Lecture 11: Travel Related Infection Flashcards
list some climate or environment related health problems
- sunburn
- heat exhaustion and heatstroke
- fungal infections
- bacterial skin infections
- cold injury
- altitude sickness
list some water-related infections in returning traveller
- schistosomiasis
- leptospirosis
- liver flukes
- strongyloidiasis
- hookworms
- guinea worms
list some arthropod-borne infections
- malaria (mosquitos)
- dengue fever (mosquitos)
- rickettsial infections (ticks:typhus)
- leishmaniasis (sand flies: Kala-azar)
- trypanosomiasis (tsetse fly: sleeping sickness)
- filariasis (mosquitos: elephantiasis)
- onchocerciasis (black flies: river blindness)
list some important tropical diseases
- malaria
- typhoid
- dengue fever
- schistosomiasis
- rickettsiosis
- viral haemorrhagic fevers
- zika fever
what is the most severe species of malaria?
plasmodium falciparum
malaria symptoms
- Fever (up to 41ºC) with sweats and rigors
- Fatigue
- Myalgia (muscle aches and pain)
- Headache
- Nausea
- Vomiting
- Urinary symptoms
malaria signs
- none
- pallor
- splenomegaly
- hepatomegaly
- mild jaundice
list the complications of malaria
- Cerebral malaria
- Seizures
- Reduced consciousness
- Acute kidney injury
- Pulmonary oedema
- Disseminated intravascular coagulopathy (DIC)
- Severe haemolytic anaemia
- Multi-organ failure and death
how is malaria diagnosed?
- thick and thin blood films: shows parasites, the concentration (as a %) and the type.
- three negative samples taken over 3 consecutive days are required to exclude malaria.
- Quantitative buffy coat (QBC): centrifugation, UV microscopy
- rapid antigen tests: OptiMal, Parasight-F
list the treatment options for uncomplicated P.falciparum malaria
- Riamet is the usual first choice for 3 days
- Quinine plus doxycycline (or clindamycin) for 7 days
- Proguanil with atovaquone (Malarone)
- Chloroquine (there are increasing rates of resistance to chloroquine)
- Primaquine (can cause severe haemolysis in patients with G6PD deficiency)
quinine side effects
nausea
tinnitus
deafness
rash
hypoglycaemia
what are the treatment options for complicated or severe P.falciparum malaria?
- IV artesunate (unlicensed in the UK)
- IV quinine + oral doxycycline (or clindamycin)
what is the general advice for preventing malaria when travelling to endemic countries?
- No method is 100% effective alone
- Use mosquito spray (e.g., 50% DEET spray)
- Use mosquito nets and barriers in sleeping areas
- Seek medical advice if symptoms develop
- Take antimalarial medication as recommended
list the main anti-malarial medications for prophylaxis
- Proguanil with atovaquone (Malarone)
- Doxycycline
- Mefloquine (risk of psychiatric side effects)
- Chloroquine with proguanil (less often used due to high resistance)
signs and symptoms of typhoid
- fever
- weakness
- abdominal pain
- constipation
- headaches
- diarrhoea (uncommon)
- vomiting (not usually severe)
- skin rash with rose-coloured spots
- confusion (if severe)
typhoid investigations
laboratory (salmonella typhi, s.paratyphi):
- culture blood, urine and stool
- culture bone marrow
typhoid fever treatment
- oral azithromycin
- IV ceftriaxone if complicated, or concerned regarding absorption
- increasing ciprofloxacin resistance
what is the most common human arbovirus infection?
Dengue
what are the classical dengue fever clinical features?
- sudden fever
- severe headache, retro-orbital pain
- severe myalgia and arthralgia
- macular/maculopapular rash
- haemorrhagic signs: petechia, purpura, positive tourniquet test
dengue diagnosis
both clinical and lab
clinical:
- thrombocytopenia
- leucopenia
- elevated transaminases
- positive tourniquet test
lab:
- PCR
- serology
complications of dengue fever
and treatment
- Dengue haemorrhagic fever (DHF)
- dengue shock syndrome (DSS)
- TREATMENT: IV fluids, fresh frozen plasma, platelets
schistosomiasis clinical features
- swimmers itch
- invasive stage: cough, abdo discomfort, splenomegaly, eosinophilia
- Katayama fever: fever, urticaria, lymphadenopathy, splenomegaly, diarrhoea, eosinophilia
- acute disease
- chronic disease
schistosomiasis diagnosis
- clinical diagnosis
- antibody tests
- ova in stools and urine
- rectal snip
schistosomiasis treatment
- praziquaantel 20mg/kg, two doses 6hrs apart
- prednisolone if severe
clinical features of rickettsiosis
tick typhus
- abrupt onset swinging fever
- headache
- confusion
- endovasculitis
- rash (macular, petechial)
- bleeding
what drug is used to manage rickettsiosis?
tetracycline
zika virus clinical features
- no or mild symptoms
- headache
- rash
- fever
- malaise
- conjunctivitis
- joint pain
- in pregnancy can cause microcephaly
- can cause Guillain-Barre syndrome
