Passmed ID Mushkies Flashcards
What is BV?
An overgrowth of predominantly anaerobic organisms e.g. Gardnarella vaginalis. This leads to a consequent fall in lactic acid producing aerobic lactobacilli, resulting in raised vaginal pH
What are Amsel’s criteria for BV?
3/4 of:
- Thin, white homogeneous discharge
- Clue cells on microscopy
- Vaginal pH > 4.5
- Positive whiff test (KOH –> fishy odour)
What is the management of BV?
Metronidazole 400mg BD for 7 days
What are some risks of BV in pregnancy?
- Increased risk of preterm labour
- LBW
- Choriomamnionitis
- Late miscarriage
What causes diphtheria?
Corynebacterium diphtheriae
How does diphtheria exert its deleterious effects?
Release exotoxin that inhibitis protein synthesis
How does diphtheria present?
- Grey diphtheric membrane on tonsils caused by necrotic mucosal cells
- Bulky cervical lymphadenopathy
- Systemic distribution –> necrosis of myocardial, neural and renal tissue
What bacterium is responsible for the most wound infections?
S. aureus
What is Truvada?
Emtricitabine/Tenofovir
What should all HIV pts with CD4 < 200/mm^3 receive prophylaxis against?
PCP with co-trimoxazole
What is the most common opportunistic infection in AIDS/
PCP
What is pneumocystis jirovecii?
A unicellular eukaryote, generally classified as a fungus but some consider it a protozoa
What is a common complication of PCP?
Pneumothorax
What are 3 extrapulmonary complications of PCP?
- Hepatosplenomegaly
- Lymphadenopathy
- choroic lesions
What investigation is often needed to demonstrate PCP?
BAL, as sputum often fails to show PCP
What is the management of PCP?
- Co-trimoxazole
- IV Pentamidine in severe cases
- Aerosolized pentamidine
- Steroids if hypoxic
What are supposedly surprisingly not notifiable diseases in the UK?
HIV and syphilis
What two infections are associated with a vaginal pH > 4.5?
Trichomonas vaginalis and BV
What is Trichomonas vaginalis?
A highly motile, flagellated protozoan
What are some features of Trichomonas vaginalis?
- Frothy, offensive, yellow/green discharge
- Vulvovaginitis
- Strawberry cervix
- pH > 4.5
- In men may cause urethritis
What is the management of trichomonas vaginalis?
2g Metronidazole single dose
What is the management of necrotising fasciitis?
IV Abx and immediate surgical debridement
How is necrotising fasciitis classified?
According to causative organism
- Mixed anaerobes and aerobes, the most common type, typically post-surgery in diabetics
- S. pyogenes
What are some features of necrotising fasciitis?
- Acute onset
- Painful, erythematous lesion
- Rapidly worsening cellulitis with pain out of keeping with physical featurss
- Extremely tender over infected tissue
What is the cause of erythema infectiosum?
Parvovirus B19
What are 2 complications of parvovirus B19 infection in pregnancy?
Hydrops fetalis and death
What is the infectivity of parvovirus B19?
Infectious from 3 weeks before the rash, no longer infectious once the rash appears
What kind of virus is parvovirus B19?
DNA virus
What can parvovirus B19 cause in immunosuppressed pts?
Pancytopenia
What can parvovirus B19 cause in SCD?
Aplastic crises (Parvo B19 suppresses erythropoiesis for about a week)
What is the main s/e of ethambutol, and as such what should be checked?
- Optic neuritis
2. Visual acuity should be checked before and after treatment
What are 3 s/e of isoniazid?
- Peripheral neuropathy
- Hepatitis
- Agranulocytosis
What are 4 s/e of pyrazinamide?
- Myalgia
- Arthralgia
- Hepatitis
- Hyperuricaemia (gout)
What are some s/e of rifampicin?
- Orange secretions
- Hepatitis
- Flu-like sx
- Potent CYP450 enzyme inducer
What must one consider in deterioration of a pt with Hep B?
HCC
What should surveillance of pts with diagnosed cirrhoses entail?
6m intervals:
- Abdominal US
- Measuring AFP levels
What is fulminant hepatitis?
A rare syndrome of massive necrosis of the liver parenchyma
What may cause fulminant hepatitis in a pt with Hep B?
Hep D co-infection
What kind of DNA is Hep B?
dsDNA hepadnavirus
What is incubation period of Hep B?
6-20 weeks
What are some complications of Hep B?
- Chronic hepatitis
- Fulminant liver failure
- HCC
- GN
- PAN
- Cryoglobulinaemia
What does an anti-HBs level >100 indicate?
Adequate response, no further testing required, receive booster at 5 years
What does an anti-HBs level 10-100 indicate?
Suboptimal response, one additional vaccine dose should be given, if immunocompetent then no further testing required
What does an anti-HBs level <10 indicated?
Non-responder, test for current or past infection, give 3 dose vaccine course again, if still fails to respond then HBIG required if exposed to virus
What are some management options for Hep B?
Pegylated IFN-a, tenofovir, entecavir, telbivudine
What happens if a pt takes metronidazole and ethanol?
A disulfiram-like reaction
- Head and neck flushing
- N&V
- Sweatiness
- Headaches
- Palpitations
What is the most common infection found in central line infections?
Staphylococcus epidermidis
Is S. aureus coagulase negative or positive?
Positive
Is S. epidermidis coagulase positive or negative?
Negative
What are two salient infections caused by S. epidermidis?
- Central line infections
2. Infective endocarditis
What are the components of the qSOFA score?
- RR > 22/min
- Altered mentation
- SBP < 100mmHg
When is a qSOFA score used?
Risk of morbidity and mortality in pts with sepsis not in IVCU
What is the sepsis 6?
- 3 in = oxygen, BS ABx, IV fluid (500ml crystalloid over less than 15 mins)
- 3 out = cultures, lactate, hourly urine output
What causes chancroid?
Haemophilus ducreyi
What causes syphilis?
Treponema pallidum
What causes lymphogranuloma venereum?
Chlamydia trachomatis
What causes granuloma inguinale?
Klebsiella granulomatis
What are some features of chancroid?
- Painful genital ulcers (sharply defined, ragged, undermined border)
- Unilateral, painful lymph node enlargement
How can you classify the features of syphilis?
Primary, secondary and tertiary stages
What are some primary features of syphilis?
- Chancre
2. Local non-tender lymphadenopathy
What are some secondary features of syphilis?
Occurs 6-10 weeks after primary infection
- Systemic = fevers, lymphadenopathy
- Rash on trunk, palms and soles
- Buccal ‘snail-track’ ulcers
- Condylomata lata (painless, warty lesions on the genitalia)
What are some tertiary features of syphilis?
- Gummas (granulomatous lesions on the skin and bones)
- Ascending aortic aneurysms
- General paralysis of the insane
- Tabes dorsalis
- Argyll-Robertson pupil
What is the incubation period of syphilis?
Between 9-90 days
What is used for treatment of thrush?
Fluconazole
What do HSV1 and HSV2 typically cause?
- HSV-1 = cold sores, oral lesions
- HSV-2 = genital lesions
- It is now known there is considerable overlap between the effects of the two!
What are some features of HSV?
- Primary infection may present with a severe gingivostomatitis
- Cold sores
- Painful genital ulceration
What is the management of gingivostomatitis secondary to HSV?
Oral aciclovir and chlorhexidine mouthwash
What is the management of cold sores?
Topical Aciclovir
What is the management of genital herpes?
Oral aciclovir
What are the signs of infection by HSV on microscopy of a pap smear?
3Ms
- Multinucleation
- Margination of the chromatin
- Moulding of the nuclei
What bacteria commonly causes reactivation of HSV, resulting in cold sores?
Streptococcus pneumoniae
What is the most common cause of CAP?
S. pneumoniae
What commonly causes CAP after the flu?
S. aureus
What is a classical cause of pneumonia in alcoholics?
Klebsiella pneumoniae
What is the formal term for a cold sore?
Herpes labialis
What causes giardiasis?
Giardia lamblia
What is Giardia lamblia?
A flagellated protozoan
How is Giardia spread?
Faeco-orally
How is Giardiasis treated?
Metronidazole
How can one diagnose Giardiasis?
- Stool microscopy for trophozoite and cysts are classically negative
- Duodenal fluid aspirates
- String tests (fluid absorbed onto swallowed string)
What blood findings are suggestive of legionella?
- Hyponatraemia
2. Deranged LFTs
What are some clinical features of Legionnaire’s disease?
- Flu-like symptoms
- Fever
- Dry cough
- Relative bradycardia
- Confusion
How is Legionnaire’s disease diagnosed?
Urinary antigens
What is the management of Legionnaire’s disease?
Erythromycin/clarirthromycin
What causes spread of malaria?
The female Anopheles mosquito
What are 4 different species of Plasmodium that cause malaria in man?
- Falciparum
- Vivax
- Ovale
- Malariae
What is a protective factor against malaria infection?
G6PDD
What is the most prevalent STI in the UK?
Chlamydia trachomatis
What percentage of young women in the UK have chlamydia?
10%
What is the incubation period of chlamydia?
7-21 days
In what percentage of men and women is chlamydia asymptomatic?1
- Women = 70%
2. Men = 50%
What are some features of chlamydia infection in women and men?
- Women = cervicitis (bleeding, discharge), dysuria
2. Men = urethral discharge, dysuria
What are some potential complications of chlamydia in women?
- PID
- Endometritis
- Increase incidence of ectopic pregnancies
- Infertility
- Perihepatitis (FHC syndrome)
- Reactive arthritis
What are some potential complications of chlamydia in men?
- Epididymitis
- Infertility
- Reactive arthritis
What is the investigation of choice for chlamydia?
NAAT
- Vulvovaginal swab in women
- Urine test in men
What age group is the national Chlamydia screening programme open to in the UK?
15-24 y/o
What is the abx management of chlamydia?
Doxycylcine (7d) or azithromycin (single dose)
What is the abx management of chlamydia in pregnancy?
Azithromycin 1g stat
Who should be contacted for men with urethral symptoms due to Chlamydia?
All contact since and in the 4 weeks prior to onset of symptoms
Who should be contacted for women and asymptomatic men with Chlamydia?
All partners from the last 6 months or the most recent sexual partner
How should contacts of confirmed Chlamydia cases be treated?
Treat then test
What should be pts with suspected meningococcal meningitis be given if in a GP surgery?
IM benpen
What is the management of meningitis?
IV cefotaxime
What is the management of Listeria meningitis?
IV amoxicillin + gentamicin
What should be given to pts with meningitis to reduce the risk of neurological sequelae?
IV dexamethasone
Which contacts of a meningitis pt should be treated?
- Prophylaxis to household and close contacts
2. Prophylaxis to those exposed to respiratory secretions
What is the abx prophylaxis for close contacts of a meningitis pt?
- Oral ciprofloxacin/rifampicin
2. If they have been in contact in 7 days before onset
How many types of influenza virus are there?
3: A, B, C
Which influenza virus subtypes account for the majority of clinical disease?
A and B
What are the features of the paediatric influenza vaccine?
- Given intranasally
- First dose at 2-3 y/o then annually after that
- Is a live vaccine
What is an allergy that is a c/i to receiving paediatric influenza vaccine?
Egg allergy
What is the valency of the adult influenza vaccine and what are its components?
Trivalent, with 2 subtypes of Influenza A and 1 of Influenza B
What kind of vaccine is the adult influenza vaccine?
Inactivated
What is a c/i to the adult influenza vaccine?
Hypersensitivity to egg protein
What is the efficacy of the adult influenza vaccine?
75%
How many days after influenza vaccination are antibodies at protective levels?
10-14 days
How should UTI in pregnancy be managed?
Nitrofurantoin
How is a UTI normally treated in non-pregnant women?
Trimethoprim/nitrofurantoin for 3 days
What does OPSI stand for?
Overwhelming post splenectomy infection
When is the risk of OPSI the greatest?
In the first 2 years following splenectomy
What infections are splenectomy pts particularly at risk of?
- Pneumococcus
- Meningococcus
- Haemophilus
What abx prophylaxis is given for splenectomy pts?
Penicillin V
What vaccinations should be offered to splenectomy pts?
- HiB
- Men A & C
- Annual influenza
- Pneumococcal every 5 years
What are some indications for splenectomy?
- Trauma
- Spontaneous rupture (EBV)
- Hypersplenism (hereditary spherocytosis)
- Malignancy (lymphoma/leukaemia)
- Splenic cysts/hydatid cysts/splenic abscesses
What are 4 complications of splenectomy?
- Haemorrhage
- Pancreatic fistula (due to damage to pancreatic tail)
- Thrombocytosis (prophylactic aspirin)
- Encapsulated bacteria infection
When should anti-retroviral therapy be started for HIV?
At the time of diagnosis
What combination of drugs does HAART usually entail?
- 2 nucleoside reverse transcriptase inhibitors (NRTIs)
AND - Protease inhibitor OR NNRTI
What is an entry inhibitor for HIV?
Maraviroc
What is the MOA of Maraviroc?
Binds to CCR5, preventing interaction with gp41
What is enfuvirtide?
A fusion inhibitor, binds to gp41
What are some examples of NRTIs (nucleoside analogue reverse transcriptase inhibitors)?
- Zidovudine
- Abacavir
- Emtricitabine
- Lamivudine
- Stavudine
- Tenofovir
What is a general side effect of NRTIs?
Peripheral neuropathy
What are 2 s/es of tenofovir?
Renal impairment and osteoporosis
What are 3 s/e of zidovudine
- Anaemia
- Myopathy
- Black nails
What are 2 examples of NNRTIs?
- Nevirapine
2. Efavirenz
What are some protease inhibitors?
- Ritonavir
2. Indinavir
What is a s/e of ritonavir?
P450 inhibitor
What is an example of an integrase inhibitor?
Raltegravir
What is the most appropriate diagnostic test for mycoplasma?
- Serology
2. Cold agglutination test
What are 2 characteristic complications of Mycoplasma pneumoniae?
- Erythema multiforme
2. Cold AIHA
What are atypical lymphocytes suggestive of?
Glandular fever
What are 3 causes of glandular fever?
- EBV (90%)
- CMV
- HHV6
What is the classic triad of infectious mononucleosis?
- Sore throat
- Pyrexia
- Lymphadenopathy
What percentage of pts with infectious mononucleosis have splenomegaly?
50%
What develops in 99% of pts with infectious mononucleosis if they take ampicillin/amoxicillin?
A maculopapular, pruritic rash
How is infectious mononucleosis diagnosed?
Heterophile antibody test (Monospot test)
What is the management of infectious mononucleosis?
- Rest, fluid, avoid alcohol
- Simple analgesia for aches or pains
- Avoid contact sports for 8 weeks
Which 2 vaccinations are routinely offered to pregnant women in the UK?
Influenze and pertussis
What is the abx of choice for UTIs post-partum?
Trimethoprim (is present in milk but not harmful)
What is the MOA of trimethoprim?
Dihydrofolate reductase inhibitor
What are 2 s/e of trimethoprim?
- Myelosuppression
- Transient rise in creatinine
- Hyperkalaemia
Why does trimethoprim cause a transient rise in creatinine?
It competitively inhibits the tubular secretion of creatinine resulting in a temporary increase (blocks ENaC channel in the distal nephron), also leading to hyperkalaemia
What status is very important in the management of bites?
Tetanus status
To whom should IM human tetanus Ig be given to in A&E?
High risk wounds e.g. compound fractures, significant degree of devitalised tissue
What is the dosage for Abx prophylaxis in splenectomy pts?
- Penicillin V 500mg BD
2. Amoxicillin 250mg BD
A pt goes somewhere sunny and develops a cold sore, why?
Sunlight is a common trigger for cold sores
How can you classify the causes of diarrhoea in HIV?
- HIV enteritis
2. Opportunistic infection
What are some opportunistic infections that can cause diarrhoea in HIV?
- Cryptosporidium and other protozoa (most common)
- CMV
- MAI
- Giardia
What is the most common infective cause of diarrhoea in HIV pts?
Cryptosporidium
When is MAI infection typically seen in HIV?
When CD4 count is <50
How is MAI managed?
- Rifabutin
- Ethambutol
- Clarithromycin
What is a good initial IV bolus to give for HIV?
500ml over 15min
For every hour that IV Abx are delayed for sepsis, what is the percentage increase in mortality?
8%
How can you define traveller’s diarrhoea?
3 loose to watery stools in 24 hours
What is the most common cause of traveller’s diarrhoea?
E coli
What are 3 causes of acute food poisoning?
- B. cereus
- S. aureus
- C. perfringens
What is the typical hx for giardiasis?
- Prolonged, non-bloody diarrhoea
2. Chronic diarrhoea, malabsorption and lactose intolerance can occur
What is the typical hx for shigella?
Bloody diarrhoea, vomiting and abdo pain
What is the typical hx for campylobacter?
Flu-like prodrome usually followed by crampy abdo pain, fever, and diarrhoea (can be bloody)
What condition may a campylobacter infection mimic?
Appendicitis
What is a complication of campylobacter infection?
Guillain-Barre syndrome
What is the typical history for amoebiasis?
Gradual onset bloody diarrhoea, abdo pain and tenderness which may last for several weeks
Reheated rice and diarrhoea cause?
Bacillus cereus
What is the MOA by which B. cereus causes diarrhoea in reheated rice?
Their spores germinate in cooked rice and produce toxin if the cooked product is kept insufficiently chilled
What is the the standard therapy for TB?
- RIPE 2 months
2. RI 4 months
What is the treatment for latent TB?
- RI for 3 months OR
2. I for 6 months
When may directly observed therapy be used for TB treatment?
3x a week dosing regimen
- Homeless with active TB
- Pts with poor compliance
- All prisoners
How does dengue usually present?
Fever and joint pains
How does leptospirosis usually present?
- Biphasic pattern of fever and headaches
2. Continuing muscle and abdo pain
What causes typhoid?
Salmonella typhi
What causes paratyphoid?
Salmonella paratyphi
How is typhoid transmitted?
Faeco-oral route
What are some distinguishing features of typhoid infection?
- Relative bradycardia
- Constipation
- Rose spots (40% pts, more common in paratyphoid)
When should re-infection with syphilis be suspected?
If the RPR test rises by 4-fold or more
What is the RPR test?
Rapid plasma reagin test
What does the Enzyme Immunoassay Test (EIA) for syphilis measure?
Acute IgM Ab to syphilis, may be negative in reinfection
What is the TPPA test?
T. Pallidum particle agglutination test, often remains positive in pts who have been previously infected
What is the 1st line treatment for syphilis?
IM Benpen
What is the management of gonorrhoea?
IM ceftriaxone 1g (+ oral azithromycin, depending on guideline)
How can you classify serological tests for syphilis?
- Cardiolipin test = VDRL, RPR
2. Treponemal specific Ab tests = TPHA
How long does HIV seroconversion take?
3-12 weeks
What is seroconversion?
The period where an antibody response is created and is detectable
If pts take an ELISA test and are HIV negative, when are they recommended to retake the test to confirm they are HIV free?
After 3 months
In what percentage of pts is HIV seroconversion symptomatic?
60-80%
What are the typical symptoms of HIV seroconversion?
- Sore throat
- Lymphadenopathy
- Malaise, myalgia, arthralgia
- Diarrhoea
- Maculopapular rash
- Mouth ulcers
- Rarely meningoencephalitis
What bacterium is the cause of immune-mediated neurological disease after a pneumonia?
Mycoplasma pneumoniae
What are 5 live attenuated vaccines?
- BCG
- MMR
- Oral polio
- Oral typhoid
- Yellow fever
What are three toxoid (inactivated toxin) vaccines?
- Tetanus
- Diphtheria
- Pertussis
Abx tx for exacerbation of chronic bronchitis?
Amoxicillin or clarithromcyin
Abx tx for uncomplicated CAP?
Amoxicillin