A species of parasitic worm known as Ascaris lumbricoides is being linked to a sudden increase in fertility among indigenous women in Bolivia, according to new research by the University of California, Santa Barbara (UCSB).
Now, scientists are trying to explore the possibility of using the roundworm to develop treatments that can enhance overall fertility in people.
In a study featured in the journal Science, Aaron Blackwell and his colleagues at UCSB examined the health of 986 Tsimane women who have been infected by the roundworm for most of their lives.
While the Tsimane are known to have up to nine children on average for each family unit, the researchers discovered that those infected by the roundworm were able to conceive an additional two children.
The team added that up to 70 percent of the Tsimane is infected with a parasitic worm, while an estimated one-third of the world's population carries some form of parasitic infection.
On the other hand, an infection of hookworms that was detected in the indigenous women significantly reduced the average number of children they were able to bear.
Blackwell and his colleagues saw that a lifetime of hookworm infection led to three fewer children for the Tsimane.
The researchers believe the change in the women's immune system during pregnancy could have resulted in the fetus not being rejected by their bodies.
"We think the effects we see are probably due to these infections altering women's immune systems, such that they become more or less friendly towards a pregnancy," Blackwell said.
He said that studying the impact of these parasitic worms could potentially lead to the creation of fertility enhancing treatments, but he also pointed out that a considerable amount of research is still needed before they can recommend the procedure to anyone.
Other Parasitic Worms That Influence Human Health
Previous studies have also looked into the potential of parasitic infections in altering the immune system of their hosts.
Dr. Anne Cooke of the University of Cambridge studied the effects of helminths, or multi-celled parasitic worms, on people with type 1 diabetes.
She observed that the product of such organisms is capable of inhibiting the spontaneous development of the autoimmune disease.
The impact, however, varied for each type of parasitic worm, with the infectious agent Salmonella typhimurium having a significant impact even when administered late and the Acanthocheilonema viteae nematode not having any effect on the development of type 1 diabetes at all.
Glasgow researcher Dr. Iain McInnes and his colleagues wrote in their paper that a protein produced by filarial nematodes was able to lessen inflammation and other adverse effects of arthritis in mice induced with the condition.
Multiple sclerosis patients infected with parasites experienced far less effects of the condition compared to those without parasitic infection, according to a study published in the Annals of Neurology.
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