Unprecedented Spread of Bird Flu in Dairy Cows Raises Alarms Globally

This year has seen an unprecedented spread of avian influenza, or bird flu, affecting dairy cows in the U.S. for the first time and resulting in human infections across various countries. Scientists are concerned about potential mutations that could facilitate human-to-human transmission, though currently, the risk remains low.

Avian influenza, commonly known as bird flu, has alarmed public health officials in the United States due to an unprecedented spread in dairy cows this year. Four dairy workers have also tested positive for the virus. This severe variant of the H5N1 strain has been causing lethal outbreaks in commercial poultry and sporadic infections in various animal species globally since 2020. Surprisingly, it has infected cows for the first time this year.

Different bird flu strains have also appeared in humans in Australia and Mexico. Scientists are particularly worried about the virus mutating in ways that make it easier to transmit between humans, potentially sparking a pandemic. However, the World Health Organization (WHO) currently assesses the risk to humans as low. Here are some reported cases of human infection with bird flu in 2023.

United States: In March, the first known cases in dairy cattle were identified in Texas. The infection spread to dairy herds in 12 states, with genetic tests indicating the virus is similar to the H5N1 strain impacting wild birds and poultry. Four dairy workers who tested positive exhibited mild symptoms like conjunctivitis.

Mexico: On June 5, the WHO reported Mexico's first human case of H5N2 avian influenza. The patient died, but chronic illness was cited as the primary cause of death.

Australia: On June 7, the WHO announced a child in Australia had contracted H5N1 bird flu after traveling to Kolkata, India. Australia is also dealing with outbreaks of other bird flu strains on poultry farms.

India: On June 11, the WHO reported a new human case of H9N2 bird flu in a four-year-old child in West Bengal, marking the country's second case of this subtype.

Vietnam: In March, a 21-year-old student died from H5N1 bird flu, with no prior medical conditions but recent exposure to wild birds.

Cambodia: By June 20, Cambodia reported five human cases of H5N1.

China: Human cases of H5N6, H9N2, and H10N3 bird flu strains were detected, with two H5N6 fatalities in Fujian province.

Germany: On July 4, Germany reported a highly pathogenic H7N5 bird flu outbreak on a farm near the Dutch border, the first of its kind according to WOAH records.

(With inputs from agencies.)