(Section D: Other Infectious Agents) Lecture 27 Flashcards
Malaria
* Source
* Cases
* Deaths
- Infected mosquitoes
- ~249 million cases
- 608,000 deaths (2012)
What is the majority of cases malaria in?
Children under age of 5
Plasmodium
* Motility
* Type of parasite
* Hosts
- Apicomplexa
- Obligate parasite
- 2 hosts (vertebrate and arthropod)
What type of hosts are vertebrates and arthropods for Plasmodium?
- Vertebrate: Intermediate host (asexual reproduction)
- Arthropod: Definitive host (sexual reproduction)
Plasmodium species
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium ovale
- Plasmodium malariae
- Plasmodium knowlesi
Plasmodium falciparum
Deadly to humans
* 48 hour cycles of fever
Plasmodium vivax
48 hours fever cycle
* Similar to Plasmodium ovale but differ in blood group
Plasmodium ovale
48 hour fever cycle
Plasmodium malariae
Long term illness
* 72 hour fever cycle
What is the 48 hour fever cycle known as?
Tertian Cycle
Plasmodium knowlesi
Zoonotic (comes from animals)
* 24 hour fever cycle
Anopheles
- Mosquito species that transmits malaria (30-40 species)
- Only females transmit disease (needs blood for eggs)
- Males only eat sugar to survive
Anopheles
* Anatomy
(7)
- Proboscis
- Salivary glands and duct
- Dorsal Diverticulum
- Crop
- Anterior midgut junction
- Stomach
- Malphighian tubule
Proboscis
To pierce and bite
What function does the saliva of mosquitoes do?
Serves to numb the bite site and anticoagulant
Dorsal Diverticulum and Crop
Store and digest sugar
Anterior midgut junction
Separates sugar and blood meals
Stomach
For the blood meals
Malpigion tubules
Serves as kidneys
Do mosquitoes have a closed circulatory system?
No
* Hemolymph is circulatory fluid that encloses all the organs
Plasmodium Life Cycle
* Mosquito
- Biting infected organism + Getting blood meal
- Fertilization + Form zygote (diploid)
- Ookinete (tetraploid + motile)
- Sporogony (creates sporozoites)
- Cyst ruptures (sporozoites go to salivary glands via hemolymph)
Plasmodium Life Cycle (mosquito)
* What does mosquito pick up when it bites an infected host?
Gametocytes
* Male - Microgametocytes
* Female - Macrogametocytes
Plasmodium Life Cycle (mosquito)
* How does fertilization occur?
- Male gametocytes undergo exflagellation (matures, release sperm)
- Fertilizes female gametocytes
- Forms zygotes (diploid)
Plasmodium Life Cycle (mosquito)
* What happens to ookinetes?
Forms in the stomach of the mosquito
* Moves through the epithelium to wall of stomach
* Ookinetes - Tetraploid