MI: Fever in the Returning Traveller Flashcards

1
Q

List some diseases caused by mosquitoes.

A
  • Malaria
  • Elephantiasis
  • Dengue
  • Yellow fever
  • West Nile virus
  • Zika virus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the vector for malaria?

A

Anopheles mosquito (female)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the five species of Plasmodium.

A
  • Plasmodium falciparum (75%)
  • Plasmodium vivax (20%)
  • Plasmodium ovale
  • Plasmodium malariae
  • Plasmodium knowlesi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Outline the life cycle of Plasmodium within humans.

A
  • Mosiquito bite infects humans with sporozoites
  • Within humans there is an exoerythrocytic stage (liver) and an erythrocytic stage
  • It replicates within liver and can remain dormant for years (vivax and ovale [hypnozoites])
  • It then infects erythrocytes and asexually reproduces, the ruptures to release the parasite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why does falciparum cause greatest mortality?

A
  • Invades RBCs of all stages
  • May be drug resistant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the incubation time for malaria

A

Up to 1 month for falciparum

Longer for others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which malaria types is this?

A

Falciparum

  • Little headphones
  • More than one in each cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the components of malaria prevention.

A
  • Awareness of risk
  • Bite prevention - repellants / nets
  • Chemoprophylaxis eg. malarone
  • Diagnose promptly and treat without delay
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe the clinical features of malaria.

A
  • Fevers - cyclical or continuous with spikes
  • Malaria paroxysms - chills, high fever, sweats

Malarae - 3 days
Others - 2 days

Usually 10-15 days after bite
Vivax - much longer - hypnozoite stage (liver)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is this?

A

Schizont
A malaria parasite which has matured and contains mainy merozoites
Indicative of severe malaria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the definition of severe malaria?
List some clinical features.

A
  • High parasitaemia - >2% (low transmission areas) or >5% (high transmission areas)
  • OR visualised schizont

Organ failures

  • Altered consciousness
  • Respiratory distress or ARDS
  • Hypoglycaemia
  • Metabolic acidosis
  • Circulatory collapse
  • Renal failure, haemoglobinuria (blackwater fever)
  • Hepatic failure
  • Coagulopathy +/- DIC
  • Severe anaemia or massive intravascular haemolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the main investigation for malaria?

A

Perform 3 thick and thin blood films

  • Thick - screening for parasites (sensitive)
  • Thin - identifying the species and quantifying the parasite (proportion of red cells that have been parasitised)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which stain would you use in malaria blood film?

A

Field’s or Giemsa stain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

List two examples of malaria rapid antigen tests.

A

Paracheck-PF (plasmodial HRP-II)

OptiMAL-IT (parasite LDH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Outline the treatment options for non-falciparum malaria.

A

Chloroquine + primaquine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What must you do before giving someone primaquine?

A

Screen for G6PD deficiency as primaquine can cause extensive haemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the complications of non-falciparum malaria?

A

Very rare but there are reports of splenic rupture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What counts as ‘mild’ falciparum malaria?

A
  • Not vomiting
  • Parasitaemia < 2 %
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Outline the treatment options for mild falciparum malaria.

A
  • First line - artemisinin-based combined therapy (ACT) e.g. Riamet (artemether-lumefantrine)
  • Malarone (atovaquone and proguanil)
  • Quinine and doxycycline
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Outline the management of severe falciparum malaria.

A
  • ABCDEFG approch
  • Correct hypoglycaemia
  • Cautious hydration
  • Organ support if necessary
  • IV artesunate 1st line
    (SEAQUMAT trial)
  • Daily parasitaemia monitoring
  • Follow on with oral antimalarials
21
Q

Why is quinine not first-line in severe falciparum malaria?

A

Extensive side effects:

  • Cinchonism: tinnitus, dizziness, nausea and vomiting
  • Arrhythmias
  • Hyperinsulinaemia
22
Q

What is the vector for dengue?

A

Aedes mosquito

23
Q

What typs of virus is the dengue virus?

A

RNA virus with 4 main serotypes

24
Q

Outline the clinical features of dengue.

A

Febrile phase lasts for around 4 days

25
Q

What are the complications of dengue? In which circumstances does this tend to occur?

A

Dengue haemorrhagic fever and dengue shock - occurs in individuals who have previously been infected with a different dengue serotype and are then infected by another serotype

26
Q

List some diagnostic tests for dengue.

A
  • Blood/urine PCR
  • Serology (IgM 5-7 days)
  • RDT
27
Q

How is dengue treated?

A

Identify those at risk of severe disease

Supportive

28
Q

What is the term used to describe a high temperature with a relatively normal heart rate? List some causes.

A

Sphygmothermic dissociation

  • typhoid,
  • brucellosis,
  • yellow fever,
  • tularaemia
29
Q

What is typhoid fever caused by?

A

Salmonella typhi and paratyphi

30
Q

What type of organism is Salmonella typhi?

A

Gram-negative rod

31
Q

Outline the clinical features of typhoid fever.

A
  • High prolonged fever (no rigors)
  • Classical ‘pea green diarrhoea’
  • Headache
  • Relative bradycardia (sphygmothermic dissociation)
  • Rose spots (rare)
  • Constipation
  • Hepatosplenomegaly
  • Dry cough
32
Q

Describe the stages of typhoid?

A
  1. Constipation, gradual rise in body temperature, relative bradycardia
  2. Pesistant fever, hepatosplenomegaly, rose spots
  3. GI bleeding, sepsis
33
Q

What is the incubation period of typhoid?

A

1-2 weeks

34
Q

List some complications of untreated typhoid.

A
  • GI bleeding - congested Peyers patches
  • Perforation
  • Septicaemia
  • Encephalopathy
35
Q

How is typhoid diagnosed?

A
  • Cultures - stool, blood, bone marrow (rarely)
  • Serology

Widel (RDT) - cheap but false positives

36
Q

What is the treatment for Typhoid?

A

Oral rehydration solution

Antibiotics

  • Uncomplicated empirical - azithromycin
  • Complicated - IV ceftriaxone
37
Q

What is mononucleosis caused by?

A

EBV or CMV

38
Q

What is a characteristic clinical feature of mononucleosis?

A

Tonsillar enlargement with exudates

39
Q

List some investigations for mononucleosis.

A
  • Monospot
  • IgM EBV/CMV

NOTE: always consider HIV

40
Q

What is a characteristic microscopic feature of mononucleosis?

A

Atypical lymphocytes

41
Q

What is leptospirosis and how is it spread?

A

Infection caused by Leptospira (spirochetes)

Commonly spread by rodents - associated with sewers and dirty water contaminated by rodent urine

42
Q

Describe the clinical presentation of leptospirosis

A

Weil’s - jaundice, renal failure, haemorrhage

Causes positive agglutination test - vascular

43
Q

How is leptospirosis diagnosed and treated?

A

Diagnosis

  • PCR serum/urine/CSF
  • Serology - IgM ELISA

Treatment

  • Doxycycline
  • Ceftriaxone
  • Penicillin
44
Q

What is Lyme disease and how is it spread?

A

Infection by Borrelia
Spread by Ixodes ticks

45
Q

Describe the clinical presentation of lyme disease.

A
46
Q

How is Lyme disease diagnosed and treated?

A

Diagnosis

  • Clinical
  • ELISA
  • PCR blood/CSF (imperfect)

Treatment

  • Doxycyline
  • Amoxicillin
  • Ceftriaxone in neuroborreliosis
47
Q

What is lymphogranuloma venereum (LGV)?

A

STD caused by Chlamydia trachomatis (invasive serovars)

Sexual transmission then travels from innoculation site into lymphatic system

48
Q

Describe the clinical presenation of LGV

A
49
Q

How is LGV diagnosed and treated?

A

Diagnosis

  • Serology
  • Direct fluorscent antibody test
  • PCR infected area/pus

Treatment

  • Drainage of buboes/abscesses
  • Antibiotics - doxycycline (1st), azithromycin (2nd)

(Contact tracing)