Fever in the returning traveller Flashcards
What are you most worried about if a pt comes in with fever, low Hb and low platelets after recently returning from travelling?
Malaria
- it can come up month afterwards
- important to check if they’ve had any bites, if they had any vaccines before travel, check their sexual history
Some forms of malaria can remain dormant in the liver for years and then start causing harm
What is the lifecycle of malara?
Anophele’s mosquito infected with malaria bites a human to take blood and injects sporozites into the persons blood which enter the liver and are processed and become merozoites which are released into blood and enter RBCs
What are the different species of malaria and how effective is prophylaxis?
plasmodium falciparum = rapidly fatal - most common reported in UK (mostly in W. Africa)
P.vivax and P. Ovale = relapse even decades after acquisition
- vivax = increasing cases from indian subcontinent
P.Knoelesi = emerging pathogen in south east asia
84% of cases are in people that do not take prophylaxis
When should you think of malaria?
fever, malaise, muscle pain, headache, diarrhoea
More severe: neurological features, coma, renal failure
Most presentations are within 2-4 weeks (vivax/ovale can present years later)
What tests are used to diagnose malaria?
antigen card tests and blood films (3 over 2-3 days) - if first test comes back negative insist on 2 more tests
What are the treatments for falciparum?
Mild - PO therapy with quinine/doxy, riamet
Severe - IV artesunate or less ideally quinine
Should be treated with combo therapies to prevent resistance
What is the prevalence of common, significant and unfamiliar fevers after travelling?
Common
- <64% travellers returning from developing countries have fever
- 8% travellers to developing countries feel unwell enough to seek medical advice
Significant
- most are mild self limited processes
- life threatening illnesses are often indistinguishable in the early stages
Unfamiliar
- most clinicians don’t have an understanding of the infections that can be acquired around the globe therefore systematic approach is key
What are the most common infectious diseases obtained whilst travelling?
22% of cases are non-specific
21% malaria
6% dengue
15% fever and abdominal pain = think typhoid
14% respiratory
rickettsial infection (africa especially)
46% of those with systemic disease require hospitalisation
What are some of the key questions to assess in a travel history?
Timing of travel, location, duration, types of transportation, stop overs
- many infections can be excluded if return was >1month ago
- dating the last exposure really helps to narrow the field
What activities did they do, these locations and timings
- these include water sports, hiking, sex, drugs
also be mindful that the travel may be a red herring
What are some key clinical features to examine when you suspect an infectious disease from travelling?
Skin lesions, lymph nodes, retinal or conjunctival changes, enlarged liver/spleen, genital lesions and neuro findings
- 40% of malaria may not have fever on initial presentation
What investigations would you carry out if you suspect an infectious disease following travelling?
FBC - check if eosinophils or platelets are low, clotting factors, LFT
Blood and urine cultures, blood film (at least 3 over a couple of weeks if you suspect malaria), CXR (check for lung infiltrates)
What are some danger signs to be aware of if you suspect an infectious disease following travelling?
Haemorrhagic manifestations, respiratory distress, CV instability, confusion, lethargy, stiff neck, focal neurology
What are the differences between the bites from malaria infected mosquitos and those carrying dengue?
Dengue infected mossies tend to bite during the day and tend to bite multiple people whereas malaria mossies tend to bite one person for whole meal and that tends to be at night
What is rickettsial infection?
Bacterial genus = obligate intracellular parasite that normally lives within host endothelial cells = cant be grown in artificial culture because it needs cells
Transmitted by many anthropods: ticks, fleas, lice
Causes: typhus rickettisialpox, african tick bit fever, rocky mountain spotted fever, queensland tick typhus
What occurs with african tick bite fever and what is the treatment ?
infected tick jumps from grass and normally ascends a limb and bites
- symptoms with 2 weeks = fever, headache, muscle pain, rash
Treatment = doxycycline
What is histoplasmosis and how prevalent is it in centra USA?
Fungi that grows in soil contaminated with bird or bat dropppings
Spores breathed in if material disturbed
Common fungi in HIV pts
80% of those living in eastern and central USA are skin test positive for it
What are the clinical features of histoplasmosis?
most people are unaffected
some develop an acute respiratory illness with fever, chest pain and cough
Chronic disease can arise in those with pre-existing lung problems or immunosuppressed - can look like TB
Disseminated disease can be fatal
Treatment: itraconazole, amphotericin
RISK of catching it: caving in equador - bat poo on the floor which histoplasmosis can live in
What is schistomsomaiasis?
Parasite that lives in freshwater snails
- worms cause eosinophil levels to rise (however haematological malignancy can also cause them to rise)
What does strongyloides cause?
Haemorrhagic fever - always think about it as it can be fatal
- flu like symptoms, vomiting, body pain
What is the clinical care pathway for strongloides?
minimum risk
- cared for in DGH if necessary but alert infection control and CCDC
Moderate risk
- admit to isolation facility in newcastle/london
- notify CCDC
High risk
- Full CCDC, contact tracing, body suits
What other conditions can present as haemorrhagic fever?
meningococcal sepsis, leptospirosis, plague, dengue
What is MERS?
Middle east respiratory syndrome
- risk for travellers is low but it is important to be aware of
- symptoms: cough, fever and SOB
- no treatment available but pt needs to be isolated
What are the symptoms of rabies?
initially= non-specifically unwell - low grade fever - sore throat - headache - nausea then -irritability, confusion, fever, reducing conscious levels
What are some of the key elements to ask about a pts travel history?
Needs to be taken in all febrile or non-specifically unwell pts
- specific locations, sex, drugs, vaccines, meds, missed doses, always check for malaria, use online resources
