Response to the first wave of pandemic (H1N1) 2009: Experiences and lessons learnt from China

Abstract

More than 2 years after the start of pandemic H1N1, the world is fortunate that the impact, to date, has been moderate. An evaluation of the global response to the first wave of the pandemic is still ongoing. The results of an analysis of the situation in China is presented in order to gain a better understanding of the episode; to summarize the experiences in preparedness, control and mitigation of the pandemic; and to identify issues for further consideration and investigation in order to improve the response to possible next waves of the pandemic. China's response shows how a huge challenge can be transformed into an opportunity, and may offer some valuable lessons to face another wave of the pandemic or other potential public health emergencies in the future, not only for China but also for the international community.

Description of Hospitalized Cases of Influenza A(H1N1)pdm09 Infection on the Basis of the National Hospitalized-Case Surveillance, 2009–2010, Japan

“…CFR in those aged 20 years and older was significantly higher than that in those aged under 20 years. These results were consistent with the results from previous reports and reaffirmed that A(H1N1)pdm09 virus infection led to high morbidity in the young population and a high CFR in the elderly population (4,(7)(8)(9)(10)(11).…”

“…This rate is similar to those found in Mexico, Chile, and Brazil and 50z of the rate observed in Australia, the Unites States, and Argentina during the same period (6,7). Consistent with the results described in other reports, over 80z of hospitalized cases in the present study were young (＜20 years) (4,(7)(8)(9)(10)(11)35). It is interesting to note that the results from several studies have indicated that the elderly were not disproportionately affected by the virus, perhaps because of cross immunity to A(H1N1)pdm09 in this population (12)(13)(14).…”

Regional variation in mortality impact of the 2009 A(H1N1) influenza pandemic in China

“…The mortality burden associated with A(H1N1)pdm in persons aged 0–64 years was slightly higher relative to that of seasonal epidemics, consistent with an age shift in the distribution of deaths reported in most countries . Persons under 65 years accounted for 19–26% of pandemic‐related excess deaths in our study, consistent with estimates from European countries and Hong Kong SAR (9–30%), but substantially lower than estimates based on laboratory‐confirmed deaths in China (87%) . Age biases in testing propensity toward younger cases and increased difficulties in detection of influenza viruses in older people with underlying conditions could account for such discrepancies .…”

Seasonal Influenza A H1N1pdm09 Virus and Severe Outcomes: A Reason for Broader Vaccination in Non-Elderly, At-Risk People

“…Hospitalizations [8,9] and severe cases[1,10] were also higher than expected in young people, and risk of complications such as pneumonia, respiratory failure, shock, sepsis, need for ICU or death in those under 40 years of age were between 2.5 and 4 times higher than in seasonal influenza [1]. …”