A man with pain and inflammation in his genitals had worms dancing inside his scrotum. The blood test revealed the presence of juvenile forms of the species Wuchereria bancrofti, a type of parasitic nematode, or roundworm. It is found in tropical regions and is transmitted by mosquitoes. The case study is published in the New England Journal of Medicine.
A 26-year-old man living in New Delhi recently presented to a hospital in the city after suffering from pain, swollen testicles and a mild fever for about a month. After performing a quick ultrasound, doctors spotted several parasitic worms contained inside his scrotum (the sac of skin that contains the bursa).
A blood test later revealed that it was a juvenile form of worms of the species Wuchereria bancroftia type of parasite.
Sign of filarial dance in the scrotum
Wuchereria bancrofti completes its cycle in two hosts: mosquitoes (intermediate host) and humans (definitive hosts). Concretely, a female mosquito biting an infected person absorbs the parasite. Inside this mosquito, the parasite then transforms into a mobile larva. When it bites a human being again, the parasite enters the bloodstream of its new host.
After being “delivered” by these insects, the worms pass through the human lymphatic system. Adult worms can live for about seven years, mating in the meantime to produce millions of offspring, called microfilaires, which continue to migrate inside the body. The penchant of the filiform parasite for “pirouettes” is well known (we then speak of ” filarial dance”) and the ultrasound imaging below perfectly illustrates this phenomenon.
Together, these parasites cause a disease called lymphatic filariasis. It can cause tissue swelling (lymphedema), elephantiasis (significant swelling of the legs and arms, for example) and swelling of the scrotum. Moreover, it is the first disease transmitted by insects to have been discovered.
According to the Pan American Health Organization, more than 120 million people are infected with lymphatic filariasis in the world at any time. Infections usually start in childhood and symptoms show up later in life. They can lead to physical disabilities as well as psychological difficulties, such as depression, which sometimes lead to social exclusion and poverty.
Although in some cases surgery is required to remove the worms, in this patient’s case a three-week course of diethylcarbamazine, an antiparasitic drug, was fortunately enough to kill all the worms.