Experts: Trinidad and Tobago should stay vigilant against bird flu

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DR FARLEY CLEGHORN, an epidemiologist and infectious disease specialist, has stressed the importance of continued vigilance in the Caribbean regarding the H5N1 avian influenza virus, commonly known as the bird flu.

He was speaking to Newsday during a phone interview on November 23.

While the current risk remains low, he said robust surveillance systems are critical in preventing potential outbreaks. Cleghorn noted the virus's ability to mutate and form new strains through genetic recombination, making it an ongoing global challenge.

"Like all influenza viruses, H5N1 undergoes yearly mutations, complicating efforts to control its spread."

He said the Caribbean is particularly vulnerable due to the region's migratory bird patterns and extensive poultry industry. To mitigate the risk, he stressed the need for continuous surveillance across human, animal, and environmental health sectors.

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"Vigilance and a co-ordinated, multi-disciplinary approach are crucial in managing this threat."

Central to this strategy is the "One Health" model, which promotes collaboration between health ministries, veterinary services and environmental agencies.

This approach has garnered increased attention in the Caribbean, with Cleghorn expressing optimism about recent efforts to create more integrated strategies for combating zoonotic diseases. He believes a unified, multisectoral response is essential for early detection and prompt action.

A recent "One Health Multidisciplinary Workshop" organised by the Caribbean Public Health Agency (Carpha) in Port of Spain sought to enhance regional health security.

The two-day workshop brought together over 70 experts from ten Carpha member states, along with representatives from 13 regional and international agencies and focused on improving food safety and disease surveillance across the Caribbean.

Although the global risk of H5N1 remains low, with only a few human cases reported since 2022, Cleghorn said certain occupational groups, such as poultry workers, remain at risk.

He discussed infections in the US, which have been linked to occupational exposure, and emphasises the importance of maintaining effective surveillance to detect early signs of the virus in both humans and animals.

"Should the virus mutate or enter poultry farms in the region, the risk could increase rapidly, making robust surveillance essential."

Cleghorn recommends seasonal flu vaccination, particularly for high-risk groups such as the elderly and young children. He also advises people to avoid crowded spaces during flu season, seek medical attention if symptomatic, and consider antiviral treatments like Tamiflu.

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While poultry vaccines are available in some countries, Cleghorn said their use in TT would depend on a comprehensive risk assessment based on up-to-date surveillance data.

Dr Shayne Ramsubhik, a poultry health consultant, also weighed in on the evolving nature of H5N1.

In an e-mail exchange with Newsday, he said the current strain, which evolved from the Goose/Guangdong lineage first identified in China, has spread across multiple continents, including Africa, Asia, Europe and North America.

Ramsubhik said the virus is primarily transmitted through wild waterfowl and shorebirds, which shed the virus in their faeces, saliva, and nasal discharge.

Given TT's proximity to migratory bird flyways, wetlands and the illegal bird trade, Ramsubhik warned the region remains particularly vulnerable. He expressed concern over recent reports of H5N1 in cows, which could potentially expose humans to the virus through the consumption of milk."

In the event of an outbreak, Ramsubhik stressed the importance of implementing strict biosecurity protocols on farms. These include restricting movement, enforcing cleaning and disinfection procedures, using personal protective equipment (PPE), and controlling access by wild birds.

Both Cleghorn and Ramsubhik agree that, while vaccination may play a role in controlling future outbreaks, the most effective strategy remains robust biosecurity and sound husbandry practices within the poultry industry.

Veterinary virologist at UWI, Prof Chris Oura, has expressed concerns about the high-virulent strain. What makes it worrying, he says, is its ability to jump across species, now infecting a wide range of mammals.

“It is spreading across various regions, including North and South America, and has even reached Antarctica and the Caribbean, impacting islands like Cuba.”

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While acknowledging the virus has not yet gained the ability to spread easily from person to person, he describes its potential as a major concern.

“If it does, it could lead to a global pandemic, similar to what the world experienced with covid19.”

He echoes previous concerns about migratory wild birds, which he says often carry the virus without showing symptoms.

“If these birds come into contact with domestic poultry, the virus can spread rapidly. Given the country’s reliance on poultry for food security, an outbreak could severely disrupt food supplies, possibly leading to the culling of entire flocks.”

Oura urges farmers to be vigilant in preventing contact between wild birds and domestic poultry. He recommends keeping poultry away from areas where wild birds stop to rest, ensuring that feed is not accessible to them, and maintaining good hygiene on farms.