28.10

Question 1

Malaria is a ___ infection that is transmitted usually by female ___ ___. It is NOT directly transmitted by person-person contact.

Answer 1

Blood

Female anopheles mosquitoes - because of blood meals for egg development

Question 2

There are 2 main types of malaria: ___ ___ and ___ ___ malaria (protozoan parasites). ___ malaria is esp. common in sub-Saharan Africa and other tropical regions. ___ malaria is esp. common in the Asia-Pacific region. The majority of severe malaria disease and death is due to ___ ___.

Answer 2

P. falciparum
P. vivax
Falciparum
Vivax
Majority due to P. falciparum

Question 3

Young children and ___ women are at greatest risk of malaria infection.

Answer 3

Young children and pregnant women

In pregnancy, malaria can cause miscarriage, stillbirth and low birth weight

Question 4

There are no animal reservoirs of Plasmodium, EXCEPT for P. ___.

Answer 4

Knowlesi

Question 5

P. ___ develops in hepatocytes and only some rupture. Therefore, some of the parasite stays dormant in hepatocytes in the liver and may reactivate later.

Answer 5

Vivax

In falciparum - NO dormant infection

Question 6

Clinical features of uncomplicated/mild malaria (usual) include flu-like illness (fever, headaches and malaise. Clinical features of severe malaria include severe ___, ___ complications like coma, convulsions and long-term neurological deficits, ___ distress and ___ acidosis. Others include hypoglycaemia, kidney failure and coagulopathies.

Answer 6

Severe malaria: severe anaemia, cerebral complications, respiratory distress and metabolic acidosis

Question 7

Malaria infects ___ ___ cells and is disseminated to all organs. It can block blood vessels e.g. in the brain. ___ ___ cells are cleared from circulation or directly destroyed. This can result in severe multi-system disease: coma (cerebral malaria), severe anaemia, respiratory distress and acidosis.

Answer 7

Red blood cells

Red blood cells

Question 8

Immunity to malaria develops VERY slowly, after many episodes. There are three main types of immunity to malaria: immunity that prevents ___ malaria, immunity that prevents ___ malaria and immunity to malaria in ___.

Answer 8

Severe
Any
Pregnancy

Question 9

In falciparum malaria (or vivax maybe), there are waves of parasitaemia over time. This is due to antigenic ___. The parasite changes its ___ to avoid the developed immune responses. This is one of the reasons for slow development of immunity to malaria.

Answer 9

Antigenic variation

Changes its coat

Question 10

If heterozygous (carrier) for the ___ ___ trait, you have significant protection to malaria, esp. the severe forms.

Answer 10

Sickle cell trait

Question 11

In children with higher levels of antibodies to EBA175, there was ___ infections of malaria.

Answer 11

Less

Question 12

The RTS,S vaccine contains a segment of the CS protein - a major antigen of ___ (form of malaria parasite). It is presented in a virus like particle with HBV surface antigen. After phase 3 trials, there was only modest efficacy, and only to P. falciparum.

Answer 12

Sporozoites

There are LOTS of merozoite antigens - challenge to vaccine development