When a Virus Comes to Town: An Interview with CDC Chief Chang Feng-yee

Q: As the weather warms up, the H7N9 avian flu epidemic has slowed significantly. Has it been thwarted?

A: Historically, H7N9 hadn’t previously caused any human deaths before this time. But now it meets the definition of an emerging infectious disease. To battle this disease, it’s necessary to find the source of the virus.

Right now we know that the virus comes from birds. Investigations in mainland China have shown that traditional markets are the primary means of infection, and in response, Shanghai has temporarily closed three traditional markets to control the spread of disease. Because chickens, ducks and pigeons may carry the H7N9 virus, the virus showed up in environmental samples taken from those traditional markets. But the information China has given about wild birds and poultry farms so far is limited, so we’re not yet sure of the spread of the virus among bird populations.

Washing your hands, keeping away from birds, and cooking foods thoroughly are effective ways to prevent H7N9 at this stage.

Next, this virus is of low pathogenicity in birds (i.e., they don’t become sick). We don’t know whether it’s there unless we test for it, which makes it hard to control. It also means we won’t be able to find the virus’s ultimate source right away.

The Council of Agriculture, after closely monitoring Taiwan’s bird population, hasn’t seen any signs of H7N9 yet, but things could change come fall and winter. That is, when migratory birds fly south to Taiwan, they have the chance to come into contact with birds in Taiwan, and at that time it’ll be very important to manage bird-to-bird and bird-to-human contact.

We know from virology that H7N9 appears to be more able to bind to mammalian cells than H5N1 is, and that’s troubling. At the current stage, all we can say is that the state of the epidemic is still unclear and the crisis hasn’t abated.

Q: Disease prevention isn’t something we can do all on our own. Since Taiwan isn’t a member of the WHO, what hurdles do we face in disease prevention? Is it hard to obtain information about the epidemic?

A: Even though Taiwan’s not a member of the WHO, Taiwan has been attending World Health Assembly (WHA) meetings as an observer since 2009, gaining experience on health issues of global concern at the conferences. This will help us formulate our disease prevention policy.

Also, the WHO has admitted Taiwan into the International Health Regulations (IHR) system, establishing a channel of direct communication. Now we can log onto the IHR’s public health information website to gain the latest international news on diseases. We’re able to get the latest information on the status of H1N1 and H7N9 infections before the WHO publishes its press releases on its website.

The hitch is that the CDC isn’t yet able to join the WHO’s Global Influenza Surveillance and Response System (GISRS) and become a WHO-approved national influenza center, so it can’t immediately share flu virus strain information through the GISRS with the WHO’s other national influenza centers. So we have to go through other channels to obtain H1N1 and H7N9 virus strains, and this takes time.

To prevent the transmission of avian viruses to humans, the government has strengthened management of the barrier between birds and humans, forbidding the slaughter and sale of live birds in traditional markets starting May 17.

Q: Having seen SARS, H1N1 and H7N9, what progress and inadequacies have we seen in Taiwan’s disease prevention work?

A: In 2003 when SARS came to Taiwan, the epidemic spanned four months. We paid a painful cost due to insufficient government communication, a patient reporting and management system that needed strengthening, patient isolation and nosocomial infection control measures not yet implemented, inadequate personal protective equipment and other holes in the system.

The Department of Health has aggressively pushed disease prevention reform over the last decade, amending the Communicable Disease Control Act, boosting the effectiveness of epidemic monitoring systems, and building reserves of anti-virus preparations and vaccines.

The H1N1 epidemic of 2009 gave us the chance to test our defenses. At that time, the death rate of H1N1 novel influenza in Taiwan (1.8 per million) was just a third of the average of OECD member states, and a fifth that of the US, proving that Taiwan’s disease prevention system had improved greatly after the SARS scare.

Q: What are our disease prevention strategies for H7N9?

A: Immediately after gaining information from online channels on March 31, the CDC called an emergency meeting, instituting emergency measures and contacting their counterpart agency in mainland China that evening for verification. Then we put out a press release and contacted medical institutions to inform the public and medical personnel. On April 3, H7N9 was listed as a notifiable infectious disease, and we set up the Central Epidemic Command Center (CECC) as a communication platform for all bodies dealing with the H7N9 flu.

Regarding disease prevention, we’ve set five lines of defense. The first is virus monitoring. This includes the notifiable infectious disease monitoring system, National Health Insurance information combined with community virus monitoring, real-time monitoring of pneumonia and flu deaths, and a real-time emergency room disease monitoring and warning system. The purpose of all this is to gain a fuller understanding of developments in the flu epidemic.

People working in poultry farming are a high-risk group, so we inoculate them first with seasonal flu vaccine to reduce the chances of genetic exchange between different virus strains within their bodies.

We are also strengthening border quarantine controls by boosting quarantine measures in ports and airports. Anyone entering Taiwan from an infected area who displays signs of respiratory tract infection is to be taken to a hospital for a checkup and isolated until such time as an H7N9 infection is excluded.

The second line of defense is to control bird-to-bird and bird-to-human contact.

Nowadays Taiwan’s major poultry farms are surrounded by nets to prevent contact with wild birds. But with small farms and home-raised poultry, it’s near impossible to close all gaps.

Protecting our wetlands is vital for reducing direct contact between migratory birds and humans; it’s also needed in order to give migratory birds some living space.

More importantly, we must control bird-to-human contact effectively. The government has declared a prohibition on selling or slaughtering live poultry at traditional markets starting May 17. Over the past decade, the government has been constantly discouraging such practices with incentives and advertising, but has been unable to cut it off completely. This time, we must succeed.

The third line of defense is to stock antiviral medications. People confirmed as having H7N9 and those who have had close contact with them will be eligible for publicly funded antiviral medications until the CECC is disbanded.

The fourth line of defense is healthcare. The CECC has released a set of H7N9 clinical treatment protocols to clinicians to boost the treatment capacities of healthcare centers.

The fifth line of defense is vaccine R&D.

Two of the WHO’s national influenza centers—the US Centers for Disease Control and Japan’s National Institute of Infectious Diseases—have agreed to provide the Taiwan CDC with H7N9 flu vaccine strains for preparations for vaccine production. As for issues of vaccine mass production and purchasing, we need to make appropriate choices in accordance with the development of the disease.

Currently there’s no evidence indicating sustained ­human-to-human transmission of H7N9, and the epidemic has been maintained at Phase 3 on the WHO Phase scale (bird-to-human, or limited human-to-human), so the government hasn’t issued any recommendations to restrict travel or trade. There is no cause for public alarm.