Travel related infection Flashcards
Unfamiliar features of imported diseases (5)
Presenting features Isolation requirements Diagnostic methods Treatment/Management Unexpected complications
Give examples of how vulnerability with travellers increases away from home? (5)
- Temptation to take risks away from home - food, sex
- Different epidemiology of some diseases - HIV, aids, polio
- Incomplete understanding of health hazards
- Stress of travel
- Refugees: deprivation, malnutrition, disease, injury
Name 4 infections that are common worldwide
- influenza
- community-acquired pneumonia
- meningococcal disease
- sexually transmitted diseases
Climate or environment related health problems
Sunburn Heat exhaustion and heatstroke Fungal infections Bacterial skin infections Cold injury Altitude sickness
Give some examples of water related infections
Schistosomiasis Leptospirosis Liver flukes Strongyloidiasis Hookworms Guinea worms
Examples of Arthropod-borne infections
Malaria (mosquitos)
Dengue fever (mosquitos)
Rickettsial infections (ticks: typhus)
Leishmaniasis (sand flies: Kala-azar)
Important Tropical Diseases include (7)
Malaria Typhoid Dengue Fever Schistosomiasis Rickettsiosis Viral haemorrhagic fevers Zika fever
What is the vector for malaria
female Anopheles mosquito
Malaria: 5 species - what one can be severe?
Plasmodium falciparum Plasmodium vivax Plasmodium ovale Plasmodium malariae Plasmodium knowlesi
Malaria - Clinical features - symptoms and signs
- fever rigors aching bones abdo pain headache dysuria frequency sore throat cough
signs - splenomegaly
hepatomegaly
mild jaundice
Complications of Malaria (6)
- Cerebral malaria (encephalopathy)
- Blackwater fever
- Pulmonary oedema
- Jaundice
- Severe anaemia
- Algid malaria
Cerebral malaria (encephalopathy) often affects
non- immune visitors, children in endemic areas hypoglycaemia, convulsions, hypoxia
Blackwater fever causes
severe intravascular haemolysis, high parasitaemia, profound anaemia, haemoglobinuria, acute renal failure
Malaria - diagnosis
Thick & thin blood films
Giemsa, Field’s stain
Quantitative buffy coat (QBC)
centrifugation, UV microscopy
Rapid antigen tests
OptiMal
ParaSight-F
Severity assessment - Complicated malaria = one or more of???
Impaired consciousness or seizures Hypoglycaemia Parasite count 2% Haemoglobin 8mg/dL Spontaneous bleeding / DIC Haemoglobinuria Renal impairment or pH <7.3 Pulmonary oedema or ARDS Shock (algid malaria) - Gram negative bacteraemia
Treatment options for uncomplicated P. falciparum malaria (4)
Riamet ® (artemether-lumefantrine) 3 days
Eurartesim ® (dihydroartemisinin-piperaquine) 3 days
Malarone ® (atovaquone-proguanil) 3 days
Quinine 7 days S/E nausea, tinnitus, deafness (cinchonism), rash, hypoglycaemia plus oral doxycycline (or clindamycin)
Treatment options for complicated or severe P. falciparum malaria?
- IV artesunate (unlicensed in UK)
- IV quinine
PLUS plus oral doxycycline (or clindamycin)
Treatment of P. vivax, P. ovale, P. malariae, P. knowlesi?
what can you afford to eradicate liver hypnozoites
chloroquine 3 days
Riamet - 3 days
primaquine
Typhoid (Enteric) Fever -organism names
Salmonella typhi
Salmonella paratyphi
Typhoid Fever: Clinical features - week 1-4
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, tachycardia, neutropenia
3rd week (Complications): intestinal bleeding, perforation, peritonism, metastatic infections
week 4 (Recovery): 10 - 15% relapse
Typhoid fever incubation period
Incubation period: 7 days - 4 week
Typhoid Fever: Diagnosis - clinical vs lab
Clinical - not easy, evolution of features
Laboratory (Salmonella typhi, S. paratyphi)
Culture blood, urine & stool
Culture bone marrow
Typhoid Fever: Treatment
Oral Azithromycin
IV Ceftriaxone - (complicated)
Commonest human arbovirus infection
Dengue
Transmission of Dengue
Aedes aegypti
Classical Dengue Fever (5)
- Sudden fever
- Severe headache, retro-orbital pain
- Severe myalgia and arthralgia
- Macular/ maculopapular rash
- Haemorrhagic signs: petechiae, purpura, positive tourniquet test
the rashes of Dengue fever
Macular rash
Petichial rash
Dengue Diagnosis - clinical (4)
laboratory
Clinical Thrombocytopenia Leucopenia Elevated transaminases Positive tourniquet test
PCR, serology
Dengue Management
prevention?
No specific therapeutic agents
avoid bites new vaccine (Dengvaxia), 2016; limited use
Dengue Management - complications (2) - how to treat?
- Dengue haemorrhagic fever (DHF)
- Dengue shock syndrome (DSS)
Rx: IV fluids, fresh frozen plasma, platelets
Schistosomiasis is found in
fresh water and freshwater snails
Schistosomiasis types (3)
S. haematobium
S. mansoni
S. japonicum
Schistosomiasis - Clinical features
- Swimmers Itch - 1st few hours
- Invasive stage - 24 hrs
- Katayama Fever
- Acute disease (6-8 weeks)
- Chronic disease
Schistosomiasis - Clinical diagnosis
Antibody tests
Ova in stools and urine
Rectal snip
Schistosomiasis - treatment (2)
PRAZIQUANTEL 20mg/kg, two doses 6hrs apart
Prednisolone if severe
Tick typhus - what will show on the skin
Tick-bite eschar
Maculopapular rash
Rickettsiosis - types
most common in UK and give a few more examples
Tick typhus (R. conorii, R. africae)
- Rocky Mountain Spotted Fever (R. rickettsii)
- Epidemic typhus (R. prowazekii)
Rickettsiosis - CLINICAL features, diagnosis/management?
abrupt onset swinging fever, headache, confusion, endovasculitis, rash (macular, petechial), bleeding
- serology
tetracycline
Viral Haemorrhagic Fevers- ones rare to the UK but serious include? (4)
Ebola
Congo-Crimea haemorrhagic fever
Lassa fever
Marburg disease
Some features of the Zika virus
flavivirus
- daytime-biting Aedes mosquitos
- sexual contact, blood transfusions
Zika - clinical features (6)
no or mild symptoms - headache, rash, fever, malaise, conjunctivitis, joint pains (like dengue)
Zika - in pregnancy
microcephaly and other neurological problems
Zika infections can cause what condition?
Guillain-Barre syndrome
Zika has no antiviral therapy so what must you do instead?
Mosquito control measures
Vaccines in development
Examination signs - rash often caused by
typhoid, typhus, dengue
Examination signs - jaundice - what condition
- hepatitis, malaria, Yellow fever
Examination signs - lymph nodes
- leishmania, trypanosomiasis
Examination signs - liver - condition?
- malaria, typhoid, amoebic abscess
Examination signs - spleen - condition ?
visceral leishmaniasis, typhoid, malaria
Investigations for a returning traveller
FBC malaria films liver function tests stool microscopy & culture urine analysis & culture blood culture(s) CXR
Treatments for a returning traveller?
Isolation: ?personal protective equipment
Supportive measures (resuscitation)
Empirical treatment if patient unwell
Antimicrobial therapy based on likely diagnosis
aim to treat life-threatening conditions e.g. typhoid, septicaemia
