2: Tropical Infection Flashcards
What is malaria
Infection parasite plasmodium
Where do the majority of cases of malaria occur
African
What causes most deaths from malaria worldwide
Plasmodium Falciparum
Where is plasmodium falciparum found the most
Africa
What is plasmodium vivax
Central America - most dominant parasite outside of of Africa
Where does plasmodium vivax cause most cases
Central America
Where is plasmodium knowlesi found
South East Asia
What causes malaria
bit of anopheles mosquito
What is the incubation period of plasmodium falciparum
6-days
When does plasmodium falciparum occur
3-months on returning from hot country
Does plasmdium falciparum have a liver stage
No
Describe plasmodium falciparum severity
Causes most-severe illness
How do you remember plasmodium falciparum causes severe malaria
plasmodium Falciparum = Fucking bad malaria
What is the most common cause of benign malaria
plasmodium vivax
What is the incubation period of plasmodium vivax
14 days
Does plasmodium vivax have a liver stage
Yes
What is plasmodium malaria associated with
Nephrotic syndrome
Does plasmodium malaria have a liver stage
No
what is the incubation period of plasmodium malaria
30-days
what is the incubation period of plasmodium ovale
11-days
does plasmodium ovale have a liver stage
Yes
what is the incubation period of plasmodium knowlesi
9-days
does plasmodium knowlesi have a liver stage
No
what are risk factors for malaria
Immunocompromised
Pregnant
what are 3 protective factors for malaria
G6PD
Sickle Cell trait
Absence duffy antigen
why is G6PD a protective factor for malaria
Increases RBC lysis due to oxidative stress - increases chance that infective cells are lysed
why is absence of Duffy antigen protective
duffy antigen is required for plasmodium vivax to enter cells
what is Duffy antigen absent in
sickle cell anaemia
what are symptoms of malaria
- Flu like
- Fever
what causes a tertian fever
- Ovale
- Vivax
what is a tertian fever
Fever on every third day
what is a quartan fever
Fever on every fourth day
what has a quartan fever
Malaria
in which malaria is fever irregular
- Ovale
- Knowlesi
aside from cyclical fevers, how does malaria present
- Paleness
- Bleeding
- GI: diarrhoea and abdominal pain
- Hepatosplenomegaly
- Jaundice
what is the problem with malaria
it has several non-specific symptoms and is easily missed - therefore suspect all individuals who return from endemic region with fever
in the mosquito, what is malaria called
sporozoite
what happens to sporozoites in the liver
become schizogony
what happens to sporozoites in falciparum, malaria and knowlesi
become merozoites
what happens to sporozoites in vivax and ovale
Enter the liver where they remain dormant for months-years as hypnozites
what happens to merozites
enter RBC where they undergo asexual reproduction to form trophozoites, then schizont
what then happens
another female mosquito bites they take up the RBC containing gametes - they mature in the mosquitos gut and undergo sexual reproduction
what investigation is used for malaria
thick and thin blood-smears
when is malaria unlikely
3 negative blood films
what indicates severe malaria on blood film
schizonts
what is used as an initial screen
rapid diagnostic test
how will malaria present on FBC
haemolytic anaemia
how is moderate plasmodium falciparum managed
Artemisin based combination therapy
what indicates individual with falciparum needs severe management
> 2% parasite count
how is severe falciparum managed
IV artesunate
if parasite count is above 10%, what is offered
Plasma exchange therapy
how is non-falciparum managed
Artemisin based combination therapy
what should not be given to pregnant women
Artemisin based combination therapy
what should patients with vivax and ovale be given
Primaquine
name a artemisia based combination therapy
artemether and lumefantrine
what can be given as prophylaxis for malaria
Chloroquine and proguanil
what advice should pregnant women be given about travelling to areas with malaria
Do not travel - if unable to avoid take chloroquine or proguanil and folate
what can be used as prophylaxis for malaria in children over 2-months
DEET
