To the Editor: I report an infection with Dracunculus medinensis diagnosed incidentally on x-ray. The patient was a Sudanese immigrant, who had sustained a left knee joint effusion after falling. During management at Royal Perth Hospital, a calcified lesion with a serpentine appearance was seen on x-ray within soft tissues near the left knee joint. Its characteristic appearance, combined with the patient’s background, led to a diagnosis of D. medinensis (known as guinea-worm), a nematode parasite which causes dracunculiasis.

The patient’s knee effusion was managed conservatively and improved within a few weeks. The effusion was secondary to the fall and believed to be unrelated to the calcified D. medinensis.

Transmission of dracunculiasis is through consumption of contaminated water. The guinea-worm larvae mature and migrate towards the skin surface over 1 year (during which the patient remains asymptomatic), with over 90% of the worms appearing from the lower limbs. When in contact with water, the exposed guinea-worm releases larvae, and the lifecycle is completed when people ingest contaminated water.1 If the guinea-worms die before maturation, they usually calcify.

The Global Dracunculiasis Eradication Campaign was established in 1981 with the aim of eliminating dracunculiasis through water sanitation efforts.1 With no vaccine or treatment, prevention is the only method of eliminating dracunculiasis. Since the campaign was established, the number of people affected by dracunculiasis has decreased by 98%. Currently, Sudan alone accounts for 73% of cases.1

Our patient migrated to Australia as a refugee from Sudan during the civil war. Her village in Sudan had only one source of water used for daily activities, including drinking. The patient knew many people with dracunculiasis, but did not know she had been infected.

When calcified guinea-worms are discovered during routine radiological examination, they usually do not need treatment. Many people are not aware they have been infected. Muller reported 89% of patients with calcified guinea-worms were asymptomatic.2

No known previous case of a radiologically diagnosed calcified guinea-worm has been reported in Australia. The consequences of war and famine, with a resultant increase in refugees and immigrants from affected nations, is likely to increase the number of incidental calcified guinea-worms found in non-endemic countries. This disease may have a significant impact if affected immigrants arrive during the incubation period (when asymptomatic) and the parasite emerges from the skin after immigration (rather than calcifying), similar to the patient described by Spring.3 Thus, it is important for health personnel to be aware of dracunculiasis, including its radiological manifestations.