WHO acknowledges bird flu patient in Mexico died of other medical conditions

The World Health Organization confirmed Friday that Mexican authorities believe the man with a rare human case of bird flu actually died from other co-morbidities.

On June 5, the WHO shared an update that a 59-year-old patient died with the H5N2 strain of bird flu, or avian influenza. It was the first laboratory-confirmed human case of the H5N2 strain reported globally and the first-ever reported case in Mexico.

This strain is different than the bird flu strain that is currently circulating in livestock in the United States. Three dairy workers have been infected in the U.S., all of whom have recovered.

Following the first release, Mexican Health Secretary Jorge Alcocer Varela pushed back on the WHO's statement, saying the man died from a separate condition and not bird flu, although the WHO said the patient only tested positive for bird flu, not that he had died of bird flu.

In the latest update, the WHO said health officials in Mexico had concluded the man died because of his co-morbidities.

"A national multidisciplinary group of experts was formed to investigate the cause of death. It included infectious disease specialists, pneumonologists, microbiologists and intensive care professionals," the WHO wrote. "Upon review of the patient's clinical history and records, the national multidisciplinary team concluded on 6 June that, although the patient had a laboratory-confirmed infection with avian influenza A(H5N2) virus, he died due to complications of his co-morbidities."

Additionally, the WHO said national authorities performed a genetic analysis on the strain and found it had a 99% similarity with the strain seen in birds this year in the Texcoco State of Mexico.

The Mexico patient had no history of exposure to poultry or other animals, according to the WHO. Mexico has been dealing with an outbreak of the virus in poultry.

On April 17, the patient developed fever, nausea, diarrhea, shortness of breath and general malaise. He was hospitalized on April 24 at the National Institute of Respiratory Diseases in Mexico City and died the same day.

The patient's relatives said he had been bedridden for three weeks for other reasons prior to contracting bird flu, the WHO said.

Mexican authorities reported the human case to the WHO on May 23.

No further cases have been documented during health officials' investigation, according to the WHO. All the people the patient was in contact with at his home and in the hospital have tested negative for influenza viruses.

In the U.S., an outbreak of the H5N1 strain has been found to sicken millions of birds as well as older dairy cows. So far, three farmworkers have been sickened in the U.S., one in Texas and two in Michigan.

All three had mild symptoms and have recovered. There is no evidence of human-to-human transmission and the risk to the general public is low, according to the Centers for Disease Control and Prevention.