Full-body showers and disinfectant foot dips: How one Singapore egg farm protects its chickens from bird flu

SINGAPORE: In the far north-west, Singapore’s only three egg farms sit within a 4km distance of one another, in surroundings largely untouched by the rapid urbanisation seen elsewhere in the country.  
This Lim Chu Kang area has been earmarked by authorities for development into a high-tech agri-food zone, to raise production and strengthen Singapore’s food security. 
But an evolving development around the world threatens to upend those plans – by threatening the existence of the egg farms.
The spread of avian influenza, or bird flu, has killed or led to the culling of hundreds of millions of poultry globally in recent years.
Over a century old and carried mainly by migratory water birds, the disease has also increasingly been infecting mammals not previously thought susceptible, like alpacas, house cats, and cows.
Human cases are rare, but have been reported in nearby countries. Singapore, however, is currently free from bird flu.
And its egg farms have stringent measures as a first line of defence, to prevent the spread of infectious diseases that could compromise the health of its fowl. 
These safeguards are the “most important” strategy preventing the entry of highly pathogenic avian influenza (HPAI), said Dr Michael Banawa, head of poultry business for ASEAN, South Korea, Australia and New Zealand at pharmaceutical company Boehringer Ingelheim.  
“Humans can act as mechanical vectors, meaning they can carry the virus on their skin, clothing or equipment … This can potentially lead to the spread of the virus to other birds,” he added.
Donning a hair net, rubber boots, latex gloves and a mask, this CNA reporter got a rare look at how one of Singapore’s few egg farms stops any such transmission from happening.
The Seng Choon egg farm is a full 15 min drive from the nearest public housing estate. 
From its tranquil setting, it’s not immediately apparent that the facility is home to some 800,000 hens, with 550,000 eggs produced daily.
Pullets – hens under a year old and not yet producing eggs – and layers – mature hens that do produce eggs – are sequestered into its 22 hen houses, which resemble large sheds. 
Seng Choon’s biosecurity measures are based on the possible transmission route of pathogens. This can be airborne; through contaminated feed and water; direct contact with infected birds or indirect contact via humans and vehicles, said Dr Lai Jun Yu, the farm veterinarian who showed CNA around. 
The hen houses are hence fenced into what’s called the production zone. Access here is highly restricted, with strict protocols for personnel and vehicles entering. 
Only essential visitors and workers are allowed in, to begin with. And they must not have come into contact with other birds or visited other avian premises in the preceding three days at least. 
The process of entering the production zone starts with a full-body shower right outside, before changing into provided safety attire and accessories.
Next is a walk through an entryway with an automated disinfectant mist and foot-dip, to kill harmful microorganisms.
These safeguards help prevent birds from falling sick and having their immune systems weakened. 
The 20 staffers who stay on farm premises and take care of the hens daily have to undergo the same protocols.
“Staff are assigned to look after one to two houses, and they can only go into the assigned houses. For each house, there is designated equipment so there is no sharing of any tools or equipment between the houses. So this is to prevent cross-contamination or the spread of disease if present,” said Dr Lai.
The hen houses themselves are enclosed with ventilation systems so that poultry does not come into contact with wild birds.
Day-to-day processes are also automated to minimise human interaction where possible.
For instance, feed – made in-farm to control its quality – is delivered direct from a mill into silos in front of each house.
Waste from the hens exits through conveyor belts at the back of each house.
Eggs from the hens are transported to a collection centre via closed-off conveyor belts as well.
After the round of measures for entering the production zone come another set for the hen houses.
Workers stepping into the houses have to change into boots specific to each house, and colour-coded to differentiate inside and outside use. 
These workers then wade through another disinfectant foot-dip to minimise the pathogens or microorganisms being brought into the hen house.
CNA also got a look at Seng Choon workers vaccinating chicks against Newcastle disease, which is contagious and viral among birds. This is done using eye drops.
The farm has a tailored vaccination programme and also feeds its poultry probiotics to strengthen their immunity, said Dr Lai. 
Chicks sourced from overseas farms are accredited by authorities, and quarantined when they first arrive at the farm.
The Singapore Food Agency (SFA) and Animal & Veterinary Service (AVS) told CNA that imports from regions affected by HPAI will be suspended, and only products that have been heat-treated to inactivate the virus will be allowed. 
Asked how the Seng Choon Farm could curb the spread of infectious diseases given that chickens are kept in flocks, Dr Lai said this boiled down to the quick response of staff. 
Staff are trained to look out for and report abnormalities, such as unusual feed or water consumption, high mortality or an atypical drop in egg production.
In such situations, dead birds will be examined and samples sent for further testing.
Around the farm, extra precautions have been taken to prevent wild birds from settling in the area.
There are no fruit trees to attract birds, while the few within the production zone are frequently pruned to prevent roosting. 
Any mess or spillage of food is quickly cleaned up to prevent pests.
Together, Singapore’s three egg farms fulfil about 30 per cent of the country’s demand.
Apart from Seng Choon, there’s Chew’s Agriculture – with 1.5 million birds supplying up to a million eggs daily – and N&N Agriculture, which has between 1.1 million and 1.2 million hens producing 800,000 eggs daily.
All employ similar precautions involving zoning and sanitation.
President of the International Society for Infectious Diseases Paul Anantharajah Tambyah noted that avian influenza H5N1 – one of the subtypes that has affected humans the most – has been around in humans since 1997. 
“To date, Singapore has not recorded any cases in native animals and birds. This suggests that the measures are reasonably effective,” he said. 
N&N Agriculture’s chief executive officer Ma Chin Chew however urged Singapore authorities to speed up their decision on vaccinations for HPAI in local farms, noting the “worrying” developments in Australia. 
Chew’s Agriculture general manager Chew Zi Xuan said his poultry was vaccinated against H9N2 – a bird flu subtype that’s less pathogenic. 
“It’s still a very new thing, the vaccination for (highly pathogenic) avian influenza. I think even until now, there’s not one single effective vaccination (that is) globally recognised,” he added.
“So every country is trying different things, but this sector in Singapore is not big enough to have the real R&D going on, so we’re just waiting for what’s getting developed out there.”
This may prove urgent in coming months as birds start migrating to warmer countries, which can increase the risk of HPAI being spread. 
Some of these birds flock to the nearby Sungei Buloh wetlands to tide over the cold. 
Both Dr Banawa and Dr Tambyah said vaccinating poultry alongside strict biosecurity measures would be most effective against the spread of bird flu. 
“The tremendous avian influenza strain diversity is definitely a challenge, but what is scientifically proven is that the current vaccines available in the market are able to effectively reduce disease incidence and virus load of predominant and widely circulating highly pathogenic strain in the environment, thus minimising the risk of further spread and exposure to infection,” said Dr Banawa. 
In response to CNA’s queries, SFA and AVS said they were “reviewing” the use of HPAI vaccinations in local poultry farms.
In the event of an HPAI outbreak, the affected farm will need to be “depopulated” to eradicate and prevent the potential spread of the virus, the authorities said.
If bird flu ever were to arrive in Singapore, it would be a “disaster” for the nation’s egg supply, said Mr Ma. 
With the three farms fairly close, a single case of bird flu may well spread easily to the other two facilities.
Mr Ma estimated the potential loss to his own farm to be up to S$10 million, based on how much it costs to raise a hen. The 300 workers in his employ would also be bereft.
“That’s why I say, the only thing is, look at the sky and pray harder.”