Lecture 11: Travel Related Infection

Question 1

list some climate or environment related health problems

Answer 1

• sunburn
• heat exhaustion and heatstroke
• fungal infections
• bacterial skin infections
• cold injury
• altitude sickness

Question 2

list some water-related infections in returning traveller

Answer 2

• schistosomiasis
• leptospirosis
• liver flukes
• strongyloidiasis
• hookworms
• guinea worms

Question 3

list some arthropod-borne infections

Answer 3

• 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)

Question 4

list some important tropical diseases

Answer 4

• malaria
• typhoid
• dengue fever
• schistosomiasis
• rickettsiosis
• viral haemorrhagic fevers
• zika fever

Question 5

what is the most severe species of malaria?

Answer 5

plasmodium falciparum

Question 6

malaria symptoms

Answer 6

• Fever (up to 41ºC) with sweats and rigors
• Fatigue
• Myalgia (muscle aches and pain)
• Headache
• Nausea
• Vomiting
• Urinary symptoms

Question 7

malaria signs

Answer 7

• none
• pallor
• splenomegaly
• hepatomegaly
• mild jaundice

Question 8

list the complications of malaria

Answer 8

• Cerebral malaria
• Seizures
• Reduced consciousness
• Acute kidney injury
• Pulmonary oedema
• Disseminated intravascular coagulopathy (DIC)
• Severe haemolytic anaemia
• Multi-organ failure and death

Question 9

how is malaria diagnosed?

Answer 9

• 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

Question 10

list the treatment options for uncomplicated P.falciparum malaria

Answer 10

• 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)

Question 11

quinine side effects

Answer 11

nausea
tinnitus
deafness
rash
hypoglycaemia

Question 12

what are the treatment options for complicated or severe P.falciparum malaria?

Answer 12

• IV artesunate (unlicensed in the UK)
• IV quinine + oral doxycycline (or clindamycin)

Question 13

what is the general advice for preventing malaria when travelling to endemic countries?

Answer 13

• 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

Question 14

list the main anti-malarial medications for prophylaxis

Answer 14

• Proguanil with atovaquone (Malarone)
• Doxycycline
• Mefloquine (risk of psychiatric side effects)
• Chloroquine with proguanil (less often used due to high resistance)

Question 15

signs and symptoms of typhoid

Answer 15

• fever
• weakness
• abdominal pain
• constipation
• headaches
• diarrhoea (uncommon)
• vomiting (not usually severe)
• skin rash with rose-coloured spots
• confusion (if severe)

Question 16

typhoid investigations

Answer 16

laboratory (salmonella typhi, s.paratyphi):
- culture blood, urine and stool
- culture bone marrow

Question 17

typhoid fever treatment

Answer 17

• oral azithromycin
• IV ceftriaxone if complicated, or concerned regarding absorption
• increasing ciprofloxacin resistance

Question 18

what is the most common human arbovirus infection?

Answer 18

Dengue

Question 19

what are the classical dengue fever clinical features?

Answer 19

• sudden fever
• severe headache, retro-orbital pain
• severe myalgia and arthralgia
• macular/maculopapular rash
• haemorrhagic signs: petechia, purpura, positive tourniquet test

Question 20

dengue diagnosis

both clinical and lab

Answer 20

clinical:
- thrombocytopenia
- leucopenia
- elevated transaminases
- positive tourniquet test

lab:
- PCR
- serology

Question 21

complications of dengue fever

and treatment

Answer 21

• Dengue haemorrhagic fever (DHF)
• dengue shock syndrome (DSS)
• TREATMENT: IV fluids, fresh frozen plasma, platelets

Question 22

schistosomiasis clinical features

Answer 22

• swimmers itch
• invasive stage: cough, abdo discomfort, splenomegaly, eosinophilia
• Katayama fever: fever, urticaria, lymphadenopathy, splenomegaly, diarrhoea, eosinophilia
• acute disease
• chronic disease

Question 23

schistosomiasis diagnosis

Answer 23

• clinical diagnosis
• antibody tests
• ova in stools and urine
• rectal snip

Question 24

schistosomiasis treatment

Answer 24

• praziquaantel 20mg/kg, two doses 6hrs apart
• prednisolone if severe

Question 25

clinical features of rickettsiosis

tick typhus

Answer 25

• abrupt onset swinging fever
• headache
• confusion
• endovasculitis
• rash (macular, petechial)
• bleeding

Question 26

what drug is used to manage rickettsiosis?

Answer 26

tetracycline

Question 27

zika virus clinical features

Answer 27

• no or mild symptoms
• headache
• rash
• fever
• malaise
• conjunctivitis
• joint pain
• in pregnancy can cause microcephaly
• can cause Guillain-Barre syndrome