Male fertility rates have actually been dropping over the previous half-centuryAn analysis from 1992 kept in mind a stable reduction in sperm counts and quality because the 1940sA more current research study discovered that male infertility rates increased almost 80% from 1990 to 2019The factors driving this pattern stay a secret, however regularly pointed out offenders consist of weight problems, bad diet plan and ecological toxic substances

Contagious illness such as gonorrhea or chlamydia are typically neglected elements that impact fertility in males. Building up proof recommends that a typical single-celled parasite called Toxoplasma gondii might likewise be a factor: An April 2025 research study revealed for the very first time that “human sperm lose their heads upon direct contact” with the parasite.

I am a microbiologist, and my laboratory research studies ToxoplasmaThis brand-new research study reinforces emerging findings that highlight the value of avoiding this parasitic infection.

The numerous methods you can get toxoplasmosis

Contaminated felines defecate Toxoplasma eggs into the litter box, garden or other locations in the environment where they can be gotten by human beings or other animals Water, shellfish and unwashed vegetables and fruits can likewise harbor contagious parasite eggs.

In addition to eggs, tissue cysts present in the meat of warm-blooded animals can spread out toxoplasmosis If they are not damaged by cooking to appropriate temperature level

While a lot of hosts of the parasite can manage the preliminary infection with couple of if any signs, Toxoplasma stays in the body for life as inactive cysts in brain, heart and muscle tissueThese cysts can reactivate and trigger extra episodes of extreme disease that damage vital organ systems.

Related: 32 frightening parasitic illness

In between 30% and 50% of the world’s population is completely contaminated with Toxoplasma due to the numerous methods the parasite can spread out.

Toxoplasma can target male reproductive organs

Upon infection, Toxoplasma infect essentially every organ and skeletal muscleProof that Toxoplasma can likewise target human male reproductive organs initially appeared throughout the height of the AIDS pandemic in the 1980s, when some clients provided with the parasitic infection in their testes

While immunocompromised clients are most at threat for testicular toxoplasmosis, it can likewise take place in otherwise healthy peopleImaging research studies of contaminated mice verify that Toxoplasma parasites rapidly take a trip to the testes in addition to the brain and eyes within days of infection.

In 2017, my associates and I discovered that Toxoplasma can likewise type cysts in mouse prostatesScientists have actually likewise observed these parasites in the climax of numerous animalsconsisting of human semenraising the possibility of sexual transmission

Understanding that Toxoplasma can live in male reproductive organs has actually triggered analyses of fertility in contaminated guys. A little 2021 research study in Prague of 163 guys contaminated with Toxoplasma discovered that over 86% had semen abnormalities

A 2002 research study in China discovered that sterile couples are most likely to have a Toxoplasma infection than fertile couples, 34.83% versus 12.11%. A 2005 research study in China likewise discovered that sterilized guys are most likely to evaluate favorable for Toxoplasma than fertile guys.

Not all research studiesnevertheless, produce a link in between toxoplasmosis and sperm quality.

Toxoplasma can straight harm human sperm

Toxoplasmosis in animals mirrors infection in people, which permits scientists to attend to concerns that are challenging to take a look at in individuals.

Testicular function and sperm production are dramatically lessened in Toxoplasma-contaminated mice rats and ramsContaminated mice have substantially lower sperm counts and a greater percentage of unusually formed sperm

Because April 2025 research study, scientists from Germany, Uruguay and Chile observed that Toxoplasma can reach the testes and epididymistelevision where sperm fully grown and are saved, 2 days after infection in mice. This finding triggered the group to check what occurs when the parasite enters into direct contact with human sperm in a test tube.

After just 5 minutes of direct exposure to the parasite, 22.4% of sperm cells were beheadedThe variety of beheaded sperm increased the longer they connected with the parasites. Sperm cells that kept their head were frequently twisted and misshapenSome sperm cells had holes in their head, recommending the parasites were attempting to attack them as it would any other kind of cell in the organs it infiltrates.

In addition to direct contact, Toxoplasma might likewise harm sperm due to the fact that the infection promotes persistent swellingInflammatory conditions in the male reproductive system are hazardous to sperm production and function

The scientists hypothesize that the damaging results Toxoplasma might have on sperm might be adding to big worldwide decreases in male fertility over the previous years.

Avoiding toxoplasmosis

The proof that Toxoplasma can penetrate male reproductive organs in animals is engaging, however whether this produces health problems in individuals stays uncertain. Testicular toxoplasmosis reveals that parasites can attack human testes, however symptomatic illness is really unusualResearch studies to date that reveal problems in the sperm of contaminated males are too little to draw firm conclusions at this time.

In addition, some reports recommend that rates of toxoplasmosis in high-income nations have actually not been increasing over the previous couple of years while male infertility was increasing, so it’s most likely to just be one part of the puzzle.

No matter this parasite’s possible result on fertility, it is smart to prevent ToxoplasmaAn infection can trigger miscarriage or abnormality if somebody obtains it for the very first time throughout pregnancy, and it can be dangerous for immunocompromised individuals.

Taking correct care of your felinequickly cleaning up the litter box and completely cleaning your hands after can help in reducing your direct exposure to ToxoplasmaYou can likewise secure yourself from this parasite by cleaning vegetables and fruits, cooking meat to correct temperature levels before taking in and preventing raw shellfish raw water and raw milk

This post was upgraded to eliminate an inaccurate declaration about the occurrence of deaths due to foodborne toxoplasmosis.

This edited post is republished from The Conversation under a Creative Commons license. Check out the initial short article