Lecture 15 Flashcards
diseases where vectors are involved in biological transmission of pathogens
- malaria
- leishmaniasis
- dengue fever
- zika virus
- west nile fever
Describe Culicidae
- mosquitos
- only females bite
- visit host only for feeding
- trasnmit viruses, protozoans and nematodes
2 subspecies of culicidae
anophelinae
culicinae
Describe anophelinae
- vectors of malaria
- hosts of filarial worms
- angled upwards, spotted wings
- nocturnal
What factors influence the efficiency of malaria?
- activity period (day vs night)
- feeding preferences (exo vs endophagy, human vs animals)
- lifespan
Describe Culicinae.
- vectors of arboviruses
- host for filarial worms
- horizontal body, pointed female abdomen
5 plasmodium species involved in malaria
- P. falciparum
- P. vivax
- P. malariae
- P. ovale
- P. knowlesi
What plasmodium species involved in malaria is not anthroponotic?
P. knowlesi (zoonotic)
Exo-erythrocytic cycle of malaria
- mosquitos bite
- sporozoites develop
- migrate to liver
erythrocytic cycle of malaria
- parasites move to RBC
- asexual reproduction = gametocytes
- uptake of gameto cytes
Sporogonic Cycle of Malaria
- mosquito ingests gametocyte from blood
- in mosquitos midgut:
- gametocytes –> gametes –> zygotes –> ookinete - ookinete penetrates gut wall and becomes oocyst
- oocyst undergoes asexual reproduction making 1000s of sporozoites
- oocyst bursts, releasing sporozoits to salivary gland
- mosquito is now infectious
General onset of symptoms of malaria
begins with onset of erythrocytic cycle
7-25 days
general symptoms of malaria
- recurrent acute chills, fever, headache, sweating
- anemia
- enlarged spleen
- lethargy
- anoxia of tissues
- death
what causes the acute chills, fever, headaches and sweating?
immune response to toxins being release by dying RBCs
RBC invaded by Plasmodium Vivax
immature RBC
periodicity of Plasmodium vivax
48 hours, mild symptoms
percentage of global cases of malaria from plasmodium vivax and where
10-20%
South/Central America
How long do symptoms last of plasmodium vivax if untreated?
months to years
what is the hypnozoite stage in plasmodium vivax?
dormant liver stage that can cause a delay of onset or a relapse
what RBC are affected by plasmodium falciparum?
all RBCs
symptoms of Plasmodium falciparum
severe anemia
severe anoxia of tissues
blocked capillaries
periodicity of plasmodium falciparum
36-48 hrs
How long do symptoms last of malaria from Plasmodium falciparum if untreated?
5 months to 2 years
percentage of malaria cases due to plasmodium falciparum and where
80-90%
Sub Saharan Africa
