Can HIV modify human behavior?

Several studies suggest that HIV may have some influence on human behavior.

HIV has been wreaking havoc on mankind for decades, but some of its effects on the body are still being studied. This is the case of the behavioral modification that this virus can cause, according to some studies..

In this article we will explore this question to discover what kind of behaviors it refers to, under what conditions this effect takes place and other important characteristics.

Can HIV modify human behavior?

Although the human immunodeficiency virus was discovered in the early 1980s, and huge amounts of research have been done on it, the truth is that on some issues it remains relatively unknown. One of the questions that researchers are still trying to unravel is whether HIV can modify human behavior.

Before delving into that question, we should take a brief look at the implications of this virus in order to situate ourselves. HIV seems to come from another virus, SIVcpz, which attacked some species of apes, such as chimpanzees. Somehow, this virus made the leap to the human species, giving rise to HIV, a relentless agent against humans..

HIV is transmitted mainly through fluids, so the sexual route quickly became the main source of infection, before enough was known about it to take measures to prevent the rapid progression of the epidemic in the 1980s.

Before going on to study whether HIV can modify human behavior, it is important to know that the main problem of this virus is that, in the long term, usually 10 years thanks to the pharmacological advances that have been made in this regard, it can cause the so-called acquired immunodeficiency syndrome, or AIDS, in the host.

Once this disease has developed, the sufferer sees his or her immune system progressively deteriorate to the point where he or she becomes to become extremely prone to infections or other diseases, such as cancer. Under such conditions, the life expectancy of this person is significantly affected.

Although it is true that drugs to slow down this effect are becoming more and more efficient, the truth is that a fully effective vaccine has not yet been developed to put an end once and for all to this terrible disease.

The influence of HIV on behavior

We wondered at the beginning of this article whether HIV can modify human behavior. According to some studies that we are going to know below, everything seems to point to the fact that yes, HIV has the capacity to modify the behavior of the host, everything seems to point to the fact that yes, HIV has the ability to modify host behavior in a very specific way. in a very specific way.

Specifically, what the results of the latest research seem to affirm is that HIV would be altering the sexual behavior of people affected by this virus, and more specifically in male individuals. But, when we talk about whether HIV can modify human behavior, what exactly are we referring to in the sexual sphere?

According to the studies, it seems that HIV is causing some very subtle but effective changes in sexual behavior. very subtle but effective changes in the host, aimed at causing the host to be more sexually active and even take greater risksby having sex with a greater number of people. At the adaptive level, this mechanism makes very obvious sense: maximum propagation.

A virus is not exactly a living organism until it has attached itself to a host, but the laws of natural selection apply to it just the same. Therefore, those viruses that manage to "reproduce" (with the help of the host) in a more optimal way and thus manage to propagate in successive generations will tend to survive.

Taking into account this mechanism and the fact that HIV is transmitted through fluids, the sexual route being the easiest, it seems clear that the strategy of making the host have the maximum number of encounters possible would be an excellent method to ensure the survival of the virus, jumping from one individual to another.jumping from one individual to another, which allows it to reproduce.

Studies on the behavior modification of this virus

This is the phenomenon studied, among others, by Philip T. Starks and his collaborators, who compiled data from different studies to carry out an analysis that would allow them to answer the question of whether HIV can modify human behavior. According to the data observed, these authors affirm that, indeed, HIV is capable of such a task.

To come to this conclusion, Starks looked at the reports of participants in the studies analyzed and found that those individuals who were in the acute phase of HIV infection reported significantly more sexual encounters and more risky behaviors (new partners, failure to use protection, etc.). (new partners, non-use of protection, etc.) than those in the non-acute phase.

Not only that, but it also it seems to be observed that the higher the patient's viral load, the more risky sexual behaviors performed by the male host.. Therefore, with respect to the question of whether HIV can modify human behavior, it would seem that the answer is yes and that it becomes more efficient in this task the greater the viral load that the individual possesses.

However, researchers are cautious and ask the scientific community to put more emphasis on carrying out this type of study in order to resolve this question once and for all and give a categorical answer to the question at hand. Only then will we know beyond any doubt whether HIV can modify human behavior.

Other cases of behavior modification by viruses

For further research on whether HIV can modify human behavior, we can look at similar cases.. There are other viruses that also modify host behavior, even if the host is not human, to achieve similar effects. Let's review some of the best known cases to get a better perspective of this phenomenon.

1. IIV-6 / CrIV virus in crickets

For example, there is a virus called IIV-6 / CrIV that affects crickets, causing infertility. However, externally it does not generate any kind of manifestation, so that a cricket infected by this pathogen is visually indistinguishable from a healthy cricket. However, one of the effects observed in individuals affected by the virus is precisely similar to the one we have reviewed in this article.

It appears that crickets that are infected by IIV-6 / CrIV, would see their sexual behavior altered, so that they would have more relationships and with a greater number of individuals.. The objective is the same as the one we observed when studying the question of whether HIV can modify human behavior: to expand the virus as much as possible, ensuring its survival.

To observe this phenomenon in figures, we have to know that a healthy cricket takes on average about 10 minutes to start a courtship call to a female. In contrast, a male infected with this virus took approximately 3 minutes to perform this action, in search of sexual intercourse. As in the case of HIV, this behavioral modification took place only in the case of male hosts.

2. Massospora cicadina fungus in cicadas

There are other examples in the animal world. One of them is the fungus Massospora cicadina and the effect it has on cicadas. It seems that when an individual of this species is infected by this fungus, it suffers an effect similar to the one we saw when answering whether HIV can modify human behavior.

In fact, the effect of Massospora cicadina is even more lethal. It can cause the male host to flap its wings as a female would, in order to attract the attention of other attract the attention of other male individuals so that they can come into contact to deposit the spores of this fungus on them..

The most dramatic part of the process is that the fungus gradually decomposes the body of the carrier cicada, but this does not cause it to lose effectiveness in its dispersal mechanism, so that cicadas that have lost their genitalia and even their abdomen due to infection can be observed continuing to transmit the fungus to as many individuals as they can.

3. Entomophthora muscae in dipterans

A very similar case to the one we have seen in the previous point is that of the fungus Entomophthora muscae and dipteran insects, which include mosquitoes, flies, horseflies and other animals. Se cree que este hongo provoca en estos individuos una respuesta que se asemejaría a la cuestión de si puede el VIH modificar el comportamiento humano.

Referencias bibliográficas:

• Adamo, S.A., Kovalko, I., Easy, R.H., Stoltz, D. (2014). A viral aphrodisiac in the cricket Gryllus texensis. The Journal of Experimental Biology.
• Boyce, G.R., Gluck-Thaler, E., Slot, J.C., Stajich, J.E., Davis, W.J., James, T.Y., Cooley, J.R., Panaccione, D.G., Eilenberg, J., De Fine Licht, H.H., Macias, A.M., Berger, M.C., Wickert, K.L., Stauder, C.M., Spahr, E.J., Maust, M.D., Metheny, A.M., Simon, C., Kritsky, G., Hodge, K.T., Humber, R.A., Gullion, T., Short, D.P.G., Kijimoto, T., Mozgai, D., Arguedas, N., Kasson, M.T. (2019). Psychoactive plant-and mushroom-associated alkaloids from two behavior modifying cicada pathogens. Fungal ecology. Elsevier.
• Coyle, M.C., Elya, C.N., Bronski, M., Eisen, M.B. (2018). Entomophthovirus: An insect-derived iflavirus that infects a behavior manipulating fungal pathogen of dipterans. BioRxiv.
• Starks, P.T., Kelsey, M.M.G., Rosania, D., Getz, W.M. (2020). Does HIV infection increase male sexual behavior? Evolution, Medicine, and Public Health.