MISC - Travel Medicine Flashcards
What pre-travel advice should be given to a pt?
•General advice
–Important to consider route of transmission of different infections to discuss appropriate behavioural advice
–Non- infectious risks eg trauma
•Vaccination
–Update routine
–Travel-related considerations
•Medications
–Eg Malaria prophylaxis, self-Rx for Travellers’ Diarrhea
Describe Traveller’s diarrhoea
- definition
- attack rate
- recovery
- Usually defined a 3 or more loose stools/day
- Attack rate: 20% - 50% to developing countries
•Usually begins abruptly, generally self-limited
–Most cases resolve in 1-2 days even without treatment
–10% cases last >1 wk
–2% last >1 month
– less than 1% last >3 months
Describe the causes of Traveller’s diarrhoea
- Acute TD
- Chronic TD
•No recognized cause in 20% -50% of TD
•Acute TD:
–Most commonly identified organism: Enterotoxigenic coli (ETEC), 40-70%
–Watery: ETEC, viral, cholera
–Bloody: Shigella, Salmonella, Campylobacter, Entamoeba histolytica
•Chronic TD:
–Usually > 2 wks
–Parasites (eg Giardia NOT BLOODY STOOL!!!)
Practical management of TD
- during travel
- post travel
•During travel:
–Often resolves without treatment
–Don’t give prophylaxis, but give therapy for empiric self treatment of acute TD:
•Quinolone, eg Ciprofloxacin, but increasing resistance (especially Campylobacter in Thailand, India, Nepal)
•Alternative: azithromycin
–Sometimes also give empiric Rx for persistent diarrhoea directed against giardia. Usually tinidazole
•Post travel:
–Investigate with stool micro and culture
–If negative, consider empiric therapy
What are the empiric self treatment for acute Traveller’s diarrhoea?
Quinolone, eg Ciprofloxacin (but increasing resistance especially Campylobacter in Thailand, India, Nepal)
Alternative: azithromycin
What is the empiric Rx for persistent diarrhoea directed against giardia?
Usually tinidazole (an anti-parasitic drug used against protozoan infection)
Discuss available pre-travel vaccinations for types below:
- food/water borne
- vector-borne
- respiratory route
- bloody/body fluids
- environmental/animal exposures
- update routine vaccines
- Food/water borne: Hepatitis A, Typhoid,Cholera
- Vector-borne: Yellow fever, Japanese Encephalitis
- Respiratory route: Meningococcal, Influenza, (TB)
- Blood/body fluids: HBV
- Environmental/ animal exposures: Rabies, Tetanus
- Update routine vaccines: MMR, Polio, etc
Discuss hepatitis A vaccination
2 doses at least 6 months apart
–If long delay since 1st dose, NO need to re-start full course
–NO booster recommended
Available as hep A vaccine only or in combination with HBV or typhoid
Discuss hepatitis E vaccination
There’s NONE
During 3rd trimester of pregnancy: associated with up to 20% maternal mortality
Discuss typhoid
- organisms causing enteric fever
- risk for travellers
•Enteric fever: Salmonella typhi, S. paratyphi
•Risk for travellers
–Highest for travellers to South Asia (6 - 30 X’s). Also high risk of multi-drug resistance
–Travellers visiting friends or relatives
Discuss typhoid vaccine
- (2) types of vaccine. Period of protection
- efficacy
- recommended to whom?
•Injectable polysacchride vaccine (Typherix or Typhim Vi)
–3 yr protection
•Oral: live attenuated vaccine: 4 doses gives 5 yr protection
–Don’t use if pregnant, impaired immunity, taking antibiotics,
Discuss cholera vaccine
- clinical Px of cholera
- vaccine composition
- how it is given
- efficacy
•Clinical: profuse, watery diarrhoea
•Cholera vaccine: Dukoral
•Composed of killed V. cholerae O1 organisms and the non-toxic B subunit of cholera toxin
•Oral vaccine, 2 doses given 1-6 weeks apart, efficacy 60-80%
•Cholera rarely a risk for tourist travellers
•Approx 50% reduction in Enterotoxigenic E coli (ETEC)
–Overall reduces TD by about 10-20%
–Only 3 months protection
•Not licensed for TD in Australia
Discuss meningococcus
- major epidemic areas in 20th C
- risk areas
- vaccines; types
- travellers vaccine
Major epidemics of serogroup A infection in 5-10 year cycles in the meningitis belt throughout 20th C
•Vaccines recommended for at risk areas
–Sub-Saharan Africa (esp dry season Dec-June)
–Saudi Arabia for pilgrims during Hajj
•Vaccines
–Conjugate vaccine used in childhood: serogroup C only
–POLYSACCHARIDE vaccines (Mencevax/Menomune): protects vs serogrps A,C,Y,W135 for 3 years –less immunogenic
–Conjugate quadrivalent vaccine licensed 2011 (Menveo, Menactra)
•Minimal information re boosters (5 yrs?)
•Which vaccine?
–Most travellers also require protection for serogroups A, Y and W-135, so quadrivalent vaccine usually indicated
Rare to get meningoccaemic septicaemia without meningitis and is commonly misdiagnosed as influenza/flu. Important to check for rashes (although not everyone develops them).
Discuss yellow fever
- risk areas
- spread by what
- causes what
- vaccine
Risk areas: Africa, S America
•Acute viral disease spread by mosquitoes
•Causes hepatitis and encephalitis
•Vaccine
–Indicated for all travellers to endemic countries
–Give ≥ 10 days before entry into risk area
–Single dose gives 10 years immunity
–CIs: severe egg allergy, immunodeficiency, pregnancy, infants
Discuss hepatitis B vaccine
•Engerix, H-B-VAX II
•Dose: 0, 1, 6 months
•Accelerated schedule: days 0, 7, 21; 12 months
•No need to routinely check antibodies
•Poorer seroconversion in chronic renal failure, immunosuppression
•Risk for travellers
–Generally low
–Consider vaccination if travelling to intermediate or high prevalence areas
–Adventure travellers, Peace Corps volunteers, missionaries, & military personnel, may have increased risk
Discuss rabies vaccine
- Pre-exposure prophylaxis
- post exposure treatment!!
•Pre-exposure prophylaxis: occupational risk or travel to rural areas/high endemic countries for >3-6 months
–Three doses 1ml IM days 0, 7, 28
•Post-exposure treatment (PET)
–Give any time after exposure (best w/i 48 hrs)
(1) wound care, may need tetanus toxoid/antibiotics
(2) 4 doses of vaccine (5 in some high risk situations): Days 0,3,7,14 (28). Administer into deltoid or thigh
(If previously immunised, only 2 booster doses (days 0 & 3)
(3) Human rabies immune globulin (HRIG): 20 IU/kg into wound, give within 8 days of starting HDCV