Infectious diseases block Flashcards
What are the common signs and sx associated w fever in a returned traveller?
- Febrile
- Resp sx
- GI sx - D+V
- Lymphadenopathy
- Hepatosplenomegaly
- Rash
- Jaundice
What are the common causes of fever in a returned traveller?
- Malaria
- Dengue fever
- Thyphoid fever
What are some important things to ask about in a hx of a returned traveller?
- Travel in last 12 months, travel date and duration of stay
- Accom - urban or rural, staying w fam and friends
- Sexual exposure - sex worker, unprotected sex
- Activities and exposure - freshwater swimming, insects and animals
- Food and water
- PMH and predisposition to infection
What protection can pt have to travel related disease?
Vaccines - childhood vaccines, Hep A and B, rabies, typhoid, tetanus, yellow fever
Malaria chemoprophylaxis or insect spray and malaria nets.
What are the time frames for different diseases causing fever in returned traveller?
0-10 days - dengue fever, GI, viral
10-21 days - malaria, typhoid, primary HIV infection
>21 days - malaria, TB, parasites, chronic bacterial infection
What signs could be found on exam of a returned traveller w fever?
- Maculopapular rash - dengue, CMV, EBV, rubella, primary HIV
- Low pulse w high fever = typhoid
- Splenomegaly - mono, malaria, typhoid
- Haemorrhagic lesions - haemorrhagic and dengue fever, meningitis
- Fever + alt mental state in returned traveller could = meningo encephalitis from cerebral malaria or Japanese encephalitis
What are the ix into fever in returned traveller?
- Bloods - FBC, LFT, U&E, culture, malaria smear
- Urinanalysis and culture
- CXR
- Stool culture
- Serology of HIV, Hep B and C, syphilisis
What is malaria?
Disease transmitted by female Anopheles mosquitos at night. P falciparum is the most extreme and most from Africa. Can also get P vivax and P ovale from SE Asia.
What is the presentation of malaria?
- Abrupt onset rigors
- Then high fevers, malaise, headache, N+V, myalgia, vague abdo pain
- Jaundice and hepatosplenomegaly
- Can get diarrhoea
What is found in bloods of a pt w malaria?
Anaemia, thrombocytopenia, leukopenia and derranged LFTs.
What happens if malaria is left untreated?
Hypoglycaemia, pulm oedema, renal fail, neuro deterioration and death.
What are the sx of typhoid fever?
- Diarrhoea or constipation
- Vague abdo pain
- Sustained fever
- Anorexia and malaise
- Dry cough
What are the findings on a pt w typhoid fever?
- Pulse temp dissociation
- Hepatosplenomegaly
- Rose spots
What are the ix into typhoid and how is it diagnosed?
Ix - leukopenia, lymphopenia, raised CRP
Dx - blood, stool and urine cultures, DM and duodenal aspirates
What is the treatment of typhoid?
- IV ceftriaxone
- Once know sensitivities = PO ciprofloxacin or azithromycine
What is PUO and what are the classic characteristics?
Pyrexia of unknown origin:
- 38 degrees multiple occasions
- > 3 weeks illness
- No dx >1 week in hospital
What are the possible causes of PUO?
Infective - IE, TB, abscess
Autoimmune - Wegner’s granuloma, GCA
Neoplastic - lymphoma, leukaemia, RCC
Drugs, VTE, hyperthyroidism.
What is the management of PUO?
- Establish dx and don’t start abx until spoken to a senior
- Might be able to manage a stable pt outpt after a period of inpt observation
Give an overview of TB
- Caused by mycobacterium tuberculosis
- Aerosol infection that causes pulm infection and then haematogenous spread to anywhere else in body
- Reactivation risk ~10-15%
Who is at risk of latent TB reactivation?
- Often happens in people who have emigrated to the UK from endemic areas
- Immunocompromised pt
- Pt on immunosuppressants
What is latent TB?
Asymptomatic TB and has to be identified on screening. Can lie dormant for years w/o causing sx and then reactivate to cause sx.
How do you screen for latent TB and who is screened? What are the downsides of the tests?
Interferon gamma and quantiferon.
Downsides - don’t differentiate between active and latent TB, can get false neg and positives.
Screen - health care workers, immigrants from high prevelance countries, HIV +ve, pt about to start immunosuppressants.
What is the treatment for latent TB?
3 months rifampicin and isoniazid or 6 months just rifampicin.
What are the common sx of active TB?
- Drenching night sweats
- Weight loss
- Non resolving cough
- Persistant unexplained fever
What are the signs of active TB?
- Clubbing
- Lymphadenopathy
- Cachexia
- Hepatosplenomgealy
- Erythema nodosum
What are the ix into active TB?
- Culture is the gold standard
- Imaging = lymphadenopathy, cavitating pneumonia
- Biopsy = caseating/necrotising granulomata
What is a paradoxial reaction in TB?
TB sx get worse as bacteria die, usually when a pt starts treatment.
If the new sx are really bad pt may need steroids for the duration of their treatment.
What is TB meningitis and what are the sx?
TB in CSF - all pt w miliary TB need LP to exclude.
Sx - personality change, headaches, meningitis sx then comatose, more insidious onset than viral and bacterial
What are the ix results for TB meningitis?
LP - high protein, low glucose and lymphocytosis
MRI - leptomeningeal enhancement
How is TB meningitis treated?
The paradoxial reaction can be fatal so need steroids when start treatment and for 12 months.
What is pericardial TB and treatment?
Causes pericardial effusion and paradoxial reaction = cardiac tamponade, need 6 months treatment and steroids
What is miliary TB and how is it treated?
Disseminated TB, TB in multipe sites. Need CT/MRI head and LP to exclude CNS involvement and then can start treatment.
What are the RF for MDR TB and what protective measures are used against it?
RF - incomplete TB treatment, pt from abroad
Protective measures - infection control = neg pressure rooms and PPE
What is the treatment for TB (not for CNS TB)? How do you monitor ATT?
Intense phase = 2 months rifampicin, isoniazid, ethambutol, pyrazinamide + pyridoxine (vit B)
Continuation phase = 4 months rifampicin and isoniazid +pyridoxine (vit B)
Monitoring - LFTs and visual acuity before and LFTs throughout
What are the SE of the ATT drugs?
Rifampicin - orange tears and urine, hepatitis
Ethambutol - retrobulbar neuritis, hepatitis
Isoniazid - hepatitis, peripheral neuropathy, hepatitis
Pyrazinamide - hepatitis
What are the infection control measures surrounding TB?
Pt needs to be isolated/in side room and wear mask when leaving room for first 2 weeks of treatment. After 2 weeks pt consider non infectious to immunocompetent individuals.
What STI testing is available for an asymptomatic pt?
- Vulvo-vaginal, rectal and pharyngeal swab
- First pass urine in men
What STI testing is available for a symptomatic pt?
- Urethral, vaginal, rectal discharge = charcoal swab to microbiology for gonorrhoea, BV and thrush
- Conjunctivitis swab for gonorrhoea
- Oral/genital swab = viral swab for HSV
What pt should bacterial STI screening be offered to?
- Pt who already have a sexually transmitted infection
- Pt who ask for it
- Pt w RF for STI in their hx
What are the ix into HIV?
- HIV test to confirm
- CD4 count
- HIV viral load and resistance profile
- Serology for syphilis, Hep B, A, C
- Bloods = FBC, U&E, LFT, bone and lipid profile
What drugs are used to treat HIV and what are the important things to note about them?
Anti retro virals eg. emtricitabine. Need to avoid drug resistance by using the right meds and being compliant.
They have many DDI esp OTC prescriptions and inhaled therapy.
What does a CD4 count of <200 mean and how should a pt be treated?
AIDs. Highly at risk for opportunistic infections. Treat w co-trimoxazole as prophylaxis for PCP.
How should a pt w a CD4 count of <50 be treated?
High dose azithromicin against MAI. Need to be ix for intra ocular infection eg. CMV retinitis.
What vaccinations should HIV pt receive?
- Hep B
- Pneumococcals
- Annual flu jab
PrEP vs PEP
PrEP - for pt who are at risk of becoming HIV +ve to prevent this, 90% effective
PEP - stops pt w exposure getting HIV, emergency situation and start w/i 72 hr of exposure
How do you treat life threatening C diff?
IV metronidazole and oral vancomycin
What are the live attenuated vaccines?
BOOMY
BCG
Oral polio
Oral typhoid
Mumps
Yellow fever
