis jirveco treated?
Co-trimoxazole
How is MRSA Eradicated from skin or mucosal membranes?
Nasal Mupirocin
Chlorhexidine gluconate 4% scrub
How should a patient with Staph Bacteremia be treated?
Flucloxacillin
or
Vancomycin
Investigate:
- echo
- possible sources of infection
replace intravascular devices
Contact microbiology
Complete Staph Aureus Bacteremia sticker
What is the characteristic rash of measles? How is measles treated?
Maculopapular rash that begins on the head> neck> trunk
Treatment:
- supportive
- vitamin A
Immunocompromised:
- immunoglobulins
Vaccine- MMR
What is a clinical finding of mumps?
Tender swelling of glands
- namely parotid
What are some complications of Mumps?
Pancreatitis
Meningoencephalitis
Epididymo-orchitis
What type of rash appears following a tick bite?
Erythema Migrans
How is Mononucleosis tested for?
Monospot test
- can be false positives in pregnancy and haematological disease
Reverse transcriptase PCR
Blood film
- atypical lymphocytes
How do tapeworms present, how are the diagnosed and how are they treated?
Mild G.I symptoms. (usually well adapted to not cause symptoms)
Tape worm segments in stool
Investigations:
- eggs/ segments in faeces
Treatment:
- anthelmintic agents - Niclosamide
What are the symptoms, diagnostic tests, treatment of toxoplasmosis?
Toxoplasma Gondii
- 1/3rd of population infected
Symptoms:
*usually asymptomatic in immunocompetent
- bilateral lymphadenopathy
- fever
- hepatosplenomegaly
complication:
- encephalitis
- retinitis
- hepatitis
Investigations:
- serology
- PCR
Treatment:
- pyrimethamine + sulfadiazine + folinic acid
- steroids if eye disease
Prophylaxis: co-trimoxazole
List some causes of viral haemorrhagic fevers:
Ebola (Filovirus)
Crimean Congo fever (Bunyavirus)
Rift Valley fever (Bunyavirus)
Dengue fever (flavivirus)
Yellow fever (flavivirus)
What is the management of cholera?
Diagnostics:
- rapid dipstick testing
Management:
- Oral rehydration salts
- IV fluids - if severely dehydrated
- Zinc for children - reduces course of disease
Antibiotics if absolutely needed - doxycycline or azithromycin in pregnant
If a patient has genital herpes and is pregnant how should they be managed?
Aciclovir and C -section if primary infection occurs >28 weeks
If secondary infection then Aciclovir throughout pregnancy
What vaccine should be offered to Hepatitis patients?
Pneumococcal vaccine
When should you suspect Ebola and how should the patient be managed?
Fever and recent visit to epidemic area.
Isolated.
What pathogen is most associated with gangrene?
Clostridium Perfringens
*causes gas gangrene
What disease does Parovirus B19 cause?
Erythema Infectiosum
Which type of pneumonia is associated with reactivation of cold sores?
Strep Pneumonia
What are some of the complications of Hep C?
Rheumatological problems
Cirrhosis
Hepatocellular cancer
membranous proliferative glomerulonephritis
What is the management of Hep C?
Direct acting antivirals
- protease inhibitors combination - triple therapy
Sustained viralogical response - in which HCV is undetecacble after 6 months
How is Hep C diagnosed?
HCV PCR
HCV Serology
- autoantibodies
What is the most appropriate antibiotic for campylobacter?
Clarithromycin
What cancers is EBV associated with?
Burkitt’s Lymphoma
Hodgkin’s lymphoma
Nasopharyngeal
What is the single best step to reducing spread of MRSA?
Hand hygiene
What are the parameters of qSOFA?
Reduced GCS
Breathes >22
Blood pressure <100
How is chlamydia and gonorrhea tested for?
Males:
- first pass urine
+/- anal and throat swabs
Females:
- Vulvovaginal swabs
- Endocervical swabs
NAAT test
What examinations should be done into suspected STI?
Visual inspection of the genitals - retract foreskin
scrotal tenderness/ scrotal enlargement
Speculum of cervix
Bimanual examination of uterus
- for pain/ enlargements/ adhesions
What common investigations do you want to consider in a traveler returning with a fever?
Malaria thick and thin blood films
or
Rapid diagnostic testing
HIV test
FBC
- Lymphopenia - viral infection?
- eosinophilia - parasitic infection
LFTs
- hepatitis?
Blood cultures x 2
In malaria, how many samples do you send and over how many days and why is this?
3 samples sent over 3 consecutive days. This is due to the life cycle of malaria being released every 48 hours.
What are the complications of malaria?
Severe haemolytic anaemia
- urinalysis will show haemoglobinuria and haemasideruria
Cerebral malaria
- seizures
DIC
Seizures
AKI
Pulmonary oedema
Which drugs can be given prophylactically for malaria?
Non- drug resistant:
- chloroquine
- lots places are chloroquine resistant
- not suitable for epileptic suffers
Drug resistant:
- mefloquine
- doxycycline
*mefloquine contraindicated in psychosis
What are the symptoms of malaria P.Falciparum and what would you expect to see on blood results?
Headache malaise Nausea, vomiting Diarrhea Fever
Jaundice - haemolysis
Hepatosplenomegaly
Bloods:
- thrombocytopenia
- Low haemoglobin
What operation may increase the risk of malaria?
Splenectomy
What do the thick and thin blood films in malaria need to be stained with?
Giemsa staining
What other test out with thick and thin blood smears may done to diagnose malaria?
Plasmodium LDH can be detected
What is the treatment of P. Falciparum?
Artesunate - for severe (>2% parasitaemia)
or
Artemisinin Based Combination Therapy
IV fluids
Correction of electrolytes
Acid Base management
Correction of complications
What is the management for Non Falciparum infections?
Oral chloroquine
Doxycycline
What clinical features may be seen in HIV?
Skin:
- maculopapular rash
- Kaposi’s sarcoma
- Molluscum contagiosum
Oropharynx:
- gingivitis
- oral thrush
- oral hairy leukoplekia
Neck:
- lymphadenopathy
Eyes
- HIV retinopathy
CNS:
- Progressive multifocal leukoencephalopathy
- Toxoplasmosis - localising signs
Chest
- Pleural effusion
- TB
Abdomen
- Hepatosplenomegaly
Renal:
- HIV associated Renal disease
Anogenital:
- Anal cancer
- HSV
What additional test should be done when investigating someone for HIV?
Hepatitis serology STI screen - include syphilis Mantoux test for TB FBC LFTs U&Es
What is the natural history of HIV?
Primary infection *high viral load, low CD4
- 2 weeks following exposure.
- Fever
- maculopapular rash
- Lymphadenopathy
- Bell’s palsy
- D&V
- Oral genital ulceration *
Chronic/ Asymptomatic phase: *viral reduces, CD4 increases slightly
- average 9-12 years
Minor HIV associated disorders: Viral load increases, CD4 starts to drop
- Oral candidiasis
- Hairy leukoplakia
- Recurrent infections
- TB** - biggest killer
- kaposi’s tumour
AIDS syndrome: high viral load, CD4 <200 Aids defining illnesses - PJP - HIV wasting syndrome - Cerebral toxoplasmosis - Chronic herpes oral ulcers - Primary cerebral lymphoma
What common mucocutaneous diseases occur in HIV?
Mollucusum Contagiosum Secondary syphilis Kaposi's Psoriasis - becomes worse HSV infection Seborrhoeic dermatitis
What is the underlying cause of Kaposi sarcoma?
HHS - 8
How does progressive multifocal leukoencephalopathy present?
Stroke like episodes
Cognitive impairment
*caused by the JC virus
In cognitive impairment in AIDS what should you think?
HIV associated neurocognitive disorders (dementia)
Depression
Neurosyphilis
What is the most common cause of meningitis in AIDS?
Cryptococcus Neoformans
Amphotericin B is treatment
What would you expect to see on the blood work of an HIV patient?
Pancytopenia, normocytic normochromic anaemia
- HIV and the cytokines induces impaired haematopoiesis
What are the aims of ART in HIV?
To reduce the viral load to an undetectable level, reduce clinical progression and reduce mortality
Reduce HIV transmission
In low income countries where choice isn’t available what does the WHO recommend as a starting point for ART therapy in HIV?
2 Nucleotide reverse transcriptase inhibitors (backbone)
+
1 Non - Nucleotide reverse transcriptase inhibitor
What are some of the side effects of ART therpay?
Immune reconstitution inflammatory syndrome
- immediate. steroids treat
- a reaction that occurs as the immune system recovers and detects all these underlying infections
Lipodystrophy
- abnormal fat distribution
Rashes
Insomnia
Neuropsychiatric
What is the classical symptoms seen in HSV-1 initial infection?
Fever
Sore throat
Oropharyngeal vesicles
These are the symptoms of Gingivostomatitis
What are some of the complications of Herpes simplex virus?
Eczema herpticum
Herpes keratitis
- corneal scarring and vision loss
Meningitis
Bell’s Palsy
Immunocompromised host:
- Encephalopathy
- hepatitis
- Retinitis
When would HSV-1 require diagnostic testing?
In signs of complications: tests include: - PCR from swab - Serology markers - Immunofluorescence
What are some differentials to HSV-1 and 2?
HSV-1
Contact dermatitis
Crohn’s disease - Oral lesions
HSV-2:
- Chancroid
- Syphilis
- Lymphogranuloma Venereum
What are the complications of Shingles?
Postherpetic neuralgia
- Gabapentin
- amitriptyline
Herpes zoster Opthalmicus
- V1 branch affected
Ramsay Hunt syndrome
Encephalitis
Bladder dysfunction
- if sacral nerves affected
How is CMV treated?
Ganciclovir
What are some of the complications of flu?
Otitis media
Pneumonia
- Secondary bacterial Staph infection
- viral pneumonia
Febrile convulsions
Encephalitis
Reye Syndrome
- Encephalopathy + Fatty degenerative liver disease
- typically affects children recovering from the flu
What is the treatment for influenza and who gets it?
Oseltamivir - oral
Zanamivir - nasal inhaled
Chronic disease Immunosuppressed Pregnant <6 months BMI >40
*drugs should be given 48 hours after symptom onset.
What vaccines are given for flu and who gets them?
Live attenuated
- 2- 17 years old
quadrivalent inactivated
- 17 - 64 years old
Trivalent inactivated
>65 year old
What causes epiglottitis, how should it be managed and why is it rarely seen?
H.Influenza infection
Ceftriaxone
+
Clindamycin
Vaccine
- Hib Vaccine
How does bronchiolitis present, what are the investigations and what is the treatment?
Respiratory syncytial virus
Coryza symptoms Low grade fever Wheeze Inspiratory crackles Apnoea Poor feeding
Diagnostic:
- Nasopharyngeal aspirate
other things to consider:
- ABG/ VBG
- FBC
- CRP
Management: - supportive - Supportive feed (NG tube) - supplement oxygen \+/- - nebulized adrenaline (controversial)
Ribavirin - can be used for congenital heart disease/ lung disease patients.
What is the treatment of chlamydia and treatment of N. Gonorrhoeae?
Chlamydia - Doxycycline
N. Gonorrhoeae: - Ceftriaxone
What are some poor prognostic factors for malaria?
Increased age
Elevated serum lactate
Elevated schizonts in the blood
