Some Good News on H7N9 but No Time for Complacency
May 25, 2013
J. Christopher Daniel, Senior Associate
Global Health Policy Center, Center for Strategic and International Studies
For two months, the global health community has once again been on alert, watching closely to see if another pandemic is around the corner. Since March 31st, 131 cases (one in Taiwan, the rest in China) of avian influenza A (H7N9) have been confirmed, causing 36 deaths in China. Fortunately, only one new case has been confirmed since April, none since the first week of May. Heavily criticized for lack of transparency and slow response during the early days of the H5N1 and SARS outbreaks, China has been widely praised for its response to this outbreak. From the onset, Chinese scientists were refreshingly open in sharing samples and data, and rapidly made making the viral genome sequences public. Chinese health authorities immediately stepped up laboratory capabilities and enhanced surveillance in humans and in animals (particularly important since H7N9 does not cause visible disease in the latter), culling tens of thousands of poultry and closing many open-air (live) poultry markets and placing stringent restrictions on others. When cases have been diagnosed, rapid treatment has been emphasized to reduce the likelihood of severe complications (which include acute respiratory distress syndrome and organ failure), as well as appropriate infection control measures to limit spread.
These measures, while effective thus far, have come at considerable cost, particularly to China’s agriculture sector. Dr. Juan Lubroth, the United Nations Food and Agriculture Organization's chief veterinary officer, said this week at the World Health Assembly (WHA) that over $6.5 billion has been lost due to the outbreak’s impact on prices, consumer confidence and trade. But even as China’s Shanghai and Zheijiang provincial governments have begun to transition from emergency operations to routine surveillance and response mode, it is critical for the world to remain vigilant. Dr. Keiji Fukuda, WHO’s assistant director general for health security, acknowledged Tuesday at the WHA that the “immediate outbreak has been controlled,” but warned that it is also possible for more infections to turn up when the weather turns cooler. Although sustained human-to-human transmission has not yet been demonstrated, researchers at the University of Hong Kong today presented evidence that it is indeed possible, potentially through airborne exposure as well as through direct contact. They also found evidence indicating that asymptomatic infections among humans are possible, which would make H7N9 harder to detect and control.
But even as the spotlight recedes somewhat on H7N9, it has begun to shift to a perhaps even more worrisome global health threat. A novel coronavirus, now known as the Middle East respiratory syndrome coronavirus (MERS-CoV), was first reported in September 2012. To date, the WHO has been informed of 44 laboratory-confirmed cases of MERS-CoV in eight countries. Most cases have been in the Middle East (particularly Saudi Arabia), but it has also been seen in four other countries (UK, France, Germany and Tunisia) among people who had traveled themselves or had a close contact with a recent traveler to the Middle East. Most patients have presented with severe acute respiratory disease, requiring mechanical ventilation or other advanced respiratory support, and half of these patients have died. At the WHA yesterday, Dr. Fukuda expressed great concern about the potential for sustainable person-to-person transmission and spread of MERS-CoV (also known as “Saudi SARS”), how little we are prepared if that occurs, and about how much we still don’t know. Is there an animal host (none has yet been identified)? What types of exposures are most likely to result in infection? Do human "super spreaders" exist, similar to those who played a key role in spreading SARS in 2003? Meanwhile, an international dispute has reared its ugly head over ownership of virus samples, and whether material transfer agreement-related restrictions (how they can be used and by whom) have delayed development of diagnostic tests. Until resolved, this dispute will unfortunately divert attention and impede international collaboration when it is most needed, particularly with millions of people expected to visit Saudi Arabia for the Hajj in just a few months.
H7N9 and MERS-CoV are clearly significant threats. These pathogens, our nation’s (and the world’s) readiness to face these threats, and their potential impact, are enough of a concern that last week the White House convened a cabinet-level principals’ meeting focused upon global health security, its first in several years. In addition to some of the challenges discussed above, potential H7N9 vaccines being studied by the Centers for Disease Control and Prevention face significant challenges in both effectiveness and availability. The current situation is dynamic – as Dr. Fukuda said yesterday, “evolving, urgent and complex” – but it reminds us once again of the continuing need for monitoring and vigilance. Given how interconnected the world is today, the situation also reinforces the value of helping other countries become more resilient in being able to prevent, detect and respond to these and other emerging threats - improving their ability to implement the International Health Regulations – and thus enhancing global health security.