Preventing future H5N1 outbreaks in Vietnam

The persistence of bird flu poses a serious risk to economic and food security, as well as public health worldwide. A UK-Vietnam collaboration is helping to understand how the virus persists under the radar, to help prevent the next major outbreak.

Highly pathogenic avian influenza H5N1 virus, one of the most infamous bird flu viruses, has caused pandemics at various points in history. The name still conjures memories of panic from the recent outbreak of 2007, when many countries including the UK were affected.

Death toll

Infection in humans carries a high mortality rate, with roughly 60% proving fatal, but casualties have been relatively low due to the difficulty in spreading the virus.

Aside from human infections however, the damage caused by H5N1 viruses is huge and devastating, as it threatens local economies and farmers’ livelihoods. It is this damage that has spurred a group of Vietnamese researchers to collaborate with UK counterparts, to build the understanding that can lead to real solutions. The opportunity for this came through Institutional Links; a British Council programme with funding from the Newton Fund.

In under a year a staggering 15% of the poultry population, some 38 million birds, died or were destroyed as a result of infection.

Bird flu

Poultry farming has existed in Vietnam for around 3000-3500 years, with the industry peaking in 2003. This was followed by an abrupt fall however, when in December 2003 the first outbreak of H5N1 bird flu swept the country. In under a year a staggering 15% of the poultry population, some 38 million birds, died or were destroyed as a result of infection.  

Since 2003 measures have been put in place to prevent further outbreaks in Vietnam, including vaccinations and regular surveillance for infected animals in the live bird markets. But concern grew around the continued low-level circulation of the virus, despite the best efforts to stamp it out altogether. How was the virus persisting despite the vaccinations and detection points at bird markets? There appeared to be a missing piece of the jigsaw. 

Then, with a Newton Fund Institutional Links grant for early-stage research and travel, researchers at the Royal Veterinary College, London, and the National Institute for Animal Sciences, Vietnam, thought that by combining their complimentary expertise, they might be able to solve it. The UK side are experts in genetics, while the Vietnamese team are experts in the bird production chain. Combining these skill sets allowed them to apply genetic techniques to track the complicated movement and interactions of bird flocks.

Along the Mekong River

Free-grazing duck production in Vietnam is concentrated along the Mekong River that courses through south-east Asia, connecting China, Myanmar, Thailand, Vietnam, Cambodia and Laos. 

This production is intertwined with rice farming; flocks are fed leftovers from the rice harvest directly in the field, then moved on to the next freshly-harvested field when the new rice cycle starts. It is these flocks, which are moved large distances to graze, that might hold the key to the persistence of H5N1. 

The project looked at flock interactions, and uncovered new dynamics and ideas of H5N1 transmission. As Dr Vergne, Postdoctoral Researcher at the Royal Veterinary College summarises “These duck flocks in the South might have contact with flocks either in the field or in transport vehicles, then might travel up to 100km and have contact with other flocks”. Crucially, these ducks, which are mostly raised to lay eggs, aren’t consumed much in Vietnam. Instead, “they seem to all be sold to China so don’t pass through the live bird markets”.

Thanks to the work under the Newton Fund, the shoots of longer term policy and behavioural changes are already being seen, which can reduce the risk of H5N1 outbreaks.

Communicating to prevent outbreaks

This new understanding could prove crucial to preventing future H5N1 outbreaks, and so communicating the results has been a central part of the project.

The team in Vietnam have been doing this at a policy level, engaging the Vietnamese Government, and have recently been invited to Cambodia to highlight the international importance of the work. Change is also driven at the field-level, and so state veterinarians from the southern regions were invited to take part in a workshop to discuss the issues of H5N1 transmission and control. This led to a significant change in the perception of the risks, which will hopefully lead to behavioural change in farmers’ practices. Thanks to the work under the Newton Fund, the shoots of longer term policy and behavioural changes are already being seen, which can reduce the risk of H5N1 outbreaks.

The new knowledge generated by the Newton Fund project also provides the researchers the opportunity to engage international audiences, thus expanding their visibility. The UK team have presented their results as posters in various conferences, and will present them orally at a conference in Berlin this autumn. This exposure helps to build new contacts, and can also strengthen existing ones; the UK team have been discussing additional studies which “have been strengthened thanks to the Newton Fund project”, according to Dr Vergne.

H5N1 virus still looms as a potential catastrophe, but hopefully our new understanding of how it persists will help shape practices that secure our income, food and health against such disasters in the future.