Reina Sikkema investigates poultry markets in China

Professor Marion Koopmans, head of the Virology Department at Erasmus MC, has been the Scientific Advisor of the Centre of Disease Control (CDC) of Guangdong Province in Southeast China since 2007. This province is well known for its markets with live animals. It is therefore an ideal environment for zoonoses (pathogens that spread from animals to humans) to develop! Avian influenza is a good example of this. But where did avian influenza originate from and how does the infection spread from animal to animal and from animals to humans? PhD student Reina Sikkema is researching this in close collaboration with the CDCs in the Guangdong province in China.

In recent years, we have seen several new variants of avian influenza emerge: H5N1, H5N8, H7N7, H7N9, etc. However, we still do not know how the virus reaches the market or exactly how it spreads. The idea is to change the structure of the markets in order to prevent the virus from spreading and to protect animal and human health. Professor Koopmans was asked with her team to investigate the best way to prevent the infection and spread of the virus.

Poultry markets potential spreaders of avian flu?
The poultry industry in China is booming. There are large chicken markets throughout China that provide the Chinese with fresh chicken and eggs.
The challenge at these markets, especially in Southeast China, is that the slaughter and sale often take place at exactly the same location. The chickens are slaughtered alive and the feathers are removed using a type of 'tumble dryer'. While this means that the chicken is very fresh, the slaughter technique used for the chickens leads to several health challenges! Furthermore, these markets are also seen as potential spreaders of avian influenza. But how exactly does avian influenza spread via these markets?

poultry2Focus on avian influenza

Reina Sikkema, a qualified vet with a passion for One Health and MERS-CoV and Influenza outbreaks went to China (while pregnant!) from December 2015 to January 2016 to investigate the spread of avian influenza via live animal markets. She ultimately selected 12 markets for her research. These markets sell not just a wide range of poultry but also rabbits, dogs and goats, and sometimes even fruit and vegetables as well.

The aim of the research was to outline the entire 'virus chain': where did the virus come from, which region, how it has spread, and via which farmers and wholesalers or local chicken markets? Together with the CDC, Reina is investigating the entire market chain: 1) how does the chain/market of live poultry in Guangdong work and 2) how does the influenza virus spread through that chain?

To find out, she interviews market managers and sellers as well as policy makers about how many animals were traded, where the animals came from and where they were going to. Samples from a very wide range of surfaces are being collected as well. The samples include the chopping blocks used to slaughter the chickens, the 'feather remover in the form of the tumble dryer', the surfaces on which the carcasses are displayed but also, for example, the drinking water. In addition, extensive background information is collected for each sample, such as animal species and origin. Finally, the virus sequences are determined. These can provide even more information about the origin and characteristics of the influenza virus.

A publication containing the research results will take at least another year and that also depends on the collaboration with China and any future new outbreaks as well.

One Health perspective
What makes this research so special is that while the veterinary and human sectors do not normally collaborate in China, and currently only the human side works with the CDC, this project could really be called a One Health perspective!
Surveillance of zoonoses
Reina is currently writing her doctoral thesis "Surveillance of Zoonotic Emerging Infectious Diseases". Surveillance means careful monitoring where viruses come from and how they spread. New diseases are continuing to emerge. It is therefore important to think carefully about which disease and which virus you want to devote attention to. How do you ensure that you are ready in the event of a new disease outbreak or a new outbreak of an existing disease? The ultimate aim of the research in China is to produce an advisory report about surveillance and control of avian influenza in China. The government will then be able to intervene early in the chain before the virus can spread. An example is the tumble dryer on the chicken market: is this a source of viral spread and should the feathers therefore be removed in a different way? We hope to talk to Reina again as soon as she knows more!