Estimates of the impact of a future influenza pandemic in China

BACKGROUND The next influenza pandemic will create a surge in demand for health resources in China, with its current population of >1·3 billion persons and under-developed medical care and public health system. However, few pandemic impact data are available for China. OBJECTIVES We estimated the effects of a future influenza pandemic in China by examining pandemic scenarios of varying severity and described the time distribution of cases during a first wave. METHODS We used a Monte-Carlo simulation model and death rates, hospitalizations and outpatient visits for 1918- and 1968- like pandemic scenarios and data from the literature or experts' opinion to estimate four health outcomes: deaths, hospitalizations, outpatient medical visits and clinical illness for which medical care was not sought. For each of the two scenarios we estimated outcomes by week using a normal distribution. RESULTS We estimated that a 1968 scenario in China would result in 460,000-700,000 deaths, 1·94-2·27 million hospitalizations, 111-117 million outpatient visits and 192-197 million illnesses for which medical care was not sought. Fifty-two percent of hospitalizations occurred during the two-peak weeks of the first wave. We estimated that patients at high-risk of influenza complications (10-17% of the population) would account for 61-75% of all deaths. For a 1918 scenario, we estimated that 4·95-6·95 million deaths, 20·8-22·7 million hospitalizations and 101-108 million outpatient visits could occur. CONCLUSION Even a 1968 pandemic scenario will pose substantial challenges for the medical and public health system in China, and planning to manage these challenges is essential.