HEALTH
What are the symptoms of bird flu in humans? How does avian flu spread?
While avian influenza poses a significant threat to both animal and human health, understanding its transmission is crucial in mitigating its spread.
As dairy farmers across the United States are intensifying their efforts to combat the spread of highly pathogenic avian influenza (HPAI), commonly known as bird flu, the virus continues to affect livestock across multiple states. The U.S. Department of Agriculture has reported cases in North Carolina, Texas, Kansas, Ohio, Michigan, Idaho, New Mexico, and most recently, South Dakota.
What’s the current avian flu situation?
The outbreak has prompted these farmers to implement stringent measures, including prohibiting visitors, clearing trees to deter wild birds, and disinfecting vehicles entering their premises. In response to the threat, some farmers have even surpassed government recommendations in enhancing safety protocols. Additionally, measures such as the removal of trees to deter wild birds during migration are being adopted to minimize the risk of transmission.
The recent cases have heightened concerns among farmers and health authorities about the potential spread of the virus to both animals and humans. While bird flu primarily affects poultry, it can lead to reduced milk production in dairy herds. Although cows appear to recover from the virus, lactating cows are particularly vulnerable, necessitating isolation measures to prevent contaminated milk from entering the food supply.
The implications extend beyond dairy production, as fears of reduced demand for milk and cheese have arisen, impacting futures prices in the market. While there have been no confirmed cases of the virus in cattle raised for meat, the broader agricultural sector faces uncertainty regarding the virus’s transmission and its impact on livestock.
Bird flu response
In response to the outbreak, the USDA has issued recommendations to minimise cattle movement and enhance monitoring and testing protocols. Additionally, states have imposed additional requirements on livestock shipments to safeguard their herds. Farmers, including those from Indiana and Illinois, are taking proactive steps such as disinfecting truck wheels and isolating animals to mitigate the risk of infection. Despite these efforts, challenges persist, particularly in open-aired barns where exposure to wild birds remains a concern.
Avian flu symptoms in humans
Avian influenza viruses primarily infect birds, but they can occasionally jump to humans, leading to severe respiratory illness and, in some cases, fatalities. The symptoms of bird flu in humans can vary widely in severity, ranging from mild to severe. Common symptoms include:
- Fever: A sudden onset of high fever, often exceeding 100.4°F (38°C), is a hallmark symptom of avian flu infection.
- Cough: Dry or productive coughs may develop, often accompanied by respiratory distress.
- Sore throat: Irritation or pain in the throat may occur, worsening with coughing.
- Muscle aches: Body aches and fatigue are common, similar to symptoms of influenza caused by other viral strains.
- Difficulty breathing: In severe cases, avian flu can lead to respiratory failure, necessitating urgent medical attention.
- Other symptoms: Additional symptoms may include headache, runny or stuffy nose, fatigue, and gastrointestinal issues such as diarrhea.
It’s crucial to note that individuals with pre-existing health conditions or weakened immune systems are at higher risk of experiencing severe complications from avian flu.
Mode of transmission of bird flu
As I’ve said, avian flu viruses primarily circulate among birds, particularly wild waterfowl such as ducks and geese. However, they can also infect domestic poultry, including chickens and turkeys. Humans typically contract bird flu through direct or indirect contact with infected birds or their contaminated environments.
- Direct contact: Handling infected poultry, coming into contact with bird droppings, or exposure to surfaces contaminated with the virus can lead to transmission.
- Inhalation: Inhalation of aerosolized virus particles, particularly in environments with high concentrations of infected birds, poses a risk of infection.
- Consumption of contaminated food: While properly cooked poultry is safe to consume, handling or consuming raw or undercooked poultry products contaminated with the virus can lead to infection.
- Human-to-human transmission: While rare, certain strains of avian influenza have exhibited limited human-to-human transmission, typically within close contacts or healthcare settings. However, sustained human-to-human transmission, necessary for a pandemic, has not been observed with avian flu strains to date.
Vigilance in practicing good hygiene, such as frequent handwashing, avoiding close contact with sick birds, and thoroughly cooking poultry products, is essential in reducing the risk of avian flu transmission to humans.