Health experts had expected to eliminate the deadly tropical disease by last year, but it is being spread to people via dogs. A study now warns.
Guinea worm is often transmitted by water contaminated from fleas carrying the parasite larvae. But scientists now know that dogs can transmit it to other animals by eating fish infested with the parasite.
When the worms have hatched, they grow in the human body. After 10-14 months, the adult worm grows to 3 feet (1 meter) length.
Globally, there were around 3.5 millions cases of guineaworm in 1986. But, in 2020, only 27 such cases have been reported.
Study has shown that Guinea worm, the devastating tropical disease, is being passed to humans through dogs. The images below show a Guineaworm emerging from the leg of a dog.
When the worms have mated, they grow within a person. After about 10-14 month, the 3ft (1 metre) mature worm emerges from its legs or arms to let go of the larvae.
Although the World Health Organization had established a deadline of the last year to eradicate it, the WHO has since moved that target to 2030.
It has been revealed that dogs are eating parasite-laden fish to hinder these efforts.
This allows pets to continue the life cycle of the parasite, while humans are still susceptible.
In Chad and Ethiopia, Mali and South Sudan, the parasite can lead to trauma and disability.
A targeted surveillance revealed that 93% of all Guinea worms found worldwide in 2020 were detected in dogs from Chad in central Africa.
University of Exeter researchers spent a full year visiting the hardest-hit villages of Chad’s River Chari.
The satellite tags were used to track hundreds of dogs and provide information about their movements. Dog diets were also revealed using stable analysis of the whiskers.
Much of the fish eaten by the dogs – usually guts or smaller fish – was discarded by humans fishing on the river and its lagoons.
The study was led by Professor Robbie McDonald of Exeter’s Environment and Sustainability Institute.
He stated that dogs are the main obstacle to eliminating this terrible human disease.
“Our study shows that Guinea worm is likely to persist in Chad due to fisheries and dogs being allowed access to fish.
The satellite tags were used to track hundreds of dogs and reveal their diets using stable isotope analysis. Much of the fish eaten by the dogs – usually guts or smaller fish – was discarded by humans fishing on the river and its lagoons
“The current challenge is not to eliminate this disease only in humans, but also in animals.
“This case is an example of how a unified approach of integrating the health of animals, people and the environment can be used to eliminate this devastating human disease.”
The Carter Center was founded by Jimmy Carter and supported the work in Chad by WHO and Chad Ministry of Public Health.
Carter was 97 years old when he said six years ago that he’d ‘like the last guineaworm to die before me’.
The research has been published in the journal Current Biology.