Tentamen parasitologie 2004-2005

 

1a) Draw the lifecycle of  Taenia solium

b)     What kind of organism is T.solium?

c)      In the lifecycle: Identify and specify the different types of hosts.

d)     What kind of lifecycle is this?

2a) What is antigenic variation? (draw a graph to clarify your explanation)

 b) Name two parasites that use antigenic variation.

 c) name two mechanisms used by parasites for antigenic variation.

3a) Type II amitochondriate protests (e.g. Trichomonas vaginalis) contain a hydrogenosome.

-        What is the metabolic product from which these organelles derive their name?

-        What is the function of the production of this compound

b) Give 2 reasons why glycolysis in Trypanosoma brucei is a promisisng target for chemotherapeutic intervention.

c) The red blood cell stage of the malaria parasite (plasmodium falciparum) exports reduced gluthationto the host cell.

  - how could this be advantageous to the parasite?

 

4a) what kind of T-cell response is predominant in a helminth infection?

 b) explain the hygiene hypothesis, elaborate on the role the T-cell

 c) what role do helminths play within the hygiene hypothesis

 d) there are phospholipids in Schistosoma mansoni that can activate dendritic cells, discuss whether it would be a good idea to use these lipids to treat patients with allergies.

5a) draw the life cycle for schistosoma spp and plasmodium spp

 b) apply the three levels of prevention for each parasite group

 c) discuss the differences and similarities

6a) (picture man without a nose)

which parasite would be the likely causative agent of this pathology

 b) what other pathologies do these group of parasites cause

 c) draw the life cycle for this parasite group

 d) name the factors that are thought to influence the outcome of the disease

 e) name the samples that you would want to take to prove that this parasite is the causative agent and elaborate on what you would be detecting.

7 a) What are the major clinical complications of severe malaria (in African children)

  b) which species is the causative agent of severe malaria

  c) name at least two mechanisms of cellular damage that this species causes.

8a) The basic reproductive rate R₀ is an important concept within epidemiological modeling of parasitic diseases. In 1957 MacDonald published a formula for R_o for malaria:

   R₀  = m* a² * b₁ *b₂  /g*x

In this formula m is the total number of mosquitos. In which a is the biting rate, b₁ is the proportion of bits that results in parasite uptake. Parameter g is the recovery rate in humans. 1/g thus reflects the average duration of infection. X is the mortality rate (of the mosquito) and 1/x reflects the average lifespan of a mosquito.

a)      define R₀  for malaria

b)     what condition has to be fulfilled to make transmission possible in this situation

c)      assume R₀  = 10, which part of the mosquito population has to be killed to make malaria disappear.

d) discuss why the use of bednets is very efficient.