Please, help with this question. I know that it can have few different answers, but, please, tru to answer it from your master-specailist point of view.

[RomanRodinskiy]

Analyse the strategies of exploitation of the host and ways of avoiding the immune response by parasites and suggest, in your opinion, the best parasite among the existing ones and ways of fighting against such "elusive Avenger"?

[mistermack]

3 hours ago, RomanRodinskiy said:

Analyse the strategies of exploitation of the host and ways of avoiding the immune response by parasites and suggest, in your opinion, the best parasite among the existing ones and ways of fighting against such "elusive Avenger"?

There is no good or bad. But if you take survival of a parasite's genes as their purpose, then the parasites that don't damage their hosts are the best. A lot of viruses eventually end up not damaging their hosts, and become part of their dna, so I guess those would qualify as being the 'best' parasites. 

[RomanRodinskiy]

It's not about which parasites are best for their master at all. The question means that the best parasite is the one that best avoids its host's immune system, which makes it invisible. And so the question needs to learn which parasites can boast such characteristics and what processes and mechanisms are responsible for it.

 

[mistermack]

5 hours ago, RomanRodinskiy said:

It's not about which parasites are best for their master at all.

It seems pretty obvious that parasites that damage or kill their hosts will eventually become less numerous, if they adversely affect the survival of the population of the host. Generally the ones that do the most damage are ones that jump from one species to another, like the covid virus did. You then get an evolutionary race of parasite vs immune system. In the end, the most successful parasites will be the ones that can evolve quickest, to keep ahead of the game. 

[TheVat]

Toxoplasmosis is a champ.  Half the world has it, and most never have symptoms, and it spreads from cat litter boxes.  

The parasite's survival is dependent on a balance between host survival and parasite proliferation. T. gondii achieves this balance by manipulating the host's immune response, reducing the host's immune response, and enhancing the parasite's reproductive advantage. Once it infects a normal host cell, it resists damage caused by the host's immune system, and changes the host's immune processes.  As it forces its way into the host cell, the parasite forms a parasitophorous vacuole (PV) membrane from the membrane of the host cell. The PV encapsulates the parasite, and is both resistant to the activity of the endolysosomal system, and can take control of the host's mitochondria and endoplasmic reticulum.