H5N1 cases
Bird flu or H5N1 avian flu has sounded alarm after first human death due to the infection was reported in USA this year. Experts are monitoring the situation and more research is underway pertaining the mutation. The avian influenza first emerged in China in 1996. Since then, it has spread widely across the globe. Reportedly, this strain of the flu has higher ability to replicate n the brain making ot sever case for humans. However, due to no pre-existing immunity, the current antiviral treatment may be effective.
H5N1 bird flu samples collected from a severely ill patient in Louisiana show signs of mutations that may make the virus more transmissible to humans, the Centers for Disease Control and Prevention reported Thursday.
The unidentified patient, who was hospitalized with serious respiratory symptoms, is believed to have contracted bird flu from exposure to sick and dead birds in a backyard flock. The patient has not been identified but is reportedly over 65 with underlying health problems and is the second person in the United States who has been hospitalized with the virus. The Louisiana patient was infected with a strain of the virus different from the one affecting dairy cows and causing sporadic cases in farmworkers in the U.S.
Genetic analysis of two samples collected from the Louisiana patient suggest that the virus may have the ability to attach to cells in the human upper airway.
That’s worrisome, experts say, because bird flu viruses like H5N1 typically attach to cell receptors found in birds and other animals, but not commonly in humans. This is why bird flu typically doesn’t infect humans or spread person to person. One of the mutations was also seen in a sample from a British Columbia teenager who was hospitalized with bird flu, the CDC said.
This pathogenic avian influenza A is a subtype that is found in cows, birds and other mammals. Cases have been reported in humans too. Poultry workers or those in close contact with infected birds are at high risk What is assuring is that the CDC has detected “no person-to-person transmission spread”, the experts noted as per IANS report.
“No doubt that human infection with highly pathogenic avian influenza (HPAI) A, H5N1 virus that primarily causes bird flu, has a high potential for severe respiratory infection as well as high mortality, with over 50 per cent among around 1,000 human cases worldwide. The biggest solace is that human-to-human transmission is extremely rare and almost not heard of,” said infectious disease expert Dr. Ishwar Gilada.
H5N1 has in recent years seen a significant increase in spillover to mammals. The virus has killed a record number of birds, besides also spreading to otters, sea lions, minks, foxes, dolphins, and seals, among others. In 2024, people working on dairy farms contracted the virus from sick cattle, raising concerns about the further spread of the virus
One of the earliest strains of bird flu isolated from a human in Texas shows a unique constellation of mutations that enable it to more easily replicate in human cells and cause more severe disease in mice compared to a strain found in dairy cattle, researchers from Texas Biomedical Research Institute (Texas Biomed) report in Emerging Microbes & Infections.
The finding highlights a key concern about the H5N1 strains of bird flu currently circulating in the U.S.: the speed at which the virus can mutate when introduced to a new host.
Naturally found in wild birds and lethal in chickens, H5N1 has spread to a wide variety of mammals and began infecting dairy cows for the first time in spring 2024. As of early 2025, the outbreak had spread through herds across multiple states in the U.S. and infected dozens of people, mostly farm workers. So far, most people infected experience mild illness and eye inflammation and the virus is not spreading between people. The first H5N1 death in the U.S. was reported in January 2025 following exposure to infected chickens.
"The clock is ticking for the virus to evolve to more easily infect and potentially transmit from human to human, which would be a concern," said Texas Biomed Professor Luis Martinez-Sobrido, Ph.D., whose lab specializes in influenza viruses and has been studying H5N1 since the outbreak began last year. The team has developed specialized tools and animal models to test prophylactic vaccines and therapeutic antivirals.
“Rather the virus seems to have jumped from poultry directly to man and caused either severe disease or death. These cases occurred when humans handled chickens that were sick with the virus. The concern here is that when they looked at the virus in humans and compared it to those found in the poultry farm, the virus had already made new mutations. This shows the virus is capable of mutating quickly to adapt to human cells,” the expert explained.
H5N1: Symptoms and Precaution
Several experts suggest that India can be at ris of the flu due to its vast poultry sector, wetlands, migratory flyways etc.
Symptoms:
- Conjunctivitis
- Fever
- Fatigue
- Diarrhea
- Headache
- Cough
In severe case it may lead to sepsis, respiratory failure, pneumonia etc.
Prevention
So far, no human-to-human transmission has been reported. However, it is essential to lower the risk of contracting the virus in the first place by adhering to these precautions:
- Wash your hands regularly. If you come in contact with wildlife, animals, birds on street, ensure to wash hands with soap.
- Protective gear: Mask up, wear gloves, eye protection to keep yourself protected from contaminated dust, feathers, feces.
- Cook food thoroughly: All the poultry products should be cooked at good temperature to kill the virus.
- Limit exposure: Avoid working close with animals, poultry to reduce risk of bird flu.
You must be logged in to post a comment.