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
