In the milieu of global health research conducted by VIDD researchers, the China Initiative is a relatively new player. Dr. Lena Yao, senior project manager of the China Initiative, joined VIDD in 2009 to help guide the scientific progress in this collaboration between the Chinese government and the Hutchinson Center. The first major project Yao and her colleagues in SCHARP are tackling is the recent unsettling spread of a novel strain of Hand, Foot, and Mouth Disease among children in China.
Hand, foot, and mouth disease (not to be confused with the veterinary hoof-and-mouth disease) affects mainly children 5 years old and under, and is normally not severe. It is a well described and even ancient disease, previously primarily associated wtih the Coxsackie A16 virus. However, in 1969 a novel enterovirus called EV71 was identified as an agent of hand, foot, and mouth disease, and is far more pathogenic. Up to 10 percent of EV71 infections can be very severe, causing nerve damage, paralysis or death.
Over the past decade, EV71 outbreaks in China have reached a worrying level, Yao said. The novel virus is not limited to China, but while in other countries EV71 outbreaks are relatively small and die down after the outbreak year, in China infection rates have climbed higher and higher in each passing year.
“What’s so different about China? Why is it behaving so differently there than elsewhere?” Yao asked. “People don’t know whether it’s a mutation in the virus, or something else.”
There is no vaccine or specific treatment for EV71, and since the virus is so new, very little is known about it or the novel form of hand, foot, and mouth disease it causes. The disease is having a dramatic impact – in 2009, the Chinese Center for Disease Control and Prevention (CCDC) counted more than 1 million cases, with more than 13,000 cases of severe nerve damage – so an effective way to understand and control the epidemic is a top priority.
The CCDC has collected copious amounts of data on EV71 outbreaks starting in mid-2008 using their extensive surveillance system that amasses data nation-wide from more than 300,000 clinics. The government agency has collected more than 30 million data points on EV71, Yao said. The CCDC originally approached the American CDC for help analyzing their data and pinpointing risk factors for EV71 infection and spread, and the CDC referred the Chinese researchers to VIDD co-director Dr. Steve Self and colleagues at SCHARP.
“This is a first in Chinese history,” Yao said. “They’ve never given any nation-wide data to a foreign entity before, so we’re the first to acquire this data and perform the analysis.”
The CCDC collected weekly numbers on EV71 infection per county, along with other data related to infection, such as age, gender, disease severity and household makeup of the sick children, and temperature and wind speed of the town. SCHARP statisticians, led by VIDD staff scientist Dr. Yang Yang, have begun analyzing this data and have found that over the past few years, the disease peaks in the spring, dies down in the summer, returns at lower levels in the fall, and is nearly non-existent in the winter in most areas. Their findings indicate that infection spread is seasonal and appears temperature dependent, and that children rather than adults play a major role in the transmission of the disease. ,
VIDD and CCDC scientists are designing more detailed epidemiological studies to determine the true risk factors for EV71 infection and spread. There are also several Chinese companies and a government agency working on EV71 vaccines, Yao said, a particular challenge as this will be the first novel vaccine developed in China. VIDD researchers will collaborate with the CCDC to provide expertise on vaccine development for the EV71 work.
Eventually, the China Initiative hopes to expand into work on other infectious diseases in China, such as tuberculosis and hepatitis, Yao said. The China Initiative researchers, led by Dr. Self, submitted a grant application to the NIH in March to further support the project. Yao feels they have just begun to scratch the surface of the science behind EV71.
“Nobody is yet looking at this from the macro level, with these kinds of surveys,” Yao said. “Of course with this kind of study you always have to associate with some governmental agency, so in this case we are the lucky ones who have access to this data.”