It is a rare case that was treated in a Vietnamese hospital at the beginning of June. A young man with abscesses in the feet and hands caused by a parasitic nematode worm, never observed in the region.
The National Hospital for Tropical Diseases in Hanoi announced in a press release the admission of an extraordinary patient on June 7. The 23-year-old young man from Yen Bai province in northern Vietnam had legs and arms covered with abscesses. He also complained of fatigue and pain for several days. The person responsible for the condition of the young Vietnamese is a parasitic nematode worm never yet observed in the country, the Medina filaria.
The surgeons of the hospital of Hanoi extracted from the abscesses located on the hands of the patient five filaria of Medina of a length ranging between 30 and 60 centimeters. These worms, also called Guinea worms (Dracunculus medinensis) belong to the family of Dracunculus and are responsible for an infectious disease, dracunculiasis.
In the statement, the doctors explain that the patient used to eat live fish and crabs. He is said to have contaminated himself by ingesting Dracunculus medinensis larvae present on these uncooked animals. The water source will surely be analyzed to detect the presence of the parasite’s larvae.
The larvae are absorbed by small aquatic crustaceans, the cyclops in which they grow and become infesting (stage L3). Humans, or other mammals, get infected by drinking unfiltered, parasitic water. In its life cycle, mammals are the definitive host of this parasitic nematode. In parasites, the definitive host corresponds to the organism in which the parasite will reach its adult size and carry out its sexual reproduction (unlike the intermediate host, here cyclops).
The larvae are released in the intestine and migrate to the subcutaneous tissues where they continue their development. Once adult and in the presence of water, the female pierces the skin, which at the same time creates a painful abscess often on the feet or hands, to spill its larvae which will again infest cyclops.
As there is no specific treatment for dracunculiasis, doctors treated the young man by administering an anthelmintic targeting nematodes, and removing the worms from his wounds.
If dracunculiasis is unprecedented in Vietnam, it has been endemic to many African countries, mainly in rural areas. In the 1980s, 3.5 million people suffered from this disease. Today, it is endangered thanks to eradication campaigns. According to the World Health Organization, of the 20 countries where the disease was endemic, only two reported cases in 2017: Ethiopia and Chad (fifteen cases each). In May 2020, Ethiopia recorded seven human cases and 50 people under observation in the Gambella region. If the worm no longer infects millions of humans, it is still present in other mammals such as dogs and cats.