Tropical Medicine Flashcards
What is the HTLV1 virus and who is mostly affected in Australia?
Human T-Lymphotropic virus 1
- Very high prevalence in central Australia among the Aborginal population
- Leads to lymphoma, myelopathy, uveitis and arthropathys
- Causes a degree of immunocompromise, thus infected patients are likely to have opportunistic infections and worse versions of typical infections
What are the most common causes of sepsis among ATSI patients?
Osteomyelitis
Septic Arthritis
Nec Fasc
PID in females
Cryptococcus (Gum trees)
Melioidosis (during rainy season, more so in the top end)
Diabetic foot
Pyelonephritis (more prone to gas forming organisms)
Abscesses (anywhere)
What is the specific treatment for severe falciparum malaria?
Artesunate 2.4mg/kg IV Q12hr
IV Quinine 20mg/kg LD
- hypoglycaemia, cinchonism and arrhythmias
PO meds include Artemether + Lumefantrine combo
Also can give clindamycin and doxycycline
Who gets chemoprophylaxis for meningococcal meningitis?
What are the investigations that should be performed with fever in returned traveller?
- Thick and thin films (malaria)
- Serology (Dengue, hepatitis)
- Viral PCR (covid, flu)
- Urine M/C/S/PCR (UTI, STI)
- FBE (haemolysis, low plats in dengue)
- LFT’s (high bili, deranged LFT’s in malaria and HAV)
- UEC (AKI)
- Consider HIV screening
What are the most common causes of fever in a returned traveller?
Top causes + incubation
- Malaria (7-30 days)
- Dengue (4-7 days)
- Rickettsia
- Mononucleosis
- Enteric (Typhoid/Paratyphoid) fever 6-30 days
- Influenza (2-4 days)
- Tuberculosis (>3 months)
- Legionairres disease (5-6 days)
- Q fever (2-3 weeks)
- Melioidosis (1-21 days)
- Plague (2-8 days)
- Hep A (28 days)
- Acute HIV (2-4 weeks)
What are the most common causes of fever in returned traveller who presents with Jaundice?
- Falciparum malaria
- Severe Dengue fever
- VIral Heptatitis
- Leptospirosis
- Yellow fever
- Ebola virus
What are the most common causes of fever with abdo pain or diarrhoea in returned traveller?
Abdo pain
- Enteric fever
- Amoebic liver abscess
- Cholangitis due to liver fluke
Diarrhoea
- Enteric fever
- Shigellosis
- Giardiasis
- Travellers diarrhoea
- Cryptosporidosis
What are the most common causes of fever with rash in returned traveller?
- Dengue
- Enteric fever
- Zika virus
- RIckettsia
- Acute HIV
- Measles
- Chikungunya
- Lyme disease
What are the most common causes of fever with AMS in returned traveller?
- Cerebral malaria
- Meningococcus
- Japanese encephalitis
- West nile virus
- Rabies
- African Trypanosomiasis
What are the 3 characteristic syndromes of Dengue virus infection?
Dengue fever aka “breakbone fever”
- Retro-orbital/ocular pain
- headache
- Severe arthralgia/myalgia
- Rash
- Leukopenia
- Biphasic “saddle back fever”
Dengue Haemorrhagic fever
- Cardinal feature is plasma leakage leading to effusions, ascites and haemoconcentration (HCT rise >20%)
- positive tourniquet test (inflate cuff to midway between SBP/DBP for 10mins, if >10 petechiae >2.5cm in size present then positive)
- spontaneous bleeding (gums, urine, vaginal, IV lines etc)
- Thrombocytopaenia
- Petechiae, ecchymoses
Dengue Shock Syndrome
- Plasma leakage leads to circulatory shock and collapse
- DHF symptoms + shock = DSS
What is the empiric therapy for severe malaria?
Falciparum
- IV Artesunate 2.4mg/kg
- IV Quinine 20mg/kg
Ovale/Vivax
- PO Chloroquine 10mg/kg
What are the common MO’s and what is the treatment for water immersed wound infections?
MO’s
- Vibrio sp
- Aeromonas sp
- Mycobacterium marinum
- GAS and Staph aureus
- Shewanella putrefaciens
Antibiotics
- Penicillin ie Flucloxacillin 500mg QID
- Atypical cover ie Doxycycline 100mg BD PO
OR
Ciprofloxacin 12.5mg/kg PO BD for children <8yrs
What infectious diseases are refugees more at risk of?
- TB
- HIV
- Hepatitis A/B/C
- Malaria
- Amoebiasis
- Strongyloides
- Schistosomiasis
- Filiariasis
- Hydatid cysts
What are the different routes of Malaria transmission?
- Arthropod bite (1)
- IVDU/occupational exposure to contaminated needles
- Vertical (maternal to foetal)
- Infected blood transfusion
- Infected organ transplant
What are the characteristic history and exam findings with measles? Who is at most risk?
Hx
- Incubation period 10 days for fever and 14 days for rash
- Prodrome before rash is fever, cough, coryza and conjunctivitis
- Exposure to known infected or travel to endemic areas
Exam
- Non-itchy maculopapular rash with fever
- Cough, coryza, conjunctivitis and koplik spots (buccal mucosa)
- SIRS response with altered vital signs
- Signs of complications
Complications
-Vomiting, diarrhoea, dehydration
- otitis media
- laryngitis
- pneumonia, severe headache (encephalitis)
- painful/altered vision (optic neuritis)
