12. Travel related infection Flashcards
Why are travellers at risk of infection?
Take risks away from home Different risks of different diseases uncomplete knowledge of health hazards Stress of travel deprivation, malnutrition, disease, injury
What diseases can travellers get due to the environemnt
Sunburn, heat exhaustion and heatstroke Fungal infections Bacterial skin infections Cold injury Altitude sickness
What water based infections can travellers contract?
Schistosomiasis Leptospirosis Liver flukes Strongyloidiasis Hook worm Guinea worms
What athropod borne infections can travellers contract?
Malaria Dengue fever Rickettsial infections Leishmaniasis Trypanosomiasis Filariasis onchocerciasis
What are some emerging infections worldwide?
Zika- latin america,carribean Ebola- west africa Coronavirus- far east, worldwide MERS-CoV middle east Swine Flu Avian flue SARS- far east, worldwide West nile virus- USA
What are some important tropical disease?
Malaria Typhoid Dengue fever Schistosomiasis Rickettsiosis Viral heamorrhagic fevers Zika fever
Describe the life cycle of a malaria parasite
Mosquitos inject sprozites into the blood. These parasites travel around the blood into the blood and interfere with the making of RBC. They become entangled in the blood. They are then repassed through mosquitos where the sporozites are re-made
What are the 5 species of malaria?
Plasmodium falciparum- potentially severe Plasmodium vivax Plasmodium ovale Plasmodium malarie Plasmodium knowlesi
What are the symptoms of malaria?
Fever, rigor,aching bones
Abdo pain, headache
dysuria,frequency, sore throat, cough
What are the clinical signs of malaria?
Splenomegaly
Hepatomegaly
Mild jaundice
What are the complications of malaria?
Cerebral malaria (encephalopathy) Non-immune vissitors, children in endemic areas, hpoglycaemia, convulsions, hypoxia Blackwater fever- acute renal failrue Pulmonary oedema jaundice Severe anaemia Algid malaria
How is complicate malaria treated?
How is uncomplicated malaria treated?
Artesunate
Parenteral artesunate is used treat severe or complicated malaria.
Intravenous artesunate can cause haemolysis and follow-up blood tests are required.
Artemisinin combination therapy (ACT)
ACT may be used to treat uncomplicated malaria and is the preferred treatment for mixed infection.
How do you diagnosemalaria?
Thick and thin blood films (giemsa, field’s stain)
Quantitive buffy coat (centrigugation, UV microscopy)
Rapid antigen tests (optiMal, Parasight-F)
How do you differentiate between severe and uncomplicated malaria?
Severe malaria will have one or more of the following:
Impaired conciousness or seizures Hypoglycaemia Parasite count>2% Heamoglobin <8mg/dl SPontaneous bleeding Haemoglobinuria Renal impairement or PH<7.3 Pulmonary oedema or ARDS
How do you treat uncomplicated P.falciparum malaria
One of
Riamet (3 days)
Eurartesim (3 days)
Malarone (3 days)
Quinine (7 days)
plus oral doxyclycline
How do you treat severe P.falciparum?
IV arteesunate
plus doxycycline
How do you treat the other malarias?
Chloroquine 3 days
add primaquine for 2 weeks (check is G6DP deficient first
What is typhoid fever?
Salmonella typhi and salmonella paraatyphi infection
widespread in areas of poor sanitation and unclean drinking water
What are the clinical features of the typhoid fever?
incubation period (7 days-4 weeks) 1st week-fever, headache, abdo, discomfort, constipation, dry cough, relative bradycardia, neutrophilia, confusion 2nd week- fever peaks at 7-10 days, rose spots, diarrhoea begins, tachycarida, neutropenia 3rd week complications- intestinal bleeding, perforation, peritonism, metastatic infections week 4 (10-15% relapse)
How do you diagnsoe tyhpoid fever
Very hard to diagnose clincially, monitor symptoms and recognise pattern
Labs, culture blood, urine and stool, culture bone marrow
How do you treat typhoid fever?
Oral azithromycin- uncomplicated
IV ceftriaxone- complicated or concerns regardign absorbtion (note increasing resistance)
What are the symptoms of dengue fever?
Sudden fever, headache,retro orbital pain
Severe myalgia and athralgia
Macular/maculopapular rash
Haemorrhagic signs, petiechiae, purpura, positive tourniquet test
How do you diagnose dengue fever?
Thrombocytopenia Lecupenia Elevated transaminases Positive tourniquet test Labs, PCR, serology
Discuss the management of dengue fever
No specific therapies, take painkillers
Avoid bleeding nand dengue heamrrhagic shock syndrome or dengue shock syndrome
Treatment in that instance is IV fluids,flesh frozen plasma, platelets
Describe the life cycle of schistosomiases
parasite eggs hatch in etaer, form into parasites in snails. Penetrate skin and migrate to portal blood into the liver and mature into adults. Adult worms lay eggs in bowel, rectum. Eggs released in bowel and urine
What are the symptoms of schistossomiasis?
Swimmers itch
Invasive stage- cough, abdo discomfort, splenomegaly, eosinophilia
katayma fever- prostrate enlargeent, fever urticaria, lymphadenopathy, splenomegaly, diarrhoea, eosinophilia
Acute disease, eggs deposited in bowel (dysentery) or bladder (haematuria)
How do you diagnose schistosomiases?
Antibody tests
Ova in stool and urine
Rectal snip
How do you treat schistosomiasis?
Praziquantel (20mg/kg) two doses 6 hrs apart, prednisolone if severe
What is rickettsiosis?
Tick typhus, presnets with swinging fever, headache, confusion, endovascultits, rash, bleeding
How do you diagnose rickettsiosis?
Clinical features and serology
Managed with tetracycline
What is Zika?
Disease transmitted by mosquits, sex and blood transfusion
Relate to dengue, yellow fever, jap B encephalitits and west niel viruses
What are the signs and complications of zika?
No or mild symptoms- headache, rash,fever, malaise, conjuctivits, joint pains
may cause gullain-barre syndrome
In pregnancy can cause microcephaly and other neurological conditions
What examiantion fevers indicate what is what?
Rash- typhoid, typhus, dengue
jaundice0- hepatits, malaria, yellow fever
Lymoh nodes- leishmania, trypanosomiasis
liver- malaria, typhoid, amoebic abscess
Spleen- visceral leishmaniasis, typhoid, malaria
What general investigations are good for suspecte tropical diseases?
FBC, malaria films Liver functions tests stool microscopy and culture Blood cultures CXR
