Infectious Disease Flashcards
What is the treatment of choice for gonorrhoea?
Intramuscular ceftriaxone
How do we cover for animal or human bites?
Co-amox
How do we treat bacterial vaginosis?
Metronidazole 400mg BD for 7/7
A 30-year-old who is currently 27 weeks pregnant comes to see you about a thin, white discharge. Swabs are taken and clue cells are seen on microscopy. Dx?
Bacterial vaginosis
What is a disulfiram-like reaction?
The combination of metronidazole and ethanol can cause a disulfiram-like reaction. Clinical features of this include head and neck flushing, nausea and vomiting, sweatiness, headache and palpitations.
Which bacteria is often seen in under-re-heated rice?
Bacillus cereus
Which type of vaccine are contraindicated in HIV positive patients?
Live attenuated, e.g. TB, Yellow fever
Oral polio
Intranasal influenza
Varicella
Measles, mumps and rubella (MMR)
How do we treat trichomonas vaginalis?
oral metronidazole
What is trichomonas vaginalis?
Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis, a sexually transmitted infection. Metronidazole is an antiprotozoal medication used to treat infections caused by protozoa such as Trichomonas vaginalis. It works by inhibiting nucleic acid synthesis by disrupting the DNA of microbial cells. In the UK, according to BASHH guidelines, oral metronidazole 2g single dose or 400mg twice daily for 5-7 days are recommended first-line treatments for trichomoniasis.
A 30-year-old woman is admitted with pneumonia to hospital. She has a fever and a dry cough. On examination erythema multiforme is noted and bloods show she has a normocytic anaemia. What is the most likely causative organism?
Mycoplasma pneumoniae causes haemolysis
How do we treat genital herpes?
Oral aciclovir
How does legionella affect U&Es?
Hyponatraemia - inappropriate secretion of antidiuretic hormone secondary to bacterial pneumonia, Vasopressin decreases water excretion by the kidneys. As a result, more water is retained in the body, which dilutes the level of sodium in the body.
What is the most common cause of cold sores?
Herpes simplex virus type 1.
Type 2 often causes genital herpes
Where do you see rose spots on the abdomen?
Salmonella typhi infection can cause rose spots on the abdomen
How do we test for Lyme disease?
ELISA (blood test for serology) is the first-line investigation for suspected Lyme disease in patients with no history of erythema migrans
Which organism causes syphilis?
Treponema pallidum
How does syphilis present?
The first stage typically involves a painless genital ulcer (chancre), as reported by the patient two months ago. The second stage, which can occur weeks to months after the initial infection, is characterised by a widespread maculopapular rash and mucosal lesions such as mouth ulcers.
How do we treat pneumocystis jiroveci pneumonia?
Pneumocystis jiroveci penumonia is treated with co-trimoxazole, which is a mix of trimethoprim and sulfamethoxazole
What causes infectious mononucleosis?
Infectious mononucleosis (glandular fever) is caused by the Epstein-Barr virus (EBV, also known as human herpesvirus 4, HHV-4) in 90% of cases. Less frequent causes include cytomegalovirus and HHV-6. It is most common in adolescents and young adults.
How does mono present?
The classic triad of sore throat, pyrexia and lymphadenopathy is seen in around 98% of patients:
sore throat
lymphadenopathy: may be present in the anterior and posterior triangles of the neck, in contrast to tonsillitis which typically only results in the upper anterior cervical chain being enlarged
pyrexia
Which rash can sometimes be seen in infectious mononucleosis?
A maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis
How do we diagnose mono?
Monospot test
heterophil antibody test (Monospot test)
NICE guidelines suggest FBC and Monospot in the 2nd week of the illness to confirm a diagnosis of glandular fever.
How do we manage mono?
Management is supportive and includes:
rest during the early stages, drink plenty of fluid, avoid alcohol
simple analgesia for any aches or pains
consensus guidance in the UK is to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture
The parents of a 19-year-old man have just been messaged by their son who is currently backpacking in Thailand. Earlier in the day he was bitten by a dog whilst staying in a rural community. Prior to travelling, he received vaccination against rabies as he was going to be visiting many rural areas. What is the most appropriate advice?
He should urgently seek local medical attention, for the consideration of abx and further booster vaccination
What is the main side effect to be aware of for ethambutol?
E for eyes (optic neuritis)
What can pyrazinamide cause?
Gout
What is the main side effect to be aware of for isoniazid?
IsoNERVEzid - peripheral neuropathy
How do we treat positive syphilis in pregnancy?
IM benzathine penicillin G
What is Kaposi’s sarcoma?
Kaposi’s sarcoma
caused by HHV-8 (human herpes virus 8)
presents as purple papules or plaques on the skin or mucosa (e.g. gastrointestinal and respiratory tract)
skin lesions may later ulcerate
respiratory involvement may cause massive haemoptysis and pleural effusion
How do we treat Kaposi’s sarcoma?
radiotherapy + resection
How would cryptococcus neoformans present on LP?
cryptococcus neoformans stains well with india ink allowing it to be detected on a lumbar puncture
How does mycoplasma pneumoniae present?
Stereotypical history of mycoplasma pneumonia: worsening flu-like symptoms and a dry cough. Erythema multiforme is noted on examination
Should you treat asymptomatic bacteria in catheterised patients?
No
Where do you see strawberry cervix?
Trichomonas
What are Amsel’s criteria for BV?
Amsel’s criteria for diagnosis of BV - 3 of the following 4 points should be present
thin, white homogenous discharge
clue cells on microscopy: stippled vaginal epithelial cells
vaginal pH > 4.5
positive whiff test (addition of potassium hydroxide results in fishy odour)
What causes disulfiram-like reaction?
These effects are caused by accumulation of acetaldehyde, a major but toxic metabolite of alcohol formed by the enzyme alcohol dehydrogenase
Which antibiotic do we use to treat MRSA infections?
Vancomycin
What do we give for prophylaxis for contacts of patients with meningococcal meningitis?
Oral ciprofloxacin or rifampicin is used as prophylaxis for contacts of patients with meningococcal meningitis
Which abx do we give for pelvic inflammatory disease?
Doxycycline + metronidazole + ceftriaxone
What is diptheria?
Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae which primarily infects the throat and upper airways, leading to difficulty in breathing and swallowing. A grey coating surrounding the tonsils, fever, and cervical lymphadenopathy are classic symptoms of this disease. The patient’s recent travel from India also suggests diphtheria as it is more common in countries with less access to immunisation.
What is dengue fever?
Dengue fever is a viral illness transmitted by mosquitoes that commonly causes high fever, severe headache, pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding.H
How does typhoid fever present?
Typhoid and Paratyphoid fevers present with prolonged high-grade fever associated with relative bradycardia, malaise, headache, cough
Which abx should be avoided when taking methotrexate?
This patient should not be given trimethoprim/co-trimoxazole concurrently with methotrexate due to the risk of bone marrow aplasia. As methotrexate and trimethoprim are both anti-folate medications, the additive folate depletion when combined can lead to pancytopenia, megaloblastic anaemia, and bone marrow suppression.
Where do you see erythema migrans?
Erythema migrans is a red non-itchy rash that is classically associated with Lyme disease and develops a bulls eye appearance as it increases in size
How do we treat campylobacter?
Clari
What causes genital warts in most cases?
90% are caused by HPV 6 & 11
Which HPV strains are associated with cervical cancer?
I remember HPV 16 and 18 for cervical cancer
What does a single, painful genital ulcer generally indicate?
Chancroid
Caused by Haemophilus ducreyi