All Infections Are Parasitic
If you look at it this way
I thought one of you would challenge me by saying all infections are parasitic.
That was the lecturer's response halfway through finishing marking our scripts. It was a question on the ways parasites evade immune detection.
For some reason, that statement bypassed me. I was more bent on the message she was conveying — graduate students should not just lean on the conventional but argue the case for the possible. A single question could be explored in various ways.
Still, that comment faded into the distance.
Three days later, while catching up on missed classes, it hit me like a shocking zap!
All infections are indeed parasitic.
What is a parasitic infection?
I asked myself.
It is a unilateral relationship between a host and a parasite. The host provides nutrition for the parasite, while the parasite does nothing in return besides harming the host. This is a dysbiosis.
Parasites cannot survive outside their hosts. Outside their host, they could be in vegetative or cystic forms. Once the right setting presents itself, they come to life.
Pause for a minute and ask yourself what that reminds you of.
Viral and bacterial infections
The question of whether viruses are alive or not is a dicey one.
It’s the kind of question I wouldn’t like to pursue. We barely have an idea what life is. Arguing on such shaky grounds is a recipe for misinformation. I’d rather we focus on the features we know about viruses.
For instance, they need cellular machinery to replicate. This is as far as the conventional understanding of viruses goes. COVID-19 needed cells for them to survive. Other concepts of a virus, such as the one described by Bandea, are squeezed into the sidelines. They are not the focus of this article.
Harmful viruses are no different from parasites. They need the cell’s machinery to replicate. They cannot do so independently. They also need the perfect setting. For parasites, they encyst or turn vegetative outside a host. Once inside, they break the shell from their dormant states and become active.
It is hardly any different for the virus.
Some viruses are helpful. They don’t cause infection. They confer immunity by colonizing different niches inside their host. Colonisation is different from infection. When a microbe invades a host, it colonizes a different part of the host. If its lifestyle harms the host, then it causes infection.
Infectious microbes are all parasites. It does not exclude viruses. Neither does it preclude bacteria.
Bacteria, like viruses, have a bad reputation. They are known to cause infections and death in many communities, groups, and age brackets, in both the resource-poor and resource-rich areas. But bacteria too are helpful. From the time of birth, the kind of bacteria a child gets can influence its proclivity towards a hyperreactive immune system or a normal one.
The harmful bacteria, on the other hand, are parasites. They take up the resources offered by the host while causing harm. A dysbiotic relationship.
Adele said it best:
Sometimes it lasts in love, but sometimes it hurts instead
The slight difference is some bacteria can survive outside the host. However, once a bacterium becomes so dependent on the resources offered by a host, it can become dependent. It can lose its robustness. It becomes a fully-fledged parasite.
Fungi are a different kettle of fish. They are the most resilient multicellular agents I can conceive. Much more resilient than humans. For instance, they are the only multicellular organisms capable of breaking down lignin. They are capable of surviving even outside the host. Nothing parasitic there.
But in the same spirit, the ones that cause disease in its host affirm the parasitic relationship. In immunocompromised individuals, such as those with later stages of HIV/AIDS and transplant patients, fungal infections tend to thrive. Opportunistic infections are accurately labelled — they take the opportunity of the lack of competent immune surveillance. Individuals in this state tend to die from these infections. The agents cause suffering and death to the host, an example of what parasites do.
Organisms with the same relationship with structural differences
Voterre is keen to cite the effects of sticking to a particular classification system in biology.
By dividing organisms into prokaryotes and eukaryotes, viruses tend to get labelled by default. The viruses that infect eukaryotes are labelled just that — viruses, while those that infect bacteria are called bacteriophages. The implication is no virus that infects one group infects the other.
A false assumption.
In the same vein, classifying microbes can have this unforeseen outcome. Viruses are different from bacteria at a structural level just as bacteria are different from all the other living creatures. Structure separates one from another.
Pharmaceuticals will therefore produce antibiotics to kill bacterial infections. Antiviral medication to ward off viruses. Antiretrovirals (ARVs) for those infected with retroviruses. And antiprotozoals to eliminate protozoa. The structure guides the research teams to find ways of managing these microbes once they have been tipped into the infective stage.
But infections hide the fact that they have a dysbiotic relationship with the host. A parasitic relationship.
The role of the host serves the infectious agent but not the reverse. It is an unstable hierarchical relationship.
According to the theory of Organismal Selection, the organism tends to avoid annihilation. For the parasites — viruses, bacteria, fungi, and the classical parasites — they will do that at whatever cost. Even if it depletes its main resource.
The host, with humans being a good example, also tries to avoid annihilation. The birth and rise of pharmaceutical companies owe it to these disease states and many more.
Only focusing on the structure while forgetting about the relationship can be blinding. Science tends to start by asking about the components of the substance of interest. Systems thinking starts by asking about the relationships of the components among each other. The former classified microbes. The latter is only mildly mentioned in the life cycle. But in essence, the infectious agents are parasites from the perspective of relationships.
All of them.
What I’m trying to say is…
We all know of that one person who some have labelled a parasite.
That is the only example you need to see how infections operate. They are parasitic as far as relationships go.
I may have casually dismissed the comment from my lecturer, but now that I have explained this to you, you shouldn’t. It has implications for what we call a system. A system comprises components whose operations rely on the faithful action of other components.
If a system is faulty, remedies can be made to correct it.
If you get an infection, medication might be needed. But just as much, if the agent is parasitic, it means there are alternative ways of controlling the disease besides focusing on the structure.
A wholesome picture tends to shed more light than focusing on a pixel.
Let us focus on both.
This song inspired some of the lines used in this article. Source — YouTube