Bulgaria has reported an outbreak of avian influenza (bird flu) among poultry, according to the World Organization for Animal Health (WOAH).

Reuters reports that H5N1 was detected in a flock of 7,669 poultry in the Bulgarian village of Maritsa, resulting in the death of 764 birds.

Bulgaria’s veterinary services have informed Greek authorities due to the countries’ close geographical and trade connections. Greece reports stable conditions on its poultry farms but has initiated preventative checks.

Globally, the spread of bird flu has put governments on high alert as it impacts not only poultry but can also transmit to humans.

The U.S. has documented cases in poultry, dairy cows, and even reports of transmission to farm workers, according to the CDC. In 2024 so far, the U.S. has recorded 36 human cases, primarily in California and Colorado, says the CDC.

While the risk to humans remains low, the U.S.A.’s authorities are investigating an unusual H5N1 case in an individual with no direct contact with animals.

The World Health Organization’s report on bird flu outbreaks from 2003 to April 2024 notes that, despite only 889 cases worldwide during that period, there was a 52% mortality rate, with 463 fatalities.

Symptoms of Bird Flu in Humans

The signs and symptoms of bird flu virus infections in humans can vary widely, ranging from no symptoms or mild illness to severe complications, says the CDC.

Common symptoms include eye redness (conjunctivitis), mild flu-like upper respiratory symptoms, and pneumonia that may require hospitalization.

Individuals may also experience fever (100ºF [37.8ºC] or higher) or feel feverish, along with cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, fatigue, and shortness of breath or difficulty breathing.

In some cases, less common symptoms may arise, such as diarrhea, nausea, vomiting, or seizures. It’s important to note that fever may not always be present.