Malaria

Question 1

The burden of malaria geographically

Answer 1

Most malaria cases and deaths occur in sub-Saharan Africa. The WHO regions of South-East Asia, Eastern Mediterranean, Western Pacific, and the Americas are also at risk

Question 2

How malaria impacts morbidity and

mortality across age groups

Answer 2

Children under 5 are one of most vulnerable groups affected by malaria

• Occurs bc they have yet to gain acquired immunity
• After 5 yrs, children are generally protected from severe disease

Question 3

Manifestation of malaria in the body

Answer 3

• Starts w/infected mosquito bite
• Malaria parasites enter human “host” and undergoes 3 stages of development in human host (-Sporozoite, liver, RBC)
• Another mosquito gets malaria from infected host and transmits malaria from one host to the next host

Question 4

Sporozoites

Answer 4

• Injected by female Anopheles mosquitoes
• Take <1 hr to reach the liver
• Clinically asymptomatic (patient is carrier for disease but experiences no symptoms)

Question 5

Liver Stage Development

Answer 5

• Last 6 days-weeks (species/ strain specific)
• End Result: liver cell filled w/thousands of merozoites—> rupture & release of merozoties into blood stream
• Entirely clinically asymptomatic

Question 6

Blood Stage Development

Answer 6

• Invade RBC—> multiply large mis-shaped red cells filled w/ merozoites
• Rupture/release—> invade more red cells
• Clinical symptoms
• Some develop into male and female gametes–> taken up by Anopheles mosquito during blood meal —> responsible for malaria transmission
• Development in mosquito continue to become sporozoites—>enter salivary gland of mosquito

Question 7

Basic transmission of malaria

Answer 7

• Female mosquito bites an infected person, taking w/ it a small amount of blood containing malaria parasites
• These parasites mix w/mosquito’s saliva
• Then, are injected into person being bitten, giving them malaria

Question 8

The actors involved in malaria control

Answer 8

The Global Fund, President’s Malaria Initiative, Roll Back Malaria Partnership, UNITAID, USAID, MACEPA

Question 9

How malaria fits the epidemiological triad (pt. 1)

Answer 9

-Agent: Malaria; a protozoan that lives off other organisms

Question 10

How malaria fits the epidemiological triad (pt. 2)

Answer 10

• Host: two hosts necessary; the female mosquito and human
• While not affecting mosquitos, the parasites grow and multiply in human liver then blood cells
• Parasite grows inside rbcs and destroys them releasing daughter parasites (merozoites) that continue cycle by invading other rbcs

Question 11

How malaria fits the epidemiological triad (pt. 3)

Answer 11

• Environment: Anopheles mosquitos thrive in regions w/ warm temps, humid conditions, and high rainfall
• So tropical and subtropical areas are ideal
• Malaria is also prevalent in low-income nations where a lack of resources and political instability inhibit the building of solid malaria control programs