Male fertility rates have dropped During the last half century. An analysis of 1992 noted a constant decrease in the number of sperm and quality Since the 1940s. A more recent study revealed that male infertility rates increased by almost 80% from 1990 to 2019. The reasons why the conduct of this trend remains a mystery, but the frequently mentioned cities include Obesity, poor food and environmental toxins.
Infectious diseases As gonorrhea or chlamydia are often neglected factors that affect fertility in men. The accumulated evidence suggest that a common monocellular parasite called Toxoplasma gondii Can also be a contributor: an April 2025 study showed for the first time that “human sperm lose one’s head During direct contact “with the parasite.
I am a microbiologist, and My laboratory studies Toxoplasm. This new study strengthens the emerging results which underline the importance of preventing this parasitic infection.
The many ways to obtain a toxoplasmosis
Infected cats are disappointed Toxoplasm Eggs in the litter, the garden or other places of the environment where they can be picked up by humans or other animals. Water, crustaceans and unwashed fruits and vegetables Can also host infectious parasitic eggs.
In addition to eggs, tissue cysts present in hot blood animals can spread toxoplasmosis also if they are not destroyed by Kitchen at a good temperature.
While most of the parasite hosts can control the initial infection with little or no symptoms, Toxoplasm Stay in the body for life as Dormant cysts in the brain, heart and muscle tissue. These cysts can reactivate and cause additional episodes of serious illness that damage critical organ systems.
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Between 30% and 50% of the world’s population is permanently infected with Toxoplasm Due to the many ways to spread the parasite.
Toxoplasms can target male reproductive organs
During the infection, Toxoplasm spreads to practically all organs and skeletal muscles. Prove that Toxoplasm may also target human male reproductive organs for the first time up to the AIDS pandemic in the 1980s, when some patients presented the parasitic infection in their testicles.
While immunocompromised patients are the most at risk of testicular toxoplasmosis, it can also occur in Also healthy individuals. Infected mouse imaging studies confirm that Toxoplasm parasites quickly go to the testicles In addition to the brain and eyes some days after the infection.
In 2017, my colleagues and I found that Toxoplasm can also Train cysts in mouse prostates. Researchers also observed these parasites in the ejaculate many animalsincluding human spermraising the possibility of sexual transmission.
Knowing that Toxoplasm Can reside in male reproductive organs has caused analyzes of fertility in infected men. A small study of 2021 in Prague of 163 men infected by Toxoplasm found that More than 86% had sperm anomalies.
A 2002 study in China revealed that Infertile couples are more likely to have a Toxoplasm Infection that fertile couples, 34.83% against 12.11%. A 2005 study in China also revealed that Sterile men are more likely to test positive For Toxoplasm than fertile men.
All studies notHowever, produce a link between toxoplasmosis and the quality of sperm.
Toxoplasms can directly damage human sperm
Toxoplasmosis in animals reflects infection in humans, which allows researchers to answer questions that are not easy to examine in people.
Testicular function and sperm production are greatly reduced Toxoplasm-infected mouse,, rats And Rams. Infected mice have a significantly lower number of sperm and a higher proportion of abnormally.
In this April 2025 study, researchers from Germany, Uruguay and Chile observed that Toxoplasm can reach the testicles and epididymisThe tube where sperm ripen and are stored, Two days after the infection in mice. This observation prompted the team to test what is happening 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 decapitated sperm has increased the more they have long interacted with parasites. The sperm that kept their heads were often twisted and distorted. Some sperm had holes in their heads, suggesting that parasites were trying to invade them because it would be any other type of cell in the organs it infiltrated.
In addition to direct contact, Toxoplasm can also damage sperm because infection promotes Chronic inflammation. Inflammatory conditions in the male reproductive tract are harmful for the production and function of sperm.
Researchers speculate that the harmful effects Toxoplasm May be on sperm could contribute to large global decreases in male fertility in recent decades.
Prevent toxoplasmosis
The proof that Toxoplasm Can infiltrate male reproductive organs in animals is convincing, but it produces health problems in people remains unclear. The testicular toxoplasmosis shows that parasites can invade human testicles, but Symptomatic disease is very rare. Studies to date that show defects in the sperm of infected men are too small to draw firm conclusions at this time.
In addition, some reports suggest that toxoplasmosis rates in high income countries have not increased In recent decades, when male infertility has increased, so it is probably only part of the puzzle.
Whatever the potential effect of this parasite on fertility, it is wise to avoid Toxoplasm. An infection can cause miscarriage or congenital malformations if someone acquires it for the first time during pregnancy, and this can be fatal for immunocompromised people.
Socket Appropriate care for your catQuickly cleaning the litter and washing hands carefully afterwards can help reduce your exposure to Toxoplasm. You can also protect yourself from this parasite by washing fruits and vegetables, Cook meat at appropriate temperatures before consuming and avoiding raw crustaceans,, raw water And raw milk.
This article has been updated to eliminate an incorrect declaration on the prevalence of deaths due to food toxoplasmosis.
This published article is republished from The conversation Under a creative communs license. Read it original article.
