Between 30% and 50% of the world’s population is permanently infected with toxoplasm due to many ways in which parasite can spread, new study reveals. It may be contributing to major global declines in male fertility in recent decades.
Male fertility rates have fallen dramatically in the last half of the century. A 1992 analysis has noticed a constant decrease in sperm count and quality since the 1940s and a latest found that male infertility rates increased by almost 80% between 1990 and 2019.
The reasons behind this trend remain a mystery, but the often cited culprits include obesity, bad diet e Environmental toxins.
Infectious diseases like gonorrhea or chill These are often ignored factors that affect fertility in men.
Evidence suggests that a common unicellular parasite called Toxoplasma gondii can also be a taxpayer: one from April 2025 showed for the first time that “Human sperm loses its head up to direct contact” with the parasite.
The various ways to contract toxoplasmosis
Infected cats defecate toxoplasma eggs in the sandbox, garden or other places of the environment where they can be collected by humans or other animals. THE wateros seafood e and fruits e legumes Not washed can also host infectious parasitic eggs.
Beyond eggs, the tissue cysts Present in hot -blooded animals can also transmit toxoplasmosis if not destroyed by cooking the proper temperature.
Although most parasite hosts can control the initial infection with few or no symptoms, toxoplasma remains in the body for a lifetime as dormant cysts in the brain, heart and muscle tissue. These cysts can reactivate and cause additional episodes of serious diseases that damage critical organic systems.
Between 30% and 50% of the world population It is permanently infected with toxoplasm due to many ways in which the parasite can spread.
Toxoplasma can affect male reproductive organs
After infection, toxoplasma spreads through virtually all skeletal organs and muscles. Evidence that toxoplasm can also affect male reproductive organs first appeared during the height of AIDS pandemic in the 1980s, when some patients had parasitic infection in the testicles.
Although immunocompromised patients are those who are at the highest risk of testicular toxoplasmosis, it can also occur in healthy individuals. Image studies in infected rats confirm that toxoplasma parasites travel rapidly to the testicles, besides the brain and eyes, a few days after infection.
In 2017, toxoplasma was also found to form cysts in the rat prostate. Researchers also observed these parasites in the ejaculate of many animals, including the human semen, increasing the possibility of sexual transmission.
The knowledge that toxoplasma can reside in male reproductive organs led to fertility analyzes in infected men. A small study conducted in Prague in 2021 with 163 men infected with toxoplasma found that More than 86% had anomalies in the semen.
A study conducted in 2002 in China found that infertile couples are more likely to have a toxoplasm infection than fertile couples, 34.83% against 12.11%. A study conducted in 2005 in China also found that sterile men are more likely to test positive for toxoplasm than fertile men.
However, not all studies establish a link between toxoplasmosis and the quality of sperm.
Can directly damage human sperm
Animal toxoplasmosis reflects infection in humans, which allows researchers to address issues that are not easy to examine in people.
Testicular function and sperm production are drastically reduced in toxoplasma rats and sheeps. Infected rats have significantly lower sperm counts and a higher proportion of sperm with abnormal shapes.
In this April study, researchers from Germany, Uruguay and Chile observed that toxoplasma can reach the testicles and the epididymis, the tube where sperm mature and are stored two days after rated infection. This discovery led the team to test what happens when the parasite comes into direct contact with human sperm in a test tube.
After only five minutes of exposure to the parasite, 22.4% of sperm were beheaded. The number of beheaded sperm increased the more time they interacted with the parasites. The sperm that kept their heads were often twisted and deformed. Some sperm had holes in their heads, suggesting that the parasites were trying to invade them as they would have any other cells in the organs they infiltrate.
In addition to direct contact, toxoplasma can also damage the sperm because the infection promotes chronic inflammation. Inflammatory conditions in the male reproductive tract are harmful to the production and function of sperm.
Researchers speculate that the harmful effects that toxoplasma may have on sperm may be contributing to major global declines on male fertility in recent decades.
Prevention
Evidence that toxoplasma can infiltrate male reproductive animal organs are convincing, but it is still unclear if it causes health problems in people.
Testicular toxoplasmosis shows that parasites can invade human testicles, but symptomatic disease is very rare. The studies conducted until the moment showing defects in the sperm of infected men are very small to reach definitive conclusions at this time.
In addition, some reports suggest that toxoplasmosis rates in high performance countries have not increased in recent decades, while male infertility has increased, so it is likely that it is just a part of Puzzle.
Regardless of the potential effect of this parasite on fertility, it is advisable to avoid toxoplasma.
An infection can cause miscarriage or congenital defects If someone first contracting it during pregnancy and can be fatal to immunocompromised people.
Take good care of your cat, immediately clean the sandbox and wash your hands well then you can help reduce your toxoplasm exposure. It can also protect yourself from this parasite by washing fruits and vegetables, cooking meat at adequate temperatures before consuming and avoiding raw seafood, untreated water and raw milk.
