Malaria

Question 1

what are Protozoa?

Answer 1

single celed eukarytpic organsism

transmitted by

vector-borne

faecal oral

sexuallty transmitted

Question 2

what protzoan parasite causes Malaria

Answer 2

Plasmodium species

vectro borne protzoan parasite

Question 3

what vector transmits malaria (plasmodium species)

Answer 3

the bite of the femal anopheles mosquito

can alos occur due to blood transufsion and vertically

Question 4

what is the most common plasmoidum speciies which causes malaria?

Answer 4

Plasmoidum falciparum- is the most common- 75%

plasmoidum vivax

plasmodium ovale

plamsodim malarie

plasmodium Knowlesi

Question 5

describe the Mosquito phase of the malrai lifesycle

Answer 5

• female anopheles mosqiito
• bite human at ight for bone meal
• inject form of malaria called Sporoziotes
• enter blood and ettle in liver cells

Question 6

describe the exo-erythrocytic cyle of malaria

Answer 6

• outside RBC
• mostyl in the liver
• sporoziotes mature into schizonts (asexual repduction)
  
  • P.vivax and P.ovale can enter dormant stage hypnozioties- perssit in the liver and relpase infections
• schizonts grow and rupute- release merozoites
  
  • ​lysis of liver cells- release meroziotes into blood

Question 7

what is the name of malaria parasite stage that infects red bklood cells

Answer 7

Erthyrocitic cycke

meroziotes infect red bllood cells

form ring stage Trophoziotes that mature into schizonts-

svhizonts butrs to release more meroziotes, lysis of RBC

this lysis of RBC causes cylcicnal symptoms/fever

Question 8

when do some parasites differentiat into sexual gametocytes?

Answer 8

in teh ertythocyte stafes

gametocytes are ingested by anopheles mosquitop during blood meal int he mosquit they replicate and make there wya into mosquito slaivary glands - inoculatre new human host during bone meal

Question 9

give a quick name summary of the satges of malaria parasite lifw

Answer 9

sporozoites (infect travel to liver)

schizonts (in liver xells)

(can becoem hypoziotes P.vivax, P.ovale)

burst release Meroziotes

infect RBC-form ringstage trophoziotes

mature in schizonts- rputur- meroziotes again

gaemetocuytes

Question 10

what is the cause of temperatutre/ symtpoms cyclical appearance

Answer 10

depending on species can see regular/irregular cycles of fever-

this depends on when teh parasitic schizont cells ruputre and spread merozoites- Aexaul replication. when. rupture release TNF-a and other inflaamtory markers

in P.flaciuparum- this occurs every 48 hours , but can vary alot

Question 11

why does plasmodium falicparum cause a more severe disease in relation to the spleen

Answer 11

causes blocage of cappilarires in the spleen and reuslts in spleen dysfunction- unabel tro remove damaged RBC and thos infected with malaria parasites

Question 12

what are the clinical features of uncomplicated malaria?

Answer 12

appear 10-15 days after infectiv mosquito bite

early symtpoms mil/non-sopcpefic ferv, headahces chills

uncomplciated= limtied to milder symptoms

Question 13

describe the clinical symptoms of those with complicated malaria

Answer 13

life threatening

high fever

severe anaemai

kidney failure

jaudince

cerebral malria

convulsiosn

respriaotry distress

Question 14

who is most at risk of complciated malaria

Answer 14

children under 5, pregnant women, people with HIV/AIDS- higher risk of contracting malaria and having severe disease

Question 15

Describe the classical malaria presentation

Answer 15

Parooxysm- attack of disaes associated with schizont ruputure follows 3 phases

cold stage- cold shivers

hot stage (feels hot, flsuehd, dry skin, measurabel fever)

sweating /fever breaking stage ( fevr drops and the patient sweats)

Question 16

how is malaria diagnosed

Answer 16

thick film- identidy the presence of malaria

thin film- identidfy species of malaria and quanityf the parasitaemia.

using thin film alone has limited snesicity for malaira- which is why we use both

then use Glemsa stain

Question 17

what features on blood film, other blood tests and clinical features would indicate sevre Malaria

Answer 17

• blood film- hyper parasitaemao- >2%
• visisble schizonts on the blood film - indicate imminet rupture of schizonts
• other blood tests
  
  • sever, anemai, hypoglycaemia, renal impariemnt
• cljicnal featurees
  
  • temeprature above >39
  • jaudncie
  • imapired cosnciousnes
  • signficiant weakness
  • multiple convulsions
  • pulmonary oedema
  • significant bleeding
    
    • rarely causes shcoka alone increase risk of seocndary bacteria infectio

Question 18

describe malaria prevention methods

Answer 18

preventable and treatment nets

contorl vector- indoor resiudl spraying insecticide ,on walsla dn ceilignw ehre anophelees like to land

people living endmeci area- partial immunity to malaria follwoing repeat infeciton

sickle cell trait

Question 19

travel advice to prevent Malaria ABCD

Answer 19

awareness of rrisk

bite prevention (sleep underinsectivide treated net, mosquito net)

chemoprophylazis- antimalarias

diagnosis- if dveloep fever of 38 or more within 1 wweek after being in malaria risk area, who devekopm symptoms or within 1 year of reutrn ahsoul seek emidate care

Question 20

why is chlorquine now not used routinely as early prophylaxis?

Answer 20

wide spread reistance

now options include- doxycycline, Meflouquine, Malarone (atovaquone-proguanil)

Question 21

how do we treat uncomplicated malaria?

what is ACT?

Answer 21

drug treatmemnt depends on area- resistance

avoid monotherpay contirbuiting t drug resistance

Artermisin combined therpay (ACT)= artesunate + mefloquine

• uncomplicated P.falciparum- ACT for 3 days
• • unocomplicated P.vivax, P,ovale ,P.malariea or P. Knowlesi shoudl be treated with ACT unless the area is known to have sensitivity to chloroquine- use chlorquine instrea

Question 22

what si severe/ complicated malaria

Answer 22

treat with IV artesunate

then follow by oral ACT

treat comoplicatios