Malaria/Fever in the returning traveller Flashcards
List 10 causes of fever in the returning traveller
Malaria (check if prophylaxis taken) Dengue (rash) Typhoid Rickettsia Bacterial diarrhoea UTI Pneumonia HIV seroconversion Brucella Viral haemorrhagic fever (Ebola/lassa fever etc)
Which mosquito spreads malaria?
Female Anopheles
When and why do female mosquitoes bite?
At night
Need blood proteins for their eggs
Which 2 factors attract mosquitoes?
Heat and CO2
What type of pathogen causes malaria?
A protozoan parasite; Plasmodium
Name the 5 species of malaria-causing Plasmodium
P. falciparum P. malariae P. ovale P. vivax P. knowlesi
Which species of plasmodium usually infects animals and very rarely infects humans?
P. knowlesi
Which species of plasmodium is most common, especially in Africa and Asia
P. falciparum
Which species of plasmodium causes a benign malarial infection?
P. malariae
Which species of plasmodium causes the most severe form of malaria, with a possible parasitaemia of >2% and risk of complications associated with high mortality rates?
P. falciparum
Which 2 plasmodium species have a chronic liver stage, persisting in the liver as hypnozites, and what does this mean for the patient?
P. vivax and P. ovale
Means that symptoms can reappear (a malarial relapse) 8-24 weeks (or in some cases even a year) after apparent recovery
Which 3 species of plasmodium have a tertian rhythm and what does this mean?
P. faciparum, vivax and ovale
Means that the classic symptom of paroxysm (a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating) occurs every 48 hours
Which species of plasmodium has a quartan rhythm and what does this mean?
P. malariae
Means that the classic symptom of paroxysm (a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating) occurs every 72 hours
Give 3 features that can be seen on blood film in a P. falciparum infection
- Young trophozoites (rings)
- Absence of mature trophozoites and schizonts
- Crescent-shaped gametocytes
Give 2 features that can be seen on blood film in a P. vivax infection
- Schuffner’s dots
- >20 merozites/schizonts
Give 1 feature that can be seen on blood film in a P. ovale infection
Schffner’s dots
Which 2 species of plasmodium have a similar appearance on blood film?
P. ovale and P. knowlesi
Which 2 species of plasmodium have Schuffner’s dots on blood film?
P vivax and P. ovale
What is the treatment for a stable/mild P. falciparum infection?
Quinine for 7 days then doxycycline/clindamycin/fansidar (Sulfadoxine and pyrimethamine)
OR
Malarone (Atovoquone and proguanil hydrochloride)
OR
Riamet (artemether and lumefantrine)
What is the treatment for a severe P. falciparum infection?
Artemisinin combination therapy (ACT)
OR
Quinine and doxycycline/clindamycin
What is the treatment for both P. vivax and ovale
Chloroquine then primaquine
In P. falciparum, what can be seen on FBCs and LFTs, and in what percentage of pts?
WCC is rarely raised
70% have thrombocytopaenia
50% have deranged LFTs
30% have anaemia
Which specific investigations are used in malaria?
Thick and thin blood films
Antigen detection tests (rapid POC tests, used in settings where lab not available)
Which blood film establishes a parasitaemia?
Thick
Which blood film distinguishes malarial species?
Thin
List 3 common signs of P. falciparum malaria
Pyrexia
Splenomegaly
No signs
List 5 uncommon signs of P. falciparum malaria
Focal neurology Reduced GCS Coma Shock Hepatomegaly
List 6 common symptoms of P. falciparum malaria
Fever/rigors "Flu-like illness" Headache Back pain Myalgia Nausea/vomiting
List 4 uncommon symptoms of P. falciparum malaria
Diarrhoea
Abdominal cramps
Cough
Dark urine
List 9 major features of severe/complicated P. falciparum malaria in adults
Impaired consciousness/seizures Renal impairment Acidosis (pH,7.3) Hypoglycaemia ( less than 2.2) Pulmonary oedema Anaemia Spontaneous bleeding/ DIC Shock (BP less than 90/60) Heamoglobinuria Other indications for parental therapy- pregnancy, vomiting
Other than the features of complicated disease, give 3 more indications for parental therapy in P. falciparum malaria
Parasitaemia >2%
Pregnancy
Vomiting
What is “algid malaria”?
A form of falciparum malaria chiefly involving the gut and other abdominal viscera
- "Gastric algid malaria" is characterized by persistent vomiting - "Dysenteric algid malaria" is characterized by bloody diarrheic stools in which enormous numbers of infected red blood cells are found.
