Evaluating the importation of yellow fever cases into China in 2016 and strategies used to prevent and control the spread of the disease

Abstract@#During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow fever into China.

Sudden increase in human infection with avian influenza A(H7N9) virus in China, September–December 2016

Since the first outbreak of avian influenza A(H7N9) virus in humans was identified in 2013, there have been five seasonal epidemics observed in China. An earlier start and a steep increase in the number of humans infected with H7N9 virus was observed between September and December 2016, raising great public concern in domestic and international societies. The epidemiological characteristics of the recently reported confirmed H7N9 cases were analysed. The results suggested that although more cases were reported recently, most cases in the fifth epidemic were still highly sporadically distributed without any epidemiology links; the main characteristics remained unchanged and the genetic characteristics of virus strains that were isolated in this epidemic remained similar to earlier epidemics. Interventions included live poultry market closures in several cities that reported more H7N9 cases recently.

Epidemiological characteristics of Middle East Respiratory Syndrome outbreak in the Republic of Korea, 2015 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze the epidemiological characteristics of Middle East Respiratory Syndrome (MERS) outbreak in the Republic of Korea in 2015 and provide related information for the public health professionals in China.</p><p><b>METHODS</b>The incidence data of MERS were collected from the websites of the Korean government, WHO and authoritative media in Korea for this epidemiological analysis.</p><p><b>RESULTS</b>Between May 20 and July 13, 2015, a total of 186 confirmed MERS cases (1 index case, 29 secondary cases, 125 third generation cases, 25 fourth generation cases and 6 cases without clear generation data), including 36 deaths (case fatality rate: 19%), were reported in Korea. All cases were associated with nosocomial transmission except the index case and two possible family infections. Sixteen hospitals in 11 districts in 5 provinces/municipalities in Korea reported confirmed MERS cases, involving 39 medical professionals or staff. For the confirmed cases and death cases, the median ages were 55 years and 70 years respectively, and the cases and deaths in males accounted for 60% and 67% respectively. Up to 78% of the deaths were with underlying medical conditions. Besides the index case, other 12 patients were reported to cause secondary cases, in which 1 caused 84 infections. One imported MERS case from Korea was confirmed in China on May 29, no secondary cases occurred. The viruses strains isolated from the cases in Korea and the imported case in China show no significant variation compared with the strains isolated in the Middle East.</p><p><b>CONCLUSION</b>The epidemiological pattern of the MERS outbreak in Korea was similar to MERS outbreaks occurred in the Middle East.</p>

Estimation of hospitalization rate of laboratory confirmed influenza cases in Jingzhou city, Hubei province, 2010-2012 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To estimate the hospitalization rate of severe acute respiratory infection (SARI) cases attributable to influenza in Jingzhou city, Hubei province from 2010 to 2012.</p><p><b>METHODS</b>SARI surveillance was conducted at four hospitals in Jingzhou city, Hubei province from 2010 to 2012. Inpatients meeting the SARI case definition and with informed consent were enrolled to collect their demographic information, clinical features, treatment, and disease outcomes, with their respiratory tract specimens collected for PCR test of influenza virus.</p><p><b>RESULTS</b>From April, 2010 to September, 2012, 19 679 SARI cases enrolled were residents of Jingzhou, and nasopharyngeal swab was collected from 18 412 (93.6%) cases of them to test influenza virus and 13.3% were positive for influenza. During the three consecutive 2010-2012 flu seasons, laboratory-confirmed influenza was associated with 102 per 100 000, 132 per 100 000 and 244 per 100 000, respectively. As for the hospitalization rate attributable to specific type/subtype of influenza virus, 48 per 100 000, 30 per 100 000 and 24 per 100 000 were attributable to A (H3N2), A (H1N1) pdm2009, and influenza B, respectively in 2010-2011 season; 42 per 100 000 [A (H3N2)] and 90 per 100 000 (influenza B) in 2011-2012 season; 90 per 100 000 [A (H3N2)] and one per 100 000 [influenza B] from April, 2010 to September, 2012. SARI hospitalization caused by influenza A or B occurred both mainly among children younger than five years old, with the peak in children aged 0.5 year old.</p><p><b>CONCLUSION</b>Influenza could cause a substantial number of hospitalizations and different viral type/subtype result in different hospitalizations over influenza seasons in Jingzhou city, Hubei province. Children less than five years old should be prioritized for influenza vaccination in China.</p>

Epidemiological characteristics of human avian influenza A (H7N9) virus infection in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the epidemiological characteristics of human infections with avian influenza A (H7N9) in China and to provide scientific evidence for the adjustment of preventive strategy and control measures.</p><p><b>METHODS</b>Demographic and epidemiologic information on human cases were collected from both reported data of field epidemiological investigation and the reporting system for infectious diseases.</p><p><b>RESULTS</b>A total of 433 cases including 163 deaths were reported in mainland China before June 4, 2014. Two obvious epidemic peaks were noticed, in March to April, 2013 and January to February, 2014. Confirmed cases emerged in 14 areas of China. Five provinces, including Zhejiang, Guangdong, Jiangsu, Shanghai, and Hunan, reported about 85% of the total cases. Median age of the confirmed cases was 58 years (range, 1-91), with 70% as males. Of the 418 cases with available data, 87% had ever exposed to live poultry or contaminated environments. 14 clusters were identified but human to human transmission could not be ruled out in 9 clusters.</p><p><b>CONCLUSION</b>Human infections with avian influenza A (H7N9) virus showed the characteristics of obvious seasonal distribution, with certain regional clusters. The majority of confirmed cases were among the elderly, with more males seen than the females. Data showed that main source of infection was live poultry and the live poultry market had played a significant role in the transmission of the virus.</p>