On Wednesday, the Ministry of Health reported the first human fatality caused by screwworms in Costa Rica.

According to health officials, the victim was a 19-year-old woman from Guanacaste Province.

The disease was initially found at the Upala Canton Public Hospital, in Alajuela Province, where the woman was being treated for a mouth infection.

Following initial medical checks, doctors discovered screwworm larvae on the woman's skin. As part of the protocol in this circumstance, the patient was taken to the Mexico Public Hospital in San José Province.

On Friday, the test findings came back positive for screwworm infestation. After her death, forensic tests revealed that she perished from a variety of chronic diseases including being infected with screwworms.

The screwworm disease is caused by larvae of the fly Cochliomyia hominivorax. It is a parasitic insect whose larvae (maggots) consume live tissue in warm-blooded animals, including humans.

The female flies lay 250 to 500 eggs in exposed tissue, such as wounds. The larvae hatch and burrow into the surrounding tissue while feeding. If the wound is disturbed at this stage, the larvae dig or "screw" further into the flesh, resulting in the larva's popular name. The larvae can cause significant tissue damage and even death to the host.

In July 2022, health authorities confirmed the first case of the screwworm disease in a dog in Corredores Canton, Puntarenas Province.

The first human infection was confirmed in February. The patient was a man from Pavones District, Golfito Canton, Puntarenas Province. He received proper medical attention and overcame the disease.

In February, the U.S. donated $10 million to Costa Rica via its embassy to control and eradicate screwworm disease.

Costa Rica issued a State of Health Emergency to battle the plague.

The warning enables fly control measures to be implemented, such as active surveillance on farms where instances are found.

Additional actions include dispersing sterile male flies, which is the primary method utilized to remove the worm. About 15 million sterile male flies are being disseminated countrywide in 5 flights every week, with traps deployed to detect the existence of the fly.

Checkpoints were also established to ensure that the animals being transported were not infected.

Authorities urge the public to report any suspected cases of sick animals or people by calling the emergency line at 2587-1600.