Infectious Diseases Flashcards
What is gastroenteritis?
Inflammation all the way from the stomach to intestines presenting with nausea, vomiting and diarrhoea
What are the causative agents of viral gastroenteritis?
Rotavirus
Norovirus
Adenovirus
What is the spread, consequences and management of E. coli gastroenteritis?
Contact with infected faeces
Unwashed salads
Water
E. coli produced Shinga toxin which destroys blood cells and leads to haemolytic uraemic syndrome
Don’t give abs as it increases risk of HUS
What is the most common bacterial cause of gastroenteritis?
Campylobacter - Gram negative bacteria
Give the spread, symptoms and management of campylobacter gastroenteritis?
Raw or improperly cooked poultry
Untreated water
Unpasturised milk
Abdominal cramps
Diarrhoea ± blood
Vomiting
Fever
Azithromycin or ciprofloxacin
What is shingella?
Spread by faces contaminating drinking water, swimming pools and food.
Symptoms usually resolve within 1 week without treatment
Causes bloody diarrhoea, abdominal cramps and fever
Can produce Shinga toxin and cause HUS
What is Salmonella?
Spread by eating raw eggs or poultry
Symptoms usually resolve within 1 week
Watery diarrhoea ± blood or mucus, abdominal pain, vomiting
What is bacilllus cereus?
Gram positive rod that is spread through food that’s not refrigerated after cooking
e.g. rice
Vomiting within 5 hours
Diarrhoea within 8 hours
Resolution within 24 hours
What is Giardiasis?
Giardia lamblia is a type of microscopic parasite.
Faecal-oral transmission
Diagnosis = stool microscopy
Treatment = metronidazole
What is HIV
HIV is an RNA retrovirus
HIV-1 is most common type
Virus enters and destroys the CD4 T-helper cells
What is the transmission of HIV?
Unprotected anal, vaginal or oral sexual activity
Mother to child
Mucous membrane, blood or open wound exposure
What are some AIDS defining illnesses?
Kaposi's sarcoma Pneumocystis jirovecii pneumonia CMV Candidiasis Lymphomas Tb
What is the testing for HIV?
Antibody blood test - will only become positive 3 months following exposure
p24 antigen testing
PCR testing
What is the monitoring for HIV?
CD4 count
The lower the count, the higher the risk of opportunistic infections
500-1200 is normal
<200 considered end stage HIV/AIDS
What is the treatment for HIV?
antiretroviral therapies
Prophylactic co-trimoxazole for CD4 <200 to protect against PCP
What is the guidance for pregnant women with HIV?
C-section unless mother has undetectable viral load
Newborns to HIV positive mothers should recieve ART for 4 weeks after birth
Breastfeeding is only if viral load is undetectable
What is the post-exposure prophylaxis for HIV?
Truvada and ralltegravir for 28 days
combination ART
What is tuberculosis?
Infectious disease caused by mycobacterium tuberculosis.
Small rod shaped bacteria (acid-fast bacilli) stains red with Zeihl-Neelsen staining.
What is the presentation of tuberculosis?
Lethargy Fever or night sweats Weight loss Cough ± haemoptysis Lymphadenopathy Erythema nodosum Spinal pain
What are the investigations in tuberculosis?
Mantoux test = past infection
Ileal biopsy = active infection
Interferon-gamma release assay
CXR
Cultures
NAAT
What is the management for acute pulmonary tuberculosis?
RIPE
Rifampicine for 6 months
Isoniazid for 6 months
Pyrazinamide for 2 months
Ethambutol for 2 months
Isoniazid causes peripheral neuropathy so pyridoxine (Vitamin B6) is co-prescribed
What are the types that cause malaria?
Plasmodium falciparum (most common and severe)
Plasmodium vivax
Plasmodium ovale
Plasmodium malariae
What is the presentation of malaria?
Non-specific Fever, sweats and rigors Malaise Myalgia Headache Vomiting
Signs
Pallor due to anaemia
Hepatosplenomegaly
Jaundice
What is the diagnosis of malaria?
Blood film
3 samples are sent over 3 consecutive days to exclude malaria
What is the management of malaria?
ORAL:
- Riamet
- Malarone
- Quinine sulphate
- Doxycycline
IV:
- Artesunate
- Quinine dihydrocloride
What are antimalarials?
Proguanil and atovaquone (MALARONE)
Mefloquine
Doxycycline
What is the diagnosis of influenza?
Treatment started based on history and presentation
Viral nasal or throat swabs for PRC to confirm diagnosis
What is the management of influenza?
Public health monitor the number of cases
Antivirals for those with influenza at risk of complications:
Oral oseltamivir 75mg twice daily for 5 days
OR
Inhaled zanamivir 10mg twice daily for 5 days
Treatment started within 48hours of symptom onset
What is HPV?
Most common cause of cervical cancer.
Primary an STI
Which types of HPV cause cervical cancers?
16 and 18
What is in the HPV vaccine?
Gardasil which protects against 6, 11, 16 and 18.
6 and 11 causes genital warts
16 and 18 causes cervical cancers
What is keratitis?
Inflammation of the cornea
What are the causes of keratitis?
(most common) Viral: HSV
Bacteria: Pseudomonas or staph
Fungal: Candida or aspergillus
Contact lens
What is the presentation of keratitis/
Painful red eye Photophobia Vesicles around eye Foreign body sensation Watering eye Reduced visual acuity
What is the diagnosis of keratitis?
Fluorescein staining shows dendritic corneal ulcer
Slit-lamp = DIAGNOSTIC
Corneal swabs or scrapings
What is the management of keratitis?
Aciclovir
Ganciclovir
Topical steroids
Corneal transplant
What is lyme disease?
Caused by spirochaete Borrelia burgdorferi and is spread by ticks
What are the early features of lyme disease?
Erythema migrans:
- bulls-eye rash
- painless
Systemic features:
- headache
- lethargy
- fever
What are the late features of lyme disease?
AFTER 30 DAYS
CVS:
- heart block
- peri/myocarditis
Neruologicall
- facial nerve palsy
- radicular pain
- meningitis
What is the investigation and diagnosis of lyme disease?
Can be clinically DIAGNOSED if erythema migrans present
ELISA antibodies are first line
repeat 4-6 weeks after if still suspect
What is the management of lyme disease?
Doxycycline if early disease
Ceftriaxone if disseminated
What is the presentation of mumps?
Prodrome symptoms Parotid gland swelling Abdominal pain Testicular pain Confusion
What is the management of mumps?
Supportive
Which organism gives rise to syphilius?
Treponema pallidum
What is the management of C. diff?
- Oral vancomycin
- IV metronidazole
Fecal transplant
Most common pathogen for leg cellulitis?
Strep pyogenes
What is molluscum contagiosum?
Viral disease of skin transmitted sexual or non-sexually
What is the presentation of sexually transmitted molluscum contagiosum?
Multiple lesions on genitalia, lower abdomen and upper thigh
What is the diagnosis and management of sexually transmitted molluscum contagiosum?
Clinical diagnosis
No management required - self limiting
Which medication should be given to patients with CD4 count less than 200?
Co-trimoxazole prophylactically for PCJ pneumonia
What is the most common causative organism of cavitating pneumonias in the upper lobe?
Klebsiella
What is a common side effect after a viral gastroenteritis?
Transient lactose intolerance
