Puerto Vallarta, Jalisco, July 11, 2026 – A rancher who has lived in Puerto Vallarta more than 15 years was diagnosed with human screwworm myiasis after seeking care in Rosamorada, Nayarit, with an infected wound on his arm, state health officials said.
The case was confirmed by the federal Institute of Epidemiological Diagnosis and Reference (InDRE) after medical staff in Rosamorada sent wound samples. Nayarit Health Secretary Beatriz Adriana Ruiz Huerta said the patient received treatment, was recovering favorably, and would continue medical follow-up in Puerto Vallarta.
The reporting creates a jurisdictional detail that could otherwise confuse readers. Nayarit identified and notified the infection, but Ruiz Huerta said the case belongs epidemiologically to Jalisco because the patient has been based in Puerto Vallarta for more than 15 years. A federal epidemiological bulletin dated July 3 lists one 2026 human case under Nayarit and two under Jalisco, but the table is organized by the state that submitted the notification. It was not immediately clear whether a later bulletin would reassign the Nayarit entry.
The announcement directly ties a human diagnosis to a Puerto Vallarta resident, moving the local discussion beyond earlier animal detections. Vallarta Daily reported in June that Puerto Vallarta had seven confirmed screwworm detections within a Region 8 cluster of 43 cases, while Jalisco had already registered a human infection elsewhere in the state.
The human screwworm is not transmitted directly between people. The infection begins when a female Cochliomyia hominivorax fly deposits eggs in an open wound or, less commonly, a natural body opening. The larvae feed on living tissue and can quickly deepen the injury. Contact with a diagnosed patient does not create the same risk as an exposed wound in an area where the fly is circulating.
Mexico’s latest weekly surveillance table counted 361 confirmed human cases during 2026 and 478 since the first case was recorded in 2025. Seventeen cases were confirmed in the seven days covered by the report, and three deaths had been recorded by the July 3 cutoff. The figures show that human infection remains uncommon besides the much larger animal outbreak, but it is no longer limited to southern Mexico.
The patient’s work with cattle may have increased his exposure, but health officials have not disclosed where or when the fly laid eggs in the wound. His residence in Puerto Vallarta does not establish that the infestation began inside the city. The only confirmed timeline is that he arrived in Rosamorada with the arm lesion already infected.
Health authorities recommend washing cuts and scrapes promptly, disinfecting them, and keeping them covered until they close. Warning signs include worsening pain, swelling, a foul odor, bloody or unusual drainage, visible larvae, a sensation of movement, or a wound that does not heal.
Suspected cases in people need medical care rather than home removal of the larvae. Wounds found on cattle, dogs, cats, or other animals should be examined by a veterinarian and can be reported to Senasica at 800 751 2100 or through WhatsApp at 55 3996 4462.